Livestock-driven land use change to model species distributions: Egyptian vulture as a case study

Species distribution models (SDMs) are increasingly used to predict species ranges and their shifts under future scenarios of global environmental change (GEC). SDMs are thus incorporating key drivers of GEC (e.g. climate, land use) to improve predictions of species’ habitat suitability (i.e. as an indicator of species occurrence). Yet, most SDMs incorporating land use only consider dominant land cover types, largely ignoring other key aspects of land use such as land management intensity and livestock. We developed SDMs including main land use components (i.e. land cover, livestock and its management intensity) to assess their relative importance in shaping habitat suitability for the Egyptian vulture, an endangered raptor linked to livestock presence. We modelled current and future (2020 and 2050) habitat suitability for this vulture using an organism-centred approach. This allowed us to account for basic species’ habitat needs (i.e. nesting cliff) while gaining insight into our variables of interest (i.e. livestock and land cover). Once nest-site requirements were fulfilled, land use variables (i.e. openland and sheep and goat density) were the main factors determining species’ habitat suitability. Current suitable area could decrease by up to 6.81% by 2050 under scenarios with rapid economic growth but no focus on environmental conservation and rural development. Local solutions to environmental sustainability and rural development could double current habitat suitability by 2050. Land use is expected to play a key role in determining Egyptian vulture's distribution through land cover change but also through changes in livestock management (i.e. species and stocking density). Change in stocking densities (sheep and goats/km²) becomes thus an indicator of habitat suitability for this vulture in our study area. Abandonment of agro-pastoral practises (i.e. below ∼15–20 sheep and goats/km²) will negatively influence the species distribution. Nonetheless, livestock densities above these values will not further increase habitat suitability. Given the widespread impacts of livestock on ecosystems, the role of livestock and its management intensity in SDMs for other (non-livestock-related) species should be further explored.     

土地利用变化对鸟类栖息地连通性的影响——以鄂州市为例

土地利用变化是造成栖息地破碎、缺失与退化的重要原因。生态网络能保护重要栖息地,促进栖息地之间的物质与能量流动,对区域土地利用规划和生物多样性保护具有重要意义。以鄂州市为研究区,基于CLUE-S模型预测现状延续、生态保护和城市扩张3种土地利用情景,将生境质量作为遴选生境斑块的依据之一,以鸟类最大迁徙距离为阈值构建生态网络,从连通概率指数PC和斑块重要性指数dPC两方面,探讨土地利用变化对鸟类栖息地连通性的影响。结果表明：(1)不同情景的地类数量和空间结构均有差异,与生态保护相比,城市扩张情景的建设用地增加11603.52 hm~2,林地、耕地和水体减少5041.8 hm~2、2540.16 hm~2、3385.8 hm~2,新城区、山地风景区与水体周边是主要变化区域;(2)现状延续和城市扩张情景的生境斑块降至235块和216块,网络出现破碎化,生态保护情景增至367块,网络结构完整但空间位置改变;(3)2004—2024年PC表现为先上升后下降再上升的趋势,生态保护的PC高于现状延续和城市扩张,且利于保护短距离迁徙鸟类;(4)生态保护情景边缘型和关键小型斑块得到保护,第一等级斑块增加,城...     

基于土地利用变化的黄土丘陵区生境质量时空演变特征——以榆中县为例

生境质量是生态系统服务水平的重要表征,是区域生态安全保障和人类福祉提升的关键环节,评估土地利用变化引起的生境质量时空演变可为区域生态保护和土地管理提供科学依据。以典型黄土丘陵区县域——榆中县为例,基于Arc GIS平台和InVEST模型探讨了该县1995、2005和2015年生境质量空间格局及其演变特征。结论如下:(1)研究区土地类型和景观格局变化明显,主要土地利用变化是耕地转向建设用地和林地,以及草地和耕地之间的相互转变,这些变化导致景观异质性增强和破碎度上升。(2)生境质量空间格局一直表现为"南部高、中部居中、北部低"的态势。生境质量上升区域主要在北部,原因是"退耕还林"及"生态北山"工程的实施使得林地面积增加,下降区域主要在中部,主要是由建设用地扩张占用耕地造成的。(3)生境质量热点以及"H-H"型聚集区主要位于南部山区,而冷点和"L-L"聚集区主要位于北部黄土丘陵区,2015年生境质量空间集聚程度较1995年有所增强,"H-H"聚集区增加0.68%,"L-L"聚集区增加0.67%。对该类型区域生境质量优化提出了相应的政策建议。     

