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1.
Abandonment of farming with the resultant increase in forest cover is one of the major threats to semi-natural grasslands in marginal agricultural areas. In Sweden, the loss of semi-natural grassland is a serious nature conservation problem since it is one of the most species-rich habitats. In this study, the consequences of grassland abandonment and afforestation on butterfly diversity and butterfly dispersal costs are estimated and used to compare three different future land-use scenarios for a marginal agricultural landscape in Sweden. Based on previous butterfly surveys on grasslands in the area, a relationship between land-use type and butterfly diversity was established. By comparing land-use maps of different scenarios, the number of suitable habitat patches and total suitable habitat patch area with low, medium and high butterfly diversity could be estimated. To obtain an indication of possible fragmentation effects, a least-cost analysis was used to compare travel costs of the butterflies between suitable habitat patches for the different scenarios. The results show that different land-use scenarios affect butterfly diversity and travel costs differently. In the extreme case scenario of cessation of full-time farming and a reduction in part-time farming, nearly all valuable butterfly habitats will vanish, since the most species-rich habitats lie in the periphery of the settlement and are expected to be abandoned and afforested first. If, on the other hand, grassland management is less reduced the effect of abandonment on butterflies depends very much on which areas continue to be managed. To preserve the most important grasslands for butterflies an active management strategy for the whole study area would be needed. While it seems relatively easy to identify the areas most important to conserve from a butterfly diversity perspective, it will be more difficult to find an optimal spatial solution that also minimises dispersal costs for butterflies.  相似文献   

2.
Size-dependent resistance of protected areas to land-use change   总被引:1,自引:0,他引:1  
One of the major threats facing protected areas (PAs) is land-use change and habitat loss. We assessed the impact of land-use change on PAs. The majority of parks have been effective at protecting the ecosystems within their borders, even in areas with significant land-use pressures. More in particular, the capacity of PAs to slow down habitat degradation and to favour habitat restoration is clearly related to their size, with smaller areas that on average follow the dominant land-use change pattern into which they are embedded. Our results suggest that small parks are not going to be viable in the long term if they are considered as islands surrounded by a 'human-dominated ocean'. However, small PAs are, in many cases, the only option available, implying that we need to devote much more attention to the non-protected matrix in which PAs must survive.  相似文献   

3.
Ecosystem services are vital for humans in urban regions. However, urban development poses a great risk for the ability of ecosystems to provide these services. In this paper we first address the most important ecosystem services in functional urban regions in Finland. Well accessible and good quality recreational ecosystem services, for example, provided by urban nature, are an important part of a high-quality living environment and important for public health. Vegetation of urban regions can have a role in carbon dioxide sequestration and thus in climate change mitigation. For instance, estimates of carbon sinks can be compared to total CO2 emissions of an urban region, and the municipality can aim at both increasing carbon sinks and decreasing CO2 emissions with proper land-use planning. Large and contiguous core nature areas, smaller green areas and ecological connections between them are the essence of regional ecological networks and are essential for maintaining interconnected habitats for species and thus biological diversity. Thus, both local and regional level ecological networks are vital for maintaining ecosystem services in urban regions. The impacts of climate change coupled with land-use and land cover change will bring serious challenges for maintaining ecosystem services in urban areas. Although not yet widely used in planning practices, the ecosystem services approach can provide an opportunity for land-use planning to develop ecologically sustainable urban regions. Currently, information on ecosystem services of urban regions is lacking and there is a need to improve the knowledge base for land-use planning.  相似文献   

