Monitoring mangrove forest dynamics of the Sundarbans in Bangladesh and India using multi-temporal satellite data from 1973 to 2000 (original) (raw)
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Insights of Forest Dynamics for the Regional Ecological Fragility Assessment
Journal of the Indian Society of Remote Sensing, 2020
Forest ecosystems play a vital role in sustaining various life forms on the earth. These ecosystems support society through the provision of goods (timber, fuelwood, etc.) and an array of ecological services (carbon sequestration, nutrient cycling, etc.). However, unplanned developmental activities have been affecting the ecological integrity evident from the fragmentation of forests, barren hilltops, conversion of perennial streams to intermittent or seasonal streams, etc. During the past three decades, forests have undergone major transitions with the breaking of contiguous native forests into small parcels of land, restricting the movement of species thereby limiting the potential of species for dispersal and colonization. This paper analyzes the landscape dynamics and spatial patterns of forests fragmentation of Shimoga District, Central Western Ghats and prioritizes ecologically fragile or Ecologically Sensitive regions (ESR) at village levels based on bio-geo-climatic-social variables with the land use dynamics considering temporal remote sensing data. Results revealed that there was a net loss of 10% in forest cover from 43.83% (1973) to 34.02% (2018), primarily caused by the expansion of agriculture, horticulture, and forest plantations. Forest fragmentation has increased, evident from the decline of the interior forest to an extent of 11% from 26% (1973-2018). ESR prioritization at village level in the Shimoga district considering the ecological, geo-climatic and social variables indicate that 11% villages are ESR 1 (highest sensitivity), 30% are in ESR 2 (higher sensitivity), 36% are in ESR 3 (high sensitivity) and the remaining 23% are in ESR 4 or moderate sensitivity category. The analysis illustrates the importance of understanding spatiotemporal patterns of landscape structure for sustainable management of tropical forests.
Mangroves often allocate a relatively large proportion of their total biomass production to their roots, and the belowground biomass of these forests contributes towards globally significant carbon sinks. However, little information is available on root production in mangroves due to the difficulties in carrying out measurements of belowground processes, particularly if there is regular flooding. In this study, we examined fine and coarse root production in the east coast of the Malaysian Peninsula. Ingrowth cores were used over the course of 17 months. In September 2014, twenty cores were randomly placed in each of five plots. Three cores were collected from each plot (fifteen cores in total), once every three months. Each core was divided into five 10 cm layers and root dry mass was recorded. Standing root biomass was also measured at the time of final collection using an additional 15 cores. There was a seasonal pattern in root production, which peaked in March and December 2015, after and during the monsoon season. Root biomass in the cores peaked at 33.23 ± 6.3 t ha −1 and 21.46 ± 7.3 t ha −1 in March and December respectively. Standing root biomass in February 2016 in the forest was 20.81 ± 2.8 t ha −1. After 17 months, the final root biomass in the cores was 14% less than the standing root biomass. These data suggest surprisingly rapid growth rates and turnover for mangrove roots. Total root biomass significantly increased with root depth and 78% of the roots, in all soil layers, consisted of fine roots (< 3 mm diameter). Soil carbon, nitrogen and phosphorous concentrations were investigated in relation to belowground production, as were soil temperature, salinity and dissolved oxygen. A data review of global studies reporting similar work was carried out. The results are discussed with consideration to the significance of monsoon rainfall for mangrove ecology.
Conceptualizing Different Forest Degradation Drivers with Special Reference to India
International Journal of Environment and Climate Change
Forest deterioration has been a global issue in the 21st century as one of the most serious environmental issues. The costs of forests degradation is in reducing productivity and natural resources such as water, land, grassland etc. Deforestation affects the whole globe but it is of main concern of developing countries of the Tropics. Forest deterioration and deforestation are caused by a variety of factors that vary depending on the location. The main aim of the review is to analyse various forest degradation drivers and to establish keys to estimate the level of degradation. The various direct and indirect drivers of forest degradation are excessive mining, selective logging, population explosion, climatic-change, forest fires, biological invasion, agricultural land expansion and weak forest administration. One sort of sustainability in a managed forest is the system of several landowners, each with a modest multifunctional, multispecies plot. Other plan for sustainable developmen...
A deepening forest crisis worldwide has been documented in alarming trends in global deforestation and forest degradation. During the last decade, in particular, the forest crisis has received increasing attention and has prompted many initiatives by governments and intergovernmental agencies. Still, these and other responses appear to be insufficient in achieving a significant deceleration and reversal of the above-mentioned trends. Many have analyzed the potential explanations of why these recent responses to the forest crisis have failed to generate the significant progress needed. There seems to be broad agreement that these initiatives have focused far too much attention on the proximate causes of deforestation/forest degradation (and factors within the forest sector), and have largely ignored the underlying (root) causes of these problems. This report is the first outcome of a 16-month initiative of a diverse group of NGOs, governments, Indigenous Peoples’ Organizations, intergovernmental agencies and other stakeholders that included 7 regional workshops, one Indigenous Peoples workshop, and a Global Workshop to Address the Underlying Causes of Deforestation and Forest Degradation. The latter was attended by 125 participants from 40 countries, and took place in Costa Rica, from 18 to 22 January 1999. In all, over 40 case studies were collected, along with numerous discussion papers, documenting the underlying causes of forest loss all over the world. A number of key points clearly emerge from the actions recommended by the Global Workshop. Full participation of local communities and other stakeholders in decision-making over management of natural resources at the national and international level is required if we intend to reverse the current rates of forest loss. Also, forests are more than just stands of timber. Their rich biological diversity, particularly natural forest biological diversity, constitutes complex ecosystems that provide valuable services such as water, air purification, stabilization of climate, soil protection, and have spiritual meaning for individuals, communities, and society as a whole. These lessons seem to be absent in current international policy deliberations that affect forests, and we urge all responsible actors to include them in the future. From our participation in this process we have learned an important lesson: that a participatory process such as this carried forward by collaboration between governments, international organizations, NGOs, Indigenous Peoples and local communities can significantly advance the international agenda.
