Forest fragmentation is considered as one of the major conservation issue. The purpose of this study is to contribute to the understanding of the national assessment of spatial patterns of forest ...fragmentation and influence of deforestation on fragmentation in the Indian forests during three decade interval (1975-2005). Mapping of forest cover was carried out based on Landsat MSS and IRS P6 AWiFS data using hybrid classification techniques on 1:250,000 scale. The present study considered biogeographic zones as a major stratum for national level assessment. The forest fragmentation was analysed based on landscape indices which allow quantification and categorisation of complex forest landscapes and depict landscape composition, structure and scenario of fragmentation. The analysis revealed that in all biogeographic zones, more than 90% of total number of forest fragments consists of patches having area less than 1km2. At national level the mean forest patch size stands at 187ha. The total core area was highest for Islands (87.4%) followed by Eastern Himalayas (82.5%), Deccan (78.9%), Deserts (76.4%) and Eastern Ghats (76%). The temporal analysis shows that the loss of Indian forest area as 5.8% during 1975–2005. The annual rate of deforestation has been computed as 0.20% at national level. The decreased mean patch size, increased edge density and increased number of patches from 1975 to 2005 indicates ongoing fragmentation in biogeographic zones. The very high fragmentation in Trans Himalayas is contributed mostly by the natural factors while in other biogeographic zones, increased fragmentation is due to deforestation.
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 869,012 km² in 1930 which has decreased to 625,565 km² in 2013, a net loss of 243,447 km² (28 %) in eight decades. The highest annual average forest loss was found to be 4795 km² during 1930–1975, 1476 km² during 1975–1985, 767 km² during 1985–1995, 356 km² during 1995–2005 and 209 km² during 2005–2013. Between 1930 and 1975, forest experienced large scale deforestation at gross annual rate of 0.77 % which has declined to 0.29 % and 0.14 % for the 1975–1985 and 1985–1995 periods respectively. Quantification of annual rate of gross deforestation for the recent period indicates 0.07 % during 1995–2005 and 0.05 % 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 4.1 % 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.
Watershed prioritization based on the natural resources and physical processes involves locating critical areas of erosion, which produce maximum sediment yield to take up conservation activities on ...priority basis. The present study was taken up with a specific objective of prioritization of micro-watersheds using Multi-Criteria Decision Approach – Analytic Hierarchy Process (AHP) based SYI model (AHPSYI) under GIS environment for a case study area of Mayurakshi watershed in India. This method basically uses information of Potential Erosion Index (PEI) and Sediment Delivery Ratio (SDR), indicative of transport capacity. In the present study, sediment delivery factors viz., topography, vegetation cover, proximity to water courses and soil were translated into GIS layers and integrated using Boolean conditions to create a data layer of spatially distributed SDIs’ across the watershed. For assessment of PEI, important watershed parameters viz., land use/land cover, soil, slope, and drainage density maps were integrated in the GIS environment using Weighted Linear Combination method (WLC) by assigning weights to themes and ranks to features of individual theme using AHP technique. A comparison between AHPSYI based sub watershed prioritization map with that of prioritization map based on the observed sediment yield data revealed that about 78 % of the area showed concurrence. Thus, it can be inferred that the watershed prioritization based on only thematic layers can be dependable to maximum extent. Subsequently, proposed approach was adopted for prioritization of the study area at micro watershed scale, where area under high and very high categories together constitutes around 33 % of the study area. Around 100 micro-watersheds out of 276 watersheds are under moderate to very high category respectively, signifying the need for watershed management.
India, a mega-diverse country, possesses a wide range of climate and vegetation types along with a varied topography. The present study has classified forest types of India based on multi-season IRS ...Resourcesat-2 Advanced Wide Field Sensor (AWiFS) data. The study has characterized 29 land use/land cover classes including 14 forest types and seven scrub types. Hybrid classification approach has been used for the classification of forest types. The classification of vegetation has been carried out based on the ecological rule bases followed by Champion and Seth’s (1968) scheme of forest types in India. The present classification scheme has been compared with the available global and national level land cover products. The natural vegetation cover was estimated to be 29.36 % of total geographical area of India. The predominant forest types of India are tropical dry deciduous and tropical moist deciduous. Of the total forest cover, tropical dry deciduous forests occupy an area of 2,17,713 km² (34.80 %) followed by 2,07,649 km² (33.19 %) under tropical moist deciduous forests, 48,295 km² (7.72 %) under tropical semi-evergreen forests and 47,192 km² (7.54 %) under tropical wet evergreen forests. The study has brought out a comprehensive vegetation cover and forest type maps based on inputs critical in defining the various categories of vegetation and forest types. This spatially explicit database will be highly useful for the studies related to changes in various forest types, carbon stocks, climate-vegetation modeling and biogeochemical cycles.
