Heterogeneous Land Use Research Articles

Assessing drivers of soil properties and classification in the West Usambara mountains, Tanzania

Improved soil information in tropical montane regions is critical for conservation, sustainable agricultural management, and land use planning, but is often challenged by topographic and land-use heterogeneity. The West Usambara mountains are a part of the Eastern Arc chain of mountains of Tanzania and Kenya, a globally important tropical montane ecoregion made up of isolated fault-block mountain complexes characterized by high biological endemism, population density, and agronomic productivity. We synthesized novel and legacy soil data from published and unpublished studies to better understand the drivers of soil property distributions and soil diversity in the West Usambaras, and to serve as a foundation for improved soil mapping efforts across the Eastern Arc. Analysis of the resulting dataset of 468 sites (ranging in elevation from 1040 to 2230m.a.s.l.) revealed that soil properties varied more significantly by land use and topography than by soil type, suggesting that future mapping efforts in the region should focus primarily on soil property prediction and secondarily on soil classification. Sites under cultivated land uses had the lowest topsoil soil organic carbon (SOC) concentrations and highest pH values, and SOC generally increased with increasing elevation. Valley soils had significantly lower surface SOC concentrations but higher exchangeable bases and pH values than all other landscape positions. Soil pH decreased by an average of 3.5units across the entire elevation gradient and decreased by 1 unit with elevation even after SOC, land use and landscape position were included in multiple regression models. The relationship of cation exchange capacity (CEC) to SOC and clay content varied by landscape position. Therefore, particularly in montane regions where soils can vary significantly over short distances, multiple functions may be necessary to produce improved estimates of parameters such as CEC. Soil classification was driven most strongly by topography, with Acrisols (WRB Reference Group) and Ultisols (U.S. Soil Taxonomy (ST)) as the dominant soil types, located primarily on mid slope, upper slope and crest landscape positions, making up 47% and 75% of observed profiles, respectively. However, five ST Orders and seven WRB Reference Groups were present in the dataset, with the highest soil diversity occurring at lower slope landscape positions. Conclusions drawn from this large dataset support previous work in the West Usambaras and provide a conceptual foundation from which to build improved soil maps across the Eastern Arc and in other tropical montane systems throughout the world.

The impact of land-use mix on residents' travel energy consumption: New evidence from Beijing

Policies that encourage mixed land use are widely believed to make transport more energy efficient. However, few studies have directly examined the impacts of land-use heterogeneity on travel energy consumption at the individual level. Moreover, the definition and measures of land-use heterogeneity are debated. This paper aims to fill these gaps using the large city of Beijing, China, as a case study. Three types of land use are examined in terms of their effects on individual residents’ travel energy consumption. The results suggest that high land-use diversity and a good jobs-housing balance significantly reduces commuting travel. Interestingly, highly heterogeneous retail and housing areas may have high travel energy use, as residents are more likely to go shopping. There are obvious spatial variations in these effects. Residents of suburban ‘newtowns’, where the jobs-housing balance is particularly good, consume less travel energy. The results suggest that decreased use of conventional planning patterns, such as the socialist danwei system, and increasing urban sprawl, bring new challenges to achieving transport efficiency. Mixed land-use policies can be an effective solution to these challenges.

Determination of dominant sources of nitrate contamination in transboundary (Russian Federation/Ukraine) catchment with heterogeneous land use.

Nitrate contamination of surface water and shallow groundwater was studied in transboundary (Russia/Ukraine) catchment with heterogeneous land use. Dominant sources of nitrate contamination were determined by applying a dual δ 15N-NO3 and δ 18O-NO3 isotope approach, multivariate statistics, and land use analysis. Nitrate concentration was highly variable from 0.25 to 22mgL-1 in surface water and from 0.5 to 100mgL-1 in groundwater. The applied method indicated that sewage to surface water and sewage and manure to groundwater were dominant sources of nitrate contamination. Nitrate/chloride molar ratio was added to support the dual isotope signature and indicated the contribution of fertilizers to the nitrate content in groundwater. Groundwater temperature was found to be an additional indicator of manure and sewerage leaks in the shallow aquifer which has limited protection and is vulnerable to groundwater pollution.

