Assessing the broad-scale impact of agriculturally transformed and protected area landscapes on avian taxonomic and functional richness

Anthropogenic modification of natural habitat is resulting in a widespread loss of biodiversity. One of the primary responses of human societies to biodiversity loss has been the creation of protected areas. Two of the most important questions in conservation biology are: (1) whether protected areas are playing their intended role as reservoirs of biodiversity; and (2) whether habitat outside protected areas, particularly in agricultural landscapes, plays a significant role in maintaining biodiversity and the ecosystem services that it provides. Even though empirical evidence is still lacking on the exact mapping from functional group richness to specific ecosystem services, functional groups are good indicators of ecosystem functioning and thus service provision. We classified the South African avifauna into nine functional groups and tested at a coarse grain for differences in functional group composition between landscapes containing predominantly agricultural vs. protected areas. We used a matched pair sampling design to control for confounding variance. We found that avian functional groups respond in quantitatively and qualitatively distinct ways to agriculturally dominated landscapes. Raptors and scavengers displayed the most consistent losses, while nutrient dispersers and grazers tended to increase. Spatial detrending and randomisation tests suggested that only raptors and scavengers are negatively affected by agricultural landscapes independently of spatial autocorrelation. Thus, protected area landscapes are serving as important reservoirs of functionally important upper trophic populations while agricultural landscapes facilitate the presence of species that link aquatic and terrestrial systems. These results demonstrate the potential for complementary facets of functional diversity to exist on landscapes containing vastly different land-uses.     

Biodiversity conservation and livelihoods in human-dominated landscapes: Forest commons in South Asia

Strict protected areas are a critical component in global biodiversity conservation, but the future of biodiversity conservation may well depend upon the ability to experiment successfully with a range of institutional forms, including those that permit human use. Here, we focus on forest commons in human-dominated landscapes and their role in biodiversity conservation at the same time as they provide livelihood benefits to users. Using a dataset of 59 forest commons located in Bhutan, India, and Nepal, we estimated tree species richness from plot vegetation data collected in each forest, and drew on interview data to calculate a livelihoods index indicating the overall contribution of each forest to villager livelihoods for firewood, fodder, and timber. We found that tree species richness and livelihoods were positively and significantly correlated (rho = .41, p < 0.001, N = 59). This relationship held regardless of forest type or country, though significance varied somewhat across these two factors. Further, both benefits were similarly associated with several drivers of social-ecological change (e.g., occupational diversity of forest users, total number of users, and forest size), suggesting identification of potential synergies and complexes of causal mechanisms for future attention. Our analysis shows that forest commons in South Asia, explicitly managed to provide livelihoods for local populations, also provide biodiversity benefits. More broadly, our findings suggest that although strict protected areas are effective tools for biodiversity conservation, a singular focus on them risks ignoring other resource governance approaches that can fruitfully complement existing conservation regimes.     

Scheduling conservation action in production landscapes: priority areas in western New South Wales defined by irreplaceability and vulnerability to vegetation loss

Scheduling conservation action is necessary when the available resources for conservation are insufficient to adequately protect all of the natural features (e.g. species, vegetation types, ecosystems) in a region, at least in the short-term. We propose an approach to scheduling conservation action in production landscapes. It is based on two characteristics of potential conservation areas. The first is vulnerability — the likelihood or imminence of destruction or alteration of native vegetation. The second is irreplaceability — the likelihood that an area will be needed to contribute to a set of conservation targets nominated for the region's features. We argue that highest priority for conservation action should go to those areas with both high vulnerability (urgent protection needed to avoid destruction) and high irreplaceability (few or no alternatives if destroyed). To establish the context and rationale for our approach, we review some previous methods for scheduling nature conservation. We then apply our approach to the Western Division of New South Wales, a region of about 325,000 km², by deriving information on the vulnerability of 248 land systems to two threatening processes (clearing and cropping) and measuring the irreplaceability of potential conservation areas. Our results are maps of areas where conservation action is most urgently needed if regional conservation targets are not to be compromised.     

