K. V. Satish

Quantification and monitoring of deforestation in India over eight decades (1930–2013)

There is still large uncertainty over the status of global forest cover owing to the paucity of comprehensive and holistic studies related to long term forest cover change. The aim of the present work is to prepare a nation-wide multi-date forest cover database which describes and quantifies historical and recent changes in natural forests of India. This analysis facilitated the determination of the state of Indian forest cover changes over last eight decades. Here, we have mapped the total area under forest cover, evaluated the spatial tracking of changes in natural forests, estimated the rate of deforestation and afforestation, analysed the biogeographic zone wise and state wise forest cover change, existing land use in deforested area, influence of environmental factors such as terrain on deforestation and implication of different definitions of forest used by agencies reporting deforestation in India. The results indicated that forests covered an area of 869,012xa0km2 in 1930 which has decreased to 625,565xa0km2 in 2013, a net loss of 243,447xa0km2 (28xa0%) in eight decades. The highest annual average forest loss was found to be 4795xa0km2 during 1930–1975, 1476xa0km2 during 1975–1985, 767xa0km2 during 1985–1995, 356xa0km2 during 1995–2005 and 209xa0km2 during 2005–2013. Between 1930 and 1975, forest experienced large scale deforestation at gross annual rate of 0.77xa0% which has declined to 0.29xa0% and 0.14xa0% for the 1975–1985 and 1985–1995 periods respectively. Quantification of annual rate of gross deforestation for the recent period indicates 0.07xa0% during 1995–2005 and 0.05xa0% during 2005–2013. The lower rates of deforestation during recent period support effectiveness of conservation measures taken at national level. It was found that deforestation rate has decreased in many biogeographic zones by 2005, except for Andaman & Nicobar Islands and North East. The major deforestation has mostly occurred due to conversion of forests to agriculture. The construction of reservoirs contributed to 4.1xa0% of forest loss. The tropical forests have experienced large scale deforestation followed by subtropical forests. The findings of the study will be useful to prioritize conservation and protection of forest cover at the regional level. It shall also provide a base for future research on the impacts of deforestation on carbon flux and biodiversity.

Geospatial assessment and monitoring of historical forest cover changes (1920–2012) in Nilgiri Biosphere Reserve, Western Ghats, India

Deforestation in the biosphere reserves, which are key Protected Areas has negative impacts on biodiversity, climate, carbon fluxes and livelihoods. Comprehensive study of deforestation in biosphere reserves is required to assess the impact of the management effectiveness. This article assesses the changes in forest cover in various zones and protected areas of Nilgiri Biosphere Reserve, the first declared biosphere reserve in India which forms part of Western Ghats-a global biodiversity hotspot. In this study, we have mapped the forests from earliest available topographical maps and multi-temporal satellite data spanning from 1920’s to 2012 period. Mapping of spatial extent of forest cover, vegetation types and land cover was carried out using visual interpretation technique. A grid cell of 1xa0kmu2009×u20091xa0km was generated for time series change analysis to understand the patterns in spatial distribution of forest cover (1920–1973–1989–1999–2006–2012). The total forest area of biosphere reserve was found to be 5,806.5xa0km2 (93.8xa0% of total geographical area) in 1920. Overall loss of forest cover was estimated as 1,423.6xa0km2 (24.5xa0% of the total forest) with reference to 1920. Among the six Protected Areas, annual deforestation rate of >0.5 was found in Wayanad wildlife sanctuary during 1920–1973. The deforestation in Nilgiri Biosphere Reserve is mainly attributed to conversion of forests to plantations and agriculture along with submergence due to construction of dams during 1920 to 1989. Grid wise analysis indicates that 851 grids have undergone large-scale negative changes of >75xa0ha of forest loss during 1920–1973 while, only 15 grids have shown >75xa0ha loss during 1973–1989. Annual net rate of deforestation for the period of 1920 to 1973 was calculated as 0.5 followed by 0.1 for 1973 to 1989. Our analysis shows that there was large-scale deforestation before the declaration of area as biosphere reserve in 1986; however, the deforestation has drastically reduced after the declaration due to high degree of protection, thus indicating the secure future of reserve in the long term under the current forest management practices. The present work will stand as the most up-to-date assessment on the forest cover of the Nilgiri Biosphere Reserve with immediate applications in monitoring and management of forest biodiversity.

Development of deforestation and land cover database for Bhutan (1930–2014)

Bhutan is a mountainous country located in the Himalayan biodiversity hotspot. This study has quantified the total area under land cover types, estimated the rate of forest cover change, analyzed the changes across forest types, and modeled forest cover change hotpots in Bhutan. The topographical maps and satellite remote sensing images were analyzed to get the spatial patterns of forest and associated land cover changes over the past eight decades (1930–1977–1987–1995–2005–2014). Forest is the largest land cover in Bhutan and constitutes 68.3% of the total geographical area in 2014. Subtropical broad leaved hill forest is predominant type occupies 34.1% of forest area in Bhutan, followed by montane dry temperate (20.9%), montane wet temperate (18.9%), Himalayan moist temperate (10%), and tropical moist sal (8.1%) in 2014. The major forest cover loss is observed in subtropical broad leaved hill forest (64.5xa0km2) and moist sal forest (9.9xa0km2) from 1977 to 2014. The deforested areas have mainly been converted into agriculture and contributed for 60.9% of forest loss from 1930 to 2014. In spite of major decline of forest cover in time interval of 1930–1977, there is no net rate of deforestation is recorded in Bhutan since 1995. Forest cover change analysis has been carried out to evaluate the conservation effectiveness in “Protected Areas” of Bhutan. Hotspots that have undergone high transformation in forest cover for afforestation and deforestation were highlighted in the study for conservation prioritisation. Forest conservation policies in Bhutan are highly effective in controlling deforestation as compared to neighboring Asian countries and such service would help in mitigating climate change.

Quantifying nationwide land cover and historical changes in forests of Nepal (1930–2014): implications on forest fragmentation

This study quantifies the nationwide land cover and long-term changes in forests and its implications on forest fragmentation in Nepal. The multi-source datasets were used to generate the forest cover information for 1930, 1975, 1985, 1995, 2005 and 2014. This study analyzes distribution of land cover, rate of deforestation, changes across forest types, forest canopy density and pattern of fragmentation. The land cover legend for 2014 is consisting of 21 classes: tropical dry deciduous sal forest, tropical moist deciduous sal forest, subtropical broad-leaved forest, subtropical pine forest, lower temperate broad leaved forest, upper temperate broad leaved forest, lower temperate mixed broad leaved forest, upper temperate mixed broad leaved forest, temperate needle leaved forest, subalpine forest, plantations, tropical scrub, subtropical scrub, temperate scrub, alpine scrub, grassland, agriculture, water bodies, barren land and settlements. The forest cover statistics for Nepal obtained in this study shows an area of 76,710xa0km2 in 1930 which has decreased to 39,392xa0km2 in 2014. A net loss of 37,318xa0km2 (48.6%) was observed in last eight decades. Analysis of annual rate of net deforestation for the recent period indicates 0.01% during 2005–2014. An increase in the number of forest patches from 6925 (in 1930) to 42,961 (in 2014) was noticed. The significant observation is 75.5% of reduction in core 3 forest, whereas, patch, perforated and edge classes show the increase in percentage of fragmentation classes from 1930 to 2014. The results of this work will support the understanding of deforestation and its consequences on fragmentation for maintaining and improving the forest resources of Nepal.