1

VEGETASI POHON&

RAIN-WATER MANAGEMENT

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Environmental Benefits of Tree

Trees alter the environment in which we live by moderating climate, improving air quality, conserving water, and harboring wildlife. Climate

control is obtained by moderating the effects of sun, wind, and rain. Radiant energy from the sun is absorbed or deflected by leaves on deciduous trees in the summer and is only filtered by branches of

deciduous trees in winter. We are cooler when we stand in the shade of trees and are not exposed to direct sunlight. In winter, we value the sun

radiant energy. Therefore, we should plant only small or deciduous trees on the south side of homes.

Wind speed and direction can be affected by trees. The more compact the foliage on the tree or group of trees, the greater the influence of the windbreak. The downward fall of rain, sleet, and hail is initially absorbed or deflected by trees, which provides some protection for people, pets, and buildings. Trees intercept water, store some of it, and reduce storm

runoff and the possibility of flooding.

Dew and frost are less common under trees because less radiant energy is released from the soil in those areas at night.

Temperature in the vicinity of trees is cooler than that away from trees. The larger the tree, the greater the cooling. By using trees in the cities, we are able to moderate the heat-island effect caused by pavement and

buildings in commercial areas.

Air quality can be improved through the use of trees, shrubs, and turf. Leaves filter the air we breathe by removing dust and other particulates.

Rain then washes the pollutants to the ground. Leaves absorb carbon dioxide from the air to form carbohydrates that are used in the plant structure and function. In this process, leaves also absorb other air

pollutants such as ozone, carbon monoxide, and sulfur dioxide and give off oxygen.

By planting trees and shrubs, we return to a more natural, less artificial environment. Birds and other wildlife are attracted to the area. The

natural cycles of plant growth, reproduction, and decomposition are again present, both above and below ground. Natural harmony is

restored to the urban environment.

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10 Best Trees You Should PlantConsider Planting These Trees in Your Yard

By Steve Nix, About.com Guide

I've reviewed the popular literature for you, polled my About Forestry forum and the Internet for the most popular trees and compiled these

frequently requested trees to use as a starting place. By further studying the commercial appeal of each of these individual species and taking into

account horticulturists' praise I selected my ten best.

No Tree Is PerfectRemember, all yard trees have good and bad characteristics. It is a rare

tree that will satisfy your needs throughout its entire life span. A tree can outgrow its original purpose very quickly or grow into its intended

purpose very slowly. Understanding this concept is the key to proper tree planting in your yard.

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Tree Roots Effects on Soil

Full of benefits, trees have an enviable position in any landscape, shade, controlling soil erosion, home to many birds, fruits and flowers. Of all the parts of a tree, the roots are perhaps the most unappreciated,

as they are unseen.

RootsThere are two types of roots; primary roots that grow deep down

vertically into the soil and secondary roots that branch out horizontally. The architecture of the root system is to absorb water and inorganic

nutrients and anchor the plant to the ground.

EffectsThe roots affect the soil, depending on the type of the tree and the soil. These effects have a direct impact on all the plants grown near the tree. Normally a healthy tree represents healthy soil. A big tree takes up most of the water available in the soil, leaving the other plants dry. Growing as well as mowing lawn grass is another difficulty around a large tree, especially if the roots are protruding outside. Tree roots help control

soil erosion, however in some cases the roots have a negative effect on the soil by causing a phenomenon called allelopathy.

AllelopathyDerived from two words; allelonwhich means of each other and pathos

which means to suffer. It refers to the chemical inhibition of one species by another, by releasing a chemical affecting the development and

growth of surrounding plants. In other words, plants try to get their own space, by restricting other plants from growing too close to them.

Allelopathic chemicals secretion are not just restricted to the roots, they are also found in branches, leaves, flowers and fruits. The decomposed leaves and bark affect the top layer of soil, while the roots affect the

surrounding soil. The chemical curtails the root growth of other plants by inhibiting their nutrient source, thus influencing their evolution and

distribution.

JugloneIt is an aromatic organic allelopathic compound occurring naturally in the roots,

bark and leaves of trees in the Juglandaceae family. It releases certain enzymes that inhibits the metabolic function, stunting the growth of many plants and at times

even killing an allelopathy intolerant plant. The quantity of Juglone released depends on the weather and soil conditions. The black walnut is the most commonly known for its allelopathic properties. When Juglone sensitive plants come within 0.5

to 0.25 inches of the tree roots, they turn yellow, wilt and die. This in turn, also infects the soil.

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Trees: The Original Multi-taskers

• Provide social, ecological, and economic benefits• Their beauty inspires writers and other artists.• Their leaves and roots clean the air we breathe and the water

we drink

Top 10 Reasons Why Trees Are Valuable and Important

Trees are important, valuable and necessary to our very existence. It's not too hard to believe that, without trees we humans would not exist on

this beautiful planet.

In fact, some claim can be made that our mother's and father's ancestors climbed trees - another debate for another site.

Still, trees are essential to life as we know it and are the ground troops on an environmental frontline.

Our existing forest and the trees we plant work in tandem to make a better world.

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Studi Pengaruh Kualitas Vegetasi pada Lingkungan TermalKawasan Kota di Bandung Menggunakan Data Citra Satelit

Surjamanto Wonorahardjo, Suwardi Tedja, Benedictus EdwardLaboratorium Teknologi Bangunan

Sekolah Arsitektur, Perencanaan dan Pengembangan Kebijakan Institut Teknologi Bandung

E-mail : titus@ar.itb.ac.id

Tulisan ini membahas lingkungan termal kawasan perkotaan yang dipengaruhi oleh berbagai aspek antara lain bentuk permukaan kawasan,

kepadatan dan penggunaan bahan bangunan. Salah satu aspek fisik permukan kawasan yang diyakini para ahli dapat mempengaruhi suhu

udara adalah vegetasi seperti taman kota, pohon di tepi jalan dll.

Konsep zoning pada kota membentuk kawasan dengan keunikan karakteristik fisik permukaan dan vegetasinya sehingga membentuk

kenikan lingkungan termal seperti terbentuknya pulau-pulau panas (heat island).

Penelitian ini memanfaatkan data satelit Landsat ETM yang mengambil citranya dalam 7 band termasuk di dalamnya citra termal. Metoda ini cukup akurat karena citra (termal) satelit mempunyai resolusi 1 pixel = 60mx 60 m.

Pendataan suhu udara lingkungan juga dilakukan dengan pengukuran lapangan untuk pembanding data citra satelit tersebut.

Analisis dilakukan terhadap pengaruh tipe vegetasi (pohon, perdu, rumput di lahan terbuka dll) terhadap fisik permukaan kawasan (bentuk permukaan

kawasan, kepadatan, penggunaan bahan bangunan) dari aspek pembentukan lingkungan termalnya. Hasil penelitian menunjukkan

lingkungan termal kawasan kota sangat dipengaruhi oleh karakteristik vegetasinya.

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Manfaat pohon di perkotaan

• Save Energy• Improve air quality• Extend life of paved surfaces• Increase traffic safety• Increase real estate values• Increase sociological benefits• Protect our water resources

1. Trees Produce Oxygen

Let's face it, we could not exist as we do if there were no trees. A mature leafy tree produces as much oxygen in a season as 10 people inhale in a year. What many people don't realize is the forest also acts

as a giant filter that cleans the air we breath.

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Air hujan dan Siklus Hidrologi

• Urbanization dramatically alters the hydrologic cycle– Increases runoff– Increases flooding frequency– Decreases infiltration and groundwater recharge

• Nationwide impervious surfaces have increased by 20% in the past 20 years

Lesovedenie

Effect of vibrations of tree roots on soil permeability.Danilik, V. N., Makarenko, G. P., Tolkach, O. V.

Ural'skaya Lesnaya Opytnaya Stantsiya, VNIILM, Russia.

Measurements were made in the Urals of the wind-induced movements of 33 roots of Scots pine [Pinus sylvestris] and Norway spruce [Picea abies] trees, and of the

effect of these root movements on soil permeability.

Details are given of the procedure; measurements were made when the amplitude of crown tip swaying was 1.4-3.0 m, which corresponded to a strong wind of 11-13

m/s. Root movement occurred in the vertical and the horizontal planes, both perpendicularly and along the root.

The amplitude of the root vibrations depended on the structure of the root system, soil mechanical composition, distance from the stem, amplitude of stem sway, and

root diameter.

The greatest vibrations (0.05-1.11 mm) were those vertical and horizontal across the roots, but they rapidly decreased with increasing distance from the stem. Wind-

sway of the stems, leading to vibration of the roots and the ball of soil, increased water permeability along the roots on average by a factor of 3.7, and of the soil

within the root system by a factor of 1.2-1.9. Swaying trees accelerated the movement of water along the vibrating roots much more on light than on heavy

soils.

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Journal of ArboricultureFill soil effects on soil aeration and tree growth.

MacDonald, J. D., Costello, L. R., Lichter, J. M., Quickert, D.Department of Plant Pathology, University of California, Davis, One

Shields Avenue, Davis, CA 95616, USA.

A 4-year study was conducted to evaluate the effects of fill soil on tree growth and soil aeration. Cherry trees (Prunus × yedoensis 'Afterglow')

were grown for 3 years in a test plot in Davis, California, U.S., after which the block of trees was divided into three subplots. In one subplot, 30 cm (12 in.) of compacted fill soil was installed over the root zone, while in a second subplot, aeration piping was installed prior to fill installation.

A third subplot was left without fill (control). Oxygen diffusion rate (ODR) and moisture levels were measured in the base soil before and after

addition of fill.

Trunk diameter was measured at fill installation and 1 year later, while stem water potential was measured after 1 year. Fill soil neither reduced

soil aeration levels nor had a negative impact on tree growth. Tree growth in fill subplots was equivalent to or greater than controls.

Aeration piping did not enhance oxygen diffusion rates in the underlying field soil.

Roots developed in the fill but did not grow preferentially around aeration pipes. Although aeration deficit may play a role in fill-induced

plant injury, other factors may play an equal or greater role. These factors include soil compaction and root injury during fill installation,

and water deficit following fill installation. All factors should be considered in pre- and post-fill tree management plans.

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How Do We Know That Trees Improve Soils?

Underlying all aspects of the role of agroforestry in maintenance of soil fertility is the fundamental proposition that trees improve soils. How we

know that this is true?

1. The soil that develops under natural forest and woodland is fertile. It is well structured, has a good water-holding capacity and has a store of nutrients bound up in the organic matter. Farmers know they will get a

good crop by planting on cleared natural forest.2. The cycles of carbon and nutrients under natural forest ecosystems are relatively closed, with much recycling and low inputs and outputs.

3. The practice of shifting cultivation demonstrated the power of trees to restore fertility lost during cropping.

4. Experience of reclamation forestry has demonstrated the power of trees to build up fertility on degraded land.

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Acta Phytoecologica Sinica

Modeling canopy rainfall interception in the upper watershed of the Minjiang River.

Li ChongWei, Liu ShiRong, Sun PengSen, Zhang YuanDong, Ge JianPingCollege of Life Sciences, Beijing Normal University, Beijing 100875, China.