4.
《农业工程》2019,39(5):416-424
Climate variations and land-use change induced by rapid urbanization can lead to crucial impacts on ecosystem Net Primary Productivity (NPP), especially in regions with intensive human activity. However, the relative contributions of land-use change and climate variations to NPP changes under different urbanization intensities are still a topic of debate. This study reports on a case study in Beijing, which is undergoing rapid urbanization, to estimate the effects of land-use change and climate variations on NPP in regions with diverse urbanization intensities in recent decades using remote-sensing data and the Carnegie-Ames-Stanford Approach (CASA) model. The results reveal obvious land-use changes in Beijing, showing an increase in both built-up and forested areas in the two inner, highly urbanized regions and a dramatic conversion from built-up area and grassy bush to forest in the two outer, less urbanized regions. Factorial experiments were performed to estimate the contributions of land-use change and climate variations to NPP changes for different regions and land-use types. An increasing trend in regional NPP was observed with decreasing urbanization intensity in all experiments. However, the increment in NPP between 2002 and 2009 tended to decrease with decreasing urbanization intensity in most experiments. Climate variation was the dominant factor in increasing NPP in the study region during 2002–2009, with a mean contribution of ∼89.5% over different regions and land-use types. However, land-use change contributed to a certain extent to NPP changes for specific land-use types (e.g., ∼28.1% for forests) in regions of intensive urbanization. Eco-engineering approaches such as increasing vegetation cover, especially forest, in built-up areas and reforestation and afforestation in non-built-up areas may be useful in mitigating the impacts of urbanization on NPP, especially in intensively urbanized regions.  相似文献   

5.
Abandonment and Expansion of Arable Land in Europe   总被引:4,自引:0,他引:4  
Abandonment of arable land is often assumed to happen mostly in marginal areas where the conditions for arable cultivation are relatively unfavorable, whereas arable expansion is expected to occur mostly in areas with favorable conditions. This assumption, used in many land-use change forecasts, was never properly tested, mainly because the relatively short period of full-coverage land-use inventories did not allow a systematic analysis of the phenomena. With the recent release of CORINE 2006 this has changed. In this article, we explore the typical locations of abandonment and expansion of arable land in Europe during the period 1990–2006 by means of logistic regressions. More specifically, we test whether or not locations of abandonment and expansion can be inferred from the location characteristics of arable land in 1990. If the above assumption holds, this should be the case. We demonstrate that although arable expansion indeed happens in locations that resemble the bulk of arable land in 1990 (the presumably favorable locations), arable abandonment does not necessarily happen in locations that resemble the bulk of uncultivated land (that is, the presumably unfavorable locations). In other words, the assumption does not hold. Particularly, areas close to the road network were found to be associated with both high abandonment rates and high expansion rates, which suggest that abandonment is not limited to areas that are marginal in terms of agricultural production.  相似文献   

6.
The dynamic relationship between vegetation and climate is now widely acknowledged. Climate influences the distribution of vegetation; and through a number of feedback mechanisms vegetation affects climate. This implies that land-use changes such as deforestation will have climatic consequences. However, the spatial scales at which such feedbacks occur remain largely unknown. Here, we use a large database of precipitation and tree cover records for an area of the biodiversity-rich Atlantic forest region in south eastern Brazil to investigate the forest-rainfall feedback at a range of spatial scales from ca 10(1)-10(4) km2. We show that the strength of the feedback increases up to scales of at least 10(3) km2, with the climate at a particular locality influenced by the pattern of landcover extending over a large area. Thus, smaller forest fragments, even if well protected, may suffer degradation due to the climate responding to land-use change in the surrounding area. Atlantic forest vertebrate taxa also require large areas of forest to support viable populations. Areas of forest of ca 10(3) km2 would be large enough to support such populations at the same time as minimizing the risk of climatic feedbacks resulting from deforestation.  相似文献   

7.
Conservation management can no longer rely on protecting pristine habitats, but must consider the wider landscape. This is especially true on oceanic islands where endemic species are believed to be particularly susceptible to the extinction risks that accompany land conversion. Despite this, there is a paucity of studies examining how endemic communities on oceanic islands may be distributed across such human-modified habitats. Taking Príncipe Island in West Africa as a case study, we investigate how avian communities vary across the habitats (primary forest, secondary forest, agricultural areas) of this globally important centre of endemism. Here, recent policy reforms aimed at poverty alleviation and increased food production are rapidly altering the current land-use mosaic. Across all habitats, 27 bird species were encountered. Survey points in secondary forest and agricultural areas were, on average, more diverse and held higher overall abundances of birds than those within primary forest. This was true for both the entire avian assemblage and the endemic species alone. Nevertheless, two IUCN-listed species were restricted to primary forest, and many other endemics occurred at higher densities within this habitat. We demonstrate that agricultural areas and novel habitats, such as secondary forest, can hold high abundances of endemic species and thus have the potential to act as a resource for biodiversity conservation. A double-stranded approach to conservation is therefore required that both protects the integrity of the primary forest and controls the rapid changes in agricultural land-use to ensure that it continues to support a large component of the endemic avifauna.  相似文献   

