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Assessment of forest communities and dependence of local people on NTFPs in Askot landscape, Uttarakhand, Phase 1
(Wildlife Institute of India, Dehradun, 2018) Bisht, S.; Adhikari, B.S.; Shrivastava, A.K.
The study was conducted from January 2013 - October 2017 between 1000-3900 m in Gori and Dhauli sub-watersheds in Askot landscape in Pithoragarh district of Uttarakhand under Biodiversity Conservation and Rural Livelihood Improvement Project (BCRLIP). A preliminary information was collected regarding vegetation community in the landscape through existing knowledge and reconnaissance surveys. Vegetation plots were laid to study the structure, composition and regeneration pattern in various forest communities in the landscape. Questionnaire survey was conducted in different villages to study the use pattern of various Non-Timber Forest Products and state of traditional knowledge among local communities. A checklist of 596 species of plants was prepared including some rare and endangered species, of which 132 trees, 121 shrubs, 24 climbers, 36 orchids and 283 herbs were recorded after carrying out a reconnaissance of the landscape. The collected vegetation data was analyzed and 11 forest communities were identified based on TWINSPAN viz, P. roxburghii, Q. floribunda, Q. leucotrichophora, Q. lanuginosa, A. nepalensis, T. dumosa, Q. semecarpifolia, M. duthiei, A. pindrow, P. wallichiana and B. utilis. Lopping, weed infestation, forest fire and grazing are some of the threats to the plant biodiversity in the landscape. A Species richness map and disturbance level map was prepared in Arc Gis for the landscape. Based on collected information, a list of nine potential indicator species (Polygonum, Strobilanthes, Diplazium, Ageratina adenophora, Alnus nepalensis, Quercus leucotrichophora, Quercus lanuginosa, Macaranga pustulata, Rhododendron arboreum and Pinus roxburghii) were prepared. Three plant species (Ageratina adenophora, Alnus nepalensis, and Quercus leucotrichophora) were selected as indicator species, which will be used for long-term monitoring protocol to detect biodiversity change in the landscape by the local communities.
Assessment of forest communities and dependence of local people on NTFPs in Askot landscape, Uttarakhand, Phase 1 - report
(Wildlife Institute of India, Dehradun, 2015) Bisht, S.; Adhikari, B.S.; Uniyal, V.K.
The Askot landscape represents a great diversity of ecosystems within a very short altitudinal range ie. from 600-7000 m. The assessment of vegetation was done during October, 2012 - October, 2014 covering the entire Gori sub-watershed between 600-2300 m in Askot Landscape in Pithoragarh district of Uttarakhand under Biodiversity Conservation and Rural Livelihood Improvement Project (BCRLIP). A checklist of 573 species of plants was prepared including some rare and endangered species, of which 124 trees, 112 shrubs, 24 climbers, 35 orchids and 278 herbs were recorded after carrying out a reconnaissance of the valley. The data collected for vegetation was analysed and forest communities were identified based on TWINSPAN analysis and various village surveys were conducted to find out the use of various Non Timber Forest Products such as fuelwood, fodder, timber, medicinal plants etc. in the study area. A total of 11 forest communities were identified in the Gori valley, viz. Macaranga pustulata, Shorea robusta, Engelhardtia spicata, Diploknema butyracea, Pinus roxburghii, Alnus nepalensis, Quercus leucotrichophora, Litsea umbrosa, Quercus lanuginosa, Q. leucotrichophora-Neolitsea cuipala and Sorbus foliolosa along an elevational gradient between 600-2300m. It was observed that the total basal area of Q. lanuginosa forest was highest (38.8 m2 ha-1) followed by Q. leucotrichophora (32.7 m2 ha-1) and Pinus roxburghii (31.8 m2 ha-1) and minimum for Q. leucotrichophora-Neolitsea cuipala forest (10.8 m2 ha-1) and Sorbus foliolosa forest (9.2 m2 ha-1). Among