The headwaters of the Minjiang River are on the eastern edge of the Tibetan plateau. Canopy rainfall interception plays an important role in the water balance at the

regional-scale. Many studies on canopy rainfall interception have been carried out at the stand level but less effort has been devoted towards understanding canopy interception at large

scale, neither in the Minjiang River basin nor other areas. In this study, modeling canopy rainfall interception in subalpine forests and meadows in the upper reaches of the Minjiang River was carried out by using field surveys, MODIS data, and RS,

GPS and GIS technologies. LAI (leaf area index), vegetation cover and canopy capacity per unit leaf area were the main parameters used in the model. LAI was derived from the vegetation index

and measured using a LAI-2000 in the forests and LAI-3000 in the sub-alpine meadows. The LAI of coniferous stands were multiplied by a correction factor

because of the clumped arrangement of needles in the crown. Normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI) were composed by

red, near-infrared and blue reflectances from the 500 m 32-day composites available from the MODIS level 3 surface reflectance (MOD09A1).

The results indicated that LAI was non-linearly correlated to NDVI and EVI. EVI was preferable to NDVI as NDVI saturates in well-vegetated areas and the degree of correlation between LAI and EVI is higher than that between LAI and NDVI. The

results showed that the LAI of vegetation in the upper reaches of the Minjiang River were in the following categories: 28.57% between 0 and 2, 63.06% between 2 and 4.5,

and 8.37% above 4.5. LAI was estimated using EVI, and the results showed that LAI could better reflect the

spatial distribution of the vegetation. LAI in the upper watershed was lower than down river due to a large number of trees in the down river. Vegetation cover was

derived from NDVI. The spatial distribution of canopy capacity per unit leaf area was modeled on the basis of a vegetation-classification map (1:1000000).

Canopy rainfall interception in the well-vegetated areas was higher than that in other areas.

The model was validated using field measurements made in Wolong and Miyaluo and some additional sites in the upper watershed of the Minjiang River. Empirical

expressions to describe evaporation from the wet canopy were derived from additional sites and evaporation from the wet canopy was closely correlated to

rainfall. Based on the empirical expressions, simulation results showed that there was a 15.4

percent error in Wolong and a 19.4 percent error in Miyaluo

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Semakin banyak pohon, semakin sedikit limpasan permukaan air hujan

Fayetteville, Arkansas: increasing tree canopy from 27-40% reduced their storm water runoff by 31%

South Miami residential study found that a 21% existing tree canopy reduces the storm water runoff by 15%

For every 5% of tree cover added to a community, storm water is reduced by approximately 2%

Communal Benefits of tree

Even though trees may be private property, their size often makes them part of the community as well. Because trees occupy considerable space, planning is required if

both you and your neighbors are to benefit.

With proper selection and maintenance, trees can enhance and function on one property without infringing

on the rights and privileges of neighbors.

City trees often serve several architectural and engineering functions. They provide privacy, emphasize views, or screen out objectionable views. They reduce

glare and reflection. They direct pedestrian traffic. They provide background to and soften, complement, or

enhance architecture.

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Pergerakan air hujan di dalam profil tanah

2. Trees Clean the Soil

The term phytoremediation is a fancy word for the absorption of dangerous chemicals and other pollutants that have entered the soil. Trees can either store harmful pollutants or actually change

the pollutant into less harmful forms.

Trees filter sewage and farm chemicals, reduce the effects of animal wastes, clean roadside spills and clean water runoff into streams.

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Bagaimana pohon mempengaruhi air hujan ?

• Above ground effects:– Interception, evaporation and absorption of

precipitation• Ground surface effects:

– Temporary storage• Below ground effects:

– Infiltration, permeation and filtration

Journal of the Indian Society of Soil Science

Impact of growing trees/grasses on physical properties of a saline soil.

Nandagoudar, S. A., Patil, S. G., Manjunatha, M. V., Hebbara, M., Gupta, R. K., Minhas, P. S.

AICRP on Management of Salt-affected Soils and Use of Saline Water in Agriculture, Agricultural Research Station, Gangawati, Karnataka 583 227, India.

A field experiment was conducted at Agricultural Research Station, Gangawati, Karnataka, India, to study the effect of tree species alone or

in combination with grasses on physical properties of a saline soil.

Six tree species viz. Casuarina equisetifolia, Acacia nilotica, Dalbergia sissoo, Azadirachta indica, Sesbania grandiflora and Hardwickia binata

and napier grass (Pennisetum purpureum) were planted in 1991 and physical properties were determined during 1995-96.

Due to the improvement in soil organic carbon, physical characteristics such as porosity, infiltration rate, hydraulic conductivity and aggregate stability improved under different tree covers, while, bulk density and

erodibility of soil decreased.

Acacia nilotica and Casuarina equisetifolia had higher influence on these bio-physical properties than the other species. Grasses when

planted with trees had complementary effect

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Hydrological Sciences JournalMeasurement of rainfall interception by xerophytic shrubs in re-

vegetated sand dunes.

Wang XinPing, Li XinRong, Zhang JingGuang, Zhang ZhiShan, Berndtsson, R.Shapotou Desert Experimental Research Station, Cold and Arid Regions

Environmental and Engineering Research Institute, Chinese Academy of Sciences, 260 Donggang West Road, Lanzhou 730000, China.

More than 40 years of re-vegetation using mainly xerophytic shrubs Artemisia ordosica Krasch. and Caragana korshinskii Kom. at Shapotou Desert Experimental Research Station near Lanzhou, China has resulted

in established dwarf-shrub and herbaceous cover on sand dunes. Precipitation, as the sole source of water replenishment in the semiarid

area, plays a pertinent role in sustaining the desert ecosystem. A field study was conducted to (a) measure interception loss on shrub

canopies during individual rainfall events, (b) determine the canopy storage capacity of individual plants, and (c) explore the relationship

between interception and rainfall parameters.

The total rainfall and its respective partitions as throughfall were determined and the interception losses in the studied ecosystem were quantified. Interception loss was shown to differ among the xerophyte

taxa studied. During the growing seasons, the average shrub community interception loss is 6.9% and 11.7% of the simultaneous overall

precipitation, for A. ordosica and C. korshinskii, respectively. Taking into account the observed rainfall conditions and vegetation cover

characteristics, it was concluded that the interception loss was 2.7% of the total annual precipitation verified in the period for the A. ordosica

community with an average cover of 30%, canopy projection area of 0.8 m2 and canopy storage capacity of 0.75 mm.

In contrast, interception loss for the C. korshinskii community was 3.8% with an average cover of 46%, canopy projection area of 3.8 m2 and

canopy storage capacity of 0.71 mm.

For individual plants of both shrubs, the proportion of interception loss to gross rainfall decreased notably as the rainfall intensity increased

between 0 and 2 mm h-1, while it tended to remain constant at about 0.1-0.2 for A. ordosica and 0.1-0.3 for C. korshinskii when the rainfall

intensity was >2 mm h-1.

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Food production, poverty alleviation and environmental challenges as influenced by limited water resources and population growth. Volume 1A. 18th International Congress on Irrigation and Drainage, Montréal,

Canada, 2002Towards improving of water management in fruit-tree

plantations under micro-irrigation.

Koumanov, K. S.Nat.Cent. Agric.Sci., Inst.Fruit Growing, 12 Ostromila, Plovdiv 4004, Bulgaria.

Precise water balance under micro-sprinkling and drip irrigation of fruit trees showed that the application efficiency was strongly dependent on

both the climatic conditions and the soil hydraulic properties.

Root activity affected irrigation water redistribution, creating zones with low soil moisture values (down to wilting point) along the skeletal roots

very soon (20 hours) after the irrigation. Under drip irrigation, soil moisture in the remaining part of the bulb was still close to field

capacity but roots were not able to access it.

When the wetted soil volume was larger, as under micro-sprinkler irrigation, root water uptake was found to be, spatially and temporarily, very dynamic. Hence, crop water use efficiency would be increased if irrigation strategy was based on physical models of evaporation from partially wetted soil surface, irrigation water redistribution in the soil,

and root water uptake.

Microsprinkling was found to affect positively microclimate in fruit-tree plantations, decreasing air temperatures and increasing significantly air

humidity. This effect was more pronounced in dry and hot conditions. The

experiments were carried out in peach and almond plantations on various soil types carried out in Bulgaria and California, USA

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3. Trees Control Noise Pollution

Trees muffle urban noise almost as effectively as stone walls.

Trees, planted at strategic points in a neighborhood or around your house, can abate major noises from freeways and airports.

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4. Trees Slow Storm Water Runoff

Flash flooding can be dramatically reduced by a forest or by planting trees. One Colorado blue spruce, either planted or growing wild, can intercept more than 1000 gallons of water

annually when fully grown. Underground water-holding aquifers are recharged with this

slowing down of water runoff

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Pengaruh di atas permukaan tanah

• Intercept rainwater on leaves, branches and trunks – slowing its movement

• Evaporation of some of this intercepted precipitation of the tree surfaces

• Absorption of a small portion into leaves or stems

Physical GeographyVegetation effects on soil and water losses on weathered granitic

hillslopes, South China.

Woo, M. K., Luk, S. H. Dep. Geography, McMaster Univ., Hamilton, Ont. L8S 4K1, Canada.

Deforestation of weathered granitic hillslopes of South China (Guangdong Province) has led to widespread erosion.

Using small experimental plots under different vegetation cover, the effects of land use on soil and water losses were examined.

Overland flow increased as the cover conditions changed from forest to fern, to tilled soil and, eventually, to bare ground. This is related to the amount of interception and infiltration, both of which decreased as the vegetation cover decreased. Most slopes consist of a combination of loose materials and weathered granite and the resistance to sediment

entrainment could not be easily determined.

The potential sediment yield increased as vegetation cover decreased. Based on empirical relationships between rainfall, overland flow and

potential sediment yield, it is demonstrated that soil and water losses can be greatly reduced as vegetation is re-established on these denuded

subtropical slopes.

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Ground Surface Effects

• Leaf litter and other organic matter can hold precipitation and stemflow on a site, reducing the amount and peak rates of runoff

• Roots and trunk bases of mature trees tend to create hollows and hummocks on the ground

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Below Ground Effects

• Organic material from leaf litter and other tree detritus tends to increase infiltration rates by increasing pore spaces in soil

• Organic material also increases the moisture-holding capacity of these sites

• Root mats of trees also tend to break up most soils further improving infiltration and moisture-holding capacity

Indian Journal of AgroforestryEffect of soil depth on early performance and characteristics of roots of

some tree species on a hill slope.

Singh, K. A.ICAR Research Complex for Eastern Region, Barapani (Meghalaya) - 793 103, India.

A field experiment was conducted in Meghalaya, India, to determine the effects of soil depths on root characteristics and biomass productivity of four tree species (Pinus kesiya, Michelia champaca, Grevillea robusta and Cupressus torulosa) planted on a

hill slope.

Changes in root characteristics revealed that vertical penetration of main root, number of roots and root weight per plant increased in proportion to soil depth occupied by the tree species. The main root changed its course of orientation

sensing impediments and moved down the hill slope. Mean root spread decreased significantly in the deep soil in case of M. champaca and P. kesiya but it increased

marginally in case of G. robusta and C. torulosa as compared to shallow soils. Broadleaved M. champaca and G. robusta had reduced root length, thicker proximal

diameter of main and lateral roots in shallow soils while in pine group of plants, either length of main root was shorter in deep soil than the shallow soil as in case of

P. kesiya or there was no significant difference in root length as in case of C. torulosa, both the tree species also grew thicker roots in the deep soils. Effect of soil

depth on plant growth became evident 18 months after planting.

The differential behaviour of tree species in response to soil depths indicated their adaptation and success on the hill slopes through changes in root characteristics particularly root spread and modification in different parts of shoot i.e., basal and breast height diameters, number of branches per plant, canopy length in case of broadleaved tree species and canopy length and canopy diameter both in case of

pine group of tree species.