This study aimed to monitor long-term land use dynamics for understanding the natural forest integrity and intactness of the Rajiv Gandhi
(
Nagarhole) Tiger Reserve (RTR) pre- and post-declarations ...as TR. We employed multi-source data from Survey of India Toposheets (1:50 k), Landsat-7, and Sentinel-2A along with Global Ecosystem Dynamics Investigation (GEDI) vegetation canopy height (10 m) data, a high-spatial resolution CORONA (1970) images and temporal Google Earth Pro images for mapping and validation. To map vegetation type, land use and land cover (LULC) transitions, and fragmentation (1980–2022) we employed a hybrid classification approach. This study also analyzed decadal forest dynamics within TRs using India’s State of Forest Reports (ISFR). Findings reveal significant forest fragmentation and habitat loss due to anthropogenic activities in the TR. Mono-plantations (teak and eucalyptus) were found inside TR, while the buffer (1 km) was occupied mainly with coffee and orange plantations which indicates the prevalence of human footprint. The overall accuracy of the current period (2022) is 92.0% with a kappa coefficient value of 0.90. These plantations were established during the British colonial period (early 1900s) for commercial purposes by clearing natural forests. The present study highlights that mono-plantations have not transitioned into natural forests even after a century. This lack of transformation could potentially compromise the integrity of the native forest. Despite its ecological significance, RTR has experienced disturbance due to human footprint. Hence, there is a need for an action plan to protect this vital landscape by replacing mono-plantations with suitable species to preserve the integrity of the forest. These issues extend beyond the protected areas, impacting surrounding regions and require regular monitoring. The proposed methods can be applied to other protected areas facing similar problems in the country and world.
The focus of the study was to develop a nation-wide forest cover database of Myanmar by assessing and predicting the forest cover changes in the period of 1950 to 2027. This study estimated the net ...changes in forests at regional level along with spatial patterns of forest fragmentation using multi-source data. The results indicate forest area representing as 77.1%, 65.3%, 54.1% and 50.6% of the total geographical area of Myanmar during 1950, 1975, 2005 and 2016 respectively. This study predicted the forest cover changes in Myanmar using Module for Land use change evaluation. The five spatial variables were used to determine the relationship between deforestation and explanatory variables. The predicted forest cover of Myanmar for 2027 shows 48.4% of total geographical area under forest. The model predicted a further decrease of 14,878 km
2
of forest area in Myanmar between 2016 and 2027. The forest cover loss analysed using the classified maps of 1950 and 2016 indicated an overall loss of 34.4% of the forest cover. Ayeyarwady, Mandalay and Nayi Pyi Taw were found to be showing the highest rate of deforestation in the recent period of 2005–2016. This study has provided an insight for understanding of long-term deforestation trends of Myanmar. It offers a valuable inputs for effective management of forest resources and restoration programs as it delineates and forecast the spatial changes in forests from past to future.
The present study focuses on the spread of rubber monoculture in the state of Tripura during past three decades (1990–2021) in the northeast region of India which is known for its rich biodiversity, ...shifting cultivation, and extensive forest dynamics. Earth observation (EO) data of seven time periods from Landsat missions (1990, 1995, 2000, 2004, and 2009) and Sentinel-2 (2016 and 2021) were the main source for mapping and were supplemented with MODIS-EVI temporal spectral profiles, GEDI-derived vegetation heights (2019), and Google Earth high-resolution historical images for additional cues to support discrimination, mapping, and accuracy assessment. The methodology for rubber used its unique phenology from spectral-temporal profile and multi-year comparison of patches and their dynamics for age-class mapping. The results indicate that in the state of Tripura (geographic area 1.08 Mha), the area under rubber increased from 0.3% in 1990 to 8.9% of the geographic area in 2021. The overall classification accuracy for the maps created for the years 1990, 1995, 2000, 2004, 2009, 2016, and 2021 was 84.2%, 83.9%, 84.8%, 88.0%, 86.0%, 86.7%, and 89.5%, respectively. New areas under rubber originated from various land cover classes including open forests, shifting cultivation lands, and scrub. Recent expansion has resulted in 84.3% of rubber plantations under the 10-year age class. Implications of this transformation of the natural landscape, biodiversity and biomass, and carbon pool assessment are discussed.
•Classified spatial data of forest types, historical forest cover and fires were used.•Ecosystem level analysis has been carried out for all the forest types using multiple threat ...factors.•Statistical hotspot analysis and spatial landscape model is used in delineation of the deforestation and degradation hotspots.•The deforestation and degradation hotspots can be useful in strategic conservation planning.