Evaluation of MODIS and Landsat multiband vegetation indices used for wheat yield estimation in irrigated Indus Basin

Crop yield estimation has significant importance for policy makers to make timely dicisions on import/export of particular crop. Traditionally, in Pakistan crop yield estimation is being carried out by Village Master Sampling (VMS) that is laborious and time-consuming. Satellite imagery is also being used as an alternative to estimate vegetation health and yield. Various vegetation indices are being used for the purpose however, their efficiency to estimate yield has not been tested. In this study, a comparison was performed among various satellite-based vegetation indices e.g. Soil Adjusted Vegetation Index (SAVI), Modified Soil Adjusted Vegetation Index (MSAVI) Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), to evaluate most appropriate index that performs better in cropping area of irrigated Indus Basin (a complex basin with spatially heterogeneous land use). A stepwise regression based model was developed for remotely sensed crop (i.e. Wheat) using multi-band MODIS and Landsat 8 products based on Land use and Land cover map developed by Semi-Supervised Classification. The results revealed that SAVI showed a fairly acceptable association with reported yield data as compared to other indices. The correlation coefficient (R2) was estimated at 0.60. Yield estimated by SAVI obtained from Landsat 8 showed good results with R2 and Pearson correlation (r), estimated at 0.74 and 0.88 as compared to SAVI obtained from MODIS with 0.63 and 0.79 respectively. The results support that SAVI vegetation indices is reliable for quick and efficient wheat area mapping under Pakistani’s farm conditions.

Mesoscale simulations of atmospheric CO2 variations using a high‐resolution model system with process‐based CO2 fluxes

A new coupled high‐resolution biosphere–atmosphere model (TerrSysMP‐CO2) is applied to simulate mesoscale and diurnal variations of atmospheric CO2 mixing ratios. The model is characterized by process‐based parametrization calculating atmospheric dynamics and biogenic processes considering the prognostically varying CO2 content at the surface. An advanced parametrization of soil respiration is used distinguishing between heterotrophic and autotrophic respiration and explicitly considering the effect of varying soil moisture. In addition to biogenic CO2 fluxes, high‐resolution anthropogenic emissions are included in the simulations.The model performance is verified with eddy‐covariance fluxes and meteorological and CO2 concentration measurements at various heights of a tower. It is found that a correct representation of turbulent mixing is most critical for a precise prediction of near‐surface CO2 mixing ratios and respective vertical gradients. High‐resolution simulations were performed for a region with complex terrain, heterogeneous land use and densely populated areas. The relative influence of diverse land use, orography as well as of synoptic and mesoscale transport on the spatio‐temporal CO2 distribution is analyzed. The results indicate that, in regions with hilly terrain at night and in the morning, the CO2 patterns are strongly influenced by terrain‐induced local circulations. Moreover, in densely populated regions, fossil fuel emissions are an important source of atmospheric CO2. Finally, the simulated canopy fluxes and atmospheric conditions, calculated using two different crop physiological parameter sets, are compared.

A site-level comparison of lysimeter and eddy covariance flux measurements of evapotranspiration

Abstract. Accurate measurements of evapotranspiration are required for many meteorological, climatological, ecological, and hydrological research applications and developments. Here we examine and compare two well-established methods to determine evapotranspiration at the site level: lysimeter-based measurements (EL) and eddy covariance (EC) flux measurements (EEC). The analyses are based on parallel measurements carried out with these two methods at the research catchment Rietholzbach in northeastern Switzerland, and cover the time period of June 2009 to December 2015. The measurements are compared on various timescales, and with respect to a 40-year lysimeter-based evapotranspiration time series. Overall, the lysimeter and EC measurements agree well, especially on the annual timescale. On that timescale, the long-term lysimeter measurements also correspond well with catchment water-balance estimates of evapotranspiration. This highlights the representativeness of the site-level lysimeter and EC measurements for the entire catchment despite their comparatively small source areas and the heterogeneous land use and topography within the catchment. Furthermore, we identify that lack of reliable EC measurements using open-path gas analyzers during and following precipitation events (due to limitations of the measurement technique under these conditions) significantly contributes to an underestimation of EEC and to the overall energy balance gap at the site.

