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THE VEGETATION AND FLORISTIC COMPOSITION ALONG THE BRAHMAPUTRA RIVER AND THE BRAHMAPUTRA VALLEY, ASSAM, INDIA

REPORT

Submitted by

Pranab Bujarbarua Department of Botany

Handique Girls’ College, Guwahati

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CONTENTS

Chapter 1: Introduction ………. 5

Chapter 2: Vegetation and Forest Type ………. 9

Chapter 3: Conspectus of the Flora of Brahmaputra Valley ………. 16

Chapter 4: Significance of the Flora ………. 21

Chapter 5: Utility of the Floristic Diversity ………. 22

Chapter 6: High Priority Taxa ………. 24

Chapter 7: Threats ………. 26

Chapter 8: Problems of Forest Management in the Brahmaputra Valley………. 29

Chapter 9: Discussion ………. 32

Bibliography ………. 37

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List of Appendix:

Appendix I - Floristic diversity of the national parks of Assam 43 Appendix II - Floristic diversity of the Islands of Brahmaputra river 44 Appendix III - Floristic diversity of Assam worked out by different workers 45 Appendix IV - Comparisons of Evergreen species distributed in Brahmaputra

and Barak valley 46 Appendix V - Endemic plant taxa of Assam 49 Appendix VI - List of primitive families and genera and representative 53

species in the Brahmaputra valley. Appendix VII - Economically important plants of Brahmaputra valley 55 Appendix VIII - Wild relatives of cultivated plants found in the Brahmaputra 57

valley Appendix IX - Rare, Threatened and Endangered Plant Taxa of Assam 59

Annexure

Annexure I - List of Orchids of the Brahmaputra valley 61

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Photo Plates

1. Tree and Timber yielding plants

2. Economically important plants

3. Medicinal plants

4. Parasitic angiosperms

5. Orchids

6. Potential floricultural plants

7. Wild edible fruits

8. Other common plants

9. Invasive species

10. Gymnosperms and ferns

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Acknowledgement

The report ‘The vegetation and floristic composition along the Brahmaputra river

and the Brahmaputra valley, Assam, India’ has been submitted under the contract

agreement between the undersigned and the Tetratech. I am deeply indebted to Dr. K.K.

Dwivedi, CEO, AIFRERMIP and Mr. S. K. Choudhury, Officer in Charge, Tetratech, Guwahati

and who have given me the opportunity to work under assignment. It gives me great

pleasure to express my deep sense of gratitude to Dr. Dwivedi for his useful suggestions. I

am also thankful to Dr. Udayan Borthakur, Co-ordinator of the project for his fruitful

discussions and encouragement throughout the study.

I acknowledge the help and suggestions of the villagers of Mulai Kathoni, Jorhat,

forest officials of Panidihing bird sanctuary, Garampani WLS and Mr. Joynal Abedin (Benu

da) for his suggestions during my visit to Dibru-Saikhowa BR.

Last but not least my heartiest thanks to Dr. Jayanta Das for their fruitful

suggestions. Some of the photographs used in the report are taken from Dr. A.K. Baishya,

Dr. P.J. Bora, Dr. Bandana Nabis Das and Mrs. Prabhali Doley. I acknowledge their help in

this regard.

Pranab Bujarbarua Assistant Professor

Department of Botany Handique Girls’ College,

Guwahati

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Chapter 1

INTRODUCTION

Northeast India consisting of eight states of Assam, Arunachal Pradesh, Manipur,

Meghalaya, Mizoram, Nagaland, Tripura and Sikkim comprising an area of about 2, 62, 179

Km2 is known for its rich biological and cultural diversity. Based on its physiography and

biological composition, the region can broadly be categorized into the Eastern Himalaya,

Northeast hills and Brahmaputra plains. Its unique location at the confluence of the Indo-

Malayan, Indo-Chinese and Indian biogeographical regions coupled with its physiography

has generated a profusion of habitats, which harbors diverse biota with high level of

endemism. The region is part of Himalaya and Indo-Burma biodiversity hotspots, two of 34

such hotspots in the world (Mittermier, 2004). It is also home of over hundred ethnic

communities and a large percentage of the population is dependent on traditional natural

resource-based livelihoods. Northeast region is characterized by high rainfall and humidity.

This along with varied altitudinal gradients influence the climate that ranges from tropical

plains to temperate and alpine hills. These diverse climates supports almost all types of

vegetation from cultivated plants to grasslands, meadows, marshes, swamps, scrubs, mixed

deciduous and humid evergreen forest, temperate and even alpine vegetation.

Assam, one of the sister states of Northeast India is regarded as biogeographical

gateway for much of India’s biological resources. Nestling between the eastern Himalayan

foot hills and the Patkai and Barail ranges of hills, the state is one of the largest north

eastern states of India. It is characterized by distinct habitats, landscape, broad valleys and

hills. Though largely plain, the Barail range is mountainous. Both sides of this range are the

Brahmaputra and Barak valleys. Situated between 24o2’- 27 o6’N latitude and 89o8’-96o E

longitude, the political boundary of Assam extends to an area of 78,523 sq km of which total

forest area is about 27,673 sq km that is about 35.28% of the total geographical area of the

state (Forest Survey of India, 2011). This area excludes the unclassed state forest which is

approximately 5865 sq. km. The occurrence of heterogenic physiography coupled with

varied climatic conditions on and around the state has made the vegetation luxuriant and

diverse that support unique flora and fauna. The variations in forest types and their

vegetation composition in Assam occur mainly due to the range of climatic conditions and

to certain extent due to local edaphic factors (Baishya, 1999).

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The mighty river Brahmaputra traverse the state from east to west covering a

distance of about 1300 km thereby separating the sub-himalayan region of Assam from the

southern parts and forms the gorgeous Brahmaputra valley with an elevation of about 122m

at Sadiya the eastern most and 30m at Dhubri the western most part of the valley. The

uniqueness of Brahmaputra river system lies in its glacial origin, location in a highly seismic

zone, heavy and intense rainfall resulting in flash flood, high sedimentation rate and an

intricate link with the ecology of the beels (wetlands) in the plains.

Map 1: Map of Assam showing topographic feature & River Network (Source: Assam: National Disaster Risk Reduction Portal)

Brahmaputra valley being the largest plain in the northeast region and has a great

significance not only for agriculture and industry of the region but also for its rich vegetation

preserved in the various protected areas i.e. biosphere reserves, national parks and wildlife

sanctuaries etc. There are 5 national parks, 20 wildlife sanctuaries and a number of reserve

forests are present in this valley, of which two national parks viz. Manas and Dibrusaikhowa

have also been categorised as biosphere reserves. The forest types are mostly tropical which

harbours a rich pool of biodiversity.

The rich flora of the area has been the centre of attraction for various botanists since

early 19th century which began with the famous Assam tea delegation comprising N. Wallich

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(1820-1832), W. Griffith (1848), Robinson (1841) provided some floristic account of the

region. Some of the earlier contributors to the flora of Assam are Carter (1921), Hooker et al

(1872-1892), Kanjilal (1934-40), Bor (1940), etc. Baishya (1999) gave a detailed account of

the florstics of Assam. Chowdhury (2005) compiled a detail account on the flora of Assam.

More recently, Barooah and Ahmed (2014) made a comprehensive checklist of the

angiosperms and gymnosperms of the state.

Flora of Assam by Kanjilal et al was the beginning of botanical studies by Indian

Botanists. Subsequently, a number of Botanists contributed to the understanding the flora

of the state (Rao & Verma 1969, Kar & Panigrahi 1963, Jain & Hajra 1975, Rao 1974, Islam

1990, Sarmah 1989 and Sas Biswas et al 1990). Many workers have attempted the floristic

studies of different districts as well as the protected areas of the state (Gogoi 1976, Barua

1978, Hajra 1978, Sarmah 1989, Barua 1992, Sarkar 1993, Singh 1993, Nath & Choudhury

1994, Bora 1999, 2001, Barooah & Borthakur, 2003, Bujarbarua 2004, Begum, 2010, Begum

et al., 2010, Nath, 2012, 2015 etc.). Bhagawati et al (2006) made an effort to prepare the

biodiversity status of the state of Assam along with the strategy action plane for

conservation.

Although the state has been well explored floristically, yet there are areas with

ample scope of floristic study particularly protected areas of the state. Moreover, a detailed

account of the flora of the present state of Assam is yet to be brought out. Considering the

vastness and ecologically diverse area, there is plenty of scope to increase these numbers as

many areas are still unexplored or underexplored. One such most important area of the

state is the river bank vegetation. The river bank vegetation, ecologically termed as riparian

is highly dynamic vegetation. River’s riparian zone acts as a bridge between terrestrial and

aquatic habitat. These areas are represented by a particular type of vegetation that grows

along the sides of rivers under the influence of a waterway, such as rivulet banks or

riverbanks. Riparian i.e. river bank vegetation at a particular location and time results from

interactions between the physical conditions created by geomorphic and hydrologic

processes in the stream channel and responses by the plants (La Fayette & DeBano, 1990).

The present report is being prepared with an aim to work out the

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- vegetation types and flora along the course of the river Brahmaputra river.

- documentation agro biodiversity, invasive species, grassland habitats, plants of

economic and other uses in the areas along the Brahmaputra river, and

- screening of the rare, threatened, endangered as well as the endemic taxa.

Work plan:

The study was primarily based on the literature survey. Moreover, field visits to the

various locations in the protected areas along the river Brahmaputra and other riparian

locations along the river was also conducted to validate the secondary data.

Sl no. Component 1st Month 2nd Month 3rd Month

1 2 3 4 1 2 3 4 1 2 3 4

1 Literature Survey

2 Field Visit

3 Data compilation

4 Report Preparation

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Chapter 2

VEGETATION AND FOREST TYPE

The geographical areas of the state lies in the transitional zone of Indo-Malayan and

Indo-Chinese and India, along with two migratory route of birds - the Central Asian flyway

and East Asian-Australian flyway which enriches floristic and faunal composition of the

region (Islam & Rahmani, 2004). The major types of plant communities found in the state

can be grouped under Moist Evergreen Forest, Moist Semi-Evergreen, Moist and Dry

Deciduous forest, Hydrophytes in vast stretches of wetlands (riparian belts, swamps and

marshes), Bamboo brakes, Scrubland and Grass land (both wet and dry). The forest types of

northeast India including the state of Assam have already been described by Champion and

Seth (2005). The state of Assam falls in the tropical climate belt in the northeastern region

of India (Srivastava et al. 2002) and maximum forest area of the state included under

tropical moist deciduous type (Agarwala 1990). In general the vegetation of Assam is

primarily tropical type that covers large areas and embraces evergreen, semi evergreen,

deciduous forests and grass lands. Stretches of riparian forest along the bank of rivers are

also very prominent. The variations in forest types and their vegetation composition in

Assam occur mainly due to the varied physiographic, edaphic conditions and range of

climate. As there are not much altitudinal variations in the plains particularly in the

Brahmaputra valley, it has little significance in determining the forest types of Brahmaputra

valley.

It may be mentioned here that majority of the protected areas of the state are

situated at the Brahmaputra valley and most of these are either well explored or under

explored floristically. It is thus obvious that the vegetation and forest types of these

protected areas have already been worked out. From all such available sources and personal

observation, the vegetation and forest type along the Brahmaputra river in Assam may be

considered as tropical moist evergreen, tropical semi evergreen, moist deciduous forest,

Grass land and savannah, wetlands and swamps, riparian forest and degraded lands. A brief

account of these forests given as follows -

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2.1. Tropical Moist Evergreen Forests:

The moist evergreen forests is characterised by the stratification of the plants into

different storeys. These type of forests are prevalent in specific areas of upper Assam in the

districts of Tinsukia, Dibrugarh, Sibsagar, Jorhat and in few places of Dhemaji and

Lakhimpur. Luxuriant and gregarious growth of broad leaved lofty tree species of

angiosperms along with a number of tree ferns, epiphytes including orchids are the

characteristic features of these forests. Although it is difficult to demarcate easily various

storeys in these forests, but a few tall trees along with some medium sized form the canopy

and merge with large shrubs intermingle with climbers and dense undergrowth of low

shrubs and herbs (Chowdhury, 2005). Rowntree (1954) termed these forests as

Dipterocarpus – Mesua formation.