土地利用变化对生境网络的影响——以苏锡常地区白鹭为例

生境网络对于物种更具有生态意义。研究土地利用变化对生境网络的影响,对破碎景观中种群的扩散和迁徙至关重要。研究结果有助于区域生境网络的恢复和完善,从物种的角度而非景观结构的角度优化生态网络。以城市化快速发展、土地利用变化明显的苏锡常地区为研究区域,优势湿地鸟类白鹭为代表物种,构建物种生境斑块约束条件概念模型,提出按照物种生活习性特征划分、选择生境斑块的方法,并从斑块和网络结构两个视角分析了土地利用变化对生境网络的影响。结果表明:(1)2000—2010年研究区白鹭生境的适宜地类总面积虽有所增加,但主要由于大量新增线性人为干扰致使白鹭生境网络质量下降;(2)白鹭生境网络在研究区不是全区覆盖的回路,基本由宜兴—溧阳片、无锡滨湖片、苏州吴中片和苏州阳澄湖片4个小片网构成,其完整程度按照宜溧片、滨湖片、吴中片、阳澄湖片降次排列;至2010年,宜溧片破坏最为严重,滨湖片和吴中片次之,阳澄湖片受破坏程度相对最弱。总体上,白鹭生境境况在10年间恶化明显,土地利用变化朝着不利于白鹭持续生存的方向发展。     

Detecting plant spatial pattern change after disperser loss: A simulation and a case study

Disruption of seed dispersal processes may affect plant population spatial structure. We used a spatial simulation model and an empirical case study to assess the conditions under which the loss of seed dispersers has a detectable effect on a species' spatial pattern. Our simulation experiments suggested that detecting spatial change following disperser loss will be difficult, except when rates of fruit removal are initially high and then completely disappear. To contextualize the simulation modeling, we used spatial point pattern analyses to characterize the spatial pattern of two large-seeded species (Leucopogon nutans, a fire-killed seeder shrub and Macrozamia riedlei, a long-lived, resprouting cycad) in the jarrah (Eucalyptus marginata) forests of southwestern Australia. The plant species' primary disperser, the emu (Dromaius novaehollandiae), was absent from one of the sites we considered, but present at the other two. There was no detectable difference for either plant species in the strength of aggregation between sites with and without emu. However, even if disperser loss may not greatly affect local spatial structure for most plant species, it is likely to be important for long distance dispersal and genetic structuring of populations, so accurate characterization of the dispersal kernel is critical, especially in terms of plant emigration.     

Using remote sensing image texture to study habitat use patterns: a case study using the polymorphic white-throated sparrow (Zonotrichia albicollis)

Aim Ecological factors that vary along spatial scales can greatly influence the outcome of evolution. However, often it is difficult for researchers to identify significant ecological variables that might be associated with the geographical distribution of phenotypes and genotypes in nature. In this paper, we use remote sensing image texture analyses to investigate breeding territories of the white‐throated sparrow (Zonotrichia albicollis), a polymorphic passerine species that has been shown to segregate spatially according to morph. Our aim was to examine how an integrative measure of landscape feature, such as image texture, could be used to distinguish subtle differences in habitat use and, presumably, habitat selection. Location A population of white‐throated sparrows located 1.5 miles east of the Cranberry Lake Biological Station in the Adirondack Mountains of St Lawrence County, New York, was used in this study; the study site itself was approximately 1 km². Methods We analysed 27 territories (16 white males; 11 tan males) to determine if image texture can be used to distinguish differences in vegetation and structure in territories of the two colour morphs. First (variance)‐ and second (homogeneity)‐order image texture measurements with three different window sizes were derived using the green, red, and near infrared bands of Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data. Texture was then placed into t‐tests to determine statistical differences between the territories of the two male morphs. Results Significant differences between the territories of the two morphs were found in both variance and homogeneity texture measures in the red and green ASTER bands in all three window sizes. There were no differences with any near infrared texture measures. Main conclusions Examination of first‐ and second‐order statistical measures indicated that the territories of tan males have significantly more spectral variance than the territories of white males, while white males’ territories are significantly more homogeneous. These findings are consistent with the previous finding of the morphs settling in ‘high’ and ‘low’ neighbour density habitats that differ with respect to the amount of useable area on their borders. Previous study has also suggested that white and tan male territories differ according to overall landscape structure, not vegetation composition. Therefore, we suggest that red and green spectra may be more useful when examining differences in territory structure and possibly territory quality of similar edge‐type species. Our results suggest that image texture is a useful tool for ecological and evolutionary modelling of the distributions of phenotypes/genotypes across landscapes.     