The effect of land type diversity and spatial heterogeneity on farmland birds in Norway

The decline in farmland birds observed throughout Europe during recent decades has attracted much attention. Agricultural intensification or land abandonment are commonly forwarded as key drivers. Several countries have established agri-environmental schemes (AES) to counter these negative trends among farmland birds. This paper reports a study of the relationship between land use and bird species in the agricultural landscape of Norway. The main objective was to investigate the effect of spatial heterogeneity and diversity of land use on total richness and abundance of farmland birds at a national level.Monitoring the distribution and abundance of birds is part of the Norwegian monitoring programme for agricultural landscapes. The monitoring programme is based on mapping of 1×1km squares distributed across the entire agricultural landscape. Within these squares permanent observation points are established for bird monitoring. Detailed interpretation of aerial photographs provides the land classification. We tested the relationship between landscape metrics at different levels of land type detail and species richness and abundance of farmland and non-farmland birds.There was a positive relationship between species richness and abundance of farmland birds and agricultural area. For non-farmland birds the relationship was negative. Spatial heterogeneity of land use was a significant positive factor for both farmland and non-farmland species. High land type diversity was positive for farmland bird richness, but negative for abundance. Non-farmland bird richness was not affected by land type diversity, but abundance had a negative response.The results presented in this paper highlight the importance of a spatial heterogeneous landscape. However, we also found that land type diversity could negatively affect the abundance of both farmland and non-farmland birds. Our findings suggest a need for different management approaches depending on whether the aim is increased species richness or abundance. Achieving both aims with the same means might be difficult. We thus suggest a need for land use analyses before proper management strategies can be implemented.

Partitioning taxonomic diversity of aquatic insect assemblages and functional feeding groups in neotropical savanna headwater streams

Biological diversity can be divided into: alpha (α, local), beta (β, difference in assemblage composition among locals), and gamma (γ, total diversity). We assessed the partitioning of taxonomic diversity of Ephemeroptera, Plecoptera and Trichoptera (EPT) and of functional feeding groups (FFG) in neotropical savanna (southeastern Brazilian cerrado) streams. To do so, we considered three diversity components: stream site (α), among stream sites (β1), and among hydrologic units (β2). We also evaluated the association of EPT genera composition with heterogeneity in land use, instream physical habitat structure, and instream water quality variables. The percentage of EPT taxonomic α diversity (20.7%) was smaller than the β1 and β2 diversity percentages (53.1% and 26.2%, respectively). The percentage of EPT FFG collector-gatherer α diversity (26.5%) was smaller than that of β1 diversity (55.8%) and higher than the β2 (17.7%) diversity. The collector-gatherer FFG was predominant and had the greatest β diversity percentage among stream sites (β1, 55.8%). Our findings support the need for implementing regional scale conservation strategies in the cerrado biome, which has been degraded by anthropogenic activities.

Tree plantations are hot-spots of plant invasion in a landscape with heterogeneous land-use

Invasion of alien plant species is one of the main reasons for biodiversity loss in terrestrial ecosystems. However, alien plant species are not evenly distributed in the landscape. We studied which factors determine the actual level of neophyte invasion in a landscape with heterogeneous land-use and which habitats are the most infected. Since neophyte species with different life-forms can respond differently to the factors determining the invasion, species groups of annual, herbaceous perennial and woody neophytes were also analyzed separately.The study was conducted within the field site network of the Kiskun-LTER program (Hungary), in 16 sites of 5km×5km. Fifteen habitat types were distinguished belonging to five major land-use/land cover types (agricultural land, abandoned agricultural land, tree plantation, semi-natural grassland and semi-natural forest). Present and past land-use, landscape composition and environmental variables were included as factors with a potential impact on the level of invasion.The most important factor determining invasion level was present habitat type, followed by the past habitat type of the location and landscape context. Tree plantations, agricultural habitats and recently abandoned agricultural habitats had the highest level of invasion.As expected, annual neophytes were most abundant in agricultural habitats, while perennial herbaceous neophytes were most abundant in old-fields and plantations, and woody neophytes in tree plantations. Past agricultural land-use was reflected in the higher levels of invasion of annuals and perennials, and past forestry practice resulted in higher levels of invasion of woody neophytes. In a landscape with a higher proportion of tree plantations, not only the tree plantations, but primary woodland patches also showed higher levels of invasion by woody neophyte species.Our results indicate the importance of present and past land-use in plant invasion and suggest that tree plantations are hot-spots of plant invasion and threaten the remnants of semi-natural vegetation.