Thus, the little difference in root number under different soil depths and tendency to spread extensively under shallow soil depth leading to minimal variation in total

biomass productivity helped P. kesiya to be most adaptive on the shallow soils of the hill slopes followed by M. champaca, a broadleaved tree species

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Nutrient Cycling in Agroecosystems

Shade tree effects in an 8-year-old cocoa agroforestry system: biomass and nutrient diagnosis of Theobroma cacao by vector analysis.

Isaac, M. E., Timmer, V. R., Quashie-Sam, S. J.Faculty of Forestry, University of Toronto, 33 Willcocks St., Earth Science Centre,

Toronto, M5S 3B3, Canada.

Farm product diversification, shade provision and low access to fertilizers often result in the purposeful integration of upper canopy trees in cocoa

(Theobroma cacao) plantations. Subsequent modification to light and soil conditions presumably affects nutrient availability and cocoa tree

nutrition. However, the level of complementarity between species requires investigation to minimize interspecific competition and improve resource

availability. We hypothesized beneficial effects of upper canopy trees on cocoa

biomass, light regulation, soil fertility and nutrient uptake. We measured cocoa standing biomass and soil nutrient stocks under no shade

(monoculture) and under three structurally and functionally distinct shade trees: Albizia zygia (D.C.) Macbr, a nitrogen fixer; Milicia excelsa (Welw.),

a native timber species; and Newbouldia laevis (Seem.), a native small stature species. Vector analysis was employed to diagnosis tree nutrition.

Cocoa biomass was higher under shade (22.8 for sole cocoa versus 41.1 Mg ha-1 for cocoa under Milicia), and declined along a spatial gradient

from the shade tree (P<0.05). Percent canopy openness differed between the three shade species (P=0.0136), although light infiltration was within

the optimal range for cocoa production under all three species.

Soil exchangeable K was increased under Newbouldia, while available P decreased and total N status was unaffected under all shade treatments. Nutrient uptake by cocoa increased under shade (43-80% and 22-45% for N and P, respectively), with K (96-140%) as the most responsive nutrient

in these multistrata systems.

Addition of low-density shade trees positively affected cocoa biomass close to the shade tree, however proper management of upper stratum

trees is required for optimum cocoa productivity and sustainability

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Below Ground Effects

• Deep roots tend to improve the rates of percolation of water from upper soil horizons into lower substrates

• Trees take up water through their roots that is eventually transpired onto leaf surfaces and evaporated

• Tree roots act as natural pollution filters (biofilters) using nitrogen, phosphorus and potassium.

Indian Forester

Pattern of root distribution in 30-month old five tree and two shrub species of an arid region of north-western India.

Virendra Singh, Rajbahadur, Hooda, M. S., BalkrishanDepartment of Agroforestry, Chaudhary Charan Singh Haryana Agricultural

University, Hisar, Haryana, India.

Structure and distribution of root systems were studied in 30-month old trees of 5 species (Acacia nilotica, Leucaena leucocephala, Dalbergia

sissoo, Azadirachta indica and Prosopis cineraria) and 2 shrub species (Prosopis juliflora and Cajanus cajan) raised at a spacing of 4×0.5 m at

Hisar, Haryana. Maximum penetration of root systems was observed in P. cineraria (138 cm depth), followed by Acacia nilotica, D. sissoo, L. leucocephala and P.

juliflora, while Azadirachta indica and C. cajan showed comparatively shallow root systems (85 and 65 cm depth, respectively). P. juliflora

showed the maximum root spread (347 cm), followed by L. leucocephala (228 cm), Acacia nilotica (216 cm), D. sissoo (187 cm), Azadirachta

indica (95 cm), C. cajan (80 cm) and P. cineraria (31 cm). The top 30 cm of soil had the maximum distribution of root biomass in C. cajan,

Azadirachta indica and L. leucocephala (45-62% of the total), whereas the maximum distribution of root biomass in P. juliflora, Acacia nilotica

and D. sissoo (34-40% of the total) was in the top 30-60 cm of soil. Root distribution in P. cineraria was almost uniform throughout the soil column. The superficial location of a high proportion of roots in stands of C. cajan, Azadirachta indica and L. leucocephala indicates that these species will show strong root competition if intercropped with crops, in comparison with Acacia nilotica, D. sissoo and P. juliflora in which most

of the roots had a subsurface location. A vertical root system and narrow crown in P. cineraria make this species the most suitable for

agroforestry systems

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5. Trees Are Carbon SinksTo produce its food, a tree absorbs and locks away carbon dioxide in the wood, roots and leaves. Carbon dioxide is a

global warming suspect. A forest is a carbon storage area or a "sink" that can lock up as much carbon as it produces. This locking-up process "stores" carbon as wood and not as an

available "greenhouse" gas.

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EPA’s Tree Canopy Target Goals

• Set to protect a community’s green infrastructure and maximize the environmental benefits

• For metropolitan areas east of the Mississippi– Average tree cover for all land use 40%– Suburban residential 50%– Urban residential 25%– Central business districts 15%

What Makes a Good Soil Improving Tree?

It would be useful to have guidelines on which properties of a tree or shrub species make it desirable for the point of view of soil fertility.

This would help in identifying naturally occurring species and selecting trees for systems which have soil improvement as a specific

objective.

Nitrogen fixation and a high biomass production have been widely recognized as desirable. However, many properties are specific to particular objectives of systems in which the trees are used. Even

species that are shunned for their competitive effects may have a role in certain designs.

An example is the way in which Eucalyptus species with a high water uptake, which adversely affects yields in adjacent crops, have been

employed to lower the water table and so reduce salinization.

26SIKLUS ENERGI Peranan Matahari

6. Trees Clean the Air

Trees help cleanse the air by intercepting airborne particles, reducing heat, and absorbing such pollutants as carbon

monoxide, sulfur dioxide, and nitrogen dioxide. Trees remove this air pollution by lowering air temperature,

through respiration, and by retaining particulates.

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Faktor Komplikasi

• Presence of soil compaction• Presence of soil textural discontinuity

– Has the site been disturbed in the past?• Management of the ground surface

– Is litter layer removed?– Is soil surface exposed in winter?– How much of the surface is like a natural forest? (number

and size of trees)

The properties which are likely to make a woody perennial suitable for soil fertility maintenance or improvement are:

1. A high rate of production of leafy biomass.

2. A dense network of fine roots, with a capacity for abundant mycorrhizal association.

3. The existence of deep roots.

4. A high rate of nitrogen fixation.

5. A high and balanced nutrient content in the foliage; litter of high quality (high in nitrogen, low in lignin and polyphenols).

6. An appreciable nutrient content in the root system.

7. Either rapid litter decay, where nutrient release is desired, or a moderate rate of litter decay, where maintenance of a soil cover is required.

8. Absence of toxic substances in the litter or root residues.

9. For soil reclamation, a capacity to grow on poor soils.

10. Absence of severe competitive effects with crops, particularly for water.

11. Low invasiveness.

12. Productive functions, or service functions other than soil improvement.

28

Pergerakan air dalam tanah

Forces affecting the energy of soil waterMatric force (absorption and capillary)

GravityOsmotic forces

29

• Field Capacity is the amount of water held in the soil after gravitational water had drained away

• Movement of water is the soil is controlled :– Gravitational forces if saturated– Matric forces if unsaturated

Pergerakan air dalam tanah

7. Trees Shade and CoolShade resulting in cooling is what a tree is best known for. Shade

from trees reduces the need for air conditioning in summer. In winter, trees break the force of winter winds, lowering heating

costs. Studies have shown that parts of cities without cooling shade from trees can literally be "heat islands" with temperatures as much

as 12 degrees Fahrenheit higher than surrounding areas.

30

• Infiltration is the mode of entry of all water into the soil

• Rate of infiltration determined:

– Initial water content

– Surface permeability

– Internal characteristics of the soil

• Intensity and duration of rainfall

• Temperature of soil and water

Soil Factors Influencing Infiltration

8. Trees Act as WindbreaksDuring windy and cold seasons, trees located on the windward side act as windbreaks. A windbreak can lower home heating bills up to 30% and have a significant effect on reducing snow drifts. A reduction in wind can also reduce the drying effect on

soil and vegetation behind the windbreak and help keep precious topsoil in place.

31

• Soil compaction reduces the infiltration rate• Microrelief under trees provides catchment basins during heavy rains• Removal of litter layer reduces the infiltration rate

Soil Factors Influencing Infiltration

9. Trees Fight Soil Erosion

Erosion control has always started with tree and grass planting projects. Tree roots bind the soil and their leaves break the

force of wind and rain on soil. Trees fight soil erosion, conserve rainwater and reduce water

runoff and sediment deposit after storms.

32

Forest soils have a high percentage of macropores

The frost type found in forest soils promotes infiltration year-long

10. Trees Increase Property Values

Real estate values increase when trees beautify a property or neighborhood. Trees can increase the property value of your home by

15% or more.

Soil Factors Influencing Infiltration cont.

33

Absorbs several times its own weightBreaks the impact of raindrops

Prevents agitation of the mineral soilDiscourages formation of surface crusts

Importance of the Litter Layer

34

Forest Ecology and Management

Spatial distribution of root length density and soil water of linear agroforestry systems in sub-humid Kenya: implications for agroforestry

models.

Radersma, S., Ong, C. K.Department of Soil Quality, Agricultural University, P.O. Box 8005, 6700 EC

Wageningen, Netherlands.

IN SIMULTANEOUS AGROFORESTRY SYSTEMS TREES CAN COMPETE WITH CROPS FOR WATER, ESPECIALLY IN SEMI-ARID AREAS. HOWEVER, IN THE (SUB)HUMID

TROPICS, ON P-FIXING OXISOLS/FERRALSOLS SMALL DECREASES IN SOIL WATER CONTENT CAUSED A DECREASE IN P-TRANSPORT TO ROOTS AND THEREWITH A SOIL-DRYING INDUCED P-DEFICIENCY. THE AIM OF THIS STUDY WAS TO ASSESS

THE SPATIAL DISTRIBUTION OF SOIL WATER CONTENT IN CROP FIELDS BORDERING TREE LINES AND ITS RELATION WITH ROOT LENGTH DENSITY

DISTRIBUTION OF THE TREES THROUGHOUT THE SOIL PROFILE. TO ACHIEVE THIS, SOIL WATER CONTENT AND TREE ROOT LENGTH DENSITIES THROUGHOUT THE

SOIL PROFILE WERE MEASURED OVER A PERIOD OF 2 YEARS IN AN EXPERIMENT WITH LINES OF FOUR TREE SPECIES IN THE MIDDLE OF MAIZE FIELDS IN SUB-

HUMID WESTERN KENYA. SOIL WATER CONTENT WAS SIGNIFICANTLY REDUCED (2-7 VOL.%) NEAR TWO OF THE THREE FAST-GROWING TREE SPECIES,

EUCALYPTUS GRANDIS AND GREVILLEA ROBUSTA, BUT NOT NEAR CEDRELLA SERRATA AND THE SLOWER GROWING MARKHAMIA LUTEA. THESE DIFFERENCES WERE RELATED TO DIFFERENCES IN WATER USE. EUCALYPTUS AND GREVILLEA SHOWED HIGH WATER USE AND CEDRELLA AND MARKHAMIA LOW WATER USE. HOWEVER, SOIL WATER CONTENT DISTRIBUTION WAS NOT RELATED TO ROOT

LENGTH DENSITY DISTRIBUTION. ROOT LENGTH DENSITIES HARDLY DECREASED WITH DISTANCE TO GREVILLEA AND CLEARLY DECREASED WITH DISTANCE TO

CEDRELLA. MOST WATER-UPTAKE MODELS, INCLUDING THOSE OF AGROFORESTRY MODELS, ASSUME THAT ROOT LENGTH DENSITY DISTRIBUTION

THROUGHOUT THE PROFILE IS PROPORTIONAL TO WATER EXTRACTION THROUGHOUT THE PROFILE.

