Depletion Of Vegetation Cover Research Articles

Can species distribution models and molecular tools help unravel disjunct distribution of Rhododendron arboreum?

The apparent absence of Himalayan low-elevation taxa in the central Indian region and resumption of their distribution in the high elevation of Western Ghats has puzzled biogeographers for several decades. Many theories have been proposed to explain this but attempts remain futile owing to insufficient empirical support. Here, we have employed a montane tree species, Rhododendron arboreum to investigate this pattern by integrating past ecological niche modelling with molecular signatures. Reconstruction of paleo-ecological niche from interglacial to Last Glacial Maxima (LGM) portrayed a gradual depletion of vegetation cover with extreme impoverishment in the Holocene. A similar pattern was also reflected from genetic signatures; population history revealed a very recent split between the Himalayas and Western Ghats in the late Quaternary. A few other tree species exhibiting the same disjunction demonstrated a similar modification of paleo-ecological niche from last interglacial. The study clearly indicated that the populations in the Western Ghats to be a relictual remnants of a once continuous distribution of R. arboreum.

ОЦІНКА ВПЛИВУ ФАКТОРІВ УРБАНІЗАЦІЇ НА НЕБЕЗПЕКУ АКТИВІЗАЦІЇ КАР-СТОВИХ ПРОЦЕСІВ У РЕГІОНАХ УКРАЇНИ

The article presents the analysis of the exogenous geological process activation hazards, namely karst, in the conditions of urbanization processes. The scale of geoecological problems is shown to be directly or indirectly determined by the scale of urbanization. The relevance of the research is associated with the study of the nature of changes in the expansion of karst rocks in regions with different levels of urbanization in the period 2001 – 2020. The main aim is to analyze the hazards of karst development in relation with the factors of urbanization processes in the regions of Ukraine based on the indicator method. The particular characteristics of the impact of urbanized territories on the initiation of natural disasters and geological hazards have been determined. The urbogenic load of the regions was assessed using determined and calculated earlier indicators of ecological and ecological-demographic urbanization. The assessment of the dependence between the hazard indicator of the spread of karst rocks and the indicator of ecological urbanization in the regional context has been carried out. It is shown that in the third part of the regions, the growing hazard levels of karst processes practically coincide with the growth of the ecological urbanization index. A nearly doubling of the area of karst terrains was noted during 2001 – 2020 in all administrative regions. The coefficient of expansion of karst territories for the specified period has been calculated. Four groups of regions were identified according to the increase in karst areas in comparison with the hazards of karst processes and the index of ecological-demographic urbanization. Expansion of open karst areas in the Transcarpathian, Odessa, Rivne, Kherson, Chernivtsi regions was noted. For this group of regions, a tendency to increase the areas of surface karst in accordance with an increase in the values of urbanization indicators has been established. This is due to the exploitation of natural territorial resources, changes in the nature of land use, depletion of vegetation cover, anthropogenic loads on the ground, and imbalances in the interaction of surface and underground waters in urbanized areas. Thus, the Ukraine’s regions with different urbogenic load are differentiated depending on the territorial indicator of the danger of karst terrains, as well as the dynamics of changes in the areas of karst rocks.

Natural And Human-Induced Land Degradation And Its Impact Using Geospatial Approach In The Kallar Watershed Of Tamil Nadu, India

Land degradation is human-induced and natural process that adversely affects the land, to function effectively within a complex ecosystem. In recent years, the Kallar watershed has encountered various kinds of multifarious problems on both land and water in the urban and its environs. The upper part of the study area is facing water scarcity problems in the past few years, but which included no such rare occurrences in the past. The mid-portion in the vicinity of foothills are highly affected by soil erosion, whereas the lower portion of the area has faced problems like land degradation, such as an unusual increase of wastelands and conversion of good agriculture lands into construction plots. Apart from these, the study area is frequently affected by nature induced disasters like a landslide, forest fire, flooding, and drought. In this complex situation, the qualitative assessment of human-induced land degradation and its impact is essential. For this, Geospatialbased Multi-Criteria Evaluation (MCE) as a multidisciplinary approach has been adopted. To assess land degradation, six major criterions are preferred such as terrain (slope, elevation), environment (landuse/land cover, NDVI), soil erosion, and demography (population density). Considerable weights and ranks were assigned through an empirical MCE method. Based on the criteria, the land degradation was carefully delineated into five significant categories such as low (38.3%), moderately (23.6%), marginally (15.4%), highly (4.8%), and severely degraded (17.8%). The depletion of vegetation cover on hilly terrain and subsequent cultivation without proper protection measures constitute the possible reason for severe soil erosion and land degradation.