8.
Bats are considered important bioindicators and deliver key ecosystem services to humans. However, it is not clear how the individual and combined effects of climate change and land-use change will affect their conservation in the future. We used a spatial conservation prioritization framework to determine future shifts in the priority areas for the conservation of 169 bat species under projected climate and land-use change scenarios across Africa. Specifically, we modelled species distribution models under four different climate change scenarios at the 2050 horizon. We used land-use change scenarios within the spatial conservation prioritization framework to assess habitat quality in areas where bats may shift their distributions. Overall, bats’ representation within already existing protected areas in Africa was low (∼5% of their suitable habitat in protected areas which cover ∼7% of Africa). Accounting for future land-use change resulted in the largest shift in spatial priority areas for conservation actions, and species representation within priority areas for conservation actions decreased by ∼9%. A large proportion of spatial conservation priorities will shift from forested areas with little disturbance under present conditions to agricultural areas in the future. Planning land use to reduce impacts on bats in priority areas outside protected areas where bats will be shifting their ranges in the future is crucial to enhance their conservation and maintain the important ecosystem services they provide to humans.  相似文献   

9.
Ecosystem services (ESs) are gaining ground in urban policy as a key to attaining sustainable cities. However, strategic and land-use planners need operational and accessible tools to better understand the consequences of policy and planning measures. Based on a study of the City of Stockholm and its surrounding region, we argue that spatially explicit land-use mapping is a good base for modeling and visualizing the supply of urban ESs provided by different patterns of Service Providing Units. By adding more detailed characteristics of land use through the concept of Service Providing Elements (SPEs), and by assessing synergies and trade-offs between these attributes, implications for the supply of ESs at different scale levels could be identified and discussed. Detailed land-use mapping and ES modeling were applied to two future land-use alternatives. The supply of eight urban ESs was found to vary significantly between the two alternatives depending on the ratios of different SPEs, even within identical land-use classes. One of the land-use alternatives had significantly higher potential for food and energy provision, much higher air cooling and air quality regulation capacity especially in densely built areas, showed less surface sealing, and provided better conditions for mental recreation. The exception was supply of physical recreation opportunities, where the other land-use option had an advantage. These differences became more accentuated when we zoomed in on two local urban areas. Based on these findings, our main conclusion is that, in order to provide planning and policy-making with an adequate knowledge base, it is necessary to move beyond land-use classes, as defined by European data sets like Urban Atlas, and toward tools capable of capturing more detailed aspects of land use and its relations to the supply of urban ESs. This should be made a priority, especially in early stages of planning and policy formation, and also used to support development of urban by-laws, procurement arrangements, neighborhood and building certification, etc. The approaches used in the study can serve as a valid starting point for further development of such tools and methods compatible with planners’ ordinary working modes. However, to make such progress possible, the ecosystem service research community needs to step up to the challenge of delivering locally specific and useful data on how urban land-use links to ES supply, including synergies and trade-offs between different ESs.  相似文献   

10.
A monographic book volume on the history of the rural landscape of Europe is presented (Emanuelsson, The rural landscape of Europe. How man has shaped European nature, 383, 2009). The focus is on various land-use phases, their history from the Neolithic period to modern time and the survival of traditional farming today in Europe. This is described and illustrated by examples from marginal farming areas, particularly in mountainous regions of southern and northern Europe. Some of these are important as modern analogues when interpreting past cultural landscapes.  相似文献   

11.
Multiscale Characterization of Land-Use Patterns in China   总被引:12,自引:0,他引:12  
This article explores the pattern of land use in China to understand the relationships between land use and factors that can be used to predict it. Such understanding is important for development of comprehensive models of land-use dynamics. Correlation and regression analyses are used to identify the most important explanatory variables from a large set of factors generally considered important in predicting the distribution of land use. We found that the spatial distribution of all land-use types in China is best described by an integrated set of biophysical and socioeconomic factors. Specific attention is given to the influence of the scale of analysis on study results. Both data resolution and the extent of the study area influence the discovered relationships. Relationships obtained at a certain scale of analysis therefore may not be directly applied at other scales or in other areas. The relevance of the systematic and quantitative characterization of the land-use patterns in China for the parameterization of spatially explicit land-use models is discussed. Received 20 July 1999; accepted 10 March 2000.  相似文献   