The giant Dipterocarpus retusus attaining a height of over 40m is the most

prominent species in the top storey. The associated species are Alianthus grandis, Altingia

excels, Artocarpus chama, Artocarpus lakoocha, Cinnamomum bejolghota, Mesua ferrea,

Michelia champaca, Phoebe cooperiana, Shorea assamica, Tetremeles nudiflora etc.

The common species composed of middle storey are Actonodaphne angustifolia, A.

obovata, Aglaia hiernii, Antidesma bunius, Aquilaria malaccensis, Baccaurea ramiflora,

Beilschmiedia brandisii, Callicarpa arborea, Canarium strictum, Castanopsis indica,

Chukrasia tabularis, Cinnamomum glanduliferum, Cryptocarya floribunda, Dillenia indica,

Diospyros variegate, Dysoxylum procerum, Elaeocarpus sp, Engelhardtia spicata, Evodia

meliaefolia, Ficus benjamina, Flacourtia jangomas, Garcinia acuminate, Garcinia kydia, G.

xanthochymus, Gynocardia odorata, Litsea monopetala, L. glutinosa, Macaranga

denticulate, Magnolia griffithii, Magnolia hodgsonii, Mesua ferrea, Mesua assamica (Kayea

assamica), Michelia baillonii, Olax acuminate, Persea bombycina, Phoebe goalparensis,

Quercus milroyii, Sapium baccatum, Sterculia guttata Symplocos ferruginea, Syzygium

cumini, Terminalia myriocarpa, Vatica lancaefolia. etc.

The lower storey is often found in association of sparsely distributed species viz.

Alangium chinensis, Aphanomixis polystachya, Camellia caudata, Croton roxburghii, Dillenia

indica, Dysoxylum binectariferum, Litsea assamica, Litsea salicifolia, Mallotus philippinensis,

Saurauia panduana, Symplocos ferruginea, Syzygium oblatum, Turpinia nepalensis,

Zanthoxylum rhetsa, etc.

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The common shrubs in these forests are Actephila excels, Antidesma acidum,

Antidesma acuminatum, Ardisia paniculatum, Boehmaria malabarica, Brassiopsis

glomerulata, Callicarpa longifolia, Chloranthus officinalis, Dendrocnide, sinuata, Euonymus

attenuates, Glochidion assamicum, Morinda angustifolia, Wendlandia tinctoria, etc.

The lianas, vines and stragglers often show gregarious growth mingled with the

species of plants in the storeys associated with a number of shrubs. The common species

found are – Clematis acuminata, Celastrus monosperma, Cryptolepis sinensis, Desmos

cochinchinensis, Dioscorea esculenta, Erythropalum scandens, Fissistigma bicolour, Gnetum

montanum, Hoya acuminata, Jasminum nervosum, Naravelia zeylanica, Tetrastigma

dubium, Tetracera indica, etc. Apart from these a number of climbers developed terrestrial

but become epiphytic on trees and shrubs or creeping in nature. The common species are

Piper peepuloides, P. sylvaticum, Pothos cathcartii, Raphidophora sp. etc.

2.2. Tropical Semi-evergreen forests:

Semi-evergreen forests are mainly confined to along the north and south banks of

river Brahmaputra; Bura-pahar and the projection of Karbi-Anglong towards Brahmaputra

(Chowdhury, 2005). This forest is mainly dominated by medium or short trees where large

numbers of shrubs are entangled by lianas and stragglers. Ground vehetation is occupied by

bulbous, rhizomatus plants scattered in association with herbaceous angiosperms; ferns and

fern allies. Moreover, these forests are adorned with luxuriant growth of several epiphytic

plants primarily orchids and ferns. Besides, large bamboo and cane thickets are found along

the edges of forests and in degraded forest as secondary growth. The common species

found in the forests are Actinodaphne obovata, Aesculs assamica, Albizia procera,

Anthocephalus chinensis, Antidesma bunius, Aphanomixis polystachya, Artocarpus chama,

Baccaurea ramiflora, Beilschmiedia fagifolia, Bauhinia purpurea, Bischofia javanica, Bridelia

retusa, Castanopsis armata, Cinnamomum bejolghota, Duabanga grandiflora, Dysoxylum

binectariferum, Elaeocarpus floribunda, E. sphaericus, Engelhardtia spicata, Gmelina

arborea, Lagerstroemia parviflora, Litsea glutinosa, L. monopetala, L. salicifolia, Macaranga

denticulate, Talauma hodgsonii, Mallotus ferrugineus, Mangifera sylvatica, Michelia

champaca, Persea villosa, Stereospermum personatum, Syzygium cumini, S. oblatum,

Tamarindus indica, Terminalia chebula, Terminalia myriocarpa, Trewia nudiflora, Toona

ciliate, Vatical lancaefolia, Wendlandia grandis, etc.

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Shrubby species in these forests composed of mainly Antidesma roxburghii,

Chloranthus elatior, Euonymus attenuates, Ficus subulata, Glochidion assamicum, Grewia

denticulata, Mussaenda roxburghii, Mycetia longifolia, Psychotria Montana, Randia spinosa,

Rhamnus nepalensis, Saprosma ternatum, Solanum torvum, Vitex trifolia, Zizyphus

mauritiana, etc.

The common species among the lianas, stragglers and vines are Ampelocissus

barbata, Argyreia roxburghii, Bauhinia vahlii, Cissus rependa, Derris ferrginea, Dioscorea

bulbifera, Entada pursaetha, Erythropalum scandens, Merremia umbellata, Naravelia

zeylanica, Paederia foetida, Pothos scandens, Rhaphidophora decursiva, Rubia cordifolia,

Smilax ochreata, Vitis planicaulis andexotic climber Mikania micrantha.

The under growth composed of several annual and perennial herbs viz. Ageratum

conyzoides, Alocasia odora, Biophytum sensitivum, Begonia palmata, Coffea benghalensis,

Crotalaria pallid, Curculigo orchioides, Elatostema integrifolia, Flemingia lineata, Globba

clarkei, Impatiens tripetala, Justicia adhatoda, Justicia japonica, Leea aequata, Mollugo

pentaphylla, Ophiorrhiza mungos, Panicum auritum, Phlogacanthus curviflorus, Polygonum

auriculatum, Saccharum ravennae, Sida rhombifolia, Solanum nigrum, Spilanthes paniculata,

Stachytarpheta jamaicensis, Synedrella nodiflora, Thysanolaena maxima, Urena lobata,

Vernonia cinerea, etc. along with ground orchids Arundina graminifolia, Calanthe angusta,

Geodorum densiflorum, Goodyera procera, Tainia latifolia, etc.

2.3. Moist Deciduous forest:

The moist deciduous forest may be categorised into Shorea (Sal) forest and mixed

moist deciduous forest. The large parts of the lower Brahmaputra valley particularly in

districts of Nagaon, Morigaon; in alluvial plains of south and north Kamrup, Darrang,

Sonitpur, parts of Nalbari, Barpeta, Dhubri, heavy alluvial plains of Kokrajhar, Bhabor and

Terai regions of Kokrajhar and Goalpara districts and parts of Karbi Anglong and Dima Hasao

are covered with Sal forest. Rowntree (1954) described these Sal forest under Shorea-

Schima-Lagerstroemis association while Bor (1938) named Shorea-Schima-Stereospermum

formation. The most conspicuous naturally growing Shorea robusta in moist Sal forest is

found near Chandubi in Kamrup district and also in the district of Dhubri, Kokrajhar,

Goalpara and some parts of Kamrup district.

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The mixed moist deciduous type of forest occupies a large area in both Brahmaputra

and Barak valleys at the foot hills of Lakhimpur, Dhemaji, Karbi-Anglong and Dima Hasao

districts. Tree species particularly Adina cordifolia, Albizia procera, Artocarpus chama,

Beilschmiedia fagifolia, Bridelia retusa, Butea monosperma, Callicarpa arborea, Careya

arborea, Caryota urens, Dalbergia ssissoo, Duabanga grandiflora, Dysoxylum binectariferum,

Engelhardtia spicata, Ficus benjamina, Hydnocarpus kurzii, Garcinia paniculata, Garuga

pinnata, Gmelina arborea, etc. occupy the upper storey.

The predominant species in the lower storey of these forests are Actephila excels,

Antidesma acidum, A. bunius, Bauhinia acuminata, Bischofia javanica, Buddleia asiatica,

Caesalpinia bonduc, Cinnamomum bejolghota, Litsea salicifolia, Premna benghalensis, Rhus

semialata, Wrightia tomentosa etc. Dendrocalamus hamiltonii, D. strictus, Melocanna

baccifera are common species of bamboo found in these forests.

2.4. Riverine forest:

River bank vegetation, ecologically termed as riparian is highly dynamic vegetation.

River’s riparian zone acts as a bridge between terrestrial and aquatic habitat. These areas

are represented by a particular type of vegetation that grows all over the evergreen and

semi evergreen zones of the state along the sides of rivers under the influence of a

waterway, such as rivulet banks or riverbanks. Generally in this type of forests commonly

found tree species are Dillenia indica, Anthocephalus indicus, Semecarpus anacardium,

Albizia lebbek, Dalbergia stipulacea, Bischofia javanica, Duabanga grandiflora,

Lagerstroemia speciosus and Bombax ceiba. The middle storey of these forests are generally

occupied by Altingia excels, Albizia lucida, Artocarpus lakoocha, Alstonia scholaris, Cedrela

toona, Dalbergia assamica, Pterospermum acerifolium. Species viz. Alpinia nigra,

Ammomum aromaticum, Lasia spinosa, Typha elephantina, Carex breviculmis, Zingiber

zerumbet, etc. are commonly found to cover the ground vegetation of this type of forest.

The annual flood submerges these forests by several centimetres every year leaving

the new alluvium and successive deposits of silts. These are first covered by the seedlings of

Tamarix, Salicornea which soon establish themselves in a dense form either in pure

formation or mixed with different grassy species. Moreover, in several places particularly in

Majuli and adjoining areas riverine areas composed of some hydrophilous herbs and sedges

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viz. Ranunculus scleratus, Anagallis arvensis, Cotula hemispherica, Ammannia baccifera,

Grangea maderaspatana, Gnaphalium luteoalbum, Polygonum chinense, Cyperus rotundus,

Fimbristylis dichotoma, Fimbristylis ovata, Scirpus articulates, etc.

2.5. Grassland and Savannahs:

This type of forest is one of the important components of the alluvial flood plains of

Brahmaputra valley as extensive areas of the state are dominated by grassland and

savannahs. This biome is primarily conspicuous in Kaziranga and Oranag national park,

Manas and Dibrusaikhowa biosphere reserves and wildlife sanctuaries viz. Sonai-Rupai,

Laokhoa, Pabitora, Barnadi, Bura Chapori etc. Generally the grassland vegetation of the

state can be differentiated into grasslands in recent alluvial deposits in low lying and char

areas annually inundated and flood water retained for a considerable period of time and

grasslands in old alluvium deposits of high land. Flood water scarcely reaches but the soil

remains moist only during rains where both pure grassland and savannah ecosystem occur

(Chowdhury, 2005).

Here tree species viz. Careya arborea, Bombax ceiba, Sterculia villosa, Lagerstroemia

parviflora, Dalbergia sissoo, Gmelina arbore, Premna bengalensis, etc. are scattered along

with grasses. The dominant grasses in wet alluvial grasslands are Apluda mutica, Phragmatis

karka, Sclerostachya fusca, Saccharum arundinaceum, S. procerum, S. ravennae, S.

spontataneum, etc. These species show luxuriant growth at the advent of rainy season,

often attain a height of over 5m and can withstand flood water. Other species of grasses

occur in these areas include Arundo donax, Arundinella pumila, Carex breviculmis, Eleusine

indica, Imperata cylindrica, Paspelidium flavidum, Paspalum conjugatum, etc.

