We examine the dynamics and spatial determinants of land change in India by integrating decadal land cover maps (1985–1995–2005) from a wall-to-wall analysis of Landsat images with spatiotemporal socioeconomic database for ~630,000 villages in India. We reinforce our results through collective evidence from synthesis of 102 case studies that incorporate field knowledge of the causes of land change in India. We focus on cropland–fallow land conversions, and forest area changes (excludes non-forest tree categories including commercial plantations). We show that cropland to fallow conversions are prominently associated with lack of irrigation and capital, male agricultural labor shortage, and fragmentation of land holdings. We find gross forest loss is substantial and increased from ~23,810 km2 (1985–1995) to ~25,770 km2 (1995–2005). The gross forest gain also increased from ~6000 km2 (1985–1995) to ~7440 km2 (1995–2005). Overall, India experienced a net decline in forest by ~18,000 km2 (gross loss–gross gain) consistently during both decades. We show that the major source of forest loss was cropland expansion in areas of low cropland productivity (due to soil degradation and lack of irrigation), followed by industrial development and mining/quarrying activities, and excessive economic dependence of villages on forest resources.
Environment, Development and Sustainability - Social representations necessarily originate from the interaction between individuals and groups in a social setting through communication and shared... 相似文献
Numerous governments around the world have adopted statutory mandates on plan content based on the assumption that they lead to greater consistency and higher quality of plans. While a number of studies have examined the relationship between mandates to develop plans and plan quality, there has been limited study of the influence of state mandates for plan content on plan quality in a regional natural resource management (NRM) planning context. This paper explores the relationship between the quality of regional NRM plans between statutory and non-statutory NRM regions in New South Wales and Queensland, Australia. An analysis of 22 regional NRM plans indicates that there is no evidence of a relationship between plan quality and the presence of statutory mandates for regional NRM plans in New South Wales and Queensland. However, the paper identifies and discusses several other factors with unexpected relationships with an impact on the quality of NRM plans in New South Wales and Queensland, Australia. 相似文献
Understanding changes in forest composition and structure is important to help formulate effective policies that promote future ability of forests to provide local livelihood needs, habitat and ecosystem services. This is particularly important in dry tropical forests that are ecologically different from other forests and are heavily used by local, forest-dependent residents. In this study, we identify biophysical, demographic and use factors associated with differences in species diversity, vegetation structure (abundance at different size classes), biomass and relative abundance of species across the Kanha–Pench landscape in Central India. We sampled vegetation in twenty transects across different human and livestock population densities and frequencies of use. We found that biomass, species diversity and vegetation (abundance at different size classes) are negatively associated with increasing population density, and species composition at different size classes is significantly different at higher frequencies of use at low population densities. Lack of difference in species composition at high population densities may be due to colonization and growth of individuals at some of these sites due to creation of new ecological niches and gaps at high human use. Relative abundance of species at different size classes also varies with frequency of use and population density. Results suggest that human use is altering relative abundance of species, which may change long-term forest composition and thus alter biomass and vegetation structure of the forest. We conclude that human use is an agent in altering long-term composition that can alter availability of tree species for local use and other ecosystem services. 相似文献
The Central Indian Highland landscape (CIHL) represents a complex, diverse, and highly human-modified system. Nearly half the landscape is cropland, yet it hosts 21 protected areas surrounded and connected by forests. Changing farming practices with increasing access to irrigation might alter this intensifying landscape in the near future particularly in light of weather variability. We analyzed a decade of remote sensing data for cropping patterns and climatic factors combined with census data for irrigation and demographic factors to understand winter cropping trajectories in the CIHL. We quantified ‘productive cropped area’ (PCA), defined as the area with planted crop that is green at the peak of the winter growing season. We find three primary trajectories in PCA—increasing, fluctuating, and decreasing. The most dominant trend is fluctuating PCA in two-thirds of the districts, ranging from ~2.11 million to ~3.73 million ha between 2001 and 2013, which is associated with village-level access to irrigation and local labor dynamics. In 58 % of all districts, clay soils were associated with winter cropping (p < 0.05). Increasing irrigation is associated with increased winter PCA in most (94 %) districts (p < 0.00001). We find strong negative association between PCA and land surface temperature (LST) in most (66 %) districts (p < 0.01). LST closely corresponds to daytime mean air temperature (p < 0.001) for available meteorological stations. Fine-scale meteorological and socioeconomic data, however, are needed to further disentangle impacts of these factors on PCA in this landscape. 相似文献