12.
Sustaining or restoring riparian quality is essential to achieve and maintain good stream health, as well as to guarantee the ecological functions that natural riparian areas provide. Therefore, quantifying riparian quality is a fundamental step to identify river reaches for conservation and/or restoration purposes. Most of the existing methods assessing riparian quality concentrate on field surveys of a few hundreds of metres, which become very laborious when trying to evaluate whole catchments or long river corridors. Riparian quality assessment obtains higher scores when riparian vegetation consists of forested areas, while land-uses lacking woody vegetation typically represent physical and functional discontinuities along river corridors that undermine riparian quality. Thus, this study aimed to analyse the ability of riparian land-cover data for modelling riparian quality over large areas. Multiple linear regression and Random Forest techniques were performed using land-use datasets at three different spatial scales: 1:5000 (Cantabrian Riparian Cover map), 1:25,000 (Spanish Land Cover Information System) and 1:100,000 (Corine Land Cover). Riparian quality field data was obtained using the Riparian Quality Index. Hydromorphological pressures affecting riparian vegetation were also included in the analysis to determine their relative weight in controlling riparian quality. Linear regression showed better predictive ability than Random Forest, although this may be due to our relatively small dataset (approx. 150 cases). Forest coverage highly determined riparian quality, while hydromorphological pressures and land-use coverage related to human activities played a smaller role in the models. While acceptable results were obtained when using high-resolution datasets, the use of Corine Land Cover led to a poor predictive ability.  相似文献   

13.
Intensive land use can fragment continuous natural areas into smaller patches, which may be too small to support viable populations of native fauna and more susceptible to invasion by alien species. We demonstrate the utility of combining species occurrence models with land-use change models to identify areas where future development may differentially affect wildlife. Occurrence data for native (e.g., gray fox, coyote, bobcat, mountain lion, striped skunk, raccoon) and non-native (e.g., domestic dogs, domestic cats, opossums) mammalian predators were collected from 188 remotely triggered camera locations across an oak woodland and vineyard landscape in northern California. The occurrence data were used in combination with landscape variables extracted using a geographic information system to build explanatory models of predator occurrence. These statistical models were used to derive two surfaces showing relative probability of occurrence for non-native and native predators. Then, a spatially explicit land-use change model was used to examine potential future predator distributions given potential future vineyard expansion. The probability distribution models generated hypothesized low probabilities of occurrence for native predators within large vineyard blocks, but higher probabilities within isolated vineyards and also in oak woodlands. The models suggest the highest probabilities of non-native predator occurrence fell within large blocks of vineyard. Using one possible future vineyard development scenario, the distribution models illustrate areas where probability of native predator occurrence may be reduced and where non-native predators may expand due to vineyard development. This technique could be applied to prioritize acquisition of critical wildlife habitat and maintain habitat connectivity for wildlife populations.  相似文献   

14.
Aim Species generally become rarer and more patchily distributed as the margins of their ranges are approached. We predicted that in such marginal sites, tree species would tend to occur where some key environmental factors are at particularly favourable levels, compensating in part for the low overall suitability of marginal sites. Location The article considers the spatial distributions of trees in Southeast Alaska (the Alaskan ‘panhandle’). Methods We quantified range marginality using spatial distributions of eight tree species across more than one thousand surveyed sites in Southeast Alaska. For each species we derived a site core/margin index using a three‐dimensional trend surface generated from logistic regression on site coordinates. For each species, the relationships between the environmental factors slope, aspect and site marginality were then compared for occupied and unoccupied sets of sites. Results We found that site slope is important for more Alaskan tree species than aspect. Three out of eight had a significant core/margin by occupied/unoccupied interaction, tending to be present in significantly shallower‐sloped (more favourable) sites in the marginal areas than the simple core/margin trend predicted. For site aspect, one species had a significant interaction, selecting potentially more favourable northerly aspects in marginal areas. A finer‐scale analysis based on the same data came to the same overall conclusions. Conclusions There is evidence that several tree species in Alaska tend to occur in especially favourable sites in marginal areas. In these marginal areas, these species amplify habitat preferences shown in core areas.  相似文献   