THE ABSENCE OF A CLEAR RELATION BETWEEN ROOT LENGTH DENSITY AND WATER EXTRACTION NEAR GREVILLEA TREE LINES OPPOSED THIS VIEW. IT CAN

BE EXPLAINED BY A DECREASE IN WATER-POTENTIAL GRADIENT BETWEEN ROOT AND SOIL AT INCREASING DISTANCE FROM THE TREE BASE. IF THE CHANGE IN ROOT LENGTH DENSITY IS SIMILAR OR SMALLER THAN THE CHANGE IN WATER-

POTENTIAL GRADIENT BETWEEN ROOT AND SOIL, THE DECREASE IN WATER-POTENTIAL GRADIENT BETWEEN ROOT AND SOIL IS OF SIMILAR OR LARGER IMPORTANCE FOR DETERMINING TREE-WATER EXTRACTION DISTRIBUTION

THROUGHOUT THE PROFILE THAN ROOT LENGTH DENSITY. THUS, MODELING OF SPATIAL AGROFORESTRY SYSTEMS CANNOT ASSUME A DIRECT RELATION

BETWEEN TREE-WATER EXTRACTION AND ROOT LENGTH DENSITY, BUT NEEDS TO INCLUDE DECREASING WATER-POTENTIAL GRADIENT BETWEEN ROOT AND

SOIL ALONG ROOTS WITH INCREASING DISTANCE TO THE STEM BASE, ESPECIALLY OVER THE HORIZONTAL DIMENSION.

35

Increases soil biotic activityIncreases incorporation of organics

Slows down lateral movement of water

Importance of the Litter Layer

36

Indian ForesterImpact of soil water availability on carbon sequestration in tree

biomass and soil in arid region of India.

Singh, G., Bilas Singh, Rathod, T. R.Division of Forest Ecology and Desert Development, Arid Forest

Research Institute, Jodhpur (Rajasthan), India.

ARID REGIONS HAVE LOW CAPACITY TO SEQUESTER CARBON DUE TO LOW SOIL WATER AVAILABILITY AND PLANT GROWTH. HOWEVER, CONSIDERING THE LARGE EXTENT OF SUCH AREAS TOTAL CAPACITY

OF CARBON SEQUESTRATION MAY BE IMPORTANT.

ONE-YEAR-OLD PLANTED SEEDLINGS OF E. CAMALDULENSIS, A. NILOTICA AND D. SISSOO WERE MAINTAINED AT DIFFERENT WATER

REGIMES BY RE-IRRIGATING THE SEEDLINGS AT 36.2 MM (T1), 26.5 MM (T2), 20.2 MM (T3), 18.1 MM (T4) AND LIVE SAVING IRRIGATION (T5) WHEN THE SOIL WATER CONTENT DECREASED TO 7.56, 5.79, 4.44,

3.23% AND DRYING OF LEAVES (T5) IN THE RESPECTIVE TREATMENTS CONDUCTED AT THE EXPERIMENTAL FIELD OF ARID FOREST

RESEARCH INSTITUTE, JODHPUR, RAJASTHAN, INDIA.

CARBON CONTENT BOTH IN DRY BIOMASS AND SOIL INCREASED WITH AGE OF THE SEEDLINGS, BUT IT DECREASED WITH

DECREASING IRRIGATION QUANTITY. A NEGATIVE CARBON BALANCE WAS OBSERVED IN T5 AT 12 MONTHS AGE. AT THE AGE OF 48 MONTHS, CARBON CONTENT VARIED FROM 14.91 TO 0.72 KG

SEEDLING-1 IN E. CAMALDULENSIS, 8.67 TO 1.74 KG SEEDLING-1 IN A. NILOTICA AND 12.42 TO 0.36 KG SEEDLING-1 IN D. SISSOO.

CARBON DENSITY WAS HIGH UNDER A. NILOTICA AND LOW UNDER E. CAMALDULENSIS.

THE STUDY SUGGESTS THAT SEVERITY OF SOIL WATER STRESS AFFECTED CARBON SEQUESTRATION, WHEREAS ENHANCED

AVAILABILITY OF SOIL WATER THROUGH IRRIGATION INCREASED CARBON STORAGE IN BIOMASS AND SOIL.

THEREFORE, THERE IS SCOPE TO INCREASE CARBON SEQUESTRATION IN DRY AREAS THROUGH RAINWATER

MANAGEMENT AND SUPPLYING ADDITIONAL IRRIGATION DURING AVAILABILITY OF WATER.

37

Australian Journal of Botany

Impacts of tree plantations on groundwater in south-eastern Australia.

Benyon, R. G., Theiveyanathan, S., Doody, T. M.Ensis, PO Box 946, Mount Gambier, SA 5290, Australia.

In some regions dependent on groundwater, such as the lower southeast of South Australia in the Green Triangle, deep-rooted, woody vegetation

might have undesirable hydrological impacts by competing for finite, good-quality groundwater resources.

In other regions, such as the Riverina in south-central New South Wales, where rising water tables and associated salinization is threatening the

viability of agriculture, woody vegetation might have beneficial hydrological impacts. In response to a growing need to better understand

the impacts of tree plantations on groundwater, annual evapotranspiration and transpiration were measured at 21 plantation sites in the Green Triangle and the Riverina. Sources of tree water uptake from

rainfall and groundwater were determined by measurements of evapotranspiration and soil water over periods of 2-5 years.

In the Green Triangle, under a combination of permeable soil over groundwater of low salinity (<2000 mg L-1) at 6-m depth or less, in a

highly transmissive aquifer, annual evapotranspiration at eight research sites in Pinus radiata and Eucalyptus globulus plantations averaged 1090

mm year-1 (range 847-1343 mm year-1), compared with mean annual precipitation of 630 mm year-1. These plantation sites used groundwater

at a mean annual rate of 435 mm year-1 (range 108-670 mm year-1). At eight other plantation sites that had greater depth to the water table or a root-impeding layer, annual evapotranspiration was equal to, or slightly less than, annual rainfall (mean 623 mm year-1, range 540-795 mm year-1). In the Riverina, where groundwater was always present within 3 m of the

surface, Eucalyptus grandis trees at three sites with medium or heavy clay, alkaline, sodic, saline subsoils used little or no groundwater,

whereas E. grandis and Corymbia maculata trees at a site with a neutral sandy soil and groundwater of low salinity used 380 and 730 mm year-1 of groundwater (respectively 41 and 53% of total annual evapotranspiration).

We conclude that commonly grown Eucalyptus species and P. radiata are able to use groundwater under a combination of light- or medium-textured

soil and shallow depth to a low-salinity water table

38

• Lead to better soil structure• Increases organic matter incorporation• Increases percolation rates and root penetration

Affect of Micropores in the Soil

39

Water Resources Research

Ecohydrological controls on soil moisture and hydraulic conductivity within a pinyon-juniper woodland.

Lebron, I., Madsen, M. D., Chandler, D. G., Robinson, D. A., Wendroth, O., Belnap, J. Department of Soils and Biometeorology, Utah State University, Logan, Utah, USA.

THE IMPACT OF PINYON-JUNIPER WOODLAND ENCROACHMENT ON RANGELAND ECOSYSTEMS IS OFTEN ASSOCIATED WITH A REDUCTION OF STREAMFLOW AND RECHARGE AND AN INCREASE IN SOIL EROSION. THE

OBJECTIVE OF THIS STUDY IS TO INVESTIGATE VEGETATIONAL CONTROL ON SEASONAL SOIL HYDROLOGIC PROPERTIES ALONG A 15-M TRANSECT IN

PINYON-JUNIPER WOODLAND WITH BIOCRUST.

WE DEMONSTRATE THAT THE JUNIPER TREE CONTROLS SOIL WATER CONTENT (SWC) PATTERNS DIRECTLY UNDER THE CANOPY VIA INTERCEPTION,

AND BEYOND THE CANOPY VIA SHADING IN A PREFERRED ORIENTATION, OPPOSITE TO THE PREVAILING WIND DIRECTION. THE JUNIPER ALSO CONTROLS THE SWC AND UNSATURATED HYDRAULIC CONDUCTIVITY

MEASURED CLOSE TO WATER SATURATION (K(H)) UNDER THE CANOPY BY THE CREATION OF SOIL WATER REPELLENCY DUE TO NEEDLE DROP.

WE USE THIS INFORMATION TO REFINE THE HYDROLOGIC FUNCTIONAL UNIT (HFU) CONCEPT INTO THREE INTERACTING HYDROLOGIC UNITS:

CANOPY PATCHES, INTERCANOPY PATCHES, AND A TRANSITIONAL UNIT FORMED BY INTERCANOPY PATCHES IN THE RAIN SHADOW OF THE JUNIPER

TREE.

SPATIAL AUTOREGRESSIVE STATE-SPACE MODELS SHOW THE CLOSE RELATIONSHIP BETWEEN K(H) CLOSE TO SOIL WATER SATURATION AND SWC AT MEDIUM AND LOW LEVELS, INTEGRATING A NUMBER OF INFLUENCES ON

HYDRAULIC CONDUCTIVITY.

40

Soil Frost Types

• Granular– Small frost crystals intermingled with soil particles– Found in woodland soils with litter– May be more permeable than unfrozen soil

• Honeycomb– Has loose porous structure– Found in highly aggregated soils and also formed in

organic layers and litter layers

Effects Of Trees On Soils

The capacity of trees to maintain or improve soils is shown by the high fertility status and closed nutrient cycling under natural forest, the

restoration of fertility under forest fallow in shifting cultivation, and the experience of reclamation forestry and agroforestry.

Soil transects frequently show higher organic matter and better soil physical properties under trees. Some species, most notably Faidherbia albida, regularly give higher crop yields beneath the tree canopy. Trees

improve soil fertility by processes which:

* increase additions to the soil;* reduce losses from the soil;

* improve soil physical, chemical and biological conditions.

The most important sets of processes are those by which trees:

* check runoff and soil erosion;* maintain soil organic matter and physical properties;

* increase nutrient inputs, through nitrogen fixation and uptake from deep soil horizons;

* promote more closed nutrient cycling.

41

American Society of Agricultural EngineersVol. 34(1): January-February 1991

Citrus Tree Spacing Effects on Soil WaterUse, Root Density, and Fruit Yield

J. D. Whitney, A. Elezaby, W. S. Castle, T. A. Wheaton, R. C. Littell

Soil water content, root density, and fruit yield measurements were made on 'Hamlin' orange trees on Milam rootstock at two tree

spacings-6 x 4.5 m (370 trees/ ha) and 4.5 x 2.5 m (889 trees/ ha). Soil water use per unit land area for the seven- and eight-year-old

trees was not significantly affected by tree spacing. Water use was greatest underneath the canopy dripline and

generally decreased with increasing soil depth to 1.65 m.

Root densities of the seven-year-old trees were greater at the 4.5 X 2.5 m spacing and generally decreased with depth.

Fruit yields per ha were greater for the 4.5 x 2.5 m spacing in the early years, were comparable for both spacings during the seventh and eighth years, and favored the 6 x 4.5 spacing in the 9th year.