The buffer effect and the selection of protected areas for waterbirds in Britain

The buffer effect predicts that where the reproductive success and survivorship of a species vary between potential habitats, sites will be sequentially filled according to a preference hierarchy. Once favoured sites reach saturation, numbers on the less-suitable/poorer quality sites will show a greater rate of increase compared with those on favoured sites. Supporting evidence for a buffer effect is readily available in the literature for many species, although this is generally restricted to small-scale analyses. In this paper we test for a buffer effect on a national scale for 19 species of waterbirds regularly wintering in the UK for which populations have increased nationally. The results provide little support for the effect, with only four species showing significant negative correlations. Nonetheless, a number of factors are likely to confound the occurrence/identification of a buffer effect for these species, including site area and data limitations. By contrast, for the majority of these 19 species, those sites where initial population totals are largest are also those with the fastest rates of population increase. Encouragingly, these sites are, therefore, more likely to be classified and managed as Special Protection Areas (SPAs) or Ramsar sites using the current numerical criteria for identifying such conservation areas.     

Just passing through: Global change and the conservation of biodiversity in protected areas

Climate and land-use changes are expected to cause many species to shift into or beyond the boundaries of protected areas, leading to large turnover in species composition. Here, we tested whether long-established protected areas in Canada were more robust to such climate change impacts than areas with no formal protection by measuring changes in modeled butterfly species distributions (n = 139) within them. We used a recently established distribution modeling technique, Maxent, to model butterfly species’ distributions in two epochs (1900-1930 and 1960-1990). We compared rates of butterfly species richness and composition change within protected areas against distributions of randomly selected, ecologically similar, but non-protected, areas. Change in species richness and composition within protected areas were, for the most part, the same as changes observed among random areas outside protected area boundaries. These results suggest that existing protected area networks in Canada have provided little buffer against the impacts of climate change on butterfly species richness, possibly because land-use change surrounding long-standing protected areas has not been substantial enough to elevate the habitat protection afforded by these protected areas relative to other areas. Although protected areas are unarguably beneficial in conserving biological diversity, their capacity to maintain habitat appears insufficient to prevent broader-scale climate changes from sweeping species beyond their boundaries.     

A gap analysis of terrestrial protected areas in England and its implications for conservation policy

Many protected area (PA) systems have developed in response to socio-economic and aesthetic criteria and need to be modified to increase their conservation value. National gap analyses are an important step in describing and addressing this problem, so we sought to determine the representativeness of English PAs devoted to biodiversity conservation by using Natural Areas (NAs), elevation and PA boundary data. We found that National Nature Reserves (NNRs) and Sites of Special Scientific Interests (SSSIs) cover only 6.3% of England and are generally small, with respective median areas of 1.1 and 0.2 km². The English PA system under-represents lowland areas and provides a median level of 2.5% protection for the NA types, with seventy nine per cent of NA types having less than 10% protection. Therefore, we suggest that England's PA system needs to be expanded, although this would probably entail modification of existing legislation to increase involvement by landowners. We also compare our results with previous appraisals that used species distribution record data and suggest that landscape-level analyses may give a more accurate and less positive assessment.     

Distribution and protected area coverage of endemic taxa in West Africa’s Biafran forests and highlands

The forests and highlands along the southern portion of the Nigeria-Cameroon border and on the island of Bioko have long been recognized as being biologically diverse. This region (referred to as the Biafran forests and highlands) is a center of endemism for a wide variety of taxa including, but not limited to, primates, anuran amphibians, birds, freshwater fish, butterflies, dragonflies, and trees. Though these groups have diverse distributions, conservation efforts have to date largely been focused on lowland areas. We conducted a GIS-based analysis of point locality records for three groups characterized by high endemism (primates, anuran amphibians, birds) in order to examine both their spatial and altitudinal distribution throughout the study area. We also evaluated the distribution of existing and potential protected areas relative to highland areas and the distribution of endemics. Our analysis suggests that the existing protected area system provides poor coverage of montane habitats and their associated endemic taxa. Complementarity analysis suggests that, if the protected area network were expanded to include a small number of highland sites, coverage of endemic taxa could be significantly improved. Many of these important highland sites are currently under intense pressure from habitat loss and hunting. If the full range of biodiversity present in the Biafran forests and highlands is to be preserved, new protected areas should be gazetted that take the varied distributions of the regions endemic taxa into account.     

Forest degradation deepens around and within protected areas in East Asia

Forest degradation in protected areas has been monitored around the world with remote sensing data, but degradation processes undetectable by widely used satellite sensors have been largely overlooked. Increased human pressures and socioeconomic development make forest protection more challenging, particularly for forest ecosystems that lie across national borders because of the differences in national socioeconomic policies and conditions within them. Here with Landsat data, Google Earth images, and field observations, we show that, in two adjacent biosphere reserves across the border of China and North Korea, over one half of primary forest landscapes have been deteriorated by exploitive uses, including seed harvesting and systematic logging. The combined effects of detectable and hidden degradation processes have further damaged forest ecosystems in the core areas in the two biosphere reserves, threatening sustainable biodiversity conservation in the region. It is urgent to develop cross-border collaborative conservation strategies that can help combat both detectable and hidden degradation processes at a regional scale.     

