Indian Eastern Himalaya Research Articles

Assessing the elevational relationship with soil physico-chemical properties under traditional large cardamom agroforestry system in the Indian Eastern Himalayas: a case study using machine learning algorithms

Assessing the elevational relationship with soil physico-chemical properties under traditional large cardamom agroforestry system in the Indian Eastern Himalayas: a case study using machine learning algorithms

A taxonomic revision of axonopus p. Beauv. (poaceae: panicoideae) in india

The status of the genus Axonopus P.Beauv. in India has been varyingly depicted by different workers so far. After comprehensive study, two species, namely A. compressus (Sw.) P. Beauv. and A. fissifolius (Raddi) Kuhlm., are justified for the country. The distributional incongruity of both species in India is unravelled here. The present record of A. fissifolius in Sikkim confirms its extended distribution to the Indian Eastern Himalaya. Additionally, this species is also reported for the first time from Meghalaya. Detailed descriptions of both species are appended here. Illustrations and photoplates, along with notes on habitat, phenology, and distribution, are also presented. A key to the Indian species of Axonopus is incorporated for correct identification and easy recognition. Bangladesh J. Plant Taxon. 31(1): 57-71, 2024 (June)

The transition from shifting cultivation to indigenous agroforestry as nature-based solution for land restoration in the Indian Eastern Himalayas

In the Indian Eastern Himalayas, shifting cultivation has long been a major cause of land degradation. However, indigenous communities, like the Hmar, have successfully transitioned from shifting cultivation to agroforestry systems such as pineapple agroforestry, leading to land restoration and increased household incomes. Despite these positive outcomes, little is known about how soil health indicators change during this transition. Thus, the present study aimed to investigate changes in selected soil health indicators and erodibility across different age classes of pineapple agroforestry systems (<5, 5–10, 11–15, and > 15 years old) compared to shifting cultivation and nearby natural forests. Soil samples were collected from six sites, including different stages of pineapple agroforestry systems, shifting cultivation phases, and a natural forest. At each site, three (10 × 10 m) quadrats were selected, and two (1 × 1 × 1 m) vertical soil pits were dug in each quadrat, sampling soil depths from 0 to 100 cm. The transition from shifting cultivation to pineapple agroforestry improved soil organic carbon (SOC) and stratification ratios while reducing soil erodibility. SOC stocks were estimated at 182.7 Mg C/ha for natural forest land and 188.2 Mg C/ha for the cropping phase in shifting cultivation. On the other hand, estimated SOC stocks for < 5, 5–10, 11–15 and > 15 years old stands of pineapple agroforestry system were 169.7 Mg C/ha, 157.2 Mg C/ha, 168.9 Mg C/ha and 177 Mg C/ha respectively. Thus, the estimated SOC stocks under > 15 years of pineapple agroforestry were comparable with adjacent natural forest land. The stratification ratios (SR > 2) for SOC and macronutrients indicated better soil quality in the pineapple agroforestry system than in the cropped land. The clay and modified clay ratios decreased with increasing age of pineapple agroforestry stands. The highest clay ratio was recorded in the topsoil of < 5-year-old pineapple agroforestry system, indicating a greater risk of exposure to rainfall events than in natural forest land and the cropping phase in the shifting cultivation cycle. It is concluded that transitioning from shifting cultivation to a pineapple agroforestry is a nature-based solution to restore degraded lands and presents an excellent opportunity for sustainable soil health and carbon sink management.