15.
Crop Expansion and Conservation Priorities in Tropical Countries   总被引:1,自引:0,他引:1  
Expansion of cropland in tropical countries is one of the principal causes of biodiversity loss, and threatens to undermine progress towards meeting the Aichi Biodiversity Targets. To understand this threat better, we analysed data on crop distribution and expansion in 128 tropical countries, assessed changes in area of the main crops and mapped overlaps between conservation priorities and cultivation potential. Rice was the single crop grown over the largest area, especially in tropical forest biomes. Cropland in tropical countries expanded by c. 48,000 km2 per year from 1999–2008. The countries which added the greatest area of new cropland were Nigeria, Indonesia, Ethiopia, Sudan and Brazil. Soybeans and maize are the crops which expanded most in absolute area. Other crops with large increases included rice, sorghum, oil palm, beans, sugar cane, cow peas, wheat and cassava. Areas of high cultivation potential—while bearing in mind that political and socio-economic conditions can be as influential as biophysical ones—may be vulnerable to conversion in the future. These include some priority areas for biodiversity conservation in tropical countries (e.g., Frontier Forests and High Biodiversity Wilderness Areas), which have previously been identified as having ‘low vulnerability’, in particular in central Africa and northern Australia. There are also many other smaller areas which are important for biodiversity and which have high cultivation potential (e.g., in the fringes of the Amazon basin, in the Paraguayan Chaco, and in the savanna woodlands of the Sahel and East Africa). We highlight the urgent need for more effective sustainability standards and policies addressing both production and consumption of tropical commodities, including robust land-use planning in agricultural frontiers, establishment of new protected areas or REDD+ projects in places agriculture has not yet reached, and reduction or elimination of incentives for land-demanding bioenergy feedstocks.  相似文献   

16.
Estimates of reserve effectiveness are confounded by leakage   总被引:2,自引:0,他引:2  
In situ conservation often requires the designation of sites where land-use is restricted, such as protected areas and no-fishing zones. Such areas are designed to reduce human impacts on the ecosystem, but the overall benefits of this approach might be compromised if 'leakage' takes place--that is, if impacts that would take place inside the restricted area are displaced to a nearby, unrestricted area. Recently, Oliveira and colleagues became the first group to measure leakage from newly created forest concessions. They showed that restricting land-use reduced deforestation within the concession areas, but dramatically increased it in the surrounding areas. We discuss these findings in the wider context of growing global interest in quantifying the effectiveness of nature reserves.  相似文献   

17.
《PloS one》2012,7(11)
The geographic distribution of Bornean orang-utans and its overlap with existing land-use categories (protected areas, logging and plantation concessions) is a necessary foundation to prioritize conservation planning. Based on an extensive orang-utan survey dataset and a number of environmental variables, we modelled an orang-utan distribution map. The modelled orang-utan distribution map covers 155,106 km2 (21% of Borneo''s landmass) and reveals four distinct distribution areas. The most important environmental predictors are annual rainfall and land cover. The overlap of the orang-utan distribution with land-use categories reveals that only 22% of the distribution lies in protected areas, but that 29% lies in natural forest concessions. A further 19% and 6% occurs in largely undeveloped oil palm and tree plantation concessions, respectively. The remaining 24% of the orang-utan distribution range occurs outside of protected areas and outside of concessions. An estimated 49% of the orang-utan distribution will be lost if all forest outside of protected areas and logging concessions is lost. To avoid this potential decline plantation development in orang-utan habitats must be halted because it infringes on national laws of species protection. Further growth of the plantation sector should be achieved through increasing yields in existing plantations and expansion of new plantations into areas that have already been deforested. To reach this goal a large scale island-wide land-use masterplan is needed that clarifies which possible land uses and managements are allowed in the landscape and provides new standardized strategic conservation policies. Such a process should make much better use of non-market values of ecosystem services of forests such as water provision, flood control, carbon sequestration, and sources of livelihood for rural communities. Presently land use planning is more driven by vested interests and direct and immediate economic gains, rather than by approaches that take into consideration social equity and environmental sustainability.  相似文献   