Spatially explicit planning is required to set focused conservation priorities and assessing future ecological implications. Spatial ecological modeling and hotspot analysis prioritizes the forest ecosystems and supports the conservation of species level biodiversity. In the present study, the hotspots of deforestation and forest fires were obtained using historical deforestation trends (1975–1985–1995–2005–2014) and fire history (2009–2014) in Andhra Pradesh, India. The priority areas were identified as deforestation and degradation hotspots using combined measures of threat from deforestation, fire hotspots and current level of forest fragmentation. The state of Andhra Pradesh represents an area of 25985km2 (16.2% of total geographical area) under forest cover in 2014. The net deforested area was estimated as 2390km2 (8.4%) from 1975 to 2014. We have calculated the region of influence in percentages and found deforestation hotspots covering an average of 40.2% forest, followed by 35.9% under high fragmentation and 19.2% under fire hotspots. Ecosystem level analysis has been carried out for all the forest types i.e., semi evergreen, moist deciduous, dry deciduous, dry evergreen, thorn and mangroves, indicating ecosystem vulnerability. According to the results of prioritization, about 10.5% of existing forest had severe ecosystem collapse and categorized as deforestation and degradation hotspot-I. Analysis of protected areas shows Nagarjunasagar Srisailam Tiger Reserve, Sri Peninsula Narasimha sanctuary, Papikonda sanctuary and Sri Venkateshwara sanctuary are representing deforestation and degradation hotspot-I. Deforestation and degradation hotspots identified in the study is an excellent surrogate for understanding anthropogenic disturbances and can be effectively useful in forest management to proceed for applicable restoration measures.
Deforestation and fragmentation are important concerns in managing and conserving tropical forests and have global significance. In the Indian context, in the last one century, the forests have ...undergone significant changes due to several policies undertaken by government as well as increased population pressure. The present study has brought out spatiotemporal changes in forest cover and variation in forest type in the state of Odisha (Orissa), India, during the last 75 years period. The mapping for the period of 1924–1935, 1975, 1985, 1995 and 2010 indicates that the forest cover accounts for 81,785.6 km
2
(52.5 %), 56,661.1 km
2
(36.4 %), 51,642.3 km
2
(33.2 %), 49,773 km
2
(32 %) and 48,669.4 km
2
(31.3 %) of the study area, respectively. The study found the net forest cover decline as 40.5 % of the total forest and mean annual rate of deforestation as 0.69 % year
−1
during 1935 to 2010. There is a decline in annual rate of deforestation during 1995 to 2010 which was estimated as 0.15 %. Forest type-wise quantitative loss of forest cover reveals large scale deforestation of dry deciduous forests. The landscape analysis shows that the number of forest patches (per 1,000) are 2.463 in 1935, 10.390 in 1975, 11.899 in 1985, 12.193 in 1995 and 15.102 in 2010, which indicates high anthropogenic pressure on the forests. The mean patch size (km
2
) of forest decreased from 33.2 in 1935 to 5.5 in 1975 and reached to 3.2 by 2010. The study demonstrated that monitoring of long term forest changes, quantitative loss of forest types and landscape metrics provides critical inputs for management of forest resources.
Carbon dioxide (CO2) and methane (CH4) are the most important greenhouse gases (GHGs) due to their significant role in anthropogenic global climate change. The spatio-temporal variations of their ...concentration are characterized by the terrestrial biosphere, seasonal weather patterns and anthropogenic emissions. Hence, to understand the variability in regional surface GHG fluxes, high precision GHGs measurements were initiated by the National Remote Sensing Center (NRSC) of India. We report continuous CO2 and CH4measurements during 2014 to 2017 for the first time from Shadnagar, a suburban site in India. Annual mean CO2 and CH4 concentrations are 399.56 ± 5.46 ppm and 1.929 ± 0.09 ppm, respectively, for 2017. After the strong El Niño of 2015–2016, an abnormal rise in CO2 growth rate of 5.5 ppm year−1 was observed in 2017 at the study site, compared to 3.03 ppm year−1 at Mauna Loa. Thus, the repercussion of the El Niño effect diminishes the net uptake by the terrestrial biosphere accompanied by increased soil respiration. Seasonal tracer to tracer correlation between CO2 and CH4 was also analyzed to characterize the possible source-sink relationship between the species. We compared CO2 and CH4 concentrations to simulations from an atmospheric chemistry transport model (ACTM). The seasonal phases of CH4 were well captured by the ACTM, whereas the seasonal cycle amplitude of CO2 was underestimated by about 30%.
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•Investigated the seasonal and synoptic variations of CO2 and CH4 at the study site•The dominance of anthropogenic emissions and respiration during morning and night•The ACTM demonstrated the potentiality of capturing the CO2 and CH4 seasonal cycle.