Hornbill abundance and habitat relationships in a human-impacted protected area in the Indian Eastern Himalaya

Asian forest hornbills play an important functional role as seed dispersers. Three of the large-bodied hornbill species in the Eastern Himalaya are declining globally. To understand their global population status, it is important to obtain reliable abundance estimates across their range. Protected areas are the strongholds for hornbill species in the Eastern Himalaya but differ in degree of disturbances and human pressures. We estimated the abundances of four hornbill species (Great Hornbill, Wreathed Hornbill, Rufous-necked Hornbill, and Oriental Pied-Hornbill) in the human-impacted Buxa Tiger Reserve in northern West Bengal. This is the first study in Asia to obtain abundance estimates of the hornbill species through comprehensive spatial coverage of the reserve. The densities of the three large-bodied species were low (< 1 bird per km2), while that of the small-bodied Oriental Pied hornbill was around 11 birds per km2. Abundance estimates ranged from a mean of 27 birds for the Rufous-necked Hornbill that is confined to the hilly areas to 161 for the Great Hornbill, 375 for the Wreathed Hornbill and 8050 for the Oriental Pied-Hornbill. Habitat quality was poor in most of the reserve with low tree density and basal area with only a few patches with higher tree density. Oriental Pied-Hornbills were associated with lower elevations and higher fruiting tree density. Despite the relatively low abundance of the large-bodied hornbill species, Buxa is an important site for hornbill conservation due to the presence of breeding populations and nests. While past and ongoing human pressures have resulted in habitat degradation, poaching pressures are low and hornbills are able to persist and breed in this landscape. Ecologically meaningful forest restoration with diverse native tree species is urgently needed to improve the habitat quality for hornbills and other wildlife.

Piper agroforestry in the Indian Himalayas: indigenous peoples’ practices, policies and incentives

BackgroundIndigenous populations across the world play a significant role in sustainable land management and conservation of biodiversity. However, indigenous agricultural practices are rarely studied in depth and remain poorly documented in many regions of the world. Documenting such practices and identifying policies and incentives that affect them can unlock their potential for better land management and biodiversity conservation.MethodsWe undertook household surveys and focus group discussions to document indigenous practices and the values of trees in Piper (Piper betle) agroforestry practiced by the ethnic Khasi (Pnar) community in the Indian Eastern Himalayas. We also undertook an in-depth vegetation sampling to quantify variations in phytosociology and tree diversity with stand age in Piper agroforestry and nearby native forests. In addition, we undertook strengths, weaknesses, opportunities and threats (SWOT) analysis and a desk review to identify policies, market support structures and incentives affecting cultivation of Piper, a cash crop of global importance.ResultsUnlike in shifting cultivation, indigenous people do not fell trees in the Piper agroforestry; instead, they allow trees to regenerate naturally and also enrich by planting tree seedlings in the gaps. Depending on the stand age, 30–49 tree species were recorded in the Piper agroforestry compared to 39 in nearby natural forests. While tree density was higher in the natural forests, greater species richness, diversity and basal area was recorded in > 25 years old Piper agroforestry stands. However, landholders do not have legally transferable or heritable rights to the land or trees.ConclusionIt is concluded that the Piper agroforestry provides a pathway for averting land degradation due to shifting cultivation, biodiversity conservation and improving livelihoods of the indigenous community. Although existing policies are supportive, Piper agroforestry is not currently benefiting from incentives and market support structures. We recommend implementation of policies, market support structures, incentives and payment for ecosystem services so that indigenous communities can benefit from the global ecosystem services they provide.

The impact of climate change and potential distribution of the endangered white winged wood duck (Asarcornis scutulata, 1882) in Indian eastern Himalaya

The White-Winged Wood duck (Asarcornis scutulata) is an endangered forest wetland bird currently on the verge of extinction due to an array of anthropogenic pressures. It has been reported that global climate change could affect the distribution of many bird species globally. Therefore, an understanding the potential distribution of the White-Winged Wood duck in future climate scenarios could facilitate the creation of immediate conservation plans and the mitigation of subsequent threats. This is the first ever study on the distribution of White-Winged Wood Duck (WWWD) where Representative Concentration Pathway (RCP) 8.5 scenario was used to forecast the distribution of the WWWD in the Indian Eastern Himalayan region in the 2050s and 2070s. The study revealed that 1.87 % of the total area of IEH has the high potential distribution of WWWD. The state of Assam alone includes 1.68 % of the highly potential habitat in the region. It was predicted that 436.61 km2 of highly potential habitat would be lost by 2070. Changes in the annual temperature range, precipitation in the wettest months (June to September), and precipitation decrease in the warmest quarter (October to December) would result in the loss of highly potential habitats. Under the influence of climate change, the habitat of WWWD in the eastern part of the region is likely to shift towards the western part. It was found that there will be a decline in potential habitat in the Indian states of Arunachal Pradesh, Assam, Nagaland, and Tripura located in the IEH under future climate scenarios. The potential of areas located at the Bhutan and Assam border would increase for supporting WWWD as this species' requires the average annual precipitation about 1000–1200 mm. However, the simultaneous anthropogenic activity would further destroy potential habitats in the future. The current study has provided baseline data on the potential distribution of WWWD in the IEH region for immediate conservation management plans.