42

Soil Frost Types

• Stalagtite– Forms partially fused, columnar ice crystals– Connects a heaved soil surface to the soil below

• Concrete– Forms intricate multiple thin ice lenses– Common in soils going through freeze-thaw sequences– Common in exposed soil areas (agriculture)– Much less permeable that other frost types

Tree effects on soil

Trees may also adversely affect associated crops. The effects of allelopathy (inhibition effects) have probably been exaggerated by mistaking them for, or confounding them with, other processes.

Competition for water is a serious but not insuperable problem in all dry environments, whereas competition for nutrients has rarely been

demonstrated.

Where the net effect of tree—crop interactions is positive, the length of the tree—crop interface, or extent of the ecological fields, should be

maximized. If the net effect is negative, the aim of agroforestry system design should be to reduce the length of the interface.

A range of properties have been identified which make tree species suited to soil improvement. For many purposes, high biomass

production, nitrogen fixation, a combination of fine feeder roots with tap roots and litter with high nutrient content are suitable. Tolerance to

initially poor soil conditions is clearly needed for reclamation. About 100 species have been identified which are known to fulfil soil-

improving functions, but there is much scope to increase this range.

43

Implications of Frost Types

• Forests and prairies rarely yield runoff regardless of steepness, even when frozen

• Forested areas provide storm water protection and protect the quantity and quality of groundwater

Hydrological Processes

Rainfall interception by an isolated evergreen oak tree in a Mediterranean savannah.

David, T. S., Gash, J. H. C., Valente, F., Pereira, J. S., Ferreira, M. I., David, J. S.Estação Florestal Nacional, INIAP, Av. da República, Quinta do Marquês, 2780-159

Oeiras, Portugal.

Redistribution of ground-level rainfall and interception loss by an isolated Quercus ilex tree were measured over 2 years in a Mediterranean oak savannah. Stemflow, meteorological variables and sap flow were also

monitored. Rainfall at ground level was measured by a set of rain-gauges located in a

radial layout centred on the tree trunk and extending beyond the crown limits.

Interception loss was computed as the difference between the volume of rainwater that would reach the ground in the absence of the tree and the volume of water that actually fell on the ground sampling area (stemflow included). This procedure provided correct interception loss estimates,

irrespective of rainfall inclination.

Results have shown a clear non-random spatial distribution of ground-level rainfall, with rainwater concentrations upwind beneath the crown and rain-

shadows downwind.

Interception loss amounted to 22% of gross rainfall, per unit of crown-projected area. Stand interception loss, per unit of ground area, was only

8% of gross rainfall and 28% of tree evapotranspiration. These values reflect the low crown cover fraction of the stand (0.39) and the specific

features of the Mediterranean rainfall regime (predominantly with few large storms). Nevertheless, it still is an important component of the water

balance of these Mediterranean ecosystems .

44

Groundwater –Surface Water Flows

45

Tree root damage to buildings. Volume 1: causes, diagnosis and remedy. Volume 2: patterns of soil drying in proximity to trees on clay soils.

Tree root damage to buildings. Volume 1: causes, diagnosis and remedy. Volume 2: patterns of soil drying in proximity to trees on clay soils.

Biddle, P. G. Willowmead, Ickleton Road, Wantage, Oxon. OX12 9JA, UK.

This 2-volume set of books provides a comprehensive analysis of, and practical guide to, how the interaction of trees, soils and water can cause foundation

movement and damage to buildings. The problems addressed are multidisciplinary, involving structural engineers, engineers, arboriculturalists, soil scientists, insurers and their loss adjusters, architects, and builders and planners, as well as providing work to the legal profession. All aspects of the problems involved are addressed. Volume 1 has 20 chapters, each with a brief summary and a case study at the end;

essential points are highlighted.

The first 10 chapters describe the interactions of trees, soils, water and buildings: (1) Introduction; (2) The tree - an account of tree physiology and growth; (3) The root

system; (4) The soil - types and behaviour in relation to water content; (5) Seasonal changes in soil moisture content; (6) Persistent moisture deficits - when the winter process of rewetting of the soil after summer drying is not complete; (7) Interaction

between trees and buildings - soil and foundation movements, buildings and persistent water deficit, and the influences of buildings on the soil and tree roots; (8)

Influence of the weather; (9) Comparative effects of different species, and of individual trees and groups; and (10) Other forms of damage by tree roots - direct physical damage and damage to drains and underground services. Chapters 11-16

describe the investigation of damage: (11) Strategy for investigating damage; (12-14) Site investigations: I. The building; II, The soil; and III. The tree; (15) Monitoring

building movement; and (16) Heave and recovery: diagnosis and prediction. Chapters 17-20 address remedy and prevention: (17) Remedial action after damage; (18)

Prediction and prevention of damage; (19) The legal framework; and (20) A revised role for the professions. Volume 1 ends with a list of references, cross references

between botanical and common names, and a subject index.

Volume 2 presents the accumulated results from 3 research projects which started in 1978 (with the Milton Keynes (UK) Development Corporation), and were extended in

1981 (under instruction from the UK National House-Building Council) and 1983 (under instruction from the UK Department of the Environment). These investigated

the pattern of soil drying, both spatially and with time, that occurs in the proximity of trees on clay soils. A total of 60 trees on open-field sites were studied.

These included a range of tree species and clay soil types. The relevance and application of these results to urban situations are addressed in Volume 1. The

methods used in the research are described in the introduction to Volume 2 - they involved the use of 5 neutron probe access tubes per tree, by means of which the soil

water profiles of each were monitored over long periods. The rest of the volume presents detailed research data for each tree, including photographs and coloured diagrams. These cover the overall time period 1978-94, although different periods

apply to different trees.

46

Black Earth Creek Study

• Black Earth Creek receives 80% of its water from groundwater

• Main recharge occurs in spring and fall

• Recharge from the agricultural uplands is highly variable

• Wooded hill slopes generate no significant runoff

• Forested slopes are significant recharge areas

Lesovedenie

Effect of soil density on the growth of the root systems of tree seedlings.

Korotaev, A. A.Lesotekhnicheskaya Akademiya, Sankt-Peterburg, Russia.

Seedlings of Picea abies, Larix sibirica, Pinus sylvestris, Betula pendula, Quercus robur and Tilia cordata were grown in soils of

density 1.2, 1.3...1.9 g/cm³.

Data are presented on depth of root penetration and total root biomass. In terms of root growth rate and the ability to penetrate

dense soil layers, oak and larch were the best and spruce and lime were the poorest species.

The critical density of clay loam illuvial soil is 1.89 g/m³ for oak, 1.84 for birch, 1.80 for birch, 1.72 for pine, 1.61 for spruce, and 1.55 g/cm³ for lime. In experiments where the soil density in the lower horizon was greater, the total root biomass produced was virtually the same, as reduced root growth in the dense soil was

compensated by more active root growth in the topsoil .

47

Urban trees enhance water infiltration

Traditional stormwater management focuses on regulating the flow of runoff to waterways, but generally does little to restore the hydrologic

cycle disrupted by extensive pavement and compacted urban soils with low permeability.

The lack of infiltration opportunities affects groundwater recharge and has negative repercussions on water quality downstream.

Researchers know that urban forests, like rural forest land, can play a pivotal role in stormwater mitigation, but developing approaches that

exploit the ability of trees to handle stormwater is difficult in highly built city cores or in urban sprawl where asphalt can be the dominant cover

feature.

keepitcleandenver.org/how.html

48

Environmental Management Volume 44, Number 4 / October, 2009

Transpiration and Root Development of Urban Trees in Structural Soil Stormwater Reservoirs

Julia Bartens  , Susan D. Day , J. Roger Harris, Theresa M. Wynn and Joseph E. Dove

Stormwater management that relies on ecosystem processes, such as tree canopy interception and rhizosphere biology, can be difficult to

achieve in built environments because urban land is costly and urban soil inhospitable to vegetation. Yet such systems offer a potentially valuable

tool for achieving both sustainable urban forests and stormwater management. We evaluated tree water uptake and root distribution in a novel stormwater mitigation facility that integrates trees directly into

detention reservoirs under pavement. The system relies on structural soils: highly porous engineered mixes

designed to support tree root growth and pavement.

To evaluate tree performance under the peculiar conditions of such a stormwater detention reservoir (i.e., periodically inundated), we grew

green ash (Fraxinus pennsylvanica Marsh.) and swamp white oak (Quercus bicolor Willd.) in either CUSoil or a Carolina Stalite-based mix

subjected to three simulated below-system infiltration rates for two growing seasons.

Infiltration rate affected both transpiration and rooting depth. In a factorial experiment with ash, rooting depth always increased with infiltration rate for Stalite, but this relation was less consistent for CUSoil. Slow-drainage rates reduced transpiration and restricted rooting depth for both species

and soils, and trunk growth was restricted for oak, which grew the most in moderate infiltration.

Transpiration rates under slow infiltration were 55% (oak) and 70% (ash) of the most rapidly transpiring treatment (moderate for oak and rapid for ash). We conclude this system is feasible and provides another tool to address runoff that integrates the function of urban green spaces with

other urban needs.

49

Trees enhance water infiltration

Virginia Tech scientists used two container experiments to establish that urban tree roots have the potential to penetrate

compacted subsoils and increase infiltration rates in reservoirs being used to store stormwater. In one study, roots

of both black oak and red maple trees penetrated clay loam soil compacted to 1.6 g cm-3, increasing infiltration rates by an

average of 153%.

In another experiment, researchers created a small-scale version of the stormwater best management practice (BMP) under study by the three universities. This BMP includes a

below-pavement stormwater detention reservoir constructed of structural soil. Structural soils are engineered mixes

designed to both support pavement loads and simultaneously provide rooting space for trees. In this study, green ash trees

increased the average infiltration rate by 27 fold compared with unplanted controls.

In the experiment, a structural soil reservoir (CUSoil, Amereq Corp., New York) was separated from compacted clay loam

subsoil (1.6 g cm‑3) by a woven geotextile in 102-liter containers. The roots of ash trees planted in the structural soil

penetrated both the geotextile and the subsoil within two years.

50

Trees and Storm Water:

• The impact of urban trees on hydrology is extremely variable and complex, in general increases in tree cover and tree size over a site will result in reduced total runoff amounts and peak runoff rates.

• Effects are greatest during the growing season

• Effects are greatest on sites whose soils are relatively impermeable

TREESHelp Cities Meet Clean Water Regulations

Tree cover in urban areas can provide cities with reduced costs forstormwater management and improvement in water quality.

AmericanForests has developed a computer software package to measure theeffects of urban tree cover and impervious surfaces on stormwater

that will help city managers meet ever tightening water quality regula-tions. Scientific research and time-tested engineering practices pro-

vide the basis for the software calculations.

51

Trees and Storm Water:

• Trees have a relatively greater effect on smaller storm runoff amounts than on large storm events

• Surface and below-ground effects on runoff are much more significant than the above-ground effects

www.treesaregood.com/treecare/tree_benefits.aspx

52

All of the effects on runoff are greatest when urban trees are large and well-established on undisturbed sites

Vegetasi pohon sangat berpengaruh positif terhadap lingkungan termalnya dalam hal laju penurunan temperatur udara dan temperatur

udara rata-rata. Dengan demikian maka mekanisme pohon dalam pengendalian

lingkungan termal dapat diintepretasikan sebagai berikut :

- Pohon berpengaruh positif terhadap temperatur udara berdasarkan mekanisme pembayangan (canopy effect), di mana pohon memayungi

daerah di bawahnya dari sinar matahari langsung sehingga tidak menjadi panas dan berpengaruh pada udara.