Non Timber Forest Products 24, 26, 16 and 24 species were being used as fodder, fuelwood, timber and medicinal plants, respectively. Q. leucotrichophora has the highest preference among fodder followed by Bauhinia vahlii, Boehmeria rugulosa and Ougeinia oogenensis. Lyonia ovalifolia followed by Rhododendron arboreum, Q. leucotrichophora and Woodfordia fructicosa among fuelwood; Shorea robusta followed by Alnus nepalensis, Pinus roxburgii and Q. leucotrichophora among timber; and (ii) Eupatorium adenophorum followed by Terminalia chebula, Zanthoxylum alatum and Pleurospermum angelicoides among medicinal plants. Lopping, forest fire and weed infestation were among major cause of disturbance to forest resources. Impact of lopping on Quercus lanuginosa, Rhododendron arboreum and Q. leucotrichophora, forest fire in W and NW aspects due to the dominance of Chir pine forests and infestation of Cannabis sativa, Eupatorium adenophorum, Urtica dioica and Impatience edgeworthii was highest in NW aspect. The common species used for medicinal purposes by the villagers were Emblica officinalis, Terminalia chebula, Litsea monopetala, Celtis australis, Bauhinia vahlii, Syzygium cumini, Myrica esculenta, Berginia ciliata, Oxalis corniculata, Eupatorium adenophorum, Adhatoda zeylanica, Terminalia chebula, Cissampelos pareira, Viola canescens, Fragaria nubicola, Tinospora cordifolia and different orchid species in Gori valley. Twelve potential plant indicator species viz., Chimnobambusa falcata, Eupatorium adenophorum, Alnus nepalensis, Quercus leucotrichophora, Quercus lanuginosa, Macaranga pustulata, Rhododendron arboreum, Pinus roxburghii, Aconitum heterophyllum, Dactylorhiza hatagirea Picrorhiza kurrooa and Pleurospermum angelicoides were identified based on the information collected during the surveys as well as through secondary information. The distribution map of each species was generated according to climatic zone in ArcGIS software along with their potential distribution range. Finally, a species richness map was prepared to show the high species richness zone in the study area.
Assessment of habitat use by black-necked crane (Grus nigricollis) and eflows of Nyamjang Chu Hydroelectric Project in Tawang district, Arunachal Pradesh
(Wildlife Institute of India, Dehradun, 2018) Gopi, G.V.; Johnson, J.A.; Adhikari, B.S.; Bhattacharya, M.; Wattham, T.; Sivakumar, K.
Nyamjang Chu River flowing in Zemithang valley of Tawang district, Arunachal Pradesh is on e of the only two known Black-necked crane wintering sites in India. In 2006, the Government of Arunachal Pradesh awarded the development of a hydropower project in the Nymjang Chu River at Zemithang valley to Bhilwara Energy Limited. On behalf of BEL WAPCOS ltd and RS Envirolink technologies pvt. limited carried out the EIA and EMP were strongly opposed and challenged by many scientific as well as social institutions. Citing flaws in the methods adopted for floral and faunal studies the baseline setting for the ecological aspects and prediciton of impacts on wildlife habitat and environment of the region. Recently the honorable National Green Tribunal (NGT) observed gross errors in the EIA and EMP such as omission of key, rare and threatened species such as omission of key, rare and threatened species such as the Black-necked crane in the report and ordererd that the WII to conduct a detailed study in this regard. The primary scope of the WII study was to assess the habitat requirements of the Black-necked crane and Assess the environmental flows requirement for protection and conservation of Black-necked crane habitats at the proposed Nyamjang Chu Hydroelectric project site in Zemithang valley
Assessment of habitat use by Black-necked crane (Grus nigricollis) and elflows of Nyamjang Chu Hydroelectric project in Tawang District, Arunachal Pradesh.
(Wildlife Institute of India, Dehradun, 2018) Gopi, G.V.; Johnson, J.A.; Adhikari, B.S.; Bhattacharya, M.; Wattham, T.; Sivakumar, K.
