Sandeep Shrestha NRS 534 Role of Corridor Conservation in Landscape Ecology of Nepal By studying Island Biogeography theory(IBA) in Protected area management course during undergraduate study , I have understanding of this theory implicated in Protected area management systems as :1) Make protected area(PA) as large as possible,2) Protected areas should encompass wide range of contiguous and different ecosystems and 3)Protected area should be connected through some linkages for effective immigration and emigration of animal species and preventing isolation. I think the 3rd implication of IBA provides Knowledge based science to link PA ( which we assumes as Island) through a linear strip of vegetation cover, which we referred such linkages as " corridor" in Wildlife science. According to Wikipedia, wildlife corridor is a link of wildlife habitat through native vegetation giving two or more large areas of similar wildlife habitat.
The role of Corridor is important in Landscape ecology for following reasons: As habitat ( can be considered as patch in spatial scale) becomes fragmented due to human factors or natural forces, species becomes isolated resulting into the loss of reduced population viability thereby facing greater risk of extinction. In such situation, linking species between these patches will result into species colonization and gene flow between species reducing potentiality of species being vulnerable to extinction. In this regard, maintaining corridor will serves species to move/disperse across the different habitat patches in landscape helping species to exchange genes , maintain viable population and accommodating larger space.
Wildlife corridor are identified as a) Regional corridor with width(>500 m) and connecting primary landscapes between larger important area of habitat b) Sub regional corridor with width (>300m) and wide enough to provide landscapes connection for species movement and dispersal c) Local corridor with width (>30m) are small and providing local connection of remaining vegetation patches. Wildlife corridor can be manmade and natural corridors. Man made corridors are built across highway roads connecting forest , green ways and riparian buffer. Natuurburg Zanderij Craito build in Netherland is excellent example of manmade corridor. Experimental corridors are also designed to evaluate corridor effectiveness. Large scale corridors are corridor connecting habitat locally or internationally and connect larger blocks of Protected areas. Florida Wildlife Corridor and Yellowstone to Yukon are the successful examples of Large scale corridors.
One of the large scale corridor implemented is Terai Arc Landscape(TAL) in Nepal. Before corridor management implemented ,I would like to brief on historical conservation background of Nepal. Nepal started conservation in species level focusing conserving species like One horned rhinoceros, Royal Bengal Tiger, Elephant and Gharials. Later after 1970's the country 's started ecosystem level conservation and the first National Park , Chitwan National Park was established in 1973. Currently the protected area(PA) occupies 19.7% of total land of country and consists 10 National Park, 3 Wildlife reserve, 1 hunting reserve and 6 conservation areas. The PA's are successful in conserving endangered species like rhinos, tigers, elephants, vultures, several species of birds, fishes and reptiles . However PA management system was challenged by increasing human wildlife conflict ( for eg communities living nearby protected area suffering huge loss of agricultural/livestock depredation, household damages and human injuries and death from Park animals. Thereafter Buffer zone management system was adopted in 1990's to reduce human- willdife conflict as well as dependency of local people on PA resources. Under Buffer zone management system several areas (small patch size ) were reforested and these patches started offering extra additional habitat to Park animals, which substantially helped local communities in income generation through ecotourism and independency on Park resources. As adjacent forest areas of PA 's continues to expand through community effort it was felt that certain long ranging globally threatened species like Tigers cannot be protected by PA's themselves. This led to Paradigm shift of PA management system to Landscape Level Management conceptualizing Corridor connectivity in PA's leading to implementation of Terai Arc Landscape in 2001 - Largest corridor in Nepal.
TAL, comprising 51,000km 2 is the largest forest corridor connecting 6 PA's of lowland region of Nepal as well connecting these PA's to 7 PA's of India. This landscape harbors globally important biodiversity of Terai Dun Savannah, grassland ecoregions and 3 Ramsar wetlands adopting landscape approach to conserve Asia's Large mammals like One horned rhinoceros, Royal Bengal Tiger, Elephants, Dolphins and different prey species of tiger. The forest corridor comprise 3 large river systems flowing from hilly region creating critical habitats and connectivity between churia hills and lowland terai. TAL comprises 7 corridors of which 4 corridors link within regional PA's and 3 forest corridor link with 4 PA's of India.