2.6. Wetlands and swamps:

The mighty river Brahmaputra with its tributaries flows along the entire length of

Assam through a distance of 760 km. Extensive flood plains of Brahmaputra annually

inundated large patches of marshy depressions and swamps, perennial water reservoirs

locally called beels and community ponds. Almost all the national parks, biosphere reserves,

wildlife sanctuaries of the valley encompass vast patches of wetlands. The plants growing in

wetlands are usually termed as hydrophytes. Members of the families like Araceae,

Cyperaceae, Eriocaulaceae, Lemnaceae, Nymphaeaceae are common in these ecosystems.

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The growth and development of hydrophytes vary according to their habitats. Therefore the

hydrophytic vegetation of the valley is unique in terms of its floristic elements and will e

dealt separately elsewhere.

2.7. Degraded forest:

The impact and interference of both biotic and abiotic factors on the forest has

resulted in the formation of degraded forest in the state and the Brahmaputra valley is not

an exception to this. About 45% of the reserve forests are gradually depleted. The

commonly found plant species in these forests are Oroxylum indicum, Duabanga

grandiflora, Bombax ceiba, Saurauia nepaulensis, S. roxburghii, Croton roxburghii,

Macaranga denticulata, Eurya acuminata, Maesa indica, Clerodendrom viscosum, Callicarpa

arborea, Rubus rugosus, Eriobotrya benghalensis, Mikania micrantha, Ageratum conyzoides,

Saccharum spontaneum, Urena lobata, Solanum torvum, Leucas plukenetii, Zizyphus

mauritiana, Schizostachyum polymorphum, Lantana camara, Imperata cylindrica, etc.

CONSPECTUS OF THE FLORA

The flora of the state of Assam is rich both in terms of diversity and luxuriance.

stated earlier that lot of floristic studies have been

till date leading to the addition of the data on the floristics of the state. Moreover

protected areas situated along the riverine areas of the state particularly Dibrusaikhowa BR,

Kaziranga NP, Oranag NP, Pabitora WLS, Laokhowa WLS along with other protected areas of

the Brahmaputra valley have already been explored floristically.

national parks of the valley is given in the

greatest river island of the Brahmaputra and that of Umananda has also been studied

(Appendix II).

Fig. 1: Comparative account of the flora of the national parks of the Brahmaputra valley

As per conventional estimates the state flora comprise of 3017 species

1999). Chowdhury (2005) gave an account of the 4273 species of

taxa comprising of 1448 genera distributed in 272 families of vascu

These include fern allies, ferns gymnosperms and angiosperms.

Ahmed (2014) compiled a detailed checklist of Angiosperms and Gymnosperms of the state

by listing 3854 taxa (including infra

of which, 2752 taxa are dicotyledons, 1080 taxa are monoco

15995

580

882

0

100

200

300

400

500

600

700

800

900

1000

Nameri NP Rajib Gandhi (Orang) NP

Num

ber o

f the

taxo

n

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Chapter 3

CONSPECTUS OF THE FLORA OF BRAHMAPUTRA VALLEY

The flora of the state of Assam is rich both in terms of diversity and luxuriance.

stated earlier that lot of floristic studies have been made in the state right from 18

till date leading to the addition of the data on the floristics of the state. Moreover

protected areas situated along the riverine areas of the state particularly Dibrusaikhowa BR,

itora WLS, Laokhowa WLS along with other protected areas of

the Brahmaputra valley have already been explored floristically. A list of flora of the 5

national parks of the valley is given in the Appendix I. The floristic composition of Majuli,

river island of the Brahmaputra and that of Umananda has also been studied

Fig. 1: Comparative account of the flora of the national parks of the Brahmaputra valley

As per conventional estimates the state flora comprise of 3017 species

Chowdhury (2005) gave an account of the 4273 species of comprising infra

taxa comprising of 1448 genera distributed in 272 families of vascular plants of Assam.

fern allies, ferns gymnosperms and angiosperms. More recently Bar

Ahmed (2014) compiled a detailed checklist of Angiosperms and Gymnosperms of the state

3854 taxa (including infra-specific taxa) under 1394 genera and 236 families. Out

of which, 2752 taxa are dicotyledons, 1080 taxa are monocotyledons and 22 taxa are

95 111 108 115

322372

233

377450

591

471

560

Rajib Gandhi (Orang) NP

Manas NP & BR Dibru-Saikhowa NP & BR

Kaziranga NP

National Parks

The flora of the state of Assam is rich both in terms of diversity and luxuriance. As

made in the state right from 18th century

till date leading to the addition of the data on the floristics of the state. Moreover, the

protected areas situated along the riverine areas of the state particularly Dibrusaikhowa BR,

itora WLS, Laokhowa WLS along with other protected areas of

A list of flora of the 5

of Majuli, the

river island of the Brahmaputra and that of Umananda has also been studied

Fig. 1: Comparative account of the flora of the national parks of the Brahmaputra valley

As per conventional estimates the state flora comprise of 3017 species (Baishya

infra-specific

lar plants of Assam.

ently Barooah and

Ahmed (2014) compiled a detailed checklist of Angiosperms and Gymnosperms of the state

specific taxa) under 1394 genera and 236 families. Out

tyledons and 22 taxa are

Family

Genera

Species

gymnosperms (Appendix III). The flora of Assam represents

However, the figures are provisional as still many areas are underexplored and constant

changes are taking place in the flora due to human

ecological factors. As far as the habit is concerned, the percentage of tree in the flora is only

20% while the herbs occupy the highest 47% of the flora of the state.

Looking at the details of the floristic

observed that the floristic diversity of Brahmaputra valley is much rich than the Barak valley

as over 90% of the total flora of the state have been reported from Brahmaputra valley

According to Das (1942), Brahmaputra valley harbours more of Giant and diverse tree

species than in the Barak valley (Appendix IV

the two valleys are readily apparent with the localised elements not found any were else in

the state.

India82%

Fig. 2: Percentage of Angiosperms of Assam in the Indian flora

India5%

Fig. 3: Percentage of Angiosperms of Assam in the world

17

The flora of Assam represents 18% of the Indian flora.

However, the figures are provisional as still many areas are underexplored and constant

changes are taking place in the flora due to human interference, biotic pressure and other

As far as the habit is concerned, the percentage of tree in the flora is only

20% while the herbs occupy the highest 47% of the flora of the state.

Looking at the details of the floristic composition of the two valleys of the state

the floristic diversity of Brahmaputra valley is much rich than the Barak valley

0% of the total flora of the state have been reported from Brahmaputra valley

, Brahmaputra valley harbours more of Giant and diverse tree

Appendix IV).The difference in the floral compositions of

the two valleys are readily apparent with the localised elements not found any were else in

India82%

Assam18%

Fig. 2: Percentage of Angiosperms of Assam in the Indian flora

World94%

India5%

Assam1%

Fig. 3: Percentage of Angiosperms of Assam in the world

8% of the Indian flora.

However, the figures are provisional as still many areas are underexplored and constant

interference, biotic pressure and other

As far as the habit is concerned, the percentage of tree in the flora is only

composition of the two valleys of the state it is

the floristic diversity of Brahmaputra valley is much rich than the Barak valley

0% of the total flora of the state have been reported from Brahmaputra valley.

, Brahmaputra valley harbours more of Giant and diverse tree

).The difference in the floral compositions of

the two valleys are readily apparent with the localised elements not found any were else in

18

Chapter 4

SIGNIFICANCE OF THE FLORA

Vascular plants of the Brahmaputra valley show richness and luxuriance of the flora

due to occrrrence of over ninety percent species of the the flora of Assam. The luxuriant

vegetation and flora of the valley creates the treasure house multidimensional biotypes in

the area with prevalence of a number of endemic plant species and some important

primitive angiosperms. Apart from these, it is blessed with very high degree of

taxonomically and ecologically valued floral species. The richness of the composition is

reflected with more than 250 species of Orchids, 33 species of Bamboo, 12 species of Canes

and number of plants with medicinal properties. The forest cover of the state represents

35.28% area of the state with 17.68% of geographical area in Reserve Forest and 5% of

geographical area under protected area net work (Anonymous, 2011). It is noteworthy that

there are a larger numbers of rare, threatened and endangered species found in the state

outside the formal forest areas too.

Looking at the endemism in flowering plants, it is observed that the northeast region

has the largest concentration of endemic plants, as out of total 5725 endemic species found

in India, northeast region has a total of 1808 endemic species (Nayar, 1996). Although, the

comprehensive account of the endemic taxa of the state Assam is yet to be worked out, the

Botanical Survey of India listed 102 species of angiosperms belonging to 75 genera as

endemic taxa for the political boundary of Assam, of which majority i.e. 91 species

belonging to 68 genera are found in the Brahmapurta valley (Appendix V). The physio-

climatic conditions of the state particularly of the Brahmaputra valley are the place of active

speciation. Moreover, many endemic taxa are recorded from type locality and to pin point a

particular taxa as endemic to the valley may cause confusion as several part of northeast

region and also the country is under explored or unexplored.

The largest representation of endemic taxa from the state belongs to families

Poaceae, Lauraceae, Magnoliaceae, Orchidaceae and Piperaceae. Genus Piper has the

highest endemism in the valley with 6 species followed by other genera viz. Calamus,

Dioscorea and Magnolia are with 3 species each.

19

Several groups of flowering plants viz. Orchids, Legumes, Cucurbits, etc. exhibit

remarkable species diversity in the Brahmaputra valley. Apart from these, spectacular

species diversity has been observed in the genera like Dendrobium, Elaeocarpus, Piper,

Garcinia, Calamus and Dipterocarpus in the Brahmaputra valley. Families viz. Poaceae,

Orchidaceae, Fabaceae, Asteraceae, Araceae, Cucurbitaceae, Lauraceae, Arecaceae,

Zingiberaceae, etc. also contribute rich gene pool of the valley. The Brahmaputra valley has

made one of the greatest contributions to world agriculture by discovering the cultivation of

tea. The valley produces some of the finest and expensive teas in the world and has the

indigenous species Camellia sinensis var. assamica.

The area is also known for several plants of botanical curiosities. Various interesting

plants viz. species of Utricularia, Drosera, (all insectivorous plants), Sapria himalayana

(parasitic angiosperm reported from Sadiya probably extinct in the state), Balanophora

dioica, (parasitic angiosperm), etc. are available in the valley. Some of the phylogenetically

primitive families such as Magnoliaceae, Anonaceae, Schizandraceae, Menispermaceae,

Altingiaceae, Lardizabalaceae, etc. grow in the Brahmaputra valley and further eastwards

but do not occur in other parts of India (Appendix VI). The distribution pattern of these

primitive plants show that they are mostly localised and confined to the major forest types

i.e. evergreen and semi evergreen forests and also on the riparian belts. This array of

floristic richness has prompted many naturalists to describe Assam as the ‘Biological

Gateway’ of northeastern India. Armen L. Takhtajan (1969), the eminent plant taxonomist

and geographer observed ‘the cradle of flowering plants lies in between Assam and Fiji’.

The flora of the valley has distinct affinity with the nearby Nepal, Bhutan, Indo-

Burma, Sino-Himalayan, Malaysian and to a lesser extent with peninsular India. Species viz.

Albizzia procera, Antidesma acidum, Bischofia javanica, Bombax ceiba, Cassia fistula, Costus

speciosus, Duabanga grandiflora, Hedychium coccineum, Hodgsonia macrocarpa, Oroxylum

indicum, Tetremeles nudiflora are some examples of Indo-Burma and other southeast Asian

floristic elements found in the flora of Brahmaputra valley. Besides, the taxa like Camellia,

Eurya, Hoya, Maesa, Magnolia, Michelia, Hypericum, Viola, Sarauia etc. are some of the

examples of Sino-Himalayan affinity found in the flora of the valley. Some plants of African

and American flora are naturalized in the valley for eg. Pyrularia edulis of Santalaceae found

20

in western Assam and another solitary member in America are the best examples of

transpacific distribution.