Assessment of medicinal and aromatic plant species on their collection, usage, demand, markets, price trends and life cycle in Lahaul and Pangi landscape, Himachal Pradesh
(Wildlife Institute of India, Dehradun, 2021) Kumar, Amit; Sathyakumar, S.; Goraya, G.S.; Gupta, A.K.; Adhikari, B.S.; Rawat, G.S.
Nested in the Western Himalaya, the state of Himachal Pradesh (30° to 33°N and 75° to 79° E) is known for its rich biological diversity. It covers an area of 55,673 km2 with >3,300 distinct plants species. Interestingly, the alpine areas of Lahaul and Spiti are one of the major hot spots of wild MAPs in the Western Himalaya. Unfortunately, the remote valleys such as Lahaul, Pangi, Spiti, Kinnaur including micro-watersheds lying in the cold-arid regions of Himachal Pradesh are relatively less studied in terms of available growing stock and population status of MAPs. Notably, there is a general lack of literature on medicinal plants at the catchment, watershed and valley levels. Further, the information on recent levels of trade of MAPs are available only from a few localities of the Western Himalaya. Like other areas, these areas have also been facing additional stress due to over-exploitation of forest resources, including the unscientific and premature harvesting of MAPs from the wild, which functions parallel to the illegal and hidden markets thus, putting tremendous pressure on the wild resource base resulting in the dwindling populations and precarious livelihoods of local communities. The rising demand of herbal products has caused excessive harvesting of many of the important MAPs from these regions, putting their wild population at the risk of extinction. Keeping aforementioned aspects in view, the current study was proposed which aims to study selected Medicinal and Aromatic Plant (MAP) species in Lahaul and Pangi landscape of Himachal Pradesh with focus to ensure sustainable harvesting and cultivation by (i) identifying usage patterns of MAPs, and (ii) studying existing value chains. In order to address the project objectives, the present study has been categorized into 12 key tasks. The current study revealed that the major issues adversely impacting the MAP species in the Lahaul and Pangi landscape include illegal/ over/ premature/ unorganized harvesting of Medicinal and Aromatic Plants (MAPs), high demand and non-transparent operations in the markets of MAPs. Besides these issues, few gaps such as knowledge on available stock of MAPs, lack of information on cultivation and harvesting methods of key MAP species specific to Lahaul and Pangi landscape, lack of information on end users and middlemen and inadequate information on quantity of raw material traded have been reported. In order to optimize the benefits to the local communities and adopt the concepts of sustainable harvesting and benefit sharing, it is important to assess the availability, market trends and methods for collection of MAPs including gathering information on population of selected MAPs. This will help in identifying High Conservation Value Areas (HCVAs) and delineating MPCAs for in-situ conservation in the landscape. Assessment of medicinal and aromatic plant species on their collection, usage, demand, markets, price trends and life cycle in Lahaul and Pangi landscape, Himachal Pradesh Additionally, identification of large traders and industries that acquire their raw materials from Lahaul and Pangi will strengthen the implementation of Access and Benefit Sharing model on pilot basis. Furthermore, identification of hidden markets viz., local, regional and national, price trends, value addition and strengthening BMCs will help in sustainable management of MAPs in the landscape. The first step towards conservation is identifying the existing population base, and information on the species distribution and abundance. Identification of the best cultivation practices, R&D to reduce long-gestation periods, cost effective technology, organic-farming, buy-back mechanisms, policy-revision in the interest of stakeholders, protocols for post-cultivation management, quality-control and awareness training are some measures in this direction. It can be concluded that in order to optimize the benefits to the local communities, and to adopt the concepts of sustainable harvesting and benefit-sharing, it is important to assess the availability, market trends and methods for collection of MAPs, including gathering information on population of selected MAPs. A major step towards species conservation can be spreading awareness on the dwindling populations amongst the stakeholders. It is also important to identify alternative sources of income for the locals to create in them confidence that wild harvest of MAPs was not the only source of cash income and, thus to dissuade them from ruthless wild harvest and to make them participate in conservation programs. Identifying and building the capacities of stakeholders including the forest officials, locals, school children, traditional healers and plant traders can help in community based natural resource management. These issues need to be addressed to ensure long-term conservation of the MAP resources of the landscape in a way that livelihood needs of the local communities depending on this resource are not compromised. The following key recommendations have emerged after this study:  Documentation of the Conservation Status of Key MAPs i Setting aside Conservation Areas around Viable Populations of Priority MAPs ii Strengthening of Biodiversity Management Committees (BMCs) iii Value addition by adopting best Post-Harvest Management Techniques iv Developing Farm-scale Agro-Techniques for Priority MAP Species v Developing Germplasm Banks of the Priority MAP Species vi Study and Monitor Impacts of Climate Change
Ecological Assessment of Siswan Reserve, Punjab
(Wildlife Institute of India, Dehradun, 2017) Bhardwaj, A.K.; Srivastav, A.; Pandav, Bivash; Singh, Pratap; Adhikari, B.S.; Uniyal, V.P.; Badola, R.; Das, A.