On the identification of representative in situ soil moisture monitoring stations for the validation of SMAP soil moisture products in Australia

Summary The high spatio-temporal variability of soil moisture complicates the validation of remotely sensed soil moisture products using in situ monitoring stations. Therefore, a standard methodology for selecting the most representative stations for the purpose of validating satellites and land surface models is essential. Based on temporal stability and geostatistical studies using long-term soil moisture records, intensive ground measurements and airborne soil moisture products, this study investigates the representativeness of soil moisture monitoring stations within the Yanco study area for the validation of NASA’s Soil Moisture Active Passive (SMAP) products at 3 km for radar, 9 km for radar–radiometer and 36 km for radiometer pixels. This resulted in the identification of a number of representative stations according to the different scales. Although the temporal stability method was found to be suitable for identifying representative stations, stations based on the mean relative difference (MRD) were not necessarily the most representative of the areal average. Moreover, those identified from standard deviation of the relative difference (SDRD) may be dry-biased. It was also found that in the presence of heterogeneous land use, stations should be weighted based on proportions of agricultural land. Airborne soil moisture products were also shown to provide useful a priori information for identifying representative locations. Finally, recommendations are made regarding the design of future networks for satellite validation, and specifically the most representative stations for the Yanco area.

Evapotranspiration Estimation for an Oasis Area in the Heihe River Basin Using Landsat-8 Images and the METRIC Model

The Heihe River Basin is the second largest inland river basin in arid northwestern China. Accurate estimation of regional evapotranspiration (ET) and its spatial distribution in the oasis area plays an important role for water resource management in the whole basin. The objective of this study was to estimate the temporal and spatial variations of ET for different land cover types in the oasis. To estimate ET values in the growing season of 2013, 14 Landsat-8 images of the study area were processed using the Mapping Evapotranspiration at High Resolution with Internalized Calibration (METRIC) model. A new approach selected hot extreme pixels separately for the desert and oasis sub-areas due to large differences in soil thermal characteristics. Results indicated large temporal-spatial variations in ET in the oasis. The largest ET values occurred over water bodies, followed by arable land, low-lying land and forest. The desert-oasis transition zones (shrubland, sparse forest, medium- and low-coverage grassland) had lower ET values, while the lowest ET values occurred in unused lands (salt meadows, sandy and Gobi deserts). Monthly ET values of all land cover types increased from April, peaked in July, before decreasing until October. Overall, METRIC can provide reasonable ET estimates in a heterogeneous land use types under advective environmental conditions with the selection of appropriate extreme pixels.

Assessment of the importance of spatial scale in long-term land use modeling of the Midwestern United States

This study assesses the value of enhanced spatial resolution in the agriculture and land use component of an integrated assessment (IA) model. IA models typically represent land use decisions at finer resolution than the energy and economic components, to account for spatial heterogeneity of land productivity and use. However, increasing spatial resolution incurs costs, from additional input data processing, run time, and complexity of results. This study uses the Global Change Assessment Model (GCAM) to analyze land use in the Midwestern United States in three levels of spatial aggregation, and three climate change mitigation scenarios. For visualization and simplification of higher resolution model output, we use non-metric multidimensional scaling. We find that the level of spatial aggregation influences the magnitude but not the direction of land use change in response to the modeled drivers, and in the examples analyzed, increasing spatial resolution reduces the extent of land use change.

Identifying and validating freshwater ecoregions in Jinan City, China

Summary Freshwater ecoregion is currently widely used by biologists, conservators and resource managers. Most of ecoregion delineations are developed at the basin scale and are not fully adapted in a practical manner because operational water resources management is primarily conducted by political administrative departments. In this study, an ecoregion delineation framework was proposed to classify three-level ecoregions in Jinan City with geographic information systems and cluster analysis. The first level ecoregion was composed of three watersheds (a part of the Yellow River, Xiaoqing River and Tuhaimajia River) plus the urban area, which was primarily determined on the basis of the city administrative divisions and river watersheds. The classification of the second level ecoregion is primarily based on the spatial heterogeneity of land use. The third level ecoregion was delineated for each second level ecoregion by using the cluster analysis on water quality. At the same time, administrative boundaries were used to rectify the boundaries of each ecoregion in this study to facilitate the administration of each ecoregion. Furthermore, ecological health assessment (IBI) based on fish communities were employed to validate the freshwater ecoregion. The results demonstrated that 73.3% of ecoregions were in line with the distribution of fish IBI, indicating that the freshwater ecoregions are acceptable for future water resources management.