Gymnospermic diversity in India accounts for 48 species (Singh & Mudgal, 1997) and

northeast region is represented by more than 28 species. Although the members of this

group of plant is less, they are equally important for providing timber, wood, pulp, resins,

tars, turpentine, etc. These gregarious plants mostly dominate the Himalayan landscape of

the state Arunachal Pradesh and Sikkim in northeast region. However, in Assam they are

poorly represented. In Brahmaputra valley they are restricted to Darrang, Dibrugarh,

Goalpara, Golaghat, Lakhimpur, Sibsagar and Sonitpur districts. As many as 5 species of

gymnosperm occur in the valley belonging to the families Cycadales, Coniferales and

Gnetales. Species viz. Cycas pectinata, Podocarpus nerifolia, Gnetum gnemon and G.

montanum are some of the common species of gymnosperm which grow naturally in the

valley.

In India the pteridophytic flora i.e. fern and fern allies are represented by over 1200

taxa under 204 genera distributed almost all the climatic zones of the country. The

northeastern region of India is regarded as the richest area of pteridophytic diversity that

supports more than 800 taxa of which 97 species are endemic. In Assam, fern allies and

ferns are the important component of biodiversity and Baishya (1999) and Chowdhury

(2005) estimated separately on the diversity of the pteridophytic flora of the state.

Borthakur et al. (2001) enumerated 87 genera and 221 species of fern and its allies from the

state. All those estimates suggest that the members of the family Polypodiaceae has the

highest representation followed by Thelypteridaceae, Pteridaceae and Athyriaceae in the

Brahmaputra valley. Besides the species of the genera Lygodium, Stenochlaena is very

widely distributed in the various forests of the valley. In the wetlands, generas viz. Azolla,

Ceratopteris and Salvinia are commonly found. Another fern of amphibian nature viz.

Marsilea is also commonly found in the valley. Other interesting species of ferns found in

the valley are Psilotum nudum, Huperzia phlegmaria, Osmunda regalis, Angiopteris evecta

etc. Likewise, the species representation of other cryptogamic group of plants such as Moss

(Musci), Liverworts (Hepaticae), Lichens, etc. are also remarkable in the Brahmaputra valley.

The northeastern region is also very rich in wild relatives of cultivated plants. The

region along with the rest part of the country is popularly known as Hindustani Centre of

21

origin of cultivated plants (Vavilov, 1926, 1951) and forms the richest reservoir of genetic

variability of many groups of crop plants. The state of Assam serves as a centre of origin of

economically important plants viz. Musa, Citrus, Mangifera, Zizyphus, Camellia sinensis var.

assamica. Singh and Varaprasad (2008), identified Brahmaputra valley as ‘Probable

Agricultural Heritage’ site due to unique and significant diversity in important crop plants.

According to Rao (1994), wild relatives of 189 economically important species such as Citrus,

Banana, Mango, Sugarcane, Pulses, cereals and other fruit plants are located in northeast

region including Assam. Hore (2001) estimated tentative number of crop diversities in some

major crops includes - Rice (9650+ races), Maize (15 races and 3 sub races), Banana (14

spp.), Citrus (17 spp., 52 varieties), Sugarcane and their wild relatives (15 spp.) and Bamboo

(60 spp.) in the northeast region.

22

Chapter 5

UTILITY OF THE FLORISTIC DIVERSITY

The rich floristic diversity of Brahmaputra valley has tremendous utilitarian value.

Plant resources available in the area starting from their timber yielding value can also be

used as medicines, as food, as source of essential oils, gums, for making paper and pulp,

dyes, resins, tannins, essential oils, fibres, etc. The valley harbours about 40 high prized

timber yielding plant species. There are over 1000 species of plant reported to have

medicinal properties available in the valley with commercial importance and are also used

by different communities for treating various ailments. Some of the highly valued medicinal

plants of Brahmaputra valley are Dioscorea bulbifera, Acorus calamus, Hydnocarpus kurzii,

Oroxylum indicum, Piper peepuloides, Rauvolfia serpentina, etc. Proper exploration of these

resources will lead to the discovery of novel drugs.

The state of Assam particularly Brahmaputra valley is famous for orchid diversity and

the orchid cut flowers are prized all over the world for their long lasting ornamental value

and are good source of revene generation. Many epiphytic and terrestrial orchids of

surpassing horticultural potential as well as the progenitors of the present day commercial

hybrids are available in the area. A list of the orchids of the State of Assam particularly of

Barhmaputra valley is presented in the Annexure I. Besides, several ornamental plants with

prospect for floriculture are found in the valley. Plant species viz. Agapetes, Arisaema,

Aster, Bauhinia, Begonia, Camellia, Cassia, Hedychium, Holmskioldia, Impatiens, Jasminum,

Mussaenda, Primula, Raphidophora, Tacca, etc. are potential floricultural plants.

The state is one of the important areas of northeast region as far as the production

of canes and bamboos are concerned. As many as 12 species of canes and 33 species of

bamboos are found in the Brahmaputra valley, which are of great importance in developing

forest based cottage industries in different parts of the valley. Apart from bamboos and

canes Thysanolaena maxima (broom stick), Imperata cylindrica (Thatch grass) are other

economically important grasses of the valley. A list of economically important plant species

are presented in Appendix VII.

Moreover, the cross cultural ethnobotany of the valley is also very rich as the area is

resided by diverse ethnic communities with wide range of uses of plants of different groups.

23

Saklani & Jain (1994) reported 332 plant species of Assam used as food, drinks, medicine

and also in cultural aspect. The statistics will go up if the information on ethnobotanical uses

of plants from new areas and different ethnic communities of the valley is incorporated. Use

of plants for a variety of purpose indicates the intimate relationships and dependence of

people of the area with the plant resources of their viscinity.

It may be mentioned here that majority of the total population of the area live in the

villages, interior areas nearby forests, and are enriched with plenty of traditional knowledge

system of resource utilization. About 40 species of various wild plants are marketed as food

and vegetables in local tribal and village markets of the valley. Patiri & Bora (2007) reported

350 species of wild edible plants of Assam used as green vegetables including root & root

like vegetables; some are also used as fruits and condiments along with seeds, Bark and

flowers.

The valley has a rich diversity of wild relatives of cultivated plants (Appendix VIII).

Wild crop diversity is considered as valuable biological assets as they are reservoir of various

genes of agronomic and economic importance needed for genetic improvement of crop

plants (Singh, 2010).

Like higher plants, the cryptogams are equally important as they are used in various

aspects such as food, medicine, dye, antibiotic, ornamental purpose, etc. Fronds of

pteridophytic plants viz. Diplazium esculentum, Drypetes elongata, etc. are eaten as

vegetables. Some species of Selaginella, Lycopodium, Adiantum, etc. are also used as

medicine. Similarly species of lichen such as Everniastrum cirrhatum is used as food,

Heterodermia diademata as antibiotic, Parmotrema tinctorum as dye. Different species of

edible mushroom such as Agaricus, Auricularia, Clavaria, Morchella, Pleurotus, etc. are

commonly available in the forests of the valley and are often sold in the local markets.

24

Chapter 6

HIGH PRIORITY TAXA

The rich plant diversity of the region in the recent years is witnessing serious threats

due to various abiotic and biotic factors. The gradual increase of human population,

developmental, oil extraction and other anthropogenic activities coupled with natural

calamities particularly seasonal flood and erosion of river banks, monocultural practice are

contributing directly or indirectly towards the loss of habitat of several plant species. As a

result several plant taxa become threatened and endangered in the flora of Assam and

Brahmaputra valley as well. Some species become rare due to over exploitation for

medicinal, ornamental and other industrial uses. According to an estimate of Botanical

Survey of India, about 700 plant species of northeast region fall under various threat

categories of which 43 species belong to Assam. Baishya (1999) compiled a list of 60 rare

and threatened plant taxa from Assam. Barooah and Ahmed (2014) categorised 871 taxa of

angiosperms and gymnosperms of the state under different conservational status. Among

these, 167 taxa are recorded to be endemic, 318 taxa are kept under critically endangered,

endangered and vulnerable and 386 taxa are identified as rare to the state.

The number will be much more if all the members of the family Orchidaceae are

included in the threat list. It may be mentioned that the entire family Orchidaceae is kept

under the Appendix II of the CITES. Orchid species viz. Vanda coerulea, Renanthera

imschootiana and all the species of Paphiopedilum found in the region as well as outside the

region are included under the Appendix I of CITES.

Sapria himalayana of family Rafflesiaceae which was reported from Sadiya long back

is at present presumed to be extinct in the state. IUCN-CAMP, 2003 categorised 18 plants of

the state in various threat categories. Some critically endangered species of the

Brahmaputra valley are region are Livistona jenkinsiana, Swertia chirayita, Smilax glabra,

etc. Plant viz. Aquilaria malaccensis, Brucea mollis, Cibotium barometz, Citrus macroptera

var. assamensis, Dendrobium nobile, Flickingeria fugax, Garcinia pedunculata, Homalomena

aromatica are endangered in the valley and vulnerable species include Elaeocarpus

sphaericus, Gynocardia odorata, Hydnocarpus kurzii, Mahonia napaulensis, Oroxylum

indicum, Piper peepuloides, Rauvolfia serpentina. A list of rare, threatened and endangered

25

plant taxa as prepared by Botanical Survey of India for the state of Assam in presented in

the Appendix IX (Nayar et al. 1987, 1988 & 1990; Baishya, 1999). The IUCN categories of

these taxa are also provided wherever available.

The present status in terms of exact location with GPS co-ordinates, population

density, regeneration capacity are required to be work out to formulate the conservation

strategy of these threatened and endangered plant taxa. Moreover, existence of certain

taxa is also need to be verified in view of recent nomenclatural changes. There is a chance of

wipe out many valuable plant species in a few decades if they are not given proper attention

for conservation.

26

Chapter 7

THREATS

The geographical isolation from rest part of the country has helped to protect the

biodiversity of northeast India from large-scale developmental activities. But the situation

has changed gradually and the biodiversity of the region is now confined to only a few

pockets. It was the British who first cleared the natural forest for tea plantation and

propagation of commercial species like teak (Tectona grandis), sal (Shorea robusta), hollock

(Terminalia myriocarpa), simul (Bombax ceiba), gamari (Gmelina arborea), etc. The forest of

the state has attracted the attention of the world in the middle of the 19th century with the

advent of railways in Bengal and is identified as the starting point of forest destruction in

the region. Shifting agricultural practice is another cause of forest destruction in the state of

Assam although it is prevalent only in the hill districts of Assam. However, in the extension

areas of Kaziranga National Park i.e. in Karbi Anglong hills this kind of agricultural practice

may lead to the destruction of the forest cover. To meet the increasing demand of the

growing population, the period of jhum cycle has been reduced to considerable rate,

affording no chance for natural regeneration and soil fertility. The rate of forest degradation

is also supported by the invasion of weeds. It has been observed that various species of

native and exotic weeds viz. species of Ageratum conyzoides, Argemone maxicana,

Chromolaena odorata, Lantana camara, Mimosa rubicaulis, Mikania micrantha, Parthenium

hysterophorus, etc. have completely dominated the forested land, degraded forests and the

agricultural landscapes of the region posing serious threat to all sorts of healthy growth of

plant species, forest regeneration and agricultural productivity as well. In Kaziranga national

park, proliferation of various weeds like Mikania, Mimosa and Eichhornia, causes ecological

degradation of the habitat and is a major problem confronting the Park authorities.

Although some serious eradication efforts particularly for Mimosa, removal of water

hyacinth etc. have been made in the recent past but still it is a threat to the wildlife habitat

of the park.

Natural calamities like earthquake, seasonal flood, etc. as well as soil erosion also

lead to the shrinkage of the forest cover in the region. Of late, the various developmental

activities like construction of mega dams, hydroelectric plants, roads, etc. also act as the key

27

factors of forest destruction in the state. The impacts (upstream and down stream) of large

river dams on ecosystem and environment as a whole are well established. Building of mega

dam on the mainstream of the Brahmaputra as well as on some of its major tributaries may

adversely affect the natural importance of some protected areas of the valley, for instance

Kaziranga and Manas national park. The survival of charismatic species like rhino, flagship

species like elephant and other herbivores in these critical ecosystems are determined by

natural connectivity of the forests with waters of the rivers that makes these ecosystems

capable to sustain certain types of grasses and other vegetation. Construction of large dams

may change the flood cycle and hydrological relationship of some critical ecosystem of the

state for example Kaziranga national park. The existence of different habitat types in the

park viz. grassland, wetland and also woodland is dependent on the annual sluicing of the

landscape by flood water. Moreover, the livelihood of the people living in the catchment

areas of the river would also be at stake.

