Report in Botany

7/29/2019 Report in Botany

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PLANT ECOLOG Y

A ND GEOGRAPH Y

Presentor:

rachell b. sollano

http://www.bbc.co.uk/schools/scienceclips/ages/9_10/life_cycles.shtml





Plant Ecology- is the branch of botany

which deals with the effects of

environmental factors upon plant

growth and distribution, and conversely,

with the effects of plants upon the

earth, air, water, and other organisms.

Plant geography- deals with the

geographical distribution of varioustypes of plants upon the earth’s

surface.



Autecology- is concerned with

the individual organism and itsrelation to its environment.

Synecology- is concerned wiyhthe total complex of inter-

relations between organisms

and between them and their

environment.



Environmental factors which influencethe growth and distribution of plantsare:

Climatic Factors (Factors of theAtmosphere).

TEMPERATURE. Temperature influences

the rate at which the physiologicalactivities of plants occur and thusinfluences plant growth and distribution.



LIGHT. Light influences plant growththrough its effects on photosynthesis

, transpiration, direction of growth,

heating effect, flower production,

enzyme action, etc.



Carbon Dioxide Concentration. It

is the limiting factor inphotosynthesis and thus changes in

it affect the rate of photosynthesis.

Excess CO2 often inhibits growth.Other Atmospheric Gases. Gases

from smelters, furnaces, etc., are

often injuries to vegetation.



Wind. Affects transpiration and also

exerts mechanical effect upondirection of growth, form of plant,

etc.

Atmospheric Humidity AndPrecipitation. Water vapor

content of air, rain, snow, etc.,are factors influencing plantgrowth and distribution.



Edaphic Factors (Soil Factors).

Available Soil Water . One of the most

important edaphic factors. Plants are

often classified on the basis of their

adaptation to water supply as follows:

Hydrophytes- plants which inhabit water

or wet soil: cattails, water lilies, pond

weeds, etc. Usually weak-stemmed, withnumerous air spaces, often very fine,

thin leaves, and little or no cutin.



Xerophytes-plants which inhabit

arid or semi-arid regions: cacti,

sagebrush, Russian thistle, etc.

Leaves absent or much reduced in

size, usually with heavy layers of cutin, well-developed water-storage

tissues, stomata often reduced in

number and sunken in pits, etc.



Mesophytes-plants inhabiting regions

with moderate water supply: common

field and forest plants, such as roses,elms, maples, trillium, blue grass,

violets, oaks, etc.



Halophytes-plants which inhabits

soil with high salt content andwhich can absorb water only with

difficulty, because of high solute

concentration of soil solution.Halophytes often resemble

xerophytes structurally becauseof difficulty of absorbing water:

salt bush, greasewood, etc.



Soil Temperature. Affects rate of

root growth, respiration, water absorption, etc.

Air in the Soil. Roots normally

require oxygen for respiration andthus a deficiency of air affects root

growth. Water logged soil have little

air and plants growing in such oils

are usually badly stunted.



PHYSICO-CHEMICAL NATURE OF

SOIL. Acidity or alkalinity of soil

influence rate of absorption, nature of

materials absorbed, and other activities

of roots. Presence or absence of

essential mineral elements influences

rate of food synthesis and other

anabolic processes in plants, etc.

Physico-electrical properties of soil

particles affect absorption, drainage,

etc.



Biotic Factors (Effect of Other Living

Organisms).

GRAZING BY ANIMALS. Grazing removes

food-making organs causes stunting of

growth, etc. Also, mechanical effect of trampling.



SOIL ORGANISMS. Bacteria, fungi,

algae, protozoa, worms in soil are

important agents in increasing or

decreasing soil fertility, in altering physical

properties of soils, in attacking roots of

higher plants, etc.



INSECTS. Insect which eat or

otherwise injure plants or their parts

or which function in pollination areimportant in growth, seed production,

etc.

PARASITIC FUNGI. Disease-

producing fungi mat stunt growth,

form abnormal growths, and generallydecrease populations of susceptible

plants, often to the point of extinction

in certain regions.



COMPETITION. Struggle among

various species of plants for water, soil

salts, light, air, etc., influences

distribution of plants.

SYMBIOTIC RELATIONSHIPS. Certain

plants may cooperate for mutual

benefit, as, algae and fungi in lichens,

nodule bacteria on legume roots, etc.



Plant Communities - group of plantswhich live together under the same set

of environmental conditions.

Types of plant association:pond communities

xerophytic communities

Mesophytic communities

Swamp communities



Plant Succession – is a series of

changes in the plants of a given region

as a result of disturbances in climatic,biotic, or topographic factors.

Pioneer communi ty- the first

community which becomes established.

Intermediate commun i ties- which as a

result of the activities of the pioneer

organisms are better adjusted to the

newer environmental factors than the

pioneer communities.



Cl imax commun ity- the highest type

which can be supported by the obtaining

set of external factors and the type whichtends to perpetuate itself year after year

under similar conditions and does not

render the environment unsuitable for itsown offspring.

Plant Invasion- is the tendency for a

species or an association of species to

extend its regions of occupancy and thus

to invade new areas.



Plant geography- deals with the

geographical distribution of various typesof plants upon the earth’s surface.

Important factors in geographical

distribution:

Barriers- which prevent or discourage the

migration of certain plant species.Highways- which facilitate the migration of

species.



Plant geographical areas of North America

will be treated, as follows:

Tundra- occupies the northern edges of

North America, from Alaska to Labrador.

characteristic plants:

lichens sedges

mosses other herbsgrasses a few shrubs



Northern Evergreen Forest- across

continent from Pacific to Atlantic, south

from tundra to Vermont, Great Lakes, andthence northwest through Canada and

Alaska.

Characteristic plants:

chiefly conifers, (such as black spruce,

white spruce, hemlock, white pine, jack

pine, balsam fir, etc.

Decidous trees, (such as aspens and

birches, chiefly in cut or burned areas)



Coastal plain region, from Virginia toTexas, except Southern Florida.


live oakBald cypress

Long- leaf pine

Magnolia

Gums

Some short- leaf pine



Southern Florida, Central America,West Indies, Mexican coasts, etc.


Lianas(woody climbers)Palms

Orchids

mangroves



Texas to Manitoba, northwest intoCanada, and west to the Rocky Mts.across Kansas, Nebraska, the Dakotas,

etc.Characteristics plats:

• many species of grasses

• Asters

• Golden rods

• sunflowers



South from western Idaho andeastern Oregon through most of theregion (The Great Basin) between

the mountain of Colorado andWyoming to the Sierra Nevadas of California and south Arizona, New

Mexico, Texas, and Northern Mexicoand Lower California.



Southward from southeast Alaska andnorthwest Canada through Idaho,Montana, and the regions lying

between the Grasslands and the GreatBasin, extending south through themountains of New Mexico into

Mexico.



The slopes of the coastalmountains, from southern Alaskainto southern California.

Characteristic plants: Sitka spruce,western hemlock, Douglas fie,western white pine, redwoods,western white cedar, arbor vitae,western yellow pine.

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