Differences in the Community Built Environment Influence Poor Perceived Health Among Persons With Spinal Cord Injury

ObjectiveTo assess the association between characteristics of the built environment and differences in perceived health among persons with spinal cord injury (SCI) using objective measures of the local community derived from Geographic Information Systems data. DesignSecondary analysis of cross-sectional survey data. SettingCommunity. ParticipantsPersons with chronic SCI enrolled in the Spinal Cord Injury Model Systems database (N=503). All cases were residents of New Jersey, completed an interview during the years 2000 through 2012, had a complete residential address, and were community living at the time of follow-up. InterventionsNot applicable. Main Outcome MeasurePerceived health. ResultsBivariate tests indicated that persons with SCI residing in communities with more (vs less) mixed land use and small (vs large) amounts of open space were more likely to report poor perceived health. No associations were found between perceived health and differences in the residential or destination density of the community. Adjusting for variation in demographic, impairment, quality of life, and community socioeconomic characteristics accounted for the gap in the odds of reporting poor health between persons living in areas with large versus small amounts of open space (odds ratio [OR], 0.54; 95% confidence interval [CI], 0.28–1.02). However, even after accounting for individual background differences, persons living in communities characterized by more heterogeneous land use were twice as likely to report poor health compared with persons living in less mixed areas (OR, 2.14; 95% CI, 1.12–4.08). ConclusionsDifferences in the built characteristics of communities may be important to the long-term health and well-being of persons with SCI who may have greater exposure to the features of their local area because of limited mobility. The results of this study suggest living in a community with more heterogeneous land use was not beneficial to the perceived health of persons with chronic SCI living in New Jersey. Further investigation is needed to assess if the relationships observed in this analysis are influenced by differences in infrastructure and resources across communities. Further research is also needed to investigate the role built environment plays in the long-term health and well-being of persons with SCI in other geographic locales.

Toward Improved Forecasts of Sea-Breeze Horizontal Convective Rolls at Super High Resolutions. Part II: The Impacts of Land Use and Buildings

Abstract Horizontal convective rolls form in coastal areas around Sendai Airport during sea-breeze events. Using a building-resolving computational fluid dynamics model nested in an advanced forecast system with a data assimilation scheme, the authors perform a series of sensitivity experiments to investigate the impacts of land use and buildings on these rolls. The results show that the roll positions, intensities, and structures are significantly affected by variations in land use and the presence of buildings. Land-use heterogeneity is responsible for generating rolls with evident regional features. Major rolls tend to develop downwind of warm surfaces, and they dominate over neighboring rolls; thus, a heterogeneity-scale mode is imposed on the inherent roll wavelength. The roll’s rapid growth is attributable to warm surfaces that initiate a strong coupling among turbulent thermals, convective updrafts, pressure perturbations, and secondary flows in sea breezes. The heterogeneity-induced features differ considerably from the nearly homogeneous features that form over uniform surfaces. Additionally, the wake flow behind buildings helps organize near-surface warm air into streamwise bands that drive streaky ejections. The building-induced turbulence acts to modify secondary flows and displace roll updrafts toward building wakes. Such effects are most effective over villages with scattered houses that are aligned with the ambient wind. Building signatures are elongated in downwind open areas due to sustained secondary circulations. An analysis of turbulent kinetic energy shows that both land use and buildings regulate energy generation and transport, resulting in a clear response in roll growth. Thus, including complex surfaces in forecast models helps determine detailed characteristics and structures of roll convection over coastal regions.

Sustainable energy projects and the community: Mapping single-building use of microgeneration technologies in London

Microgeneration technologies offer the potential for distributed energy supply and consumption resulting in reduced reliance on centralised generation. Adoption of microgeneration for use in community settings is usually understood as having a beneficial contribution to sustainable development. This is particularly relevant in urban environments which present specific challenges relating to the heterogeneity of building and land use. Small-scale installations in buildings also appear to offer technological flexibility at the ‘human’ level, necessary for local participation in shaping the direction of sustainable development. This paper reports on a project concerned with identifying on-site energy generation projects in Greater London. A database was compiled comprising renewable and energy efficient microgeneration installations in multi-occupancy buildings. The relationships between each project and its associated organisations are mapped as a social network, which illustrates the heterogeneity of technologies and actors involved, as well as the flows of funding and expertise. The structure of the resulting networks indicates a lack of participation by social or not-for-profit groups who are traditionally identified as community level actors. The findings indicate that large institutional actors on the supply side may become regarded as renewable energy experts. Hence, there is a need to consider how the concept of community level actors in urban microgeneration projects is applicable to local government and commercial organisations.