Village size and forest disturbance in Bhadra Wildlife Sanctuary, Western Ghats, India

Habitat fragmentation, land cover change and biodiversity loss are often associated with village communities in protected areas, but the extent and intensity of such impacts are often inadequately assessed. We record resource use and depletion by human inhabitants by conducting ecological surveys in six villages and social surveys in all 13 villages of varying sizes in India’s Bhadra Wildlife Sanctuary (492 km²). We examined the occurrence of 10 regionally-specific ecological indicators that encompassed several aspects of human activities. Thirty transects with 180 total sampling locations recorded the occurrence of these specific habitat disturbance variables. High correlations between the variables led to the use of principal component analysis to derive an effective summary index that reflected disturbance intensity and determined village ecological impacts spatially. A generalized linear model was fit to determine the rate at which disturbance decreases as we move away from village centers. Our model indicates that village size class, distance from the village and proximity to other villages were significant predictors of the disturbance index. The index distinguished each village’s spatially explicit ecological impact. We estimated that an average area of 23.7 km² of the forest surrounding the six focal villages was altered by human activities. These six villages have directly impacted 8-10% of this protected area.     

不同土地利用结构生态系统服务功能价值的变化研究——以内蒙古自治区伊金霍洛旗为例

生态系统服务功能价值理论可定量估算各类生态系统为人类提供服务的经济价值。阐述了生态系统服务功能价值理论定量评价土地资源的作用 ,并应用和修正生态系统服务单价方法估算内蒙古自治区伊金霍洛旗1990～ 2 0 0 0年土地利用的生态效益 ,结果表明 10年内该旗生态系统服务价值减少 2 2 6 96亿元 ,证明人类经济发展对生态环境的影响巨大 ,且一旦生态环境遭到破坏则很难恢复。     

Assessing the performance of the existing and proposed network of marine protected areas to conserve marine biodiversity in Chile

The growing concern about the profound influence of human activities on marine ecosystems has been the driving force behind the creation of marine reserves in the last few decades. With almost 4200 km of coastline, Chile has not been the exception to this trend. A set of conservation priority sites has recently been proposed by the Chilean government to expand the current marine reserve network. In this study, we used the most comprehensive information currently available on the distribution of 2513 marine species in Chile to assess the efficiency of the existing system of marine protected areas (MPA) and the conservation priority sites identified by the government. Additionally, we evaluated the vulnerability of the reserve network selected with respect to threatening human activities. Our results show that both the existing protected areas and the proposed priority sites are relatively effective at protecting Chilean marine biodiversity. However, the majority of the species that are not represented within the existing or projected MPA network have very restricted distributions and are, therefore, of high conservation concern. To cover all species requires a network of 35 MPAs (46% of the total number of planning units). Many of the sites identified as irreplaceable present conflict with one or more human activities, particularly in the central region of the country. This study emphasizes the need for a systematic conservation planning approach to maximize the representation of species and prioritize those areas where conflicts between marine biodiversity conservation and human activities may occur.     

基于多源卫星数据的黑河中游绿洲区土地利用分类与作物类型提取及其时空变化分析

研究土地利用与作物种植结构变化是分析农业生产活动和生态环境变化的重要手段。黑河中游绿洲是我国西北地区最重要的绿洲之一,也是甘肃省主要的商品粮基地。为准确研究黑河中游绿洲的时空变化情况,本文利用2001—2015年MODIS卫星数据,提取分析了近15年黑河中游绿洲范围的时空变化特征;基于2001—2016年的Landsat/TM,利用支持向量机分类法获得该绿洲区土地利用分类;基于2011—2016年的HJ1A/CCD数据,利用HANTS滤波后的NDVI时间序列曲线,获得作物种植面积的精细分类。经验证,该土地利用分类精度高于88.46%,kappa系数为0.81;小麦和玉米与实地验证点对比的分类精度高于90.8%。结果表明:1)黑河中游绿洲面积总体为增加趋势,仅2014年、2015年略有减少,绿洲面积从2001年的2 701 km2增加到2015年的2 936 km2。2)2001—2016年间,裸地面积减少436.7 km2,耕地面积增加91.3 km2,草地、林地面积增加289.6 km2。3)2011—2016年,小麦、玉米种植面积均有减少,小麦共计减少195.77 km2,玉米减少144.37 km2。研究结果可为当地农业种植结构的调整和作物估产及绿洲生态保护提供一定依据和参考。     