Injudicious collection of various plant resources for medicinal, dye making and

ornamental purpose are very common that lead to the depletion of the rich bio-resources of

the state. Political and social unrest prevailed in the state for the last couple of decades are

also influencing adversely to the rich floristics of the state in general and the Brahmaputra

valley in particular.

As far as the diversity of cultivated crops is concerned, the replacement of local land

races by High Yielding Varieties (HYV) in cultivated fields has caused considerable loss in

diversities of crop and economically important plant in the region.

Along with the deforestation, degradation, encroachment and associated concerns

of logging, habitat fragmentation another important issue that need to be addressed for

Assam is the climate change. Because of its sensitive geo-ecological set-up, strategic

location with international boundary, presence of the Eastern Himalayan ranges,

transboundary river systems, inhabitation of ecosystem by people of different ethnic groups

and inherent socio-economic differences, the state is expected to be highly prone to

consequences to climate change.

28

Forest ecosystems in particular are among the natural systems that will globally be

severely affected by climate change (Pérez-García et al., 2002; Walther et al., 2002). This is

also true for the forests of Assam and its adjoining northeastern states. At the ecosystem

level, due to increase in atmospheric carbon dioxide and resultant temperature increases

and there will be changes in rainfall regimes. This may result in increase in biomass

production, alteration in forest structure and species composition and competitiveness,

(Meer et al. 2001). At the community level, changes in floral phenology will likely to impact

adversely the critical process of pollination and seed dispersal.

Climate change thus expected to impose a variety of stress on sustainable livelihood

of the poor inhabitants of the state through stresses on ecosystem function. The major

concerns are erratic & irregular rainfall patterns, longer dry spells, and implications on

agriculture calendar, productivity, new pests; food security; health and disasters like flash

floods. It is presumed that there would be a change in distribution, abundance of species,

more particularly wild, endemic species, crop plants, pests and vectors. Due to change in

habitat condition, displacement both human and other wilderness would take place. Apart

from these, the food security, mitigation of hazards and addressing the epidemics like

malaria, encephalitis etc. are other issues of major concerns for the state (Bujarbarua &

Baruah, 2009). The marginalised people of the state who are dependent on the forests for

basic livelihood needs such as fuelwood, bamboo, fodder, timber and Non Timber Forest

Products including medicinal plants may face adverse consequences due to climate change.

It worth to mention that, besides, traditional resource use, forests also provide germplasm

(Anonymous, 2011).

Thus the impacts of climate change on forest may lead to decrease in water

regulation and forest ecosystem services that may lead to increase social vulnerability. The

growing human population and livestock pressure may gradually widen the gap between

demand and supply of natural resources. These impacts will cut across multiple dimensions

of day to day life affecting not just the environment but the communities as well. Under

such circumstances, there is possibility of conflicts over reduced natural resources and may

cause strained social relations taking toll on to the cultural and spiritual services provided by

ecosystems (Bujarbarua & Barua, 2009).

29

Chapter 8

PROBLEMS OF FOREST MANAGEMENT IN THE BRAHMAPUTRA VALLEY

Environmental problems in the state of Assam have been influenced partly by the

increasing population, survival needs of the poor and the economic greed of the commercial

interests. They are also aggravated by prevalent economic disparities and unemployment,

which are deeply embedded in unsustainable patterns of production and consumption; ill

informed policies and programs; and inappropriate developing strategies. As far as the

forest resources of the Brahmaputra valley is concerned, gap in scientific knowledge,

increasing demands, lack of value addition are the main causes for which the vast potential

is yet to be tapped properly and in some cases over exploited.

Gap in scientific knowledge on various forest resources and products is a major

problem for management of resources in the state. Although considerable amounts of

revenue have been collected from forest products where local people are also directly or

indirectly involved in gathering and in some cases marketing as well, but they have hardly

any knowledge on the silvicultural management of various minor forest products. Except for

some well known commercial species, the information on distribution of various forest

products, their density, regeneration status, yield estimate and harvesting levels are lacking.

There is need to formulate sound management plan that addresses the knowledge about

the life cycle pattern of the species, productivity and yield estimation techniques.

As a result of the increasing demands of various forest resources, there is a danger of

fall in harvest in considerable rate. For example, Aquilaria malaccensis (Agar) is harvested

only after fungal attack. But due to its high commercial value, plants without fungal

infection are also harvested leading to the tremendous loss of natural population. Same

with the case of Oroxylum indicum- a high valued anticancer medicinal plant. Indiscriminate

collection of other medicinal plant species has caused wide spread loss to the natural

population of these species. IUCN-CAMP (2003) has already categorised 12 species of

medicinal plants of the state under various threat categories.

30

Valuation of biological resources is the most important aspect of its conservation,

sustainable use and management. Proper valuation of rich and vast bio-resources of the

state is yet to be done in terms of consumptive, non consumptive and productive use value.

Moreover, middle men are much benefited rather than the actual collectors as far as the

trade of forest products are concerned because of their inability to cope with exploitation

from the middle men. Poor knowledge about processing, market fluctuations cause post

harvest loss leading to insufficient returns of the products and ultimately causing over

exploitation.

Monitoring and maintaining of the complex ecosystem is important aspect of bio-

resource management. Technical aspects include choice between different methods and

techniques and development of appropriate harvesting and processing technologies. There

is also social aspect of resource management that deal with people, cultures, belief systems,

attitudes and behaviour, ethics, aspirations and social values. As far as the state of Assam is

concerned, all these aspects should be taken into consideration prior to the formulation of

management strategies. Finally, exercise of administrative power in another important

aspect to hold control over users of resources and decision-making.

In the perspective of the state of Assam, proper assessment of various forest

ecosystems and resources, their potential in supporting life and livelihood are the foremost

requirement. Moreover, there is little knowledge about the status of the forest resources,

products that are extracted commercially from the valley, their distribution, rate of growth,

threats. The sustainable management of these resources requires the collection of accurate

information and a programme of regular monitoring. Information on density and

distribution of the economically important species within the forest, population structure,

productivity, regeneration capacity and ecological impact of harvest are prerequisite for the

planning, design of management strategies and running enterprise based on raw materials

collected from the forest.

The concept of sustainable forest management can also be tested in the state as it

encompasses the wider issues and values. IIFM 2000 defined Sustainable Forest

Management (SFM) as ‘a management approach to obtain full range of forest values

31

ensuring that the ecological, economic and social needs of the present and future

generations can be met from the forest on a continuous basis’. Forest manage in this aspect

would not only provide timber on a sustainable basis but would also provide various forest

products and other services to the community living in and around it. It will also help to

preserve genetic resources and biodiversity and at the same time environmental balance

will also be maintained.

As far as the management of the wildlife habitats are concerned, lesson may be

learnt from the Kaziranga National Park. The Habitat management in Kaziranga is aimed

basically at restoration of grasslands - the main habitat of Rhino and most of the habivores

and is achieved through controlled burning. De-siltation of water-bodies and channels,

construction of temporary dam for water retention and control & eradication of weeds are

other measures adopted for habitat management of the park.

Maintanance of seral stage of grassland is the important aspect of the habitat

management in Kaziranga national park thereby preventing invasion of tree species. Thus

annual burning of grassland is practiced to discourage the growth of tree sapling. This not

only helps in enhancing the nutritional value of coarse grasses by facilitating growth of new

shoots but also attracts the herbivores. Moreover, siltation of water bodies due to flood

inside the park is a perennial problem leading to the shrinkage of water bodies. To address

this issue desiltation drives are carried out inside the park annually and are submitted useful

to maintain the water bodies which are integral part of the national park. Migratory birds

are important components of the biodiversity of Kaziranga. Therefore to retain the water in

the water bodies for attracting various migratory avifauna bunds are constructed. All these

habitat management practices are integral part of the conservation success of Kaziranga

national park. It is thus important that this success story be replicated in the other protected

areas of the state too to conserve the pristine biodiversity.

32

Chapter 9

DISCUSSION

The Brahmaputra valley is blessed with very high degree of endemic, taxonomically

and ecologically high valued plant species. The richness of the composition is reflected with

over 3000 species of flowering plants, over 250 species of Orchids, 33 species of Bamboo, 12

species of Canes and plants of other economic uses. The forest cover of the state represents

35.30% area of the state with 17.68% of geographical area in Reserve Forest and 5% of

geographical area under protected area net work. It is noteworthy that there are a larger

numbers of rare, threatened and endangered species found in the state outside the formal

forest areas too.

Recent years are witnessing considerable developments and the overwhelming

demand for forest based raw materials, especially bamboo, cane and natural health

products, which are renewable natural resources. Moreover, there is growing market

demand globally for these products. However, majority of these species in wild are under

severe threat, many are on the verge of extinction due to imprudent resource use and

management practices. Therefore it is imperative that multi-dimensional action (social,

ecological, economical, institutional) needs to be urgently taken for the conservation of

these vital resources. Management plan should be in such a way that livelihood

improvement and biodiversity conservation are in balanced state in order to reduce the

poverty and underdevelopment of the state. There is a need of sustainable management of

the important forest resources of the valley that would also contribute to the food security,

poverty alleviation, economical development, and sustainable land use, in the wider context

of sustainable development. Good forest management secures the survival of forest

ecosystems and enhances their environmental, socio cultural and economic functions. It can

both maximize forests’ contribution to climate change mitigation and help forests and

forest-dependent people adapt to new conditions caused by climate change (ASTEC, 2011).

As far as the state of Assam is concerned there is a need of policy based initiatives to

protect and conserve the pristine biodiversity of the state. It may be mentioned that the

state has lost several hectares of forest cover in recent years. There is large scale unabated

33

encroachment in the reserved forests even in the protected areas by the new settlers,

people displaced by floods and ethnic clashes in the state particularly the Brahmaputra

valley, immigrants and excessive dependence of the people in the rural areas on the forests

leading to deforestation. According to a report of forest department, 3,555 sq. km. of the

forest land is under encroachment (Anonymous, 2012). The encroachment in reserved

forests is a major concern in the management and conservation of forests of the state. The

forest survey data reveal that loss of forest cover in the State has been increasing over the

years. One of the general factors underlying these trends is land use land cover change, the

dynamics of which vary greatly across the state. The state has experienced rapid

urbanization, infrastructure development and the agricultural intensification with resulting

large scale habitat loss and degradation. Special strategy may be formulated for recovering

encroached areas.

Incorporation of some incentive mechanisms or benefit sharing mechanisms in the

community conserved areas for instance Mulai Kathoni (Jorhat) and protection of valuable

species outside the forest would be an encouraging steps towards conservation and

management of biodiversity. Important carbon stocks in many forests around the world

have been maintained and enhanced with the help of the local communities’ ranges from

conservation to reforestation.

Payments for ecosystem services may be useful in this regard for preserving,

acknowledging and rewarding good community forest management practices. Active

participation of communities in all aspects of forest management, taking into account

people’s needs, aspirations, rights, skills and knowledge, will contribute to the efficiency,

sustainability and equity of forest-based measures to tackle the degradation and threats of

climate change as well.

For reclamation of degraded forest lands and riparian sites, plantation and

ecorestoration programme may be initiated with prioritize species in relation to ecoregion/

agro-climatic zones. In riparian sites plantation of bamboo and various species of grass can

be initiated to check erosion. Eco-sensitive zones in the valley should be demarcated and

regulations may be imposed on developmental projects like mega dams, industrial activities,

34

quarrying and mining in such areas are other important measures of conservation may be

initiated.

More areas should be incorporated under protected area network. Strengthening of

the ongoing programme/project of forestry sectors, viz. Joint Forest Management, Project

Tiger, Project Elephant, Project Rhino, Eco-development programme, National aforestation

programme, etc. is important and these should be integrated with watersheds, wetlands

and also grass lands for formulating effective management planes. Special initiatives need to

be taken for protection of the areas outside the protected areas or reserve forests with rich

flora and fauna. The natural corridors of the wildlife in the valley disrupted due to change in

the land use and land cover, industrialization and other developmental activities should be

protected and restored.