18.
《Journal of Asia》2019,22(3):666-674
Climate change and land-use change are the most powerful drivers for the invasion of alien species. To understand the integrated effects of these two drivers on pest invasion risk in the future, this study assessed how they impact the invasion risk of Thrips palmi Karny, which is the most serious invasive species in the Korean peninsula. The potential distribution of T. palmi was projected with a MaxEnt model for current and future climate change scenarios (RCP 4.5 and 8.5) based on occurrence records. The potential distribution extends to the north over time, except the eastern high mountainous area, for both RCPs in 2075. The MaxEnt outputs were filtered with agricultural area using data from three land-use change scenarios derived from the Shared Socio-economic Pathways (SSPs), because T. palmi populations can only be sustained in agricultural areas. The potential risk of T. palmi, based on the potential distribution probability in the future agricultural area, increased over time under all RCPs-SSPs combinations. The total area of T. palmi occurrence increased under RCPs-SSP1 and -SSP2 but decreased under RCPs-SSP3, due to agricultural areas being converted to urban areas. In conclusion, based on future climate change scenarios, T. palmi could be distributed throughout the Korean peninsula in the future. The invasion risk in agricultural areas will increase substantially; thus, intensive control measures for T. palmi are required in the future. Our research suggests that using both climate change and land-use change in pest risk mapping study can provide informative data for management strategy.  相似文献   

19.
Biodiversity matters in many aspects for human well-being by providing timber and non-timber products. The most important ecosystems providing these products in West Africa are savannas. In the context of land-use changes, there is an urgent need to understand the impact of land-use on savanna vegetation and biodiversity. This study assesses the impact of land-use on savannas by comparing protected and communal areas. Vegetation relevés were performed in the W National Park and its surrounding communal area in Burkina Faso. Vegetation types were established using ordination and clustering methods. We analyzed to find which environmental factors determine the occurrence of the vegetation types and whether land-use has a specific effect on diversity of vegetation types occurring in both areas. Furthermore, we tested the effect of land-use on vegetation structure and the occurrence of life forms and highly valued tree species. Our results reveal five vegetation types occurring in both areas. Elevation and soil characteristics played the most important role for the occurrence of the vegetation types. Land-use had an effect on vegetation structure, diversity, and the occurrence of life form and highly valued species. Our findings suggest that traditional human land-use does not automatically lead to loss of species and degradation of savanna habitats and that combination of communal and protected areas may be of great importance for the conservation of broad spectrum of biodiversity. Our study demonstrates the complexity of land-use impact on biodiversity patterns and provides insights on what kind of management activities may be most appropriate in both areas.  相似文献   

20.
We studied the influence of site conditions on epiphytic orchids under a subtropical climate in the Kathmandu Valley, Nepal. We analysed 96 systematically distributed grid points situated in Kathmandu Valley across a land-use intensity gradient (national park to urbanised city area). Geographical Information System (GIS) and remote sensing were used for classification of land-use types. We identified 23 species of epiphytic orchids, within 13 genera, from 42 different host tree species. Host preference is obvious for some orchid species (e.g., Dendrobium nobile), with certain tree species (e.g., Schima wallichii, Ficus religiosa) hosting more orchid species than others. The orchid Rhynchostylis retusa was the most common species found on many different host tree species across the land-use intensity gradient. Host species and host bark characteristics (e.g., rugosity, pH and exposure to wind) played a vital role for orchid distribution, with lower abundance in areas of higher impact. Under strong human impact (urban city area), F. religiosa was the dominant host tree, with large individual trees (mean diameter in breast height, dbh?=?1.3?m) providing the habitat for considerable populations of R. retusa individuals. In general, epiphytic orchids were found on larger host trees in urban areas than in areas of lower human impact. We found that some hosts are more likely to harbour orchid species, especially native host species. Older larger trees with rougher bark, low pH, exposed to wind and reduced human impact provided better habitats for orchids. We suggest these characteristics should be considered in urban planning to reduce human impact on the associated orchid epiphytic community.  相似文献   

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