Relationship between soil erosion and distance to roadways in undeveloped areas of China

The presence and condition of roadways control the utilization of natural resources, which are associated with direct and indirect impacts on soil erosion in undeveloped countries. This paper addresses the relationship between soil erosion and distance to roadways in Xingguo County, an undeveloped area in Jiangxi Province of South China, for four time periods, 1958, 1975, 1982, and 2000. Soil erosion maps for each time period were interpreted using remote sensing and GIS technology for buffer zones four kilometers wide, subdivided into eight strips, each 0.5 kilometers wide, which were located alongside various types of road classes, namely trunk, town, village, and unpaved. The distribution patterns of various types of erosion were identified by GIS overlay of buffer strips and soil erosion maps. Results demonstrate that soil erosion cases found in buffer zones along both sides of trunk and town roads are the most severe, and areas with severe erosion decrease as distance from the strip to the road increases. However, moderate and slight erosion cases only have a minor relationship to the strip to road distance. There are more severe erosion cases than moderate and light erosion cases alongside village and unpaved roads, but the total area is not distinctly different from moderate and slight erosion cases, and severe erosion cases tend to decrease with an increase in the strip to road distance. Also, areas with severe erosion differentiated by time periods in the strips alongside roadways of all classes, except trunk roads, rank from highest to lowest as follows: 1975, 1958, 1982, and 2000. Notably, severe erosion areas in 1975, 1958 and 1982 are all quite extensive. Soil erosion alongside roadways of various classes is impacted jointly by historical policy, distance to roadways, and landscape. In undeveloped countries and areas, much more attention should be paid to the impacts of road construction, specifically soil erosion associated with road edge construction, and relevant measures for forest resource conservation should be formulated before initiating road construction projects.     

山东沿海地区土地利用和景观格局变化

为分析和预测山东省沿海区域土地利用和景观格局变化,该文将景观格局指数作为评价土地利用变化模拟模型的基本指标;基于RS和GIS技术分析2000-2010年土地利用和景观格局的变化特征,并尝试CA-Markov模型预测土地利用变化,发现其在景观格局预测方面的不足,因而探索和提出Spatial-Markov模型,该模型不仅适合于土地利用变化模拟,也适合于景观格局过程分析。具体包括:1)基于2000、2005和2010年的Landsat影像进行土地利用分类,分析10a间土地利用和景观格局的变化特征,表明:耕地面积不断减少,城镇和农村居民点用地不断扩张而占用大量耕地,草地等又不断开垦为耕地;区域景观格局破碎化趋势显著,人为干扰加剧,各种景观类型的分布向均匀化发展;2)基于Logistic-CA-Markov模型,以11个变量、2000和2005年土地利用分类图为基础,模拟的2010年土地利用图与观测值相比较,虽然得到的Kappa系数较高(0.8530),但难以支持对景观格局特征的预测和分析;3)提出Spatial-Markov模型,基于2000和2005年土地利用分类图模拟2010年土地利用,模拟结果的Kappa系数高达0.8872,且景观格局指数也与观测值非常接近,因此,选择该模型预测2015和2020年的土地利用和景观格局;4)预测结果表明,2010-2020年间耕地面积将继续减少,城镇、农村居民点将继续保持快速增长的态势;景观尺度除了分形维数,其他指数保持2000-2010年间的变化趋势,而在类型尺度,除水域和未利用地外,各种景观类型多个景观指数将总体保持原有的变化趋势。该研究可为山东沿海区域土地利用规划提供参考,并为土地利用预测研究提供了一种新的方法。     

基于遥感的现代与传统农业区域土地利用格局差异分析

该文以黑龙江省富锦市为研究区,以第二次土地调查数据库成果为数据源,基于GIS平台和景观指数法分析国营农场辖区即现代农业区和地方政府辖区即传统农业区的土地利用景观格局的差异,旨在为土地整治项目布局提供依据。结果表明:研究区内林带、道路、渠沟构成了区域土地利用空间格局的框架,直接影响着各种地类的规模和形状。国营农场辖区即现代农业区内林带、道路、渠沟等农业基础设施纵横交错、体系健全、井然有序,林网密度为传统业农区的1.72倍,路网密度为传统农业区的1/2,渠网密度为传统农业区2.3倍。园地、林地、牧草地、其他土地、城镇村及工矿用地散布于研究区内。耕地作为区域景观的基质,遍布整个研究区,但现代农业区与传统农业区内耕地类型存在明显差别,前者水田比例明显高于后者。土地经营管理制度不同,是导致国营农场辖区与地方政府辖区土地利用格局差异的重要原因。该项研究为科学安排土地整治项目提供参考。     