Nepal government report states the number of Tiger population has increased by 60% from 2008 and records 193 number currently. The report further states due to TAL forest corridors successful in maintaining connectivity for tigers as well providing good habitat for prey species has resulted into the increase of tiger population in Nepal. As I reviewed different research works conducted in TAL, I found 4 research papers reported tiger signs was detected higher in TAL forest corridor within PA's then corridor lying outside the PA's. These papers also found that Tiger sign was present in all TAL corridor except for one corridor indicating the good potential for tiger dispersal and genetic exchange. Further, Transboundary movement of tigers( Nepal-India-Nepal) are recorded in this corridor as well. A study conducted on Tiger of Transboundary Terai Arc landscape reported a total number of 10 tigers were common for forest of India and Trans boundary TAL corridor between 2012- 2014. These studies shows that Nepal is successful in achieving landscape conservation through corridor connectivity.
I reviewed few research papers to assess the corridor effectiveness in benefitting socio-economic status of local communities . I found that TAL forest corridors has reduced fuelwood dependency on PA , conducting different management interventions by TAL program like skill trainings, subsidy for biogas installation, nursery establishment, revolving fund establishment for conducting small business and creating job opportunity have resulted positive attitude of communities towards landscape conservation in TAL.
It seems TAL is one of the successful landscape conservation in conserving forest ecosystems in corridors and sustaining Tiger population and their prey species, I think there has been enormous challenges in future. Rapid urbanization and human pressure are deforesting some of the critical bottlenecks of this corridor. As Tiger Population are increasing, human's killing and injuries by tiger are been recorded higher in recent year further aggravating human -wildlife conflict in this landscape. Sand and gravel extraction, livestock grazing and uncontrolled forest fires further adds complexity in managing this corridor for future. Further, Nepal government envision to construct railway and major highway connecting to India border in this corridor , further posing the potential threat on sustainability of landscape conservation in this corridor.
I feel TAL is essaying a conservation model system of corridor conservation in Landscape Ecology in Nepal. As the success stories of TAL conservation is providing impressive results in biodiversity conservation, Nepal government has implemented another ambitious landscape conservation in recent year- CHAL (Chitwan Annapuran Linkanges) connecting PA's of Himalayan region to PA's of lowland terai, based on landscape metric river basin approach ( hydrological connectivity). Hence, to conclude, I would say landscape conservation through corridor connectivity seems effective in recent time, however issues like tiger-human conflict, poverty, potential of tiger poaching and developmental works may be threatening the long-term sustainability of this holistic approach of landscape level conservation in future.
Annotated Bibliography
Barber‐Meyer, S.M., Jnawali, S.R., Karki, J.B., Khanal, P., Lohani, S., Long, B., MacKenzie, D.I., Pandav, B., Pradhan, N.M.B., Shrestha, R. and Subedi, N., 2013. Influence of prey depletion and human disturbance on tiger occupancy in Nepal. Journal of Zoology, 289(1), pp.10-18. This study used the standard method in assessing the occupancy of tiger throughout the Terai Arc Landscape questioning whether tigers using 5 corridors are connecting PA source populations as well as determining the presence of prey base and human disturbances influencing tiger distribution. The tiger occupancy was conducted in 4 PA's, corridor forest, buffer forest using cluster sampling design with grid cell size of 225 km2 throughout the TAL area. The tiger occupancy was analyzed by using Program Presence V to model tiger occupancy and Alkaike Information Criteria (AIC ) to compare and select models.
I found this research paper very interesting and scientific. What I felt from this paper was, large area of TAL was used for intensive tiger survey and enormous efforts was carried in field. This research encompasses the huge manpower involved in camera trapping, detecting tiger signs and prey species. I feel based on findings of this paper scientific credibility of TAL corridor effectiveness has been assessed in Nepal . However, I feel the same established grid area for tiger survey would be used by researcher in the future as well.
Carter, N.H., Shrestha, B.K., Karki, J.B., Pradhan, N.M.B. and Liu, J., 2012. Coexistence between wildlife and humans at fine spatial scales. Proceedings of the National Academy of Sciences, 109(38), pp.15360-15365. I found this research study very interesting as it was done in 1 PA's and adjacent corridor connected in TAL. The study was conducted to determine whether human existence and disturbance would effect in spatial and temporal distribution of tigers in corridors. The study was conducted for 2 year and camera traps were deployed in different forest road trails, used commonly by humans as well as tigers. It was found that at fine spatial scale ( camera traps), abundance of prey, people walking on foot and vehicles there was no significant distribution of tiger occupancy in between PA's and Corridor. The study concluded tigers and peoples co-occurred frequently at fine scales both inside and outside the PA. However in temporal scale tigers were less active during day time as peoples activity has been higher.