- Pohon berpengaruh positif terhadap proses pendinginan (penurunan temperatur udara sore hari) berdasarkan mekanisme evapotranspiration, di mana pelepasan air dari permukaan daun pada sore hari mendinginkan

permukaan daun dan mempengaruhi temperatur udara di sekitarnya.-Pohon berpengaruh negatif terhadap proses pemanasan (naiknya

temperatur udara pagi hari) berdasarkan mekanisme ‘selimut’ di mana canopy menghalangi pertukaran panas dengan daerah sekitarnya

sehingga lingkungan di bawahnya cepat menjadi panas. Efek dari laju naik temperatur udara tidak terlalu berpengaruh pada temperatur udara

rata-rata.

53

Can urban tree roots improve infiltration through compacted subsoils for stormwater management?

Global land use patterns and increasing pressures on water resources demand creative urban stormwater management. Strategies encouraging infiltration can enhance groundwater

recharge and water quality. We examined whether tree roots can penetrate compacted subsoils and increase infiltration rates in

the context of a novel infiltration BMP (I-BMP).

Urban subsoils are often relatively impermeable, and the construction of many stormwater detention best management practices (D-BMPs) exacerbates this condition. Root paths can

act as conduits for water, but this function has not been demonstrated for stormwater BMPs where standing water and

dense subsoils create a unique environment. We examined whether tree roots can penetrate compacted subsoils and

increase infiltration rates in the context of a novel infiltration BMP (I-BMP). Black oak (Quercus velutina Lam.) and red maple (Acer rubrum L.) trees, and an unplanted control, were installed in cylindrical planting sleeves surrounded by clay loam soil at

two compaction levels (bulk density = 1.3 or 1.6 g cm−3) in irrigated containers. Roots of both species penetrated the more

compacted soil, increasing infiltration rates by an average of 153%.

Similarly, green ash (Fraxinus pennsylvanica Marsh.) trees were grown in CUSoil (Amereq Corp., New York) separated from

compacted clay loam subsoil (1.6 g cm−3) by a geotextile. A drain hole at mid depth in the CUSoil layer mimicked the

overflow drain in a stormwater I-BMP thus allowing water to pool above the subsoil.

Roots penetrated the geotextile and subsoil and increased average infiltration rate 27-fold compared to unplanted controls. 

Although high water tables may limit tree rooting depth, some species may be effective tools for increasing water infiltration and enhancing groundwater recharge in this and other I-BMPs

(e.g., raingardens and bioswales).

54

msdgc.org/wetweather/why_do_sewers_overflow.htm

55

Urban tree roots have the potential to penetrate compacted subsoils and increase infiltration rates in reservoirs being used to store

stormwater.Bartens et al. Can Urban Tree Roots Improve Infiltration through

Compacted Subsoils forStormwater Management? Journal of Environmental Quality, 2008; 37

(6): 2048

56

Landscape ecology of trees and forests. Proceedings of the twelfth annual IALE (UK) conference, Cirencester, UK, 21-24 June 2004

Investigating the impact of tree shelter belts on agricultural soils.

Carroll, Z. L., Bird, S. B., Emmett, B. A., Reynolds, B., Sinclair, F. L.Centre for Ecology and Hydrology, Orton Building, Deiniol Road, Bangor,

Gwynedd, Wales, LL57 2UP, UK.

There is growing concern that modern agricultural practices have reduced the infiltration capacity of the soil, thereby reducing the soil's ability to absorb rainwater. There are few quantitative data available, however, on the impact of land use on runoff and flood

risk.

A preliminary study was undertaken in the Nant Pontbren catchment, mid-Wales, UK. This land is used extensively for

grazing and experimental tree shelterbelts were established in selected pastures. Infiltration rates were up to 60 times higher in

areas planted with trees than in adjacent grazed pastures and significant differences were also observed for soil moisture and pH. Surprisingly, soil bulk density varied little between the two

areas.

The results indicate that more research is needed to gain a better understanding of the processes in operation. This study

demonstrates that farm trees could represent a key landscape feature, reducing runoff even when only a small proportion of the

land cover.

57

ISHS Acta Horticulturae 620: XXVI International Horticultural Congress: Asian Plants with Unique Horticultural Potential: Genetic Resources,

Cultural Practices, and Utilization

EFFECT OF RAINFALL INTERCEPTION ON SOIL MOISTURE, TREE SAP FLOW, AND FRUIT QUALITY IN PEACH (PRUNUS PERSICA)

D.G. Choi, D.C. Choi, D.H. You, H.G. Kim, J. Ryu, S.D.

Effect of soil covering with black polyethylene film for rainfall interception (RI) on soil moisture, tree sap flow, and fruit quality in ‘Okubo’ peach were investigated to find out the factor decreasing fruit quality, when it rained at

fruit mature season. Cell size of fruit was rapidly increased until the late of May, nearly stopped

at the early of June, and regrew from the late of June in the natural condition. Change of soil water was less and slower in the treatment of RI

than that in the control. The RI retarded the soil water increasing, whereas soil water in the control

plot fluctuated with rainfall amount change.

Soil water content in RI plot showed 80% lower at small raining and 40% lower at heavy raining than that in the control plot. Amount of tree sap flow

during raining was high in all treatments.

Tree sap flow kept high during the stable soil water period without rain, whereas it did lower during the unstable soil water period after rain.

Pit splitting rate was 20% in control tree and 10% in the RI.

Fruit hardness and sugar content were higher in RI treatment than that in the control. Therefore, taste of fruits in the RI treatment was better than

that of the control.

58

Agroforestry Systems (Netherlands)

Effects of mulching with multipurpose-tree prunings on soil and water run-off under semi-arid conditions in Kenya.

Omoro, L. M. A., Nair, P. K. R.Agroforestry Program, University of Florida, Gainesville, Florida, USA.

The effect of adding leaf mulches of Grevillea robusta, Cassia siamea and Gliricidia sepium on the rate of soil and water runoff from a crop

field were studied during 2 cropping seasons in an Alfisol under semi-arid conditions in Kenya.

Two rates of mulch of each species (2.24 t and 4.48 t, on dry matter basis, per ha) and a no-mulch control constituted the 7 treatments. Soil and water runoff losses after each major rainfall event and the changes

in ground and crop cover were measured.

Rainfall erosivity and changes in soil bulk density and infiltration rate were also determined. Soil losses from the plots with mulches of C. siamea, G. sepium and G. robusta were lower than those from the control. Over the 2 seasons, the cumulative soil losses from plots

mulched with cassia, gliricidia and grevillea were 11%, 57% and 81% of that of the control plot. Similarly, water runoff losses from cassia,

gliricidia and grevillea mulch plots were 28%, 48% and 58% of that of the control plot, respectively.

Thus, cassia was found to be better than gliricidia and grevillea in reducing both soil and water runoff losses. Soil bulk density did not

change while the infiltration rate at the end of the experiment was higher than in the beginning. However, there were no significant differences in

these soil physical properties among the treatments

59

So How Do We Protect Water Quality and Our Streams as Watersheds Change?

Trees and forests play an incredible role in reducing stormwater in several ways and removing or filtering pollutanting that would otherwise wind up in our

waterways.

InterceptionTree canopies intercept and capture rainfall, reducing the amount that reaches the

ground. In urban and suburban settings, a single deciduous tree can intercept between 500 and 760 gallons per year, while a mature evergreen can intercept

over 4,000 per year.

Soil InfiltrationTree roots and forest soils allow for better infiltration of rainfall with

rates of up to 15 inches per hour. The leaf littered forest floor acts like a gaint sponge, allowing for slow infiltration into soils befre releasing

it to natural channels and recharging ground water.

EvapotranspirationTree consumer stormwater through a process called evapotranspiration. Water is taken up by roots and move up through the tree until it is transpired back into the

atmosphere as water vapor. A single mature oak tree can consume (transpire) over 40,000 gallons of water each year.

PhytoremediationTrees are very good at removing pollutants such as nitrates & phosphates; and

other contaminates such as heavy metals, pesticides, solvents, oils, and hydrocarbons that are found in stormwater.

Riparian BuffersTrees and Riparian Forests protect and buffer streams and are critical to

maintaining healthy, clean streams. Tree roots provide streambank stability, reducing erosion, filter out sediments, remove nutrients, shade and cool the water,

provide habitat for many different species, and provide the primary food source for aquatic insects that are a critical part of the aquatic food chain.

Until recently, stormwater management strategies focused on detaining large volumes of water in basins that had little to no effect on removing the pollutants in

the stormwater. In December 2006, PA DEP unveiled new stormwater best management practices (BMPs) that work to protect water quality and put

stormwater back into the ground where it fell. One of the 10 principles in the BMP manual is to preserve and utilize natural systems such as forests, trees, and

native soils.

60

Trees and Forests Reduce the Impacts of Stormwater

As we begin to remove forest canopy and replace it with roads, parking lots, driveways, homes, patios, pools (impervious surfaces) and even

grass, we immediately have impact on watersheds and receiving streams (or lakes).

With the increased amount of impervious surfaces, water runs off the land, traveling on the surface towards the streams. As this ‘storm water runoff’ travels to the streams it collects pollutants and increases speed.

The changes to the landscape, not only increase the volume of water that goes to the stream, it also shortens the amount of time it takes the

water to get to the stream.

These increased or peak flows cause water to move quickly to the streams. This leads to flooding, streambank erosion, widening of

streams, sediment deposited in streams, a loss of fish habitat, and decline in water quality. In Pennsylvania there are over 12,200 miles of polluted streams and over 3,000 miles of streams that are impaired by

storm water runoff.

61

Geoderma

Analysing the space-time distribution of soil water storage of a forest ecosystem using spatio-temporal kriging.

Jost, G., Heuvelink, G. B. M., Papritz, A.Institute of Forest Ecology, BOKU-University of Natural Resources and Applied

Life Sciences, Vienna, Peter Jordan Str. 82, A-1190 Vienna, Austria.Editors: Oliver, M. A., Lark, R. M.

In forest the soil water balance is strongly influenced by tree species composition. For example, differences in transpiration rate lead to differences in soil water

storage (SWS) and differences in canopy interception cause differences in infiltration.

To analyse the influence of tree species composition on SWS at the scale of a forest stand, we compare spatio-temporal patterns in vegetation and SWS.

Geostatistical space-time models provide a probabilistic framework for mapping SWS from point observations.

The accuracy of these models may be improved by incorporating knowledge about the process of evapotranspiration. In this paper we combine a physical-

deterministic evapotranspiration model with space-time geostatistical interpolation to predict soil water storage in the upper 30 cm of soil (SWS30) for a

0.5 ha plot in a mixed stand of Norway spruce (Picea abies (L.) Karst.) and European beech (Fagus sylvatica L.) in Kreisbach, Lower Austria.

Soil water storage was measured at 198 locations by permanently installed wave guides. This was repeated 28 times, about every two weeks during the growing

seasons of 2000 and 2001. Incorporation of a process-based model in space-time prediction of SWS30 reduced the effect of precipitation on SWS30 predictions

prior to precipitation. Spatial patterns of SWS30 between the permanent wilting point and field capacity depend on the precipitation and drying history, which is affected by vegetation.

Early in the growing season spruce starts to transpire markedly, which is common for coniferous trees. During dry periods, spruce reduces transpiration earlier than

beech. Overall beech transpires more than spruce during the growing season.