Simulating land use change by integrating ANN-CA model and landscape pattern indices

Artificial neural network–cellular automata model has been applied successfully in land use change simulation. However, it has rarely been integrated with landscape pattern indices (LPIs), the embodiment of the spatial heterogeneity of land use. This paper proposed to integrate LPIs as the parameters of artificial neural network–cellular automata model. Subsequent to a description of the principles and implementation of the model, a case study was presented in Changping district. In the case study, two LPIs, the landscape similarity index and patch density, along with 10 other spatial variables, were selected as the influencing factors of land use change. Based on land use maps in years 1988 and 1998, a land use map in 2008 was simulated by the proposed model. Comparing with the actual land use map in 2008 and the simulated result of artificial neural network–cellular automata model, the results showed that the proposed model is more applicable for simulating land use change in the study area; the limitation of this model is the spatial scale and calculation method of LPIs.

系统保护规划的理论、方法及关键问题

PDF HTML阅读 XML下载 导出引用 引用提醒 系统保护规划的理论、方法及关键问题 DOI: 10.5846/stxb201304220768 作者: 作者单位: 中国科学院生态环境研究中心城市与区域生态国家重点实验室,中国科学院生态环境研究中心城市与区域生态国家重点实验室 作者简介: 通讯作者: 中图分类号: 基金项目: 国土资源部公益性行业科研专项项目(201011018) Theory, work frame and hot issues of systematic conservation planning Author: Affiliation: State Key Laboratory of Urban and Regional Ecology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,State Key Laboratory of Urban and Regional Ecology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为了减缓生物多样性丧失的趋势、将有限的保护资源用于关键区域,Margules等提出了系统保护规划(Systematic Conservation Planning)概念和方法,目前该方法已成为国际主流保护规划方法。与传统基于专家决策的保护体系规划方法不同,系统保护规划拥有量化的保护目标、保护成本,并综合考虑保护体系连通性、人为干扰因素,使用优化算法计算,从而获得空间明晰的生物多样性保护体系。在阐述规划理念、规划流程与方法的基础上,重点评述了生物多样性替代指标的选择、保护规划成本的计算、保护目标的设置、规划结果的可靠性评估等关键问题,并结合我国的具体情况,探讨了该方法在我国的应用前景,以期为推进我国生物多样性与生态服务功能的保护做出贡献。 Abstract:Biodiversity provides numerous essential services to humanity. But in past few decades, a large number of species have become increasingly threatened by anthropogenic disturbances. The current rates of extinction are estimated to be 100-1000 times greater than pre-human rates. In order to decrease the biodiversity loss rate and maximize the limited protection resources in key biodiversity areas, Margules raised the idea of Systematic Conservation Planning (SCP). It was widely used in conservation planning. In contrast to traditional method of conservation planning by expert decision, quantitative conservation targets, costs synthesized network connectivity, human disturbances and optimal algorithm were considered in SCP for obtaining a spatial-explicit conservation system. After analysis of planning theory, procedure, methods and review of existing SCP tools, four key issues in SCP research were summarized. The first issue is biodiversity indicators selection which means biodiversity mapping or quantification at genes, species, and ecosystems level to generates a biodiversity distribution matrix. It was demonstrated, at large scale, that quantification of biodiversity importance for species and ecosystems are more suitable than genes method, especially for a combination of species and ecosystems. The second is the estimation of cost that can be calculated in monetary and non-monetary terms. Many methods of cost quantification were reviewed in these paper and it indicated that conservation cost should not only incorporates socioeconomic data, but also biological features. The most important destination of SCP is to achieve some minimum representation of biodiversity features for the smallest possible cost by optimization. So an explicit conservation target is required. However, obtaining a rational target depends largely on the experiences of the experts who are forming these targets and that will inevitable bring about bias due to poor knowledge of the area and taxa. Our review suggests that a convictive method should take both static and dynamic factors into account and to construct heterogeneity target for different conservation feature(ecosystem services, vulnerability, e.g.) as the target in SCP is worthy of further study. Once outcomes of SCP were generated from mathematical algorithm, the reliability and performability are still indeterminacy. Therefore, as the fourth key issue, how to evaluate result and error from SCP are given in our context. Summing up these issues, its foreground for further application in China was also analyzed under current biodiversity situation. Distinctly, Chinese scientists need to realize that the development of ecological productive mode in China have failed to keep pace with rapid economic development. In the face of heterogeneous land use pattern, target function should take various context into consideration during planning procedure. In addition, the expropriation for biodiversity conservation means that the government expropriate land of rural collective economy organization because of dual system of state ownership and collective ownership. For this reason, the estimation of conservation opportunity cost is more meaningful than land purchase cost. This paper, therefore, by reviewing a large amount of past literatures, makes a summary and a commentary on the theory, work frame and key topics on SCP that might promote the conservation of biodiversity and ecosystems in China in the future. 参考文献 相似文献 引证文献