This study was undertaken with the following objectives: (i) Generate floral and faunal baseline information. (ii) Understand mutual linkages and issues, between local communities and the reserve (iii) Sensitize the local staff about ecological importance of this area and its attributes rapid surveys were carried out by a team of WII faculty and researchers for various taxa from October 2016 to June 2017. Surveys were carried out for generating information about large mammals, birds, reptiles, amphibians, insects and vegetation. To assess peoples perspective concerning the reserve participatory methods of focused group discussions (FGDs), social and resource mapping and time line surveys were undertaken. Visits for various rapid assessments were made more productive by conducting capacity building exercises for department staff simultaneously
Effects of climate-change on riverine forests and indicator species along river Ganga in Uttarakhand: a multi-scale approach
(Wildlife Institute of India, Dehradun, 2015) Ramesh, K.; Adhikari, B.S.
The objectives were 1.Study the distribution pattern, range shift and population response of indicator species along the Ganga in Uttarakhand, from foot-hills to snout of the Gangotri glacier. 2. Quantify structure and functional attributes of vegetation along selected climatic ecotones. 3. Detect major drivers of landscape composition and configuration in space and time, and develop spatially explicit predictive models.
Status of low and high altitude grazingland and issues of livestock (Migratory pastoralism) in Kailash Sacred Landscape-India, Wildlife Institute of India, Dehradun
(Wildlife Institute of India, Dehradun, 2021) Adhikari, B.S.; Rawat, G.S.; Garbyal, U.; Srikar, R.
Pastoralism is of three different kinds; Sedentary pastoralism, Mobile pastoralism, and Silvopastoralism. Grazing of livestock in limited grazing zones or ranches due to strict political borders leads to sedentary pastoralism. This form of pastoralism is becoming more common with the changing geo-political dynamics across the world. Sedentary pastoralists also raise crops with livestock in the form of mixed farming to diversify productivity. Mobile pastoralism includes moving herds of livestock in search of fresh forage and water, from shorter to longer distances. Transhumance is the form of mobile pastoralism where animals are routinely moved between different seasonal pastures across regions and under nomadism pastoralists their families move with the animals in search of available grazing grounds to supplement their natural resource needs. Grazing in woodlands and forests may be referred to as silvopastoral in which the livestock is periodically grazed inside the forest areas
Status of threatened medicianl and aromatic plants and their use by the Bhotiya community in Niti valley, Nanda Devi Biosphere Reserve, Uttarakhand
(Wildlife Institute of India, Dehradun, 2022) Kumar, A.; Adhikari, B.S.; Mishra, A.P.