The greater transpiration rates of beech are compensated for by greater soil water recharge after precipitation because less rainfall is intercepted.

At low water contents near the permanent wilting point SWS30 was spatially quite uniform. This was also the case at water contents nearfield capacity, probably because the soil physical parameters varied little. Space-time interpolation of

SWS30 and the prediction of soil water discharge and soil water recharge during periods of drying and rewetting demonstrate the important role of vegetation on

the spatial patterns of SWS30.

62

Benefits of Trees

Most trees and shrubs in cities or communities are planted to provide beauty or shade. These are two excellent reasons for

their use. Woody plants also serve many other purposes, and it often is helpful to consider these other functions when selecting a tree

or shrub for the landscape. The benefits of trees can be grouped into social, communal, environmental, and economic

categories.

63

Variability of surface runoff generation and infiltration rate under a tree canopy: indoor rainfall experiment using Japanese

cypress (Chamaecyparis obtusa)

Kazuki Nanko , Yuichi Onda , Akane Ito , Shun Ito , Shigeru Mizugaki , Hiromu Moriwaki

Hydrological Processes. Volume 24 Issue 5, 2010 Pages 567 - 575

To estimate the variability of surface runoff generation and the infiltration rate on a bare surface in a forested area, indoor

experiments were conducted using 13 runoff boxes and a single transplanted Japanese cypress tree (9·8 m in height) in a large-scale rainfall simulator with spray nozzles (at a height of 16 m).

The surface runoff was measured for applied rainfall and for 12 kinds of throughfall with different intensities and kinetic energy (KE) (found among measuring points and canopy structures). While no surface runoff was observed for the applied rainfall,

surface runoff was observed for throughfall in each runoff box. Compared with the applied rainfall, the throughfall had larger

drops due to canopy drip generation and thus had higher kinetic energy, which decreased the infiltration capacity.

The maximum stable infiltration rate (IRMAX) was lowest for throughfall (44·2 mm h-1). Surface runoff generation and

infiltration rates varied greatly under the canopy, even though the rainfall applications were identical and the runoff boxes had identical initial soil properties. The variability of IRMAX, ranging from 44·2 to 120·2 mm h-1, was caused by the variability of the throughfall intensity and kinetic energy. The index showing the best correlation to IRMAX was the effective unit kinetic energy

(KE0 mm: J m-2 mm-1). The prediction of surface runoff generation in a forested area requires estimations of the spatial

variations of the amount and kinetic energy of throughfall.

Copyright © 2010 John Wiley & Sons, Ltd.

64

Logging effects on soil moisture lossesZiemer, Robert R.

Date: 1978Ph.D. dissertation, Colorado State University, Ft. Collins, Colorado. 132

p.

The depletion of soil moisture within the surface 15 feet by an isolated mature sugar pine and an adjacent uncut forest in the California Sierra

Nevada was measured by the neutron method every 2 weeks for 5 consecutive summers.

Soil moisture recharge was measured periodically during the intervening winters. Groundwater fluctuations within the surface 50 feet were

continuously recorded during the same period. Each fall, a wetting front progressed from the soil surface, eventually recharging the entire soil

profile to ""field capacity"".

During the recharge period, although the top portion of the soil was at ""field capacity"", the trees continued to deplete moisture from the drier soil below the wetting front into early winter. Groundwater levels began

to rise within days after rainfall, whereas weeks or months were required for the wetting front to progress through the unsaturated zone above the

water table.

Soil moisture depletion by the isolated tree was maximum at a depth of 8 to 13 feet and extended about 15 feet away from the tree. The influence of

the tree on soil moisture depletion extended to a depth of about 18 feet and to a distance of about 40 feet. An excellent linear relationship was found between the quantity of soil moisture depleted by the tree at the

end of the summer and distance from the tree.

The isolated tree used between 2200 and 2600 cubic feet more soil moisture than a bare portion of the plot outside of the influence of the

tree.“

65

SIKLUS HIDROLOGIPeranan vegetasi pohon

References

Burgess, S. and 5 others. 1998. Trees as water pumps: restoring water balances in Australian and Kenyan soils. Agroforestry Today 10(3): 18-20).

MacDicken, K.G. 1991. Selection and Management of Nitrogen Fixing Trees. Winrock International, Morriltion, Arkansas, USA.

Nair, P.K.R., and Latt, C.R. (eds.) 1997. Directions in tropical agroforestry research. Agroforestry Systems, Special Issue, 38: 1-249.

Niang, A. and 5 others. 1999. Soil fertility replenishment in western Kenya. Agroforestry Today 11(1-2): 19-21.

von Carlowitz, P.G. 1986. Multipurpose Tree and Shrub Seed Directory. ICRAF, Nairobi.

von Carlowitz, P.G., Wolf, G.V., and Kemperman, R.E.M. 1991. Multipurpose Tree and Shrub Database. An Information and Decision-support System. GTZ, Eschborn, Germany.

Webb, D.B., Wood, P. J., Smith, J.P., and Henman, G.S. 1984. A Guide to Species Selection in Tropical and Sub-tropical Plantations. Commonwealth Forestry Institute, Oxford, UK.

Young, A. 1989. Agroforestry for Soil Conservation. CAB International, Wallingford, UK.

66

Hydrol. Earth Syst. Sci., 13, 1809-1821, 2009www.hydrol-earth-syst-sci.net/13/1809/2009/

© Author(s) 2009. This work is distributedunder the Creative Commons Attribution 3.0 License.

Significance of tree roots for preferential infiltration in stagnic soils

B. Lange, P. Lüescher, and P. F. Germann

It is generally recognized that roots have an effect on infiltration. In this study we analysed the relation between root length

distributions from Norway spruce (Picea abies (L.) Karst), silver fir (Abies alba Miller), European beech (Fagus sylvatica L.) and preferential infiltration in stagnic soils in the northern Pre-Alps in Switzerland. We conducted irrigation experiments (1 m2) and

recorded water content variations with time domain reflectometry (TDR). A rivulet approach was applied to

characterise preferential infiltration. Roots were sampled down to a depth of 0.5 to 1 m at the same position where the TDR-

probes had been inserted and digitally measured.

The basic properties of preferential infiltration, film thickness of mobile water and the contact length between soil and mobile

water in the horizontal plane are closely related to root densities.

An increase in root density resulted in an increase in contact length, but a decrease in film thickness. We modelled water

content waves based on root densities and identified a range of root densities that lead to a maximum volume flux density and

infiltration capacity.

These findings provide convincing evidence that tree roots in stagnic soils represent the pore system that carries preferential

infiltration. Thus, the presence of roots should improve infiltration.

67

SIKLUS HIDROLOGIPeranan bentang lahan

Social Benefits OF TREEWe like trees around us because they make life more pleasant. Most of

us respond to the presence of trees beyond simply observing their beauty. We feel serene, peaceful, restful, and tranquil in a grove of trees.

We are at home there. Hospital patients have been shown to recover from surgery more quickly when their hospital room offered a view of

trees. The strong ties between people and trees are most evident in the

resistance of community residents to removing trees to widen streets. Or we note the heroic efforts of individuals and organizations to save

particularly large or historic trees in a community. The stature, strength, and endurance of trees give them a cathedral-like

quality. Because of their potential for long life, trees frequently are planted as living memorials. We often become personally attached to

trees that we or those we love have planted.

68

Austral ecology   ISSN 1442-9985 2005, vol. 30, no3, pp. 336-347 

Woodland trees enhance water infiltration in a fragmented agricultural landscape in eastern Australia

ELDRIDGE David J. ; FREUDENBERGER David

Since European settlement, Eucalyptus box woodlands have been substantially modified by agricultural practices, and in many areas in southern Australia are now restricted to scattered or clumped trees.

We report here on a study to examine the impact of trees on water flow (infiltration) in an agricultural landscape with substantial areas of extant

native vegetation. We examined infiltration through coarse- and fine-textured soils within four landscape strata, the zones below Eucalyptus

melliodora and Callitris glaucophylla canopies, the intertree zone dominated by perennial grasses and a landscape homogenized by

cultivation and dominated by annual crops.

We measured sorptivity, the early phase of water flow, and steady-state infiltration with disc permeameters at two supply potentials. These different potentials enabled us to separate infiltration into (i) flow

through large (biopores) and small pores and (ii) flow through small pores only where biopores are prevented from conducting water. On the

fine-textured soils, both sorptivity and steady-state infiltration were significantly greater (approximately fivefold) under the timbered strata

compared with the grassy slopes or cultivation. Differences were attributable to the greater proportion of macropores below the tree

canopies compared with the nontimbered strata. The lack of a significant difference on the coarse-textured soils, despite their

macropore status, was attributed to differences in surface litter and plant cover, which would maintain continuous macropores at the

surface and thus conduct large amounts of water. The tendency of slopes covered by cryptogamic crusts and grasses to shed run-off and for the trees to absorb substantial quantities of water reinforced the important ecological service provided by trees, which moderates large run-off events and captures small amounts of water leaking from the grassy patches. In the absence of these 'ecosystem

wicks', run-off would find its way into regional groundwater and contribute to rising salinity.

69

NERACA AIR DI ALAM

70

Journal of Hydrology (Amsterdam)

Soil water depletion and recharge patterns in mixed and pure forest stands of European beech and Norway spruce.

Schume, H., GeorgJost, Hager, H.Institute of Forest Ecology, BOKU, University of Natural Resources and Applied Life Sciences, Peter Jordan Strasse 82, Vienna A-1190, Austria.

Automated time domain reflectometry (TDR) measurements in high resolution over soil depth and over time were performed in a mixed

beech-spruce and a spruce stand during two hydrologically contrasting seasons.

Soil drying was more intensive and reached deeper soil layers in the mixed stand, which on the other hand allowed more stand precipitation,

compensating for the higher evapotranspiration rates. These results were confirmed by a large number of spatially distributed TDR

measurements along grids of different spacing, which additionally covered a beech stand. Spatial water depletion patterns of the topsoil in spring appeared to be largely congruent with tree species distribution

and reflected the higher water consumption of fully foliated beech. Variability was highest in the mixed stand, where a spatial correlation

within a range of about 7 m was observed.

The pure stands lacked spatial correlation. The effect of the mixed stand on soil water depletion and recharge turned out to be non-additive as

compared to the pure stands of beech and spruce: changes of soil water storage under the mixed stand almost equalled the values measured in the beech stand. During selected drying periods in 2000 average daily

water extraction rates from the uppermost 60 cm of soil amounted to 1.65 mm in the beech as well as in the mixed stand, which is about 45% more

than under pure spruce.

Maximum differences of up to 84% occurred in periods with high evaporative demand. The over-proportionate evapotranspiration of the

mixed stand was exclusively attributable to beech, which deepened and intensified its fine-root system in mixture, while spruce rooted more

shallowly. The mixed stand extracted a higher percentage of water from deeper soil layers than the pure stands.

71

Peran Vegetasi

Salah satu peran vegetasi untuk mengendalikan lingkungan termal adalah melalui mekanisme evapotranspiation (proses penguapan air dari daun ke udara) yang dapat mempercepat pendinginan permukaan daun yang juga

berakibat pada penurunan temperatur udara.

Pengukuran terhadap proses evapotranspiration pernah dilakukan oleh DOE Lawrence Berkeley National Laboratory dan dilaporkan bahwa pohon

berdiameter 30 feet dapat melepas air sebanyak 40 galon / hari.