Fostering human–wildlife coexistence requires transdisciplinary approaches that integrate multiple sectors, account for complexity and uncertainty, and ensure stakeholder participation. One such approach is participatory scenario planning, but to date, this approach has not been used in human–wildlife contexts. We devised a template for how participatory scenario planning can be applied to identify potential avenues for improving human–wildlife coexistence. We drew on 3 conceptual building blocks, namely the SEEDS framework, the notion of critical uncertainties, and the three-horizons technique. To illustrate the application of the proposed template, we conducted a case study in the Zambezi region of Namibia. We held 5 multistakeholder workshops that involved local people as well as numerous nongovernment and government stakeholders. We identified 14 important wildlife species that generated multiple services and disservices. The subsequent benefits and burdens, in turn, were inequitably distributed among stakeholders. Government actors played particularly influential roles in shaping social-ecological outcomes. We identified 2 critical uncertainties for the future: the nature of governance (fragmented vs. collaborative) and the type of wildlife economy (hunting vs. photography based). Considering these uncertainties resulted in 4 plausible scenarios describing future human–wildlife coexistence. Stakeholders did not agree on a single preferred scenario, but nevertheless agreed on several high-priority strategies. Bridging the remaining gaps among actors will require ongoing deliberation among stakeholders. Navigating the complex challenges posed by living with wildlife requires moving beyond disciplinary approaches. To that end, our template could prove useful in many landscapes around the world. 相似文献
Herbivores affect plants through direct effects, such as tissue damage, and through indirect effects that alter species interactions. Interactions may be positive or negative, so indirect effects have the potential to enhance or lessen the net impacts of herbivores. Despite the ubiquity of these interactions, the indirect pathways are considerably less understood than the direct effects of herbivores, and multiple indirect pathways are rarely studied simultaneously. We placed herbivore effects in a comprehensive community context by studying how herbivory influences plant interactions with antagonists and mutualists both aboveground and belowground. We manipulated early-season aboveground herbivore damage to Cucumis sativus (cucumber, Cucurbitaceae) and measured interactions with subsequent aboveground herbivores, root-feeding herbivores, pollinators, and arbuscular mycorrhizal fungi (AMF). We quantified plant growth and reproduction and used an enhanced pollination treatment to determine if plants were pollen limited. Increased herbivory reduced interactions with both antagonists and mutualists. Plants with high levels of early herbivory were significantly less likely to suffer leaf damage later in the summer and tended to be less attacked by root herbivores. Herbivory also reduced pollinator visitation, likely due to fewer and smaller flowers, and reduced AMF colonization. The net effect of herbivory on plant growth and reproduction was strongly negative, but lower fruit and seed production were not due to reduced pollinator visits, because reproduction was not pollen limited. Although herbivores influenced interactions between plants and other organisms, these effects appear to be weaker than the direct negative effects of early-season tissue loss. 相似文献
Understanding the complex effects of biotic and abiotic factors on the composition of vegetation is very important for developing and implementing strategies for promoting sustainable grassland development. The vegetation–disturbance–environment relationship was examined in degraded alpine grasslands in the headwater areas of three rivers on the Qinghai–Tibet Plateau in this study. The investigated hypotheses were that (1) the heterogeneity of the vegetation of the alpine grassland is due to a combination of biotic and abiotic factors and that (2) at a small scale, biotic factors are more important for the distribution of alpine vegetation. On this basis, four transects were set along altitudinal gradients from 3,770 to 3,890 m on a sunny slope, and four parallel transects were set along altitudinal gradients on a shady slope in alpine grasslands in Guoluo Prefecture of Qinghai Province, China. It was found that biological disturbances were the major forces driving the spatial heterogeneity of the alpine grassland vegetation and abiotic factors were of secondary importance. Heavy grazing and intensive rat activity resulted in increases in unpalatable and poisonous weeds and decreased fine forages in the form of sedges, forbs, and grasses in the vegetation composition. Habitat degradation associated with biological disturbances significantly affected the spatial variation of the alpine grassland vegetation, i.e., more pioneer plants of poisonous or unpalatable weed species, such as Ligularia virgaurea and Euphorbia fischeriana, were found in bare patches. Environmental/abiotic factors were less important than biological disturbances in affecting the spatial distribution of the alpine grassland vegetation at a small scale. It was concluded that rat control and light grazing should be applied first in implementing restoration strategies. The primary vegetation in lightly grazed and less rat-damaged sites should be regarded as a reference for devising vegetation restoration measures in alpine pastoral regions. 相似文献
Volatile substances and gases resulting e.g. from degradation processes of chemicals in soils emit into the atmosphere and
no chemical mass balance is complete without considering this path. Closed soil chambers allow the evaluation of this transfer
to the atmosphere. This study deals with the influence of soil chambers with a glass plate cover on physical soil conditions
in the chambers and the possibility to simulate the exterior conditions within the chambers. The water content immediately
at the soil surface is an important factor for the microbial activity and the transfer of gaseous compounds to the atmosphere
as well. It is monitored by specially designed water content sensors in 1 cm depth in the chamber and as control outside.
Funnels with a cross section equal to the soil surface area of the chamber collect the rain water and channel it into the
soil chamber. This results in soil water content in the chambers very similar to that outside. For the purpose of analysing
14CO2 and volatile 14C-compounds, air is permanently pumped through the chamber. In order to simulate natural conditions, the wind speed is measured
1 cm above the soil surface outside the chambers. A control circuit adjusts the air flow through the chamber to a value corresponding
to the wind speed outside. Temperature measurements in 1 cm depth verify that there is no significant difference between the
soil chamber and the control outside. 相似文献