Nested in the Western Himalaya, the state of Uttarakhand, also known as the ‘herbal state of India,’ harbors more than 5000 species of vascular plants, of which one-third species have medicinal uses. The state abounds in a rich and varied flora and fauna, constituting the most species-rich part of the whole of the Western Himalaya. The extreme north of the state contributes approximately 1% (ca. >1,000 km2) of the total Trans- Himalayan region (ca. 98,660 km2) of India. however, in spite of rich floral diversity, the cold-arid regions of Nilang, Niti, Mana, Johar, Darma and Byans valleys of Uttarakhand along the northern frontiers that falls under Trans-Himalayan Biogeographic Province (1C) are underexplored in terms of the current levels of pressure and patterns of biodiversity. These areas have also been facing tremendous pressure due to over-exploitation of forest resources including the unscientific and illegal harvesting of MAPs from the wild. The current study was conducted to study selected threatened and high use value MAPs in Niti valley, a cold-arid region of Nanda Devi Biosphere Reserve with a focus to (i) assess the status, abundance, and use of MAPs, and (ii) suggest their sustainable harvesting and cultivation framework. The information on the focal species was gathered through primary viz., semi-structured open-ended and closed-ended questions including individual interactions and group discussions in selected villages (7) and secondary information through offline and online sources. After reconnaissance and stratification of habitats, population status of focal species was assessed using stratified random sampling. Based on extensive interactions with younger generation, elder people including local healers, plant collectors and local traders, a total of five high value (with significant economic end usage) MAPs namely Allium tracheyi, Carum carvi, Dactylorhiza hatagirea, Picrorhiza kurroa and Sinopodophyllum hexandrum were selected in Niti valley, NDBR. The selection of MAPs was based mainly on highest quantum of collection and high threat due to removal and usages.The current study highlights that the population of the focal species (except Carum carvi) are sparse albeit rapidly declining due to excessive exploitation, unscientific, illegal and premature harvesting. Therefore, keeping their current population status in view, preparation of microplans, assessment of available growing stock and sustainable management and utilization of dwindling populations is recommended. Besides over-exploitation of MAPs, knowledge on their available stock,lack of information on end users and middlemen and inadequate information on quantity of raw material traded due to secretive nature of the markets were reported. In Niti valley, the market trend, price vis a vis trade route is indiscernible for highly traded medicinal species such as Gucchi, Morchella esculenta and Keedajadi, Ophiocordyceps sinensis which sells in the market like a hot cake, and therefore has created hue and cry state among the locals. Hence, these issues need to be addressed to ensure long-term conservation of the MAPs in a way that livelihood needs of the locals depending on such resources are not compromised. The focal species are one of the highly traded MAPs from the Western Himalaya, in general and Niti valley, particularly. Therefore, considering the existing threats, habitat specificity, population size and pressure level, the focus of conservation and regulated harvest is particularly needed for(i) restricted distribution heavy pressure (RDHP) species such as Picrorhiza kurroa and Dactylorhiza hatagirea, and (ii) locally common heavy pressure (LCHP) species such as Allium stracheyi, Sinopodophyllum hexandrum and Carum carvi in Niti valley, NDBR. Bhotiyas, ethnic community of Indo-Mongoloid origin mailny depend on natural resources from the adjacent forests and alpine pastures or meadows (locally known as payar) for their livelihood. Therefore, considering the high use value, market opportunities, price of the produce, and ease of cultivation or harvesting processes, the current study proposes Allium stracheyi, Carum carvi and Saussurea costus as the potential species that can be encouraged for their cultivation in Niti valley. It will not only provide livelihood opportunites to the local inhabitants butalso check ruthless exploitation of the wild MAPs. The local inhabitants are dependent on the wild MAPs for their traditional health care system. They are knowledgeable of about 72 MAPs that are locally utilized consumption and for curing at least 24 different human ailments. However, the practice of utilising MAPs in their local healthcare system is sharply declining due to lack of education facility and market, which has led to lack of knowledge as well as transfer of knowledge to younger generations. The payar such as Bamplas, Lang, Goting, Rekhana (base of Mount Kamet) and Geldung in Ganesh Ganga; Timersain and Thali enroute Kalajowar, and Daman towards Sagar glacier in Amrit Ganga are rich in medicinal plant diversity. Thus, considering the unique medicinal diversity and traditional ways of their conservation in view, rotation grazing in the forested areas including heavily grazed payars such as Daman, Thali, Timsersain and Goting in a cycle of 2-3 years is proposed. Owing to excessive human population, it is evident that the demand visa- vis harvesting pressure on wild populations of several MAPs is increasing every year. Thus, in order to meet the accelerating demand of high use value MAPs, there is an urgent need to develop farm scale agrotechniques for priority MAP species in the absence of such efforts on lab to land tested techniques. In the current study, sustainable harvesting and cultivation framework have been designed for the selected 05 MAPs,although appropriate demonstration sites showcasing such agrotechniques in the cold-arid landscapes such as Niti valley in Uttarakhand be set up to build confidence of the plant growers or locals in adoption of such medicinal crops in their agricultural practices.