Updation of the database on floristic diversity in terms of species, ecosystems &

genetic traits with reference to status, pressures and also in regard to changing climate are

other issues of resource management. Besides, pest-resistant or drought-tolerant varieties;

genotypes of species expected to be adapted to new climate conditions are also to be

screened out. Documentation ethno-cultural interlink is also important to safe guard IPR of

the communities.

The state of Assam should try for lobbying at regional, national and international

level against the large dams coming up on the Siang, Dibang, Lohit, Subansiri and even in the

Brahmaputra river. Exchange of surface, sub-surface and ground water flow is important for

maintaining the annual flood cycle and hydrological relationship of some important wildlife

areas of the valley. Probable changes in water flow due to construction of large dams may

significantly affect the supply of water, nutrient and silt which are vital for sustenance of the

forest and various ecosystem types.

The threat to biodiversity due to invasive species alien species is considered second

only to the habitat destruction. Invasive species cause loss of biodiversity including species

extinction. The humid climate of the state is congenial for spread various invasive and alien

species like Lantana camara, Mikania micrantha, Chromolaena odorata, etc. Special

35

measures to be taken for control of the alien /invasive plant species as several interacting

factors contribute to successful invasion of these species. There is a need to increase public

awareness of the threat of invasive plants to natural and man made ecosystems. Increased

awareness wil help prevent the translocation of invasive species in new areas.

As far as the conservation efforts are concerned, research inputs are important.

Therefore comprehensive studies on the floristics, phenological responses of wild flora in

different ecosystems/habitat, identification of plant species with high carbon sequestration

potentials need to be initiated. Identification of keystone species for different eco-zones

with perspective of developing strategies for eco-restoration, research on the sensitivity of

the endemic taxa to probable change including the possible impact on restricted range are

other areas of research. Apart from these some long term study on the changes on the life

cycle, physiology, reproductive biology some economically important plant species, also

with reference to climate change may be initiated. Similarly, problems of invasive species,

natural adaptation mechanism of species and the degree of resilience of their habitats are

also required to be addressed. Intensity of diseases of wild flora due to changing climatic

conditions is another issue need to be addressed as an adaptation measures to climate

change in the state of Assam. Besides, the vulnerability of major forest types and associated

fauna found in the state to climate change in PAs, grassland, riparian forests (prone to

erosion & flooding) and patches of the rain forests in upper Assam and also areas outside

the PAs need to be initiated to assess the impacts of climate change and possible adaptation

interventions.

All these initiatives are fruitless without involvement of the local communities.

Therefore, community training and capacity building are necessary prerequisites to local

biodiversity conservation programme and also for income generation. It is imperative that

the local communities should be made aware of the benefits of nature conservation. They

should also be imparted with technical, financial, managerial, marketing and training

support so that they will have a new economic incentive to conserve the resource base of

their raw material.

36

Various government institutions like North East Development Finance Corporation

Ltd. (NEDFI), North East Council (NEC) and Department of development of North East Region

(DONER) have already started encouraging to tap the vast bio-resource of the northeast

region in general and Assam in particular involving both local citizen as well as state

governments in a sustainable way to boast the economy and to provide livelihood to the

entire population of northeast India. Citizens are provided with technical, financial,

managerial, marketing and training support, so that they have a new economic incentive to

conserve the resource base. There must be co-ordination between government

developmental policies and biodiversity conservation strategies so that the critical balance

between the ideology of conservation and the necessity of development are maintained

involving local communities as the principal stakeholders of bio-resources.

There is a need to reassess the challenges and opportunities of sustainably managing

the bio-resource of the state. The strategies should be formulated in the context of all the

imperatives of biodiversity conservation, livelihood improvements and unsustainable

commercial utilization. The rich floristic diversity with a large number of endemic plants of

state of Assam in general and Brahmaputra valley in particular not only constitutes the

‘green gold’ of the present century but also of the future. These rich genetic resources of

the region also hold promises to yield organisms. A rational, scientific and judicious

utilization of the bio-resources of the region will help us in the long run in improving the

welfare of the humanity; at the same time will also facilitate to conserve this pristine glory

for the posterity.

37

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43

Appendix I: Floristic diversity of the national parks of Assam

Nameri NP

Begum,

2010

Rajib Gandhi (Orang) NP

Nath & Choudhury,

1994

Manas NP & BR

Hajra &

Baishya, 2002

Dibru-Saikhowa NP & BR

Baishya & Bora,

2002

Kaziranga NP

Hajra & Jain, 1996

District Sonitpur Darrang & Sonitpur

Kokrajhar, Chirang, Baska

& Udalguri

Tinsukia & Dibrugarh

Golaghat, Nagaon & Sonitpur

Area 200 sq. km.

78.81 sq. km. 500 sq. km. 340 sq. km. 430 sq. km

Family 159 95 111 108 115

Genera 580 322 372 233 377

Species 882 450 591 471 560

44

Appendix II: Floristic diversity of the Islands of Brahmaputra river.

Plant Group Flora of Majuli Island (M. Islam, 1990)

Flora of Umananda Island (P. Bujarbarua, 2015)

Families 139 54

Genera 505 117

Species (Angiosperms) 692 123

45

Appendix III: Floristic diversity of Assam worked out by different workers.

Plant Group Baishya (1999) Chowdhury (2005) Barooah & Ahmed (2014)

Family Genera Species Family Genera Species Family Genera Species

Fern & Fern allies - - 297 32 97 355 - - -

Gymnosperm 4 4 7 8 13 23 7 14 22

Angiosperm

(Dicotyledons)

170 824 2251 190 1006 2823 189 1011 2752

Angiosperm

(Monocotyledons)

37 287 759 42 332 1072 40 368 1080

46

Appendix IV: Comparisons of Evergreen species distributed in

Brahmaputra and Barak Valley (after Das 1942)

Brahmaputra valley Barak valley

Magnoliaceae

Magnolia griffithii Absent

M. hookeri Absent

M. cavena Absent

M. pealina Absent

M. pterocarpa Absent

M. insignis Absent

M. hodgsoni M. rabaniana

Pachylarnax pleiocarpa Absent

Kadsura roxburghiana Absent

Annonaceae

Polyalthia simiarum Absent

Absent Cyathocalyx malabaricus

Flcourtiaceae

Hydnocarpus kurzii Absent

Clusiaceae

Garcinia affinis Absent

Absent Mammea suriga

Maesa assamica Maesa floribunda

Theaceae

Adiandra griffithii Absent

Camellia caudate Absent

Dipteroarpaceae

Dipterocarpus retusus Dipterocarpus turbinatus

D. mannii Absent

Shorea assamica Absent

Hopea shingkeng Absent

Fabaceae

47

Dalbergia assamica D. reniformis

Derris ferruginea Absent

Absent Maniltoa polyandra

Hamamelidaceae

Altingia excels Absent

Combretaceae

Absent Anogeissus acumata

Myrtaceae

Eugenia Formosa Absent

Lythraceae

Crypteronia paniculata Absent

Sapotaceae

Palaquium obovatum P. polyanthum

Ebenaceae

Absent Maba cacharensis

Apocynaceae

Chonemorpha griffithii Absent

Asclepiadaceae

Cryptolepis buchanani Absent

Lauraceae

Beilschmiedia roxburghiana Absent

B. assamica Absent

B. pseudomicrocarpa Absent

Absent Endiandra firma

Absent Cinnamomum cacharensis

Alseodaphne petiolaris Alseodaphne owdenii

Absent Alseodaphne andersonii

Persea bombycina Absent

P. globularia Absent

Phoebe goalparensis Absent

P. cooperiana Absent

Euphorbiaceae

48

Aporusa wallichii Absent

Absent Drypetes eglandulosa

Fagaceae

Lithocarpus elegans Absent

Podocarpaceae

Podocarpus nerifolius Absent

Absent P. wallichianus

Gnetaceae

Gnetum gnemon Absent

49

Appendix V: Endemic plant taxa of Assam

Sl. No. Species Family

1 Acacia diadenia Mimosoideae

2 Acacia pennata ssp. Herrii Mimosoideae

3 Adhatoda cymosa Acanthacecae

4 Agapetes kanjilali Vacciniaceae

5 Agapetes variegata var. bhareliana Vacciniaceae

6 Allophyllus chartaceous Sapindaceae

7 Ardisia pardalina Myrsinaceae

8 Artabotrys cubitti Annonaceae

9 Bambusa cacharensis Poaceae

10 Bambusa mastersii Poaceae

11 Begonia tessaricarpa Begoniaceae

12 Beilschmiedia gammieana Lauraceae

13 Beilschmiedia pseudomicropora Lauraceae

14 Bousigonia angustifolia Lauraceae

15 Camellia sinensis var. assamica Theaceae

16 Calamus floribundus var. drepauperatus (Cachar & N.C. Hills) Arecaceae

17 Calamus kingianus (Cachar & N.C. Hills) Arecaceae

18 Calamus nambariensis (Cachar & N.C. Hills) Arecaceae

19 Celastrus paniculata var. venulosoides Celastraceae

20 Chonemorpha assamensis Apocynaceae

21 Chrysoglossum assamicus Orchidaceae

22 Cinnamomum cacharensis (Cachar & N.C. Hills) Lauraceae

23 Citrus assamensis Rutaceae

24 Cymbopogon jwaracus var. asamensis Poaceae

25 Dalbergia rimosa var. griffithii Papilionoideae

26 Dendrocalamus patellaris Poaceae

27 Dendrobium assamicum Orchidaceae

28 Dendrobium aurantiacum Orchidaceae

29 Derris cuneifolia var. cuneifolia forma assamica Papilionoideae

50

30 Dinochloa indica Poaceae

31 Dioscorea cumingii var. inacquefolia Dioscoreaceae

32 Dioscorea pentaphylla var. communis Dioscoreaceae

33 Dioscorea pentaphylla var. kussok Dioscoreaceae

34 Diospyros cacharensis (Cachar & N.C. Hills) Ebenaceae

35 Diospyros kika Ebenaceae

36 Dipterocapus manii Dipterocarpaceae

37 Dischidia albiflora Asclepiadaceae

38 Drypetes assamica Euphorbiaceae

39 Ecdysanthera lakhimpurensis Apocynaceae

40 Eria calmifolia Orchidaceae

41 Eulophia santapaui Orchidaceae

42 Euonymous assamicus Celestraceae

43 Euonymous vagans ssp. Macrophyllus Celestraceae

44 Fimbristylis circumciliata Cyperaceae

45 Fissistigma santapaui Annonaceae

46 Flacourtia helferi Flacoutiaceae

47 Garcinia keeniana (Cachar & N.C. Hills) Clusiaceae

48 Garcinia lanceafolia var. oxyphylla Clusiaceae

49 Gigantochloa macrostachya Poaceae

50 Glochidion assamicum Euphorbiaceae

51 Glycosmis singuliflora Rutaceae

52 Heritiera dubia Sterculiaceae

53 Homalium ceylanicum var. debbermani Flacoutiaceae

54 Hymenachne assamica Poaceae

55 Hypericum assamicum Hypericaceae

56 Illigera gammiei Hernandiaceae

57 Ixora goalparensis Rubiaceae

58 Justicia craibii Acanthaceae

59 Litsaea assamica Lauraceae

60 Maba cacharensis (Cachar & N.C. Hills) Ebenaceae

61 Maesa kurzii Myrsinaceae

51

62 Maesa maxima Myrsinaceae

63 Magnolia baillonii Magnoliaceae

64 Magnolia caveana Magnoliaceae

65 Magnolia gustavi Magnoliaceae

66 Mesua assamica Clusiaceae

67 Michelia manii Magnoliaceae

68 Michelia montana Magnoliaceae

69 Mussaenda intuspilosa Rubiaceae

70 Myristica clarkeana Myristicaceae

71 Pachylarnax pleiocarpa Magnoliaceae

72 Pandanus assamensis Pandanaceae

73 Parakaempfera synantha Zinziberaceae

74 Paspalum longifolium var. lorirhachis Poaceae

75 Pavetta assamica Rubiaceae

76 Persea dubia Lauraceae

77 Persea globularia Lauraceae

78 Phoebe cooperiana Lauraceae

79 Phoebe goalparensis var. marliniana Lauraceae

80 Phoebe goalparensis var. boriana Lauraceae

81 Phyllostachys assamica (Cachar & N.C. Hills) Poaceae

82 Physurus hirsutus Orchidaceae

83 Piper clarkei Piperaceae

84 Piper crassistipes Piperaceae

85 Piper gullatlyi Piperaceae

86 Piper gammei Piperaceae

87 Piper jenkinsii Piperaceae

88 Piper listeri Piperaceae

89 Poa wardiana Poaceae

90 Polygonum sarbhanganicum Polygonaceae

91 Rotboellia goalparensis Poaceae

92 Salacia jenkinsii Celestraceae

93 Schizostachyum dulooa (Cachar & N.C. Hills) Poaceae

52

94 Schizostachyum griffithii (Cachar & N.C. Hills) Poaceae

95 Schizostachyum pergracile (Cachar & N.C. Hills) Poaceae

96 Sclerostachya milroyi Poaceae

97 Syzygium assamicum Myrtaceae

98 Stztguyn cyanophyllum Myrtaceae

99 Thamnocalamus prainii Poaceae

100 Trachelospermum assamense Apocynaceae

101 Typhonium listeri Araceae

102 Uvaria hamiltonii var. kurzii Anonaceae

53

Appendix VI: List of primitive families and genera and representative species in the Brahmaputra valley