Long‐term effect of integrated farming systems on soil erosion in hilly micro‐watersheds (Indian Eastern Himalayas)

AbstractSoil erosion from traditional hill agriculture is a major concern for agronomic development in the Eastern Himalayas (India). An integrated farming system (IFS: is the combination of multipurpose trees‐MPT interspersed with seasonal agricultural crops) may reduce the severity of erosion while ensuring food and nutritional security. The aim of our study was to identify an IFS, resistant to soil erosion in the hill ecosystem of Eastern Himalaya. For this, eight micro‐watershed (MW)‐based IFSs namely livestock with fodder crops (MW1), forestry (MW2), agroforestry (MW3), agriculture (MW4), agri‐horti‐silvi‐pastoral (MW5), horticulture (MW6), cultivated fallow (MW7), and abandoned shifting cultivation (MW8, as traditional land use) were established and soil erosion was measured for 24 years in the sloping land (32.0%–53.0%) of the Eastern Himalayas (Meghalaya, Northeast India). In the forests (MW2), annual average (IA: 1983–2006) runoff and soil losses were 405.5 (±113) mm and 11.0 (±2.4) Mg ha−1 yr−1, respectively. The conversion of forests to cultivation caused a decline in the parameters of hydro‐physical quality and fertility, more severely in the traditional farming (MW7&amp;8) than in the IFS mode of cultivation (MW3,5,&amp;6). Soil water conservation measures (SWCMs: contour bunding, terracing, and grassed waterways) were more effective at reducing erosion when used together compared to individually. Adoption of these SWCMs in cultivated MWs in IFS mode (MW3,5,&amp;6), reduced the runoff by 13.0%–17.1% and soil loss by 12.6%–15.1% over forests (MW2). However, in traditional agriculture (MW7&amp;8), runoff increased by 50.6%–87.6% while soil loss was 50.3%–59.8% higher over the forest. The study demonstrated that the adoption of agroforestry, agri‐silvi‐horti‐pastoral or horticulture‐based IFSs with appropriate SWCMs may be promoted to reduce soil erosion while sustaining soil quality attributes and food security in the hill ecosystem of the Indian Eastern Himalayas.

Fuelwood species diversity and consumption pattern in the homegardens from foothills of Indian Eastern Himalayas

Fuelwood species diversity and consumption pattern in the homegardens from foothills of Indian Eastern Himalayas

Post-fire restoration of land under shifting cultivation: A case study of pineapple agroforestry in the Sub-Himalayan region

Access to the knowledge associated with traditional and/or indigenous land-use systems can help develop adaptive strategies, more productive systems and, design sustainable development models and technologies. This article describes the evolution of traditional pineapple (Ananas comosus) agroforestry systems (PAFS) developed by the ethnic Hmar communities as a strategy for the restoration of land under slash-and-burn agriculture in the Sub-Himalayan region. We critically examine the social and ecological perspectives on rural livelihoods and environmental management, and documented the native tree species managed under different age groups of PAFS. We also interviewed farm managers to gain insights into the traditional farming practices and the uses and services of the different multipurpose tree species (MPTs) along with their traditional management. The study showed that PAFS are an integral part of the rural landscape in the study region exemplifying unique agroforestry systems that have evolved as a strategy to improve land under slash-and-burn on hilly landscapes. PAFS are post-fire sedentary systems evolving as a by-product of shifting agriculture. The system combines pineapple crops with remnant fallow vegetation and subsequent plantations of cash-oriented MPTs in the same farmland. MPTs such as the critically endangered Aquilaria malaccensis and the economically important tree bean (Parkia timoriana), which is no longer found in the wild are largely conserved in the PAFS. Our study demonstrates that PAFS can play a vital role in post-fire restoration of land under slash-and-burn agriculture, which is still practiced among many tribes in the Indian Eastern Himalayas.