Pohon dan tanaman mendinginkan udara dengan cara membayangi dan mungurangi jumlah sinar matahari yang mencapai tanah. Jumlah sinar

matahari yang menembus canopy dinyatakan dalam nilai transmitansi1 yang bervariasi dari 0 – 100%.

Nilai 0 berarti sinar matahari sama sekali tidak dapat menembus canopy, nilai 100 berarti tidak ada sinar matahari yang ditahan oleh canopy.

72

Journal of Arid Environments

Rain-water management for tree planting in the Indian desert.

Gupta, G. N.Arid Forest Research Inst., Division of Forest & Desert Development,

New Pali Road, Jodhpur 342005, Rajasthan, India.

The influence of different systems of water harvesting and moisture conservation on soil moisture storage, growth, biomass accumulation and nutrient uptake by Azadirachta indica (neem), Tecomella undulata (rohida) and Prosopis cineraria (khejri) was studied in Rajasthan, India,

during 1990-1992.

The ridge and furrow method of water harvesting was found to be the best treatment and significantly improved the growth of all 3 species (height by 58%, 35% and 40%, collar circumference by 73%, 56% and

63%, and crown diameter by 111%, 51% and 131%, respectively).

Biomass accumulation by A. indica and T. undulata increased 3.8-fold and 4.6-fold and root mass 4.5-fold and 3.8-fold, respectively. The

mulching treatment was beneficial to A. indica and weeding treatment to all the 3 species.

Tree roots in water harvesting plots were deeper and had a spread several times larger than the control. Nutrient uptake by

these tree species increased several-fold as a result of the different water harvesting and moisture conservation

treatments.

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SIKLUS HIDROLOGIPeranan vegetasi pohon

Economic Benefits of Tree

Individual trees and shrubs have value, but the variability of species, size, condition, and function makes determining their economic value difficult. The economic benefits of trees can be both direct and indirect. Direct economic benefits are

usually associated with energy costs. Air-conditioning costs are lower in a tree-shaded home. Heating costs are reduced when a home has a windbreak. Trees

increase in value from the time they are planted until they mature. Trees are a wise investment of funds because landscaped homes are more valuable than

nonlandscaped homes. The savings in energy costs and the increase in property value directly benefit each home owner.

The indirect economic benefits of trees are even greater. These benefits are available to the community or region. Lowered electricity bills are paid by customers

when power companies are able to use less water in their cooling towers, build fewer new facilities to meet peak demands, use reduced amounts of fossil fuel in their furnaces, and use fewer measures to control air pollution. Communities also

can save money if fewer facilities must be built to control storm water in the region. To the individual, these savings are small, but to the community, reductions in these

expenses are often in the thousands of dollars.

74

example.

                                                                                                                                                                                                                                                                    

75

Plant and SoilEffects of changes in tree species composition on water flow

dynamics - model applications and their limitations.

Armbruster, M., Seegert, J., Feger, K. H.

Institute of Soil Science and Site Ecology, Dresden University of Technology, 01735 Tharandt, Germany.

Editors: Hüttl, R. F., Bens, O.

Water-plant relations play a key role in the water cycling in terrestrial ecosystems. Consequently, changes in tree species composition may have distinct effects on the

water retention capacity as well as on the pattern of streamflow generation. Such changes may result from modified interception properties and transpiration related to

differences in canopy properties and root distribution. In order to evaluate the potential hydrological effects of the current silvicultural conversion from monocultural conifer stands into mixed or pure deciduous stands the hydrological model BROOK90

was applied to two forested upland catchments in Germany. The Rotherdbach catchment (9.4 ha, 93 yr-old Norway spruce) is situated in the Eastern Ore Mountains. The Schluchsee catchment (11 ha, 55-yr-old Norway spruce) is located in the higher

altitudes of the Black Forest.

The calibrated model is capable to describe rather well the temporal variation of streamflow but also the portions of the individual flow components. Data for a beech

scenario were adapted for each site using a standard parameter set for deciduous trees provided by BROOK90. The annual discharge in the fictional beech stand at

Rotherdbach is 30 to 50% higher compared to spruce with an increase of soil moisture and especially the slow streamflow components. This mainly results from low

interception rates during winter time. In contrast, the spruce stand has a permanently higher interception rate. Effects of tree species conversion are moderate at

Schluchsee.

The annual discharge of a fictional beech stand at Schluchsee is 7 to 14% higher compared to spruce. There in contrast to Rotherdbach, effects of tree species

conversion on soil moisture dynamics are small since vertical percolation in the highly permeable soil dominates and precipitation is abundant. Practical forestry will favorably establish mixed beech-spruce rather than pure beech stands. However, it is

critical to simulate mixed stands with BROOK90. Therefore, a simple summation of model results from spruce and beech according to their respective area in a fictional

mixed stand can only be a first approximation.

Advanced hydrological simulation of mixed stand conditions should regard interactions of tree species and spatial parameter distribution. However, this is not yet feasible due to a distinct lack of information. As a consequence, there is a strong need

to collect relevant hydrological and ecophysiological data in mixed stands in the future.

76

Infiltration is governed by two forces: gravity and capillary action. While smaller pores offer greater resistance to gravity, very small pores pull water through capillary action in addition to and even against the force

of gravity.The rate of infiltration is affected by soil characteristics including ease of entry, storage capacity, and transmission rate through the soil. The soil texture and structure, vegetation types and cover, water content of

the soil, soil temperature, and rainfall intensity all play a role in controlling infiltration rate and capacity. For example, coarse-grained sandy soils have large spaces between each grain and allow water to

infiltrate quickly. Vegetation creates more porous soils by both protecting the soil from pounding rainfall, which can close natural gaps between soil particles, and loosening soil through root action. This is why forested areas have

the highest infiltration rates of any vegetative types.

77

Infiltration is the process by which water on the ground surface enters the soil. Infiltration rate in soil science is a measure of

the rate at which soil is able to absorb rainfall or irrigation. It is measured in inches per hour or millimeters per hour.

The rate decreases as the soil becomes saturated. If the precipitation rate exceeds the infiltration rate, runoff will

usually occur unless there is some physical barrier. It is related to the saturated hydraulic conductivity of the near-surface soil. The rate of infiltration can be measured using an infiltrometer.

78

Tree PhysiologyConverging patterns of uptake and hydraulic redistribution of

soil water in contrasting woody vegetation types.

Meinzer, F. C., Brooks, J. R., Bucci, S., Goldstein, G., Scholz, F. G., Warren, J. M.

Forestry Sciences Laboratory, USDA Forest Service, 3200 SW Jefferson Way, Corvallis, OR 97331-4401, USA.

Editors: Meinzer, F. C., Goldstein, G., Phillips, N. G.

We used concurrent measurements of soil water content and soil water potential (Ψsoil) to assess the effects of Ψsoil on uptake and hydraulic

redistribution (HR) of soil water by roots during seasonal drought cycles at six sites characterized by differences in the types and amounts of

woody vegetation and in climate.

The six sites included a semi-arid old-growth ponderosa pine (Pinus ponderosa) forest, a moist old-growth Douglas-fir (Pseudotsuga

menziesii) forest, a 24-year-old Douglas-fir forest, in Washington, USA, and three Brazilian savanna sites, in Distrito Federal, differing in tree

density. At all of the sites, HR was confined largely to the upper 60 cm of soil.

There was a common threshold relationship between the relative magnitude of HR and Ψsoil among the six study sites. Below a threshold Ψsoil of approximately -0.4 MPa, overnight recharge of soil water storage increased sharply, and reached a maximum value of 80-90% over a range of Ψsoil from ~-1.2 to -1.5 MPa. Although amounts of water hydraulically redistributed to the upper 60 cm of soil were relatively small (0 to 0.4 mm

day-1), they greatly reduced the rates of seasonal decline in Ψsoil. The effectiveness of HR in delaying soil drying diminished with increasing

sapwood area per ground area.

The relationship between soil water utilization and Ψsoil in the 20-60-cm layer was nearly identical for all six sites. Soil water utilization varied with a surrogate measure of rhizosphere conductance in a similar manner at all six sites. The similarities in relationships between Ψsoil and HR, soil

water utilization and relative rhizosphere conductance among the six sites, suggests that, despite probable differences in maximum rooting depth and density, there was a convergence in biophysical controls on

soil water utilization and redistribution in the upper soil layers where the density of finer roots is greatest.

79

TREE FOR SOIL IMPROVEMENT

The following are the principal trees and shrubs that have been employed for soil improvement (from Webb et al., 1984; von Carlowitz, 1986; von Carlowitz et al., 1991; MacDicken, 1994; Young, 1989a, p. 159).

Acacia auriculiformis Acacia cyanophylla Acacia mangium Acacia mearnsii Acacia nilotica Acacia senegalAcacia seyal Acacia tortilis Albizia lebbeckAlbizia saman (Samanea saman) Anacardium occidentaleAlnus acuminata Alnus nepalensis Alnus spp.Atriplex spp. Azadirachta indica Bactris gasipaesBamboo genera Cajanus cajan Calliandra calothyrsusCasuarina cunninghamiana Casuarina equisetifoliaCasuarina glauca Centrosema pubescens Cordia alliodoraCrotalaria spp. Dalbergia sissoo Dactyladenia barteri (Acioa barteri)Dendrocalamus spp. Erythrina caffra Erythrina orientalisErythrina poeppigiana Faidherbia albida (Acacia albida)Flemingia congesta (Flemingia macrophylla)Gliricidia sepium Grevillea robusta Inga edulisInga jinicuil Leucaena diversifolia Leucaena leucocephalaMelaleuca leucadendron Melia azedarach Musanga cecropioidesParaserianthes falcataria (Albizia falcataria) Parkia biglobosa (Parkia africana)Paulownia elongata Peltophorum dasyrrachisPopulus deltoides Prosopis chilensis Prosopis cinerariaProsopis glandulosa Prosopis juliflora Prosopis tamarugoSchinus molle Senna reticulata Senna siamea (Cassia siamea)Senna spectabilis (Cassia spectabilis)Sesbania bispinosaSesbania grandifloraSesbania rostrataSesbania sesbanTamarix aphyllaTephrosia candida*Tephrosia vogelii*Tithonia diversifoliaZiziphus mauritianaZiziphus nummulariaZizyphus spina-christi

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RAIN GARDENS

Tree box filters are mini bioretention areas installed beneath trees that can be very effective at controlling runoff, especially when distributed throughout the site.1 Runoff is directed to the tree

box, where it is cleaned by vegetation and soil before entering a catch basin. The runoff collected in the tree-boxes helps irrigate

the trees.

Tree box filters are based on an effective and widely used “bioretention or rain garden” technology with improvements to enhance pollutant removal,

increase performance reliability, increase ease of construction, reduce maintenance costs and improve aesthetics. Typical landscape plants

(shrubs, ornamental grasses, trees and flowers) are used as an integral part of the bioretention / filtration system. They can fit into any landscape

scheme increasing the quality of life in urban areas by adding beauty, habitat value, and reducing urban heat island effects.

Manufactured Tree Box Filters For Stormwater Management(Source: Virginia DCR Stormwater Management Program)

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RAIN GARDENS

TREE BOX FILTERThe system consists of a container filled with a soil mixture, a

mulch layer, under-drain system and a shrub or tree. Stormwater runoff drains directly from impervious surfaces

through a filter media. Treated water flows out of the system through an under drain

connected to a storm drainpipe / inlet or into the surrounding soil. Tree box filters can also be used to control runoff volumes / flows

by adding storage volume beneath the filter box with an outlet control device.

Tree Box Filters For Stormwater Management(Source: Prince George's County, MD Bioretention Manual)