Family Genera No. of Species in Assam

Magnoliaceae

Magnolia 9

Michelia 8

Pachylarnax 1

Annonaceae

Alphonsea 1

Annona 3

Artabotrys 2

Desmos 4

Fissistigma 3

Friesodielsia 1

Goniothalamus 1

Miliusa 2

Mitrephora 1

Orophea 1

Poyalthia 4

Trivalvaria 1

Uvaria 4

Schizandraceae Kadsura 1

Menispermaceae Aspidocarya 1

Pycnarrhena 1

Lardizabalaceae Parvatia 3

Hamamelidaceae Altingia 1

Chloranthaceae Chloranthus 1

Myristicaceae

Horsfieldia 2

Knema 2

Myristica 1

Lauraceae

Actinodaphne 5

Beilschmiedia 5

Cinnamomum 5

54

Cryptocaria 2

Dehaasia 1

Endiandra 1

Lindera 5

Litsea 19

Machilus 2

Neocinnamomum 1

Persea 5

Phoebe 5

Saururaceae Houttuynia 1

Myricaceae Myrica 1

Betulaceae Betula 1

Gnetaceae Gnetum 3

Podocarpaceae Podocarpus 1

Cycadaceae Cycas 1

55

Appendix VII: Economically important plants of Brahmaputra valley

Category Name of the plant species

Timber yielding plants Albizia lebbek, A. odoratissima, Altingia excelsa, Artocarpus

chama, Chukrassia tabularis, Duabanga grandiflora, Dipterocarpus

retusus, Mesua ferrea, Michelia champaca, Species of Magnolia,

Talauma hodgsonii, Palaquium polyanthum, Schima wallichii,

Phoebe goalparensis, Shorea assamica, S. robusta, Terminalia

myriocarpa, Lagrestroemia reginae.

Paper and pulp: Besides Bamboo, plants viz. Garuga pinnata, Bombax ceiba,

Helicteres spp., Kydia calycina, etc. forms the raw material for

paper industries.

Gums and resins Canarium strictum is the important resin yielding plant of Assam.

Essential oils Brahmaputra valley is rich habitat for Cymbopogon flexuosus,

yielding Citronella oil. Other oil yielding species are Hydnocarpus

kurzii, Gynocardia odorata, Mesua ferrea, Homalomena

aromatica, Pogostemon cablin, etc. Aquillaria malaccensis is the

high valued oil yielding plant found in the state of Assam

particularly in the Brahmaputra valley.

Fibre yielding plant The important fibre yielding plant found in the area are Sterculia

villosa, Bombax ceiba, Corchorus spp., Boehmeria nivea, Butea

monosperma, Bauhinia spp., Grewia spp., Firmiana colorata, and

the species of Hibiscus.

Bamboos and canes: Some important bamboo species are - Bambusa balcooa, B.

pallida, B. cacharensis, B. tulda, Dendrocalamus hamiltonii, D.

strictus, D. giganteus, Melocanna bambusoides, M. baccifera, etc.

Cane species include Calamus flagellum, C. floribundus, C.

latifolius, C. tenuis, etc.

Medicinal plants: Adhatoda vasica, Centella asiatica, Clerodendron colebrookianum,

Costus speciosus, Zingiber gerumbet, Hollarhoena antidysenterica,

Paederia foetida, Phyllanthus emblica, Eclipta alba, Asparagus

racemosus, Terminalia bellirica, T. chebula, etc.

56

Plants with horticultural

importance

Orchids viz. Arundina bambusifolia, Rhynchostylis retusa,

Papilionanthe teres, Cymbidium aloifolium, Dendrobium spp., etc.

along with Allamanda cathartica, Bauhinia purpurea, B. variegate,

Canna indica, Cassia fistula, Celosis argentia, Cestrum nocturnum,

Clerodendrum spp., Hedychium spp., Holmskioldia sanguine, Ixora

acuminata, Saraca indica, Mussaenda spp. are some of the

important plant species with horticultural and floricultural

importance.

Dye Bixa orenella, Rubia cordifolia, Talauma hogdsonii, etc.

Cereals, pseudo-cereals

and millets

Eleusine coracana, Setaria italic, Zea mays, Oryza sativa, etc.

Grain legumes and

oilseeds

Vigna mungo, V. vexillata, V. umbellate, Cicer arietinum, Lens

culinaris, Linum usitatissimum, Brassica juncea, B. rapa, Cajanas

cajan, Sessamum indicum, etc.

Tubers Beta vulgaris, Amorphophallus bulbifer, Ipomoea batatus,

Colocasia esculenta, Dioscorea alata, D. bulbifera, D. hispida, etc.

Spices Pimpinella anisum, Ammomum aromaticum, Nigella sativa, Piper

nigrum, Piper peepuloides, Elettaria cardamomum, Cinnamomum

tamala, Syzygium aromaticum, Cinnamomum zeylanicum, Alpinia

malaccensis, Zingiber officinale, Z. zerumbet, Cymbopogon

jawarancusa var. assamensis, Curcuma amada, Curcuma longa,

etc.

Minor fruits Musa spp., Dillenia indica, Flacourtia jangomas, Baccaurea

ramiflora, Garcinia pedunculata, G. sopsopia, G. stipulata, G.

xanthochymus, Artocarpus lakoocha, Terminalia chebula,

Holboellia latifolia, etc.

57

Appendix VIII: Wild relatives of cultivated plants found in the Brahmaputra valley

Sl. No Name of the Plant Family

1 Artocarpus chama Moraceae

2 Brassica trilocularis Brassicaceae

3 Camellia kissi Theaceae

4 Cinamomum bejolghota Lauraceae

5 Cinnamonum glanduliferum Lauraceae

6 Cinnamomum pauciflorum Lauraceae

7 Citrus assamensis Rutaceae

8 Citrus indica Rutaceae

9 Coffea bengalensis Rubiaceae

10 Coffea fragrans Rubiaceae

11 Colocasia fallax Araceae

12 Colocasia mannii Araceae

13 Cucumis hystrix Cucurbitaceae

14 Cucumis trigonus Cucurbitaceae

15 Curcuma amada Zingiberaceae

16 Curcuma aromatic Zingiberaceae

17 Dioscorea hamiltonii Dioscoreaceae

18 Dioscorea sinensis var. assamica Dioscoreaceae

19 Echinochloa crusgalli Poaceae

20 Elaeocarpus floribundus Elaeocarpaceae

21 Eleusine indica Poaceae

22 Erianthus filifolius Poaceae

23 Erianthus ravennae Poaceae

24 Euonymus assamicus Celastraceae

25 Euonymus vagans Celastraceae

26 Garcinia keeniana Clussiaceae

27 Garcinia lanceaefolia Clussiaceae

28 Luffa graveolens Cucurbitaceae

29 Mangifera sylvatica Anacardaceae

30 Miscanthus nudipes Poaceae

58

31 Miscanthus wardii Poaceae

32 Momordica macrophylla Cucurbitaceae

33 Musa assamica Musaceae

34 Musa acuminate Musaceae

35 Musa velutina Musaceae

36 Narenga fallax Poaceae

37 Oryza rufipogn Poaceae

38 Piper peepuloides Piperaceae

39 Polytoca wallichiana Poaceae

40 Prunus cerasioides Rosaceae

41 Prunus nepalense Rosaceae

42 Rubus moluccanus Rosaceae

43 Saccrahum longisetosum Poaceae

44 Saccharum wardii Poaceae

45 Solanum kurzii Solanaceae

46 Syzygium assamicum Myrtaceae

47 Trichosanthes bracteata Cucurbitaceae

48 Vigna clarkei Fabaceae

49 Zingiber spectabilis Zingiberaceae

59

Appendix IX: Rare, Threatened and Endangered Plant Taxa of Assam (Both Brahmaputra and Barak valley, Source: Baishya, 2009)

Sl.