As I think numerous researches has been conducted in assessing human- wildlife conflict, and I guess this study may be the pioneer research in obtaining quantitative data on coexistence between wildlife and human at fine scales, which is one of the interesting result. The study has recommended to conduct study where conservation programs focusing in resettling humans in and around PA's are done, which I think is important in management aspects for TAL conservation. Wikramanayake, E., McKNIGHT, M.E.G.H.A.N., Dinerstein, E., Joshi, A., Gurung, B. and Smith, D., 2004. Designing a conservation landscape for tigers in human‐dominated environments. Conservation Biology, 18(3), pp.839-844.
This study has used GIS based, cost distance model ( model used is 30 years data of tiger researches, satellite imaginary and a decade of buffer zone restoration on TAL region) to identify the potential dispersal corridors of tiger along the Himalayan foothills ( TAL). The method has used GIS and remote sensing images, cost grid has been generated across landscape and modeling of corridor restoration is done.The model has identified three tiger subpopulations across the TAL.
As the study incorporates data's on tiger researches , satellite images on buffer zone, I think the study has provided scientific information by applying Using GIS Based model in wildlife researches. For me, I got understanding information of knowledge based ecological studies in applying explaining Landscape ecology of TAL. Through corridor analysis, the study has assess the critical bottle necks areas as well determined locations for strategically placing stepping stones and community forests that would restore habitat and improve dispersal potential of tiger in the corridors, which I think will contribute in managing critical corridors in future.
Thapa, G.J., Wikramanayake, E., Jnawali, S.R., Oglethorpe, J. and Adhikari, R., 2016. Assessing climate change impacts on forest ecosystems for landscape- scale spatial planning in Nepal. CURRENT SCIENCE, 110(3), p.345.
This study assesses the climate change impacts in two landscapes : TAL and Chitwan Annapurna linkages (CHAL) in Nepal. Global climate change models. General circulation modle coupled with terrain based analyses was used to identify climate change refugia in two conservation landscapes. Results from climate marcorefugia indicated lower region (TAL) forest landscapes are not resilient to climate change under A2A GHC scenario whereas hilly regions (CHAL) forest landscapes are resilient to climate change with larger patches surviving as macrorefugia.
I think this research is the first study undertaken in understandings climate change impact in 2 landscapes of Nepal. Flow chart showing steps of spatial analysis and research results has helped me to understand how climate changes study are conducted by applying different models. The predicted scenario of forest patches being fragmented in future in TAL is impressing findings of the paper, which I think will help policy maker in effective conservation planning.
Kanagaraj, R., Wiegand, T., Kramer‐Schadt, S., Anwar, M. and Goyal, S.P., 2011. Assessing habitat suitability for tiger in the fragmented Terai Arc Landscape of India and Nepal. Ecography, 34(6), pp.970-981. This paper aims on studying the factors effecting distribution of tiger , explore the tiger role in spatial scale and assess the quality of potential corridors along the Himalayan foothills in Nepal ( Western TAL region) and Northwestern India. Direct survey(Tiger - pugmarks, scats) was conducted through the established transects along the landscapes. Presence of prey species was done laying circular plots along regular intervals in study area. Statistical habitat model based on GLM was used to predict the probability of Tiger from a set of landscape explanatory variables.
I found the research results and analysis very interesting as it has incorporated Source- Sink approach in understanding tiger occupancy in these regions. This study incorporates tiger surveys in forest corridors linking Nepal's PA with India National Parks. I think this study is the good initiation between two countries in conducting transboundary research. Further, methods adopted in this paper has helped me to understand conducting tiger and prey species survey clearly.
THAPA, K. and KELLY, M.J., 2016. Density and carrying capacity in the forgotten tigerland: tigers in understudied Nepalese Churia. Integrative Zoology. This study was conducted in Churia habitat, comprising 7642 km2 offering a potential wildlife habitat across TAL. This habitat is been considered as main corridor in TAL connecting tiger population of Chitwan National Park, India to Valmiki Tiger reserve in India. The study was performed by dividing Churia habitat into 2 areas: lowland areas adjacent to Chitwan National Park (east) and another lowland areas connecting to Valmiki Tiger reserve ( West). The survey was conducted in 161 locations, diciving whole area into 4 blocks(135 Km2), with grid cells of 2x2 km2 and deploying camera stations within each grid. Distance sampling approach based on line transect survey was used to estimate prey density based on visual detection of animals. Survey result has shown the presence of 31 individuals tigers ranging from 2.3 to 2.9 tigers per 100km2 in churia habitat , which I think has explored the potentiality of this habitat in TAL landscapes. Along with tigers, detection of 28 leopards and presence of 67.2 different prey species per 100km2 has added significant contribution research findings in TAL. The most important part I noticed in this paper was quantitative analysis of carrying capacity of churia habitat, reflecting Churia habitat can hold 5.86 tigers per 100 km2 and as tiger densities are lower, the tiger population is below carrying capacity.