Mapping Phenological Functional Types (PhFT) in the Indian Eastern Himalayas using machine learning algorithm in Google Earth Engine

Phenological studies involve capturing information on dates of recurrent and seasonal biological events in plants and animals. In plants, phenological events of leaf flushing, full bloom, autumn discolouration, leaf fall etc. can be used to distinguish vegetation into separate classes. We refer here such phenological distinction as Phenological Functional Types (PhFT). The PhFT can be considered as the precursor of Plant Functional Types (PFTs) where PFT uses additional traits (e.g. leaf area, tree height, leaf structure, rate of evapotranspiration and photosynthesis, etc.) to classify vegetation. The PFT classification is essentially needed for developing and running dynamic global vegetation models (DGVMs) used in studying impacts of climate change on vegetation. We used archived long time series satellite remote sensing data, Landsat 5,7 and 8 (1985–2019), for classifying a landscape into appropriate PhFT. Normalized Difference Vegetation Index (NDVI) was calculated for the given period in the Google Earth Engine (GEE). The GEE is a cloud-based platform developed for the retrieval and processing of remotely sensed images and other data. The monthly median values of NDVI for the mentioned period was used to label each pixel into appropriate PhFT classes using Random Forest (RF) algorithm in GEE to obtain four distinct classes of evergreen forest, deciduous forest, agriculture and non-forest. The comparison of PhFT map was done with reference maps of global MCD12Q1 and the forest type map of India; with an overall moderate agreement of 68.55% and 66.22%, respectively. MCD12Q1 has an accuracy of 73% for the land cover map and the forest type map of India has 75% accuracy, whereas, we achieved an overall accuracy of 78%. The PhFT classification accuracy can further be improved using additional indices and topographic variables. The methodology demonstrated in this study can be adopted for classifying a landscape into distinct PhFT/PFT classes.

Assessing tree diversity and carbon storage during land use transitioning from shifting cultivation to indigenous agroforestry systems: Implications for REDD+ initiatives

Indigenous agroforestry systems are important reservoirs of biodiversity, and ecosystem services with a potential contribution for conservation of biodiversity while sustaining the livelihood of the rural populace. Pineapple (Ananas comosus) agroforestry systems (PAFS) form an essential constituent of the rural landscape in the Indian Eastern Himalayas and other parts of Asia. The traditional PAFS management in southern Assam is unique in that it involves shifting cultivation transitioning from native forests to a PAFS. Scarcity of information on the functioning and services in terms of species diversity and carbon storage potential in the traditional PAFS has restricted the opportunities for consideration under the nature-based solutions of climate action including REDD+. Therefore, the present study assessed the tree diversity and ecosystem carbon storage in a chronosequence from swidden agriculture through different phases of PAFS establishment. The result demonstrated that basal area in the PAFS increased with age. The most dominant species in the native forests was Palaquium polyanthum, while agricultural land use and PAFS aged <5, 11–15 and > 15 years old were dominated by Gmelina arborea, Albizia procera, Areca catechu and Hevea brasiliensis, respectively. The highest value of Shannon-Wiener diversity index (H) was recorded in native forests (2.71), and lowest in 5–10 years old PAFS. The ecosystem carbon storage declined from 261.43 Mg ha−1 in native forests to 181.07 Mg ha−1 in <5-years old PAFS. In <5 years old PAFS, the ecosystem carbon storage was 30 % lower than the native forest; while at >15 years it was merely 5 % less than the native forests. The traditional PAFS maintains a steady ecosystem carbon stock while reducing land use related carbon emission and providing additional co-benefits to the communities. Therefore, the traditional PAFS constitute a good opportunity for REDD+.