No. Species Family Status

1 Acalypha australis Euphorbiaceae Rare

2 Acanthephippium silhetense Orchidaceae VulnerableIUCN

3 Acranthera tomentosa Rubiaceae Vulnerable, Endemic, Not EvaluatedIUCN

4 Adinandra griffithii Theaeceae EndangeredIUCN

5 Albertisia mesistophylla Menispermaceae Extinct, Not EvaluatedIUCN

6 Anoectochilus sikkimensis Orchidaceae Critically EndangeredIUCN

7 Apostasia nuda Orchidaceae EndangeredIUCN

8 Begonia tessaricarpa Begoniaceae Extinct, Not EvaluatedIUCN

9 Beilschmiedia pseudomicropora Lauraceae Endemic, Not EvaluatedIUCN

10 Brassiopsis polycantha Araliaceae Rare

11 Bulbophyllum mishmeense Orchidaceae Rare, Endemic Sunipia cirrhata

12 Bulbophyllum virens Orchidaceae Rare, Endemic Sunipia virens

13 Calanthe herbacea Orchidaceae EndangeredIUCN

14 Calanthe odora Orchidaceae EndangeredIUCN

15 Cassia wallichiana Leguminosae Not EvaluatedIUCN

16 Ceropegia lucida Asclepediaceae Rare, Extinct, Not EvaluatedIUCN

17 Chrysoglossum assamicum Orchidaceae EndangeredIUCN

18 Clematis fulvicoma Rannunculaceae Rare, Not EvaluatedIUCN

19 Coelogyne trinervis Orchidaceae VulnerableIUCN

20 Dendrobium aruanticum Orchidaceae Endangered

21 Dioscorea deltoidea Dioscoreaceae Vulnerable

22 Diospyros cacharensis Ebenaceae Rare Not EvaluatedIUCN

23 Dysoxylum gotadhora Meliaceae Rare, Not EvaluatedIUCN

24 Erythrorchis altissima Orchidaceae EndangeredIUCN, Probably Extinct

25 Eulophia manii Orchidaceae Rare, Endemic, EndangeredIUCN

26 Fissistigma santapaui Annonaceae Endemic, Not EvaluatedIUCN

27 Flacourtii helferi Flacourtiaceae Rare, Not EvaluatedIUCN

28 Goniothalamus simsonii Anonaceae Rare, Not EvaluatedIUCN

29 Goodyera recurva Orchidaceae Endemic, EndangeredIUCN

30 Habenaria trifurcata Orchidaceae Rare, Not EvaluatedIUCN

31 Illigera appendiculata Hernandiaceae Rare, Not EvaluatedIUCN

60

32 Indofevillea khasiana Cucurbitaceae Rare, Not EvaluatedIUCN

33 Lagerstroemia minuticarpa Lythraceae Extinct, EndangeredIUCN

34 Leptomischus wallichii Rubiaceae Rare Not EvaluatedIUCN

35 Liparis cespitosa Orchidaceae Endemic, EndangeredIUCN

36 Liparis delicatula Orchidaceae Rare, Endemic, EndangeredIUCN

37 Liparis vestita Orchidaceae Endemic

38 Livistona jenkinsiana Arecaceae Endangered, Not EvaluatedIUCN

39 Lophopetalum chinense Hamamelidaceae Rare

40 Magnolia baillonii Magnoliaceae Rare, Not EvaluatedIUCN

41 Magnolia caveana Magnoliaceae Rare, Not EvaluatedIUCN

42 Magnolia mannii Magnoliaceae Rare, Endemic, Not EvaluatedIUCN

43 Miliusa dolicantha Annonaceae Rare, Not EvaluatedIUCN

44 Miliusa gustavi Annonaceae Endemic

45 Miliusa insignis Annonaceae Rare

46 Miliusa rabaniana Annonaceae Rare

47 Oldenlandia monocephala Rubiaceae Rare, Not EvaluatedIUCN

48 Oldenlandia scabra Rubiaceae Rare, Not EvaluatedIUCN

49 Ophiorrhiza hispida Rubiaceae Endangered, Not EvaluatedIUCN

50 Ophiorrhiza tingens Rubiaceae Vulnerable, Not EvaluatedIUCN

51 Orophea polycarpa Annonaceae Rare

52 Paphiopedilum spicerianum Orchidaceae Rare, Critically endangeredIUCN

53 Phlogocanthus asperulus Acanthaceae Rare, Not EvaluatedIUCN

54 Smithia grandis Leguminosae Rare, Not EvaluatedIUCN

55 Sterculia khasiana Sterculiaceae Rare

56 Stylidium kunthii Stylidiaceae Rare Not EvaluatedIUCN

57 Symplocos glauca Symplocaceae Rare, Not EvaluatedIUCN

58 Syzygium assamicum Myrtaceae Rare

59 Vanilla pilifera Orchidaceae Rare, EndangeredIUCN

61

Annexure – I List of Orchids of Brahmaputra valley, Assam

(Source: Singh, Phukan & Bujarbarua, 2001 and Barooah & Ahmed, 2014) Genus Species Habitat

Acampe

A. ochracea E

A. papilosa E

A. praemorsa E

A. rigida E

Acanthephippium A. striatum T

A. sylhetense T

Aerides

A. falcate E

A. multiflora E

A. odorata E

A.rosea E

Agrostophyllum

A. brevipes E

A. callosum E

A. planicaule E

Anoectochilus

A. elwesii T

A. grandiflorus T

A. luteus T

A. roxburghii T

A. setaceus T

A. sikkimensis T

A. tortus T

Anthogonium A. gracile T

Aphyllorchis A. montana T

Apostasia

A. nuda T

A. odorata T

A. wallichii T

Appendicula A. cornuta E

Arachnis A. flos-aeris E

A. labrosa E

62

Arundina A. graminifolia T

Ascocentrum A. ampullaceum E

A. curvifolium E

Biermannia B. bimaculata E

Brachycorythis B. helferi T

B. iantha T

Bryobium B. pudicum E

Bulbophyllum

B. affine E

B. capillipes E

B. careyanum E

B. cariniflorum E

B. crassipes E

B. cylindraceum E

B. delictescens E

B. ellasonotum E

B. forrestii E

B. guttulatum E

B. helenae E

B. hookeri E

B. iners E

B. muscicola E

B. obrienianum E

B.odoratissimum E

B. pectinatum E

B. polyrrhizum E

B. psychoon E

B. pumilo E

B. reptans E

B. retusiusculum E

B. sarcophyllum E

B. secundum E

63

B. tricorne E

B. triste E

B. wallichii E

Calanthe

C. angusia T

C. biloba T

C. clavata T

C. densiflora T

C.herbacea T

C. lyroglossa T

C. mannii T

C. masuca T

C. odora T

C. sylvatica T

C. triplicate T

C. vaginata T

Cephalanthera C. longifolia T

Cephalantheropsis C. gracilis T

C. longipes T

Ceratostylis

C. himalaica E

C. subulata E

C. teres E

Cheirstylis C. griffithii E

Cleisocentron C. trichomum E

Chiloschista C. lunifera E

Chrysoglossum C. assamicum T

Cleisocentron C. pallens E

Cleisostoma

C. appendiculatum E

C. arietinum E

C. filiforme E

C. loratum E

C. paniculatum E

64

C. racemiferum E

C. striatum E

C. subulatum E

Coelogyne

C. assamica E

C. barbata E

C. fimbriata E

C. griffithii E

C. nitida E

C. ovalis E

C. prolifera E

C. punctulata E

C. rossiana E

C. schultesii E

C. stricta E

C. suaveolens E

C.tomentosa E

C. trinervis E

C. viscose E

Collabium C. assamicum E

Conchidium C. muscicola E

Corymborkis C. veratrifolia T

Cremastra C. appendiculata T

Crepidium C. biauritum T

C. mackinnonii T

Cryptostylis C. arachnites T

Cymbidium

C. aloifolium E

C. assamicum E

C. bicolour E

C. cochleare E

C. dayanum E

C. eburneum E

65

C. elegans E

C. hookerianum E

C. iridioides E

C. lancifolium E

C. macrorhizon E

C. mastersii E

Cyrtosia C. javanica T

C. lindleyana T

Dendrobium

D. acinaciforme E

D. aduncum E

D. anceps E

D. angulatum E

D. aphyllum E

D. assamicum E

D. bensoniae E

D. bicameratum E

D. chrysanthum E

D. chryseum E

D. chrysotoxum E

D. crepidatum E

D. cretaceum E

D. cumulatum E

D. densiflorum E

D. devonianum E

D. eriiflorum E

D. falconeri E

D. farmer E

D. fimbriatum E

D. formosum E

D. gibsonii E

D. griffithianum E

66

D. heterocarpum E

D. hookerianum E

D. infundibulum E

D. jenkinsii E

D. keithii E

D. kentrophyllum E

D. lindleyi E

D. lituiflorum E

D. mannii E

D. miserum E

D. moschatum E

D. nathanielis E

D. nobile E

D. praciflorum E

D. polyanthum E

D. perula E

D. podagraria E

D. pulchellum E

D. salaccense E

D. spatella E

D. stuposum E

D. sulcatum E

D. terminale E

D. transperans E

D. wardianum E

D. willamsonii E

Didymoplexis D. himalaica T

D. pallens T

Dienia D. ophrydis T

Doritis D. pulcherrima E

Epigenium E. ampulum E

67

Epipogium E. indicum E

E. roseum E

Eria

E. alba E

E. amica E

E. apertiflora E

E. biflora E

E. bractescens E

E. carinata E

E. clavicaulis E

E. javanica E

E. excavate E

E. lasiopetala E

E. muscicola E

E. paniculata E

E. pannea E

E. pudica E

E. pumila E

E. sharmae E

E. spicata E

E. stricta E

E. tomentosa E

Erythrodes E. hirsute T

Erythrorchis E. altissima T

Eulophia

E. bicallosa T

E. bracteosa T

E. candida T

E. dabia T

E. graminea T

E. herbacea T

E. kamarupa T

E. mannii T

68

E. nuda T

E. spectabilis T

E. zollingeri T

Flickingeria F. fugax E

F. macraei E

Galeola G. altissima E

Gastrochilus G. dasypogon

G. inconspicuus

G. obliquus

E

E

E

Geodorum

G. densiflorum E

G. laxiflorum E

G. recurvum E

Goodyera

G. cordata T

G. foliosa T

G. hispida T

G. procera T

G.recurva T

G. repens T

G. viridiflora T

Gymnadenia G. orchidis E

Habenaria

H. commelinifolia T

H. digitata T

H. furcifera T

H. longifolia T

H. mandersii T

H. marginata T

H. plantaginea T

H. reniformis T

H. stenopetala T

H. trifurcata T

Herminium H. lanceum E

69

Herpysma H. longicaulis E

Hetaeria

H. affinis T

H. anomala T

H. rubens E/T

Kingidium K. deliciosum E

K. taenialis T

Liparis

L. assamica E

L. bootanensis E

L. caespitosa E

L. delicatula E

L. distans E

L. elliptica E

L. luteola E

L. mannii E

L. odorata E

L. paradoxa T

L. petiolata T

L. plantaginea E

L. vestita E

L. viridiflora E

Luisia

L. bracystachys E

L. macrotis E

L. microptera E

L. platyglossa E

L. psyche E

L. trichorhiza E

L. tristis E

L. zeylanica T/E

Malaxis M. acuminata T

M. latifolia T

Micropera M. obtuse E

70

M. pallida E

M. rostrata E

Neogyna N. gardneriana E

Nephelaphyllum N. cordifolium T

Nervalia

N. aragoana E

N. Juliana T

N. plicata T

Oberonia

O. acaulis E

O. anthropophora E

O. bicornis E

O. emarginata E

O. ensiformis E

O. falconeri E

O. jenkinsiana E

O. mannii E

O. mucronata E

O. myriantha E

O. obcordata E

O. pachyrachis E

O. pyrulifera E

Odontochilus O. lanceolatus E

O. tortus E

Ornithochilus O. difformis E

Otochilus

O. albus E

O. fuscus E

O. lancilabius E

O. porrectus E

Pachystoma P. pubescens T

Panisea P. demissa E

P. tricallosa E

Paphiopedilum P. venustum T

71

P. villosum T

Papilionanthe

P. teres E

P. uniflora E

P. vandarum E

Pecteilis P. susannae T

P. triflora T

Pelatantheria P. insectifera E

Pennilabium P. proboscideum E

Peristylus

P. constrictus T

P. goodyeroides T

P. hamiltonianus T

P. parishii T

P. prainii T

Phaius

P. flavus T

P. mishmensis T

P. tankervilliae T

Phalaenopsis

P. cornucervi E

P. mannii E

P. parishii E

P. pulcherrima T

Pholidota

P. articulate E

P. bracteata E

P. chinensis E

P. convallariae E

P. imbricate E

P. pallida E

P. wattii E

Phreatia P. elegans E

Pinalia

P. acervata E

P. amica E

P. excavate E

72

P. stricta E

Platanthera P. clavigera T

Podochilus P. cultratus E

Pomatocalpa P. mannii E

P. spicatum E

Pteroceras P. teres E

Renanthera R. imschootiana E

Rhinerrhiza R. divitiflora E

R. freemanii E

Rhynchostylis R. retusa E

Robiquetia R. succisa E

Saccolabiopsis S. pusilla E

Smitinandia S. micrantha E

Satyrium S. nepalense T

Schoenorchis S. gemmata E

Spathoglotis S. plicata T

Spiranthes S. sinensis T

Stereochilus S. ringens E

Stichorkis

S. distans E

S. elliptica E

S. mannii E

S. vestita E

S. viridiflora E

Sunipia S. cirrhata E

S. virens E

Taeniophyllum T. glandulosum E

Tainia T. latifolia T

T. viridifusca T

Thelasis T. pygmaea E

Thrixspermum T. centipede E

T. trichoglottis E

73

Thunia T. alba T/E

Trichotosia T. pulvinata E

Tropidia T. angulosa T

T. curculigoides T

Tylostylis T. discolour E

Uncifera U. acuminata E

U. obtusifolia E

Vanda

V. bicolour E

V. coerulea E

V. coerulescens E

V. cristata E

V. stangeana E

V. tessellate E

V. testacea E

Vandopsis V. undulate E

Vanilla

V. borneensis T

V. pilifera T

V. walkeriae T

Zeuxine

Z. assamica T

Z. cordata T

Z. flava T

Z. goodyeroides T

Z. gracilis T

Z. longilabris T

Z. membranacea T

Z. nervosa T

Z. strateumatica T

E – Epiphyte, T - Terrestrial

Note: The names of the plant taxa mentioned in the appendix and annexure are subjected

to recent nomenclatural changes.