Harihar, A. and Pandav, B., 2012. Influence of connectivity, wild prey and disturbance on occupancy of tigers in the human-dominated western Terai Arc Landscape. PloS one, 7(7), p.e40105. The study was conducted to assess tiger occupancy in human dominated western Terai Landscape of India. The landscape was divided in two tiger habitat blocks ( THBI and THBII) for field survey. Each block was divided into uniform grid size overlaid in the land cover matrix. Occupancy model using standard methods and constructing detection histories for each cell by aggregating sign along 250 m segment at 1 km to form "replicates" and Program Presence3.1 was used to import and analyze data's.
I feel this research paper has great importance in landscape conservation for TAL in Nepal. As, the study has been done in India constituting Corrbett National Park and Rajaji National park , India which connects to Nepal National Park by TAL corridor, I think data's produce from this research will help in addressing transboundary corridor effectiveness in this human dominated landscapes of TAL corridor. By reading this paper, estimating tiger occupancy methods seem similar to the ones conducted in Nepal.
Baral, N. and Heinen, J.T., 2007. Resources use, conservation attitudes, management intervention and park-people relations in the Western Terai landscape of Nepal. Environmental conservation, 34(01), pp.64-72. As, Corridor conservation has resulted increasing tiger population in recent years in TAL, I am also interested in understandings buffer zone corridor beneficiaries in local communities. In this regard, I reviewed few research paper relating socio-economic studies in TAL. This study was conducted in buffer zone corridor of Bardia National Park and Sukhalaphant Wildlife Reserve representing Western TAL. The main objective of the research was to determine impacts of TAL Conservation model on resources use and conservation attitudes. The data was collected by conducting random questionnaire survey in 234 households of 2 PA's. Interviews was performed in 15 User groups for assessing management intervention programs carried by TAL.
This paper has produced interesting results like 93% households claiming fuelwood availability from buffer zone corridor reducing dependency on PA's which I think TAL has achieved in providing corridor benefits to people. The study has asked 11 statements to respondents referring whether agree/disagree and found significant results of implementation of TAL activities . However, the major threat identified is increasing human wildlife conflict increasing in recent year posing threat for survival of wildlife species in this region, which I think is the significant result of the paper and help in building adaptive strategy for future in TAL.
Lamsal, R.P., Adhikari, B., Khanal, S.N. and Kanel, K.R., Effects of Community Based Forest Management on Livelihoods under Terai Arc Landscape Program, Nepal.
The study determines the impact of TAL program on household livelihood of communities living in TAL. The study was conducted in 400 households to obtain information before and after intervention Community based forest management by TAL programs in this landscapes. The data has been analyzed by using Principal component analysis and regression model. Under based forest management, TAL program interventions includes reforestation program, skills development, subsidy for fish farming, biogas subsidy, vegetables farming for uplifting sustainable livelihood of communities.
TAL has implemented various management programs to restore the degraded forest corridor along with uplifting local communities livelihood. I found this study impressive as research results has provided quantitative data's on TAL programs. As I have also worked in compiling success stories of TAL management programs, the quantitative informations has helped me in understanding a real picture of this landscape management. However, if the paper would have incorporated more economic analysis , then it would have given clearer and scientific view of TAL management programs in addressing sustainable livelihood of local communities.
GILBERT‐NORTON, L.Y.N.N.E., Wilson, R., Stevens, J.R. and Beard, K.H., 2010. A meta‐analytic review of corridor effectiveness. Conservation biology, 24(3), pp.660-668.
When reviewing I found papers related with tiger occupancy in TAL reflecting the effectiveness of this landscapes. However, I was in search of paper which would help me how the corridor effectiveness is assessed. I could not found research Paper in Nepal's context, but finally found this paper helping me a lot in understanding corridor effectiveness. By reading the paper A term meta analysis used for answering questions like whether corridor increases movement or will corridor effects differs among taxa. I think these questions are remarkable to assess corridor effectiveness and I hope to integrate such questions in TAL research as well.