基于遥感和GIS的平原和山区贫困县农村耕地利用演变对比

厘清耕地在不同地形环境下的利用情况与变化规律是实现农业现代化管理与脱贫攻坚的前提。结合遥感和GIS技术,该文对比了平原区贫困县(科尔沁左翼后旗)和山区贫困县(酉阳县)农村耕地数量、质量、分布与种植结构的演变差异。结果表明:1)平原县人均耕地数量远高于山区县,山区县耕地减少,但平原县耕地不降反增。2)平原县耕地质量较低,劣质耕地数量变化剧烈,山区县耕地质量略高,减少的耕地以中低质量为主。3)空间分布上耕地均呈集聚式发展,平原县耕作半径大于山区县,且向外扩张,山区县则向内收缩;平原县耕地斑块数和最大斑块指数持续增大,而山区县斑块数骤减且最大斑块略有增加;平原县平均斑块面积远大于山区县,研究期内均有不同程度地提高;平原县耕地面积加权平均斑块分维数提高,山区县则降低;平原县耕地优势分布在低地形位区,且变化不显著,山区县则优势分布在中低梯度区,且优势度增加。4)平原县普遍种植粮食作物,山区县以粮食作物为主,但经济作物占比较大且逐年增加。研究认为,地形与耕地资源禀赋的差异造成生产要素比较优势不同,进而耕地利用与农业生产模式不同,在社会经济和政策制度的驱使下,两县耕地利用朝着不同方向发展。     

亚热带低山丘陵区混播冬性牧草-水稻短期草田轮作系统的研究

1991～1994年在亚热带低山丘陵区(四川芦山县)进行的混播冬性牧草-水稻短期草田轮作系统的研究结果表明,混播冬性禾草和豆草与水稻轮作,即意大利黑麦草+紫云英→水稻、意大利黑麦草+南苜蓿→水稻和意大利黑麦草+白三叶草→水稻3个轮作系统在水稻产量高于对照的情况下获得高饲料价值,较充分地利用了禾草和豆草的共生互补作用,改善了土壤肥力状况,提高了农田生态位的利用效率,从而获得了较高的总生产效率。     

重庆典型山区耕地资产贬值特征及其发生机理

耕地边际化是山区一种典型的土地利用现象,厘清其表现特征及机理对实现土地资本增值和乡村振兴具有重要价值。基于2012和2018年重庆典型山区901份农户问卷及农产品成本收益资料,该文揭示了耕地资产价值的演变特征,并构建Probit模型识别其驱动因素与发生机理。结果表明:1)近年来,案例区耕地资产价值不断下降,单位面积玉米收益由正转为亏本,主要农作物加权净收益从2012年的1384.50元/hm~2降至2018年的252.30元/hm~2;耕地租金从1577.45降至361.65元/hm~2,同时零租金流转比例从71.09%升至82.21%,说明研究区耕地资产价值正处于下滑阶段。2)地块面积、与家庭距离、地块质量和土地细碎化是耕地零租金流转的关键因素,而务农机会成本上升是根源。耕地资产贬值的机理是,城镇化推高了劳动力成本,农业利润不断下降直至亏本,耕地资产出现贬值。期间,山区闲置或抛荒的土地资源变得愈发丰富,政府应合理引入资本,充分挖掘相对富裕的土地资源,以实现土地资本增值和发展当地经济。此外,政府应停止在山区大规模的开垦耕地,但可通过土地整治适当补充耕地,避免公共财政资金浪费和破坏生态环境。     

北京西部山区1999年生态足迹计算与可持续性分析

在剖析生态足迹分析法的理论基础和计算模型的基础上,计算北京西部山区门头沟1999年的人均生态足迹和生态容量。根据人均生态足迹和生态容量对比分析,得出1999年门头沟区处于生态赤字状态。经剖析造成生态赤字的原因,指出了该区在加强生态环境建设和养护,增加生态容量等方面应采取的措施与政策。提出以生态足迹作为山区生态可持续性评价指标的优点及当前存在的缺点。