Study on Ecological & Socio-Economic Impact of Invasive species, Prosopis juliflora and Lantana camera and their removal from forest, common and fallow land of Tamilnadu
(Wildlife Institute of India, Dehradun, 2018) Sivakumar, K.; Rawat, G.S.; Badola, Ruchi; Adhikari, B.S.; Kamalakannan, B.
Study on ecological and socio-economic impact of invasive species, Prosopis juliflora and Lantana camara and their removal from forest, common and fallow land of Tamilnadu
(Wildlife Institute of India, Dehradun, 2018) Sivakumar, K.; Rawat, G.S.; Badola, Ruchi; Adhikari, B.S.; Kamalakannan
1) Prosopis juliflora is an invasive, drought resistant, evergreen fast growing pheratophyte widely distributed in India and also in arid and semi-arid tropical countries. It is a highly valued wood source for rural people in India. The P. juliflora is believed one of the worst invaders affecting natural and man-made ecosystems and its local biodiversity in Tamil Nadu. In this context, this study was conducted aimed to assess the distribution patterns of P. juliflora and its impacts in three different agro-climatic zones of Tamil Nadu. 2) In 1959, Prosopis juliflora was introduced in Tamil Nadu to meet the fuelwood requirements of the rural poor people and to re-vegetate the degraded lands but it spread at faster and occupied almost all agro-zones of Tamil Nadu. In India, P. juliflora was considered as one of the worst invaders in the country affecting natural ecosystems and local biodiversity. In order to eradicate this species from natural forests, preparation of a restoration plan is desirable with knowledge on ecology and impacts of P. juliflora in Tamil Nadu. Keeping this in view, Wildlife Institute of India with support of Tamil Nadu Forest Department assessed the extent and abundance of P. juliflora in forest, common and fallow land of Tamil Nadu. Initially, the study was started in the southern zone of Tamil Nadu and later in other agro-climatic zones of Tamil Nadu (i.e. Cauvery delta zone (Nagapattinam district), Southern zone (Ramanathapuram district) and Western zone (Sathiyamangalam Tiger Reserve, Erode district). 3) Totally ninety transects were laid randomly in three agro-climatic zones of Tamil Nadu. Each transect of 2 km length, it had six 15 m radius plots at equal distance of 400 m to quantify the environmental parameters such as vegetation structure and composition, cover percentage of grass, native herbs, weeds, animal pellet and bird abundance, etc., was recorded by using standard methods on the same transect. Influence and impact of Prosopis juliflora and its and socio-economic status were assessed by using a questionnaire survey in entire taluks of three agro-climatic zones. 4) The results revealed that occupancy of Prosopis juliflora was more in the southern zone compared to the other two zones. Southern zone occupies 79.4% of Prosopis juliflora invaded in this region than western zone (46%), and in Cauvery delta zone (32%). Density (F = 34.35, P < 0.05) and frequency occurrence (%) of P. juliflora were also higher in the southern zone followed by western zone and Cauvery delta zone. The richness and native biodiversity of plants and related herbs, shrubs were highly ruined in southern zone followed by Cauvery delta and western zone. The highest extent of Prosopis was observed in the entire seven taluks of the Ramanathapuram district (southern zone) compare to the Nagapattinam taluks (Cauvery delta zone) and Sathyamangalam Tiger Reserve ranges (western zone). Except Prosopis juliflora and Lantana camara; Parthenium hysterophorus and 2 Chromolaena odorata caused huge smash up to the native ecosystems in some ranges of Sathyamangalam Tiger Reserves. 5) In Ramanathapuram district, the abundances of herbs such as Tephrosia purpurea, Crotons sparsiflorus, and Cleome viscosa were significantly lesser in P. juliflora invaded plots as compared to the non-invaded plots. Relative abundance of birds such as Pavo cristatus, Conturnix conturnix and Acridotheres tristis were positively correlated with P. juliflora abundance in Ramanathapuram taluks. The western zone where the habitat dominated by P. juliflora was observed with low abundances of wild ungulates. 