Urbanisation trends in developing countries: Comparative study of Yogyakarta City and Kathmandu Valley

In the beginning of the third millennium, most third world countries faced a trend of high urbanisation rates. Many medium-sized cities tend to be metropolitan cities, so-called metropolitanisation. This paper examines the urbanisation of the Kathmandu Valley and Yogyakarta and their urban growth rates despite being in different geographical plates. In addition, we also analyse the common issues with urbanisation and haphazard conversion of the agricultural land into built-up areas within the city fringes. Yogyakarta is a city in Indonesia, which is experiencing an inevitable process of urbanisation and so is the Kathmandu Valley in Nepal. The aim of this paper is to explore the urbanisation process and trends in developing countries. A highly dynamic spatial pattern of urbanisation observed in Nepal and Indonesia where the spatial transformation is the main evidence that can be used to analyse the urbanisation process. The review showed the urban area increased by 142.8 square kilometres from 1970 to 2010. The highest increasing number of urban areas occured from 1990 to 2000, dominated by fertile agricultural land beign converted into urban built-up areas. The very high increasing number of urban built-up areas do not cater for increasing population growth efficiently. In the case of the Kathamndu valley, urban built-up areas showed a slow growth trend in the 1960s and 1970s, dominated by agriculture urbanisation, but the growth became rapid from the 1980s onwards. This rapid growth is guided by higher conversion of land into urban built-up areas. The urbanisation process has developed fragmented and heterogeneous land use combinations in the valley, not complimenting the natural environmental conditions. Therefore, urbanisation processes in Yogyakarta and the Kathmandu valley require planned development to best utilize resources and their potential.

Age-friendly cities and environments: an investigation of the living environment of older people in England based on the MRC Cognitive Function and Ageing Study II

BackgroundWith trends in population ageing, the idea of age-friendly cities has been proposed with a focus on built and social environmental features related to active ageing. We aimed to describe the living environment of older people at small area level using data from the Cognitive Function and Ageing Study II (CFAS II), a representative sample of 7505 people aged 65 years and over in England. MethodsLiving environment was described at the community and street level. At community level, postcodes of the CFAS II participants were mapped onto 557 Lower Layer Super Output Areas and linked to environmental data in Neighbourhoods Statistics including area deprivation, crime, distance to services, land use, and green space. Street level assessment was based on an observational instrument designed for UK postcodes, the Residential Environmental Assessment Tool, by use of visual streetscape images of Google Street View. The measurement method was validated and showed acceptable intermethod reliability of physical and visual image audits. Three rural and urban categories (urban conurbation, urban city and town, rural areas) were defined by the 2011 rural–urban classification. FindingsTwo-thirds (n=4905) of the older population lived in an urban conurbation. More of the younger old (aged 65–79 years) than older old (≥80 years) lived in rural areas (1158 vs 396). In the overall population, we found moderate associations between area deprivation and crime (Spearman correlation=0·6), distance to services (−0·2), land use mix (0·5), and green space (−0·3), but they were weaker in rural areas. In addition to rural–urban and area deprivation differences, substantial variations in built and social environmental features were found at community and street levels: communities in urban conurbations generally had high crime, shorter distance to services, high heterogeneity of land use, and low proportion of green space with worse quality of street level conditions than did communities in rural areas. InterpretationOlder people in England live in a wide variety of environments with potential effect on health and wellbeing. Use of new technology can help to observe and explore variations in living environments at the small area level systematically and comprehensively; this provides opportunities to identify important environmental features related to healthy ageing and develop practical guidelines for policy planning to create age-friendly cities and environments through an evidence-based approach. FundingThere is no specific funding contributing to this study. Medical Research Council Cognitive Function and Ageing Study II (MRC CFAS II) was funded by the Medical Research Council (grant number G0601022).