An Investigation of Kagera River Basin Land Cover Dynamics for Sustainability of Lake Victoria Water Regime

This paper is reporting on an investigation done to assess land cover dynamics in KRB(Kagera River Basin) (KRB) over a period of 21 years i.e.1990-2011 using Remote Sensing, Hydrology and GIS techniques as a basis for initiating policy interventions for sustainability of Lake Victoria water regime.The extent of land cover changes in the KRB have not been quantified with the view of assessing the extent of exploitation of the natural resources.The assessment is important firstly for identification of causative factors and secondly as a mechanism for formulating necessary policies and remedial measures to that effect.Specifically, Landsat 5, Landsat 7 and ETM+ (2000) satellite images were used.Eight Land Cover classes were identified namely, Forests, Woodland, Bushland, Cultivated Land, Swamps, Grassland, Bareland and Urban areas.Hydrographical data were used to assess changes in quantity of water flowing from the KRB into Lake Victoria and relating it with land cover changes in KRB at in the period of study. Spatial data processing, analysis and interpretation were carried out in ERDAS Imagine and ArcGIS software environments; while water quantity data and other non spatial data were processed and analyzed in Microsoft Excel application 2007. 
 
 The study revealed a significant decline of vegetation cover and water quantity discharged from Kagera River to Lake Victoria over the study period. This contravenes the global efforts of ecological sustainability, which urge avoidance of depletion of natural resources for maintenance for ecological balance. These results are in early warning to the Management of Lake Victoria for its potential failure towards achieving the Millennium Development Goal on responsible consumption and protection of natural resources in proximity with Lake Victoria. The Management of Lake Victoria in collaboration with other relevant authorities should thus, take remedial measures to control further depletion of vegetation cover in KRB for sustainability of Lake Victoria and its ecosystem.

Impact of internally displaced persons on forest and vegetation of Jere LGA, Borno State, Nigeria

Deforestation is described as changes in the structure and composition of an area of forest after there has been some form of human intervention such as firewood, charcoal and logging. The study examined impact of internally displaced persons (IDPs) on forest and vegetation cover of Jere L.G.A. of Borno State, Nigeria. The objectives of the study were to determine the extent of impact of deforestation and depletion of vegetation cover caused by displaced persons to forest of Jere L.G.A. and also identifies the socio-economic needs of the displaced persons in camps. Data were collected from both primary and secondary sources. Primary data were generated through field observation and focused group discussion with displaced persons, while the secondary data was obtained from relevant available literature. Findings revealed that about 12 square kilometers of forest and vegetation cover were destroyed by displaced persons. The Findings also revealed that displaced persons engaged in cutting of trees for shelter, firewood, charcoal and debarking trees for medicinal purpose to earn money. The study revealed displaced persons conditioned in camps are deplorable far from the ideal situation. The study concluded that environmental impact assessment should be incorporated in the strategies for displaced persons welfare before their arrival. The study recommended that host governments, humanitarian agencies and NGOs should support the living conditions of displaced persons through socio-economic, education, skill and vocational training development that promotes lifelong learning opportunities.Keywords: Displaced persons, Deforestation, Vegetation, Firewood and Charcoal

Environmental degradation and economic growth: evidence for a developing country

This paper examines the relationship between economic growth and environmental degradation in Ecuador from 1971 to 2010. We estimate this relationship in a country with a heavy reliance on revenue from the exploitation of natural resources, the depletion of vegetation cover in recent decades and a low level of participation of industry in GDP. We show the existence of an inverse relationship between real GDP and vegetation cover, indicating that the output of this country is based on environmental degradation. Through Johansen co-integration tests, we check that there is a relationship of long-term equilibrium between the first differences of real GDP, vegetal cover and the urbanization rate. The ECM shows that there is a short-term relationship between vegetation cover, the GDP and the rate of urbanization. Finally, we did not found Granger causality between the variables. A policy implication based on our findings is that policies to protect the environment should not jeopardize economic growth and not limit the rapid urbanization in the country.

Land degradation mapping in the upper catchment of river Tons

A study on land degradation in the upper catchment of river Tons, a tributary of Yamuna river, in Uttarkashi district of the Uttarakhand state, was carried out using on-screen visual interpretation of IRS LISS-III + PAN merged data. The study area, which is largely mountainous, includes Govind Wildlife Sanctuary and National Park. Vegetation cover, slope and erosion status were used as criteria for the delineation of four major land degradation categories viz., undegraded, moderately degraded, degraded and severely degraded. More than 50 per cent of the study area is reported to be covered with snow and grassland. The moderate to severely degraded area worked out to be 42.4 per cent of the total area. The 32.8 per cent of area was found to be moderately degraded, followed by degraded (6.63%) and severely degraded (2.88%) areas. The depletion of vegetation cover on mountainous terrain and subsequent cultivation without proper protection measures is the reason for severe soil erosion and land degradation. In view of the existing land degradation situation, the catchment requires immediate treatment on priority for the sustenance of agriculture and wild life. It is expected that these measures will reduce the silt load in the river Tons and eventually, in river Yamuna.