Grassroots Approaches for Sustaining Biocultural Diversity and Livelihood Security: Insights from Indian Eastern Himalaya.

Bioculturally significant plants, which have played a key role in sustaining the livelihoods of tribal communities of Arunachal Pradesh, India, are facing threats from changing land use patterns, climatic aberrations and socioeconomic stressors. This study highlights two unique grassroots approaches to conserving these species and their associated cultural knowledge within the traditional land use systems of Arunachal Pradesh: Community Knowledge Gardens (CKGs) and Clan Reserve Forests (CRFs). Four CKGs and one CRF, transformed from existing traditional land use systems, were investigated in three socio-ecologically diverse landscapes of Nyishi, Adi and Monpa communities. Study participants, including both men and women, played an active role in devising locally compatible criteria and protocols for strengthening the conservation of key plant species within their traditional land use systems, through CKG and CRF approaches. A total of 86 plant species, conserved through the CKGs and 44 from the Adi CRF, were identified as having high food, ethnomedicinal and cultural values. The Shannon-Weaver index of richness of plant species conserved was highest in the Nyishi CKG, with a value of 38; while for Adi and Monpa it was 30 and 18, respectively. The pattern of Shannon-Weaver diversity index was in the order of 2.91, 2.64 and 2.63, respectively for the CKGs of these three communities. In comparison to individual CKGs, relatively higher species diversity (3.18) was found in the Adi CRF. Increased sharing of traditional knowledge among the community members, regular incomes and equitable sharing of the tangible and intangible benefits of using plant species were identified as important success indicators of the CKGs and CRF. In addition to providing valuable insights on biocultural knowledge and enabling the participants to strengthen their existing local land use practices for conserving valued plant biodiversity, the study outcomes have the potential to inform and strengthen the policies on environmental sustainability.

&lt;strong&gt;A new species of &lt;em&gt;Aconitum&lt;/em&gt; (Ranunculaceae) from Indian Eastern Himalayan state of Sikkim&lt;/strong&gt;

Aconitum sikkimensis, a new species from Sikkim in the Indian Eastern Himalaya, is described and illustrated in this article. A. hookeri is morphologically closest species to the new species and it resembles in colour of the flower and the shape of the lateral sepals. However, it differs in plant height (A. sikkimensis being taller than A. hookeri), the shape of leaf and degree of dissection in the lamina, number of bracts and their shape and size, length of petiole, semi-orbicular upper sepal (vs. obliquely erect), distinctly curved, pubescent petals (vs. straight, glabrous petals) having spathulate lips (vs. obovate), and well-developed staminal pilose hairs and teeth (vs. non-developed, glabrous). Based on population data, the species was assigned the threat status of ‘Critically Endangered’ following IUCN criteria.

Reinforcing Livelihood by Interdependency of HR Capacity-ICT: Relevance to Multi-cropping practice system in Indian Eastern Himalaya

The rural economy of Eastern Himalayan region of India is mostly agriculture based, dominated by traditional as well as community knowledge, has been using as source of livelihood since long years back. But with Green evolution and technological advancement, High Yielding variety of cash crop like Large Cardamom (Amomum subulatum Roxb.) and influence of skill-information-technology are emerging in a great extent respectively only to ensure sustainable livelihood. Since it is seen that only through large cardamom cultivation, it is difficult to ensure sustainability, hence concept of Multicropping is very much demanding. Here, this paper highlights the influence and interdependency of Human Resource Capacity and Information and Communication Technology (ICT) on Multicropping as well as on large cardamom cultivation to ensure sustainable livelihood in this particular region.