Journal of Geographical Sciences, 2011
Tropical forests have been recognized as having global conservation importance. However, they are being rapidly destroyed in many regions of the world. Regular monitoring of forests is necessary for an adaptive management approach and the successful implementation of ecosystem management. The present study analyses the temporal changes in forest ecosystem structure in tribal dominated Malkangiri district of Orissa, India, during 1973-2004 period based on digitized forest cover maps using geographic information system (GIS) and interpretation of satellite data. Three satellite images Landsat MSS (1973), Landsat TM (1990) and IRS P6 LISS III (2004) were used to determine changes. Six land cover types were delineated which includes dense forest, open forest, scrub land, agriculture, barren land and water body. Different forest types were also demarcated within forest class for better understanding the degradation pattern in each forest types. The results showed that there was a net decrease of 475.7 km 2 forest cover (rate of deforestation = 2.34) from 1973 to 1990 and 402.3 km 2 (rate of deforestation = 2.27) from 1990 to 2004. Forest cover has changed over time depending on a few factors such as large-scale deforestation, shifting cultivation, dam and road construction, unregulated management actions, and social pressure. A significant increase of 1222.8 km 2 agriculture area (1973-2004) clearly indicated the conversion of forest cover to agricultural land. These alterations had resulted in significant environmental consequences, including decline in forest cover, soil erosion, and loss of biodiversity. There is an urgent need for rational management of the remaining forest for it to be able to survive beyond next decades. Particular attention must be paid to tropical forests, which are rapidly being deforested.
Forestist, 2020
Forest degradation is threatening the biodiversity of moist tropical forests since the beginning of their development. Bangladesh is losing its forests and associated biodiversity continuously due to forest-dependent livelihoods. The only freshwater swamp forest of the Ratargul Special Biodiversity Protection Area in Bang-ladesh is also very prone to degradation due to anthropogenic disturbance. This distinct swamp forest has unique biological diversity compared to other forest types. To assess its degradation and to propose implications for conservation, sentinel images with 10×10 m resolution were used. Also, field data were collected and analyzed. This research produced a map of forest cover change and outlined an area that can be used in restoration planning. Branch cutting, dry season overgrazing, illegal tree felling, fuelwood collection, trampling by tourists, and insect and disease epidemics were identified as causes of degradation. Functional conservation effort ensured by strong political will and area-specific forest protection regulation is essential for the conservation of last swamp forest and its remnant biodiversity. Community-based conservation approaches need to be applied for mass awareness regarding this ecosystem's value and its sustainability.
Sweeping across Bangladesh and India, the Sundarbans forest is the world's largest contiguous mangrove forest. Although the human population density is high at the edge, Sundarbans has not encountered significant areal transformation in the last four decades. However, we argue that forest degradation can occur discontinuously within the forest without alteration of the entire forest area. In this paper, we used MODIS land products to compare the spatiotemporal ecological dynamics of the Bangladesh and Indian part of this mangrove forest between 2000 and 2010. We used the following 5 ecological parameters for our analysis: the Percent Tree Cover (PTC), Enhanced Vegetation Index (EVI), Net Primary Productivity (NPP), Leaf Area Index (LAI), and Evapotranspiration (ET). Our pixel-based time-series trend analysis for each MODIS image stack, using an ordinary least square (OLS) regression method, showed that forest degradation is happening in fragmented parcels within the forest. The degradation rate is comparatively higher in the Bangladesh part than in the Indian part of Sundarbans. Compartments 8, 10, 12, and 15 in the Bangladesh part, in particular, show high degradation, while compartment 48 and the southern edge of 45 show slight increases in PTC or EVI. Forest degradation in the Indian part of the forest is evident in the National Park and Reserve Forest blocks; however, no substantial degradation is evident in the western section. We have identified certain anthropogenic stressors (i.e., oil pollution, shrimp farming) and natural stressors (i.e., increased salinity, cyclones, forest fire) which might be responsible for the observed degradation. We have provided sustainable planning options and policy transformation alternatives for those areas under pressure from these stressors. We anticipate that our analysis of forest degradation will help management agencies, conservators, and policy makers achieve better management of this world's largest mangrove forest for a sustainable future
Impact on Forest and Vegetation Due to Human Interventions
IntechOpen eBooks, 2023
Forest and vegetation play an important role in balancing ecosystem patterns, providing food security, and blessing the environment for living beings, so the status of global forests and biodiversity, their impact and change overtime with climatic effects and challenges is important. This study's methods include a review of global forest cover and status; distribution, and assessment; biodiversity, forest carbon assessment; causes of forest loss; and the impacts and implications of CO 2 emissions. Forests encompass 31% of the world's forests, are home to 2 million to 1 trillion species, and provide habitat for 80% of amphibian species, 75% of bird species, 68% of mammalian species, and so on. Deforestation is the major cause of forest loss, with a decrease of 4.7 million ha. From 2010 to 2020, only in the Asia Pacific region and from 2000 to 2010, 13 million ha of world forests were lost. All flora, fauna, and microbes are slowly degrading and disappearing due to human activities such as deforestation, intensive use, inappropriate forest management, agriculture, encroachment of forest land, slash burn practices, forest fires, urbanization, overharvesting, environmental deterioration, etc. Because the globe has emitted over 1.5 trillion tonnes of CO 2 since 1751, the persistence of biodiversity in human-modified habitats is crucial for conservation and the provision of ecosystem services.