6) Driest environment settings of southern zone favored more P. juliflora than other two agro-climatic zones that are comparatively wet. 7) The study found that the impact of Prosopis in the forested landscapes of Tamil Nadu, especially in Sathyamangalam Tiger Reserve seemed to be adversely affecting the distribution of native biodiversity. 8) Dry zone of Tamil Nadu i.e. at Ramanathapuram the groundwater level-soil moisture conditions, humidity and temperature under the canopy cover were better in the habitats dominated by P. juliflora but in the forested landscapes such as in the Sathyamangalam TR, these environmental factors were comparatively lesser than other habitats of the zone. It reveals that P. juliflora in the forested landscape is not good for natural environmental settings as well as the biodiversity of the region. 9) In all zones that were studied in Tamil Nadu, the P. juliflora was observed to be allelopathic that discouraging other plants from growing around them and seems to be toxic to other biotas in ways that allow the invasives to monopolize the space, sunlight, and nutrients at the exclusion of other species. Plant diversity was observed significantly low at P. juliflora dominated habitats than other habitats of Tamil Nadu including in the Ramanathapuram District. In the native habitats of P. juliflora, the other species have developed a mechanism to counter the allelopathy of P. juliflora, but such defense seems to be not available to several native plants of Tamil Nadu. 10) The study could not find any significant impact of Prosopis juliflora and Lantana camara on the productivity of agricultural crops grown adjacent to the dense growth of Prosopis juliflora and Lantana camara on the bund or as a pure stand. 11) Prosopis juliflora, which is adapted to survive and thrive in diverse environments including very harsh dry environments, was a major boon for impoverished people subsisting in the Ramanathapuram District as it provides 3 them with badly needed valuable provisional services; fuelwood, charcoal, animal feed, constructional materials, reclamation of degraded soil, etc, but the Prosopis juliflora was observed to be adversely affecting both environments as well as native biodiversity in other zones of Tamil Nadu. 12) It was found that wetlands in the arid region are highly susceptible to Prosopis invasion and these wetlands were once used by migratory birds in large numbers but not nowadays that is might be due to high abundances of invasive species. 13) Although, alien invasive species such as P. juliflora and L. camara are adversely affecting the native biodiversity especially in the Western Zone and Cauvery Delta but it has livelihood values in the Southern Zone especially Ramanathpuram and adjoining districts of Tamil Nadu. 14) The study also found that the available nitrogen, phosphorus and organic carbon in the soil were high in highly invaded areas compared to less or non-invaded sites especially in the Southern Zone. 15) Economic analyses also revealed that the benefits of the P. juliflora invasion in the southern zone are higher than the costs. However, some aspects such as increased risk of water table and long-term ecological changes were not examined, thus making the total economic valuation incomplete. 16) P. juliflora and L. camara spread can be halted by actions such as clear cutting/up-rooting followed by burning of the stump of P. juliflora and keeping up-side down of stump of L. camara. Alternatively, ways can be found to utilize the existing stands of P. juliflora so that frequent harvesting can exert a check on its expansion in the non-forested landscape. Minimum, 10 years of weed management plan should be made mandatory of all Management Plans of all Protected Areas and other reserve forests of Tamil Nadu to successfully halt the expansion of these invasive species so that the native biodiversity are conserved. 12) The study concludes that complete eradication of P. juliflora and L. camara is inevitable in the forested landscapes and Protected Areas of Tamil Nadu. However, the study recommend that sustainable management and control of P. juliflora may be a better solution than eradication in the Southern Zone.