Quantification of diversity, biomass and carbon storage of climber and liana community in a foothill forest of Indian eastern Himalayas

Climbers and lianas occupy an important niche in the forest ecosystem. However, as compared to trees, studies on diversity and ecology of this life form of forest remains neglected. Thus a study was carried out at sub-humid tropical foothill forest of West Bengal, India to document the status of climber and liana diversity, biomass and carbon accumulation. Qualitative and quantitative characters were analysed with the help of random quadrate sampling method. Species richness of the climbers and liana in the forest was 42. The diversity index, concentration of dominance, Shannon and Wiener index and evenness index was estimated at 0.92, 0.038, 1.26 and 1.55, respectively. Density ranged from 15.47 to 722.81 individuals ha−1. IVI values ranged from 0.19 to 4.44. This indicates the climber and liana communities in the forest are diverse but dominance distributed. Biomass and carbon storage was highest with LSDS1.50 and 0.68 Mg ha−1, respectively and lowest with TGDS. Climber and liana ccommunities were recorded with good growth inside the forest which was reflected in their good quantity of biomass accumulation and thus have a great potential to store good quantity of biomass carbon and support the ecosystem. Understanding the forest plant life forms other than trees will be helpful to understand their ecological significance while managing the forests sustainably. The information though in the present study is only baseline and preliminary but can be helpful to plan future research to understand the contribution of these plant life forms in a forest ecosystem holistically.

Persistent loss of biologically-rich tropical forests in the Indian Eastern Himalaya

Using fine-resolution satellite imagery from multiple satellite data products, we assessed the change in forest cover of a state-managed Reserve Forest (RF) located in India’s Eastern Himalaya biodiversity hot-spot. 4.6% of forest cover was lost from Papum RF between 2013 and 2017 at the rate of 8.2 km2 year–1. Three species of hornbills: Great Hornbill Linnaeus, 1758, Wreathed Hornbill (Shaw, 1811) and Oriental Pied Hornbill (Shaw, 1808), that are functionally important are found here with nesting habitat in the areas affected by illegal logging. Therefore, we assessed the habitat loss within a 1 km radius around 29 nest trees. From 2011 to 2019, forest cover declined from 38.55 km to 21.94 km around these hornbill nest trees. Illegal logging is the main driver that is depleting forest cover within this important bird area. Our results highlight the ongoing threats to biologically-rich forests and the need for urgent measures to halt this loss. We suggest that this study has practical implications for the monitoring and governance of state-managed forests in Arunachal Pradesh.Buceros bicornisRhyticeros undulatusAnthracoceros albirostris22

Pastoral yak rearing system is changing with change in climate: an exploration of North Sikkimin Eastern Himalaya

Yak is an integral part of the livelihood of highlanders in Indian Eastern Himalaya where only subsistence agriculture is possible due to its difficult terrain and harsh climate. The tribal households of Lachen and Lachung in North Sikkim rear yaks at an altitude of 3000 to 5000 m in semi-pastoral system which is highly dependent on temperature and snowfall pattern. Any change in climatic factors is expected to affect the yaks and livelihood of the yak herders. Hence, an explorative study was conducted to understand how the pastoral yak rearing system is changing in the region with change in climate. The estimated temperature increment was 0.03–0.04 °C/annum which is corroborated by herders’ perceptions. They observed that the amount of snowfall has receded, especially in lower altitudes and the snowfall period shifted from November–December to January–March. The commencement of upward migration of yak herders advanced by 15–30 days due to increase in March temperature and the migration span extended by 45 days now. The downward migration is restricted to mid alleviation (2750–3000 m) now which was earlier about 2000 m whereas the upward migration has gone up farther about 500 m due to increasing temperature and unavailability of quality pasture. The study revealed that the pastoral yak rearing in North Sikkim is transforming to cope the impending climate change. However, to reduce the vulnerability of yak, research and extension efforts/policies should be concentrated on fodder production and pasture management suiting to the awaiting climate change.

Notes on the hairstreak butterflies Euaspa Moore, 1884 (Lepidoptera: Lycaenidae) with new distribution records to the Indian eastern Himalaya

The genus Euaspa Moore, 1884 (Lycaenidae: Theclinae: Theclini) of Zephyrus Hairstreak butterflies is represented by 14 species worldwide. Among these, four species were recorded from the Indian mainland. In this paper, E. motokii Koiwaya, 2002, previously known only from the Kachin State of Myanmar, is reported for the first time from Arunachal Pradesh in India. Also, E. mikamii Koiwaya, 2002 is recorded for the second time from India since the collection of the holotype in 1991 from the eastern Himalaya.

Ecological niche modeling as a cumulative environmental impact assessment tool for biodiversity assessment and conservation planning: A case study of critically endangered plant Lagerstroemia minuticarpa in the Indian Eastern Himalaya

Cumulative environmental impact assessment (CEIA) at river basin level for hydroelectric projects is an evolving concept and has proved to be a useful tool to assess the cumulative impact of developmental projects on the natural ecosystems. However, the generality of CEIA studies is often contested because of methodological limitations, especially in the domain of biodiversity conservation and conservation planning. Ecological niche modeling (ENM) can be a useful tool in CEIA studies for conservation planning of threatened plants in hydroelectric project (HEP) areas. We elucidate this hypothesis taking the example of Lagerstroemia minuticarpa Debberm. ex P.C. Kanjilal, a critically endangered tree species in the Indian Eastern Himalaya. Standard ecological methods were employed to document occurrence records, estimate population size, and characterize habitats. ENM was used to estimate the species potential environmental niche and distribution areas. The possible impacts of HEPs on the potential habitats were predicted by overlaying the HEPs on the potential area map as well as using the conceptual network diagram. The study revealed that the species occupies an environmental niche characterized by humid to per-humid conditions, and is distributed mostly in the Lohit and Teesta basins. Potential areas of the species with high environmental suitability coincide with 19 HEPs, which point to a potential threat to the survival of the species. Network diagram indicated that project activities might deteriorate the habitats thereby affecting the population and regeneration of the species. Our study provides a framework for developing appropriate measures for species conservation and reintroduction at basin level using ENM.

Assessment of eco-diversity status of Homalomena aromatica (Spreng.) Schott and its habitat in tropical forest of Indian Eastern Himalaya

Homalomena aromatica (Spreng.) Schott is one of the economically important plant species occurring in the North east and Eastern Himalayan region of India which received least attention in its ecological and conservation studies. The current study has been undertaken in the north eastern state of Arunachal Pradesh. The population, phytosociological status of its habitat, regeneration and species association of H. aromatica were worked out using standard ecological methods. Out of the 15 selected forest sites for survey, H. aromatica was found only in 9 sites. A total of 288 species representing 99 families are documented from the selected sites where Euphorbiaceae, Meliaceae, Araceae, Dipterocarpaceae and Poaceae are found dominant in all the 9 sites. Species diversity index (H?) of all the three habits i.e. the tree, shrub, and herb were found highest in Happy Valley site followed by Ganga Lake. A total of 219 individuals of H. aromatica recorded which were found confined within the altitudinal ranges of 350m-450m asl. The IVI (1.95 to 9.64) and Frequency % (5 to 12.5) range of H. aromatica found significantly low at all the survey sites. Pearson’s correlation analysis reveals that there is a positive relationship between the population size and the species diversity index, where shrub showed the strongest relationship (r(7)=0.900, P=0.001) followed by tree r(7)=0.736, P=0.024 and the herbs with weakest relationship (r(7)=0.39, P=0.269). The Chi-square test of association indicated significant association of 10 species with H. aromatica in the various sites where Alocasia acuminate (Aracaceae), Amomum sp. (Zingiberaceae) and Pteris sp. (Pteridaceae) showed highest association with higher Chi square value. The poor population status with average density of 3041.67/hectare and 8.89 frequency percentage as well the existing anthropogenic threats to the species recorded in the present study has warrants for its immediate conservation.