县域土地利用变化下生态系统服务价值损益预测——以重庆市巴南区为例

土地利用/覆被变化是全球变化的研究热点,评估县域土地利用变化对生态系统服务价值损益的影响对促进生态环境保护和推动城乡区域协调发展具有重要意义。基于重庆市巴南区2000年以来连续5期遥感影像及CLUE-S模型,量化土地利用变化对生态系统服务价值的影响并预测2020-2030年服务价值损益的时空动态。结果表明2000-2020年巴南区土地利用变化主要表现为耕地持续转化为其他用地类型和林地面积的大幅增长,该趋势将在未来10年内延续。2000-2030年耕地占巴南区面积的比例下降了39.58%,而林地占比将增长28.86%并在2025年后取代耕地成为最主要的地类;建设用地、水域和未利用地面积占比分别增长8.29%、2.25%和0.18%。土地利用类型变化下巴南区生态系统服务价值在2000-2020年由11.69亿元增长到27.64亿元,并将持续增长至2030年的30.19亿元。耕地和林地转化为建设用地、耕地转化为林地（尤其是转化为针叶林和针阔混交林）分别是服务价值损失及增益的主要方式。2000-2030年巴南区生态系统服务价值总损失0.58亿元、总增益19.09亿元,净增益18.50亿元。土地利用结构变化和生态系统服务当量因子价值升高分别贡献了净增益的70.96%和29.04%。巴南区生态系统服务价值损益与地形密切相关。2000-2030年间巴南区生态系统服务价值由匀质分布逐渐形成北低南高的发展格局;价值损益在全局和局域尺度上均呈现出显著的正向空间自相关特性。巴南区现有的土地利用模式能够兼顾经济发展及生态环境保护两方面的需求。未来需要继续实行生态保护工程、合理规划城市用地边界、严守耕地红线以推动城乡区域协调发展。     

基于个体的空间显性模型和遥感技术模拟入侵植物扩张机制

基于个体的空间显性模型和遥感技术,以互花米草为例,模拟了自1997到2010年的种群扩张动态,揭示了土地利用变化与潮间带高程的影响;并通过全局敏感性分析揭示了种子扩散、成体存活率、有性和无性繁殖等种群统计学特征对互花米草种群扩张的相对重要性。研究结果发现:1)有性繁殖与无性繁殖共同决定互花米草种群快速扩张;2)潮间带高程和土地利用变化显著影响模型预测的精度,对互花米草种群扩张有非常重要的影响;3)成体存活率与种子长距离扩散是影响互花米草种群扩张速度最重要的因素;无性繁殖比有性繁殖对种群扩张的影响更大;种子长距离扩散比本地扩散更为重要,同时,小概率的种子长距离扩散事件对种群扩张有非常重要的影响。为了经济有效地控制外来入侵植物的扩张,应该抑制种子的长距离扩散和移除种子长距离扩散形成的位于入侵前沿的小斑块。     

Using value of information to prioritize research needs for migratory bird management under climate change: a case study using federal land acquisition in the United States

In response to global habitat loss, many governmental and non‐governmental organizations have implemented land acquisition programs to protect critical habitats permanently for priority species. The ability of these protected areas to meet future management objectives may be compromised if the effects of climate change are not considered in acquisition decisions. Unfortunately, the effects of climate change on ecological systems are complex and plagued by uncertainty, making it difficult for organizations to prioritize research needs to improve decision‐making. Herein, we demonstrate the use of qualitative value of information analysis to identify and prioritize which sources of uncertainty should be reduced to improve land acquisition decisions to protect migratory birds in the face of climate change. The qualitative value of information analysis process involves four steps: (i) articulating alternative hypotheses; (ii) determining the magnitude of uncertainty regarding each hypothesis; (iii) evaluating the relevance of each hypothesis to acquisition decision‐making; and (iv) assessing the feasibility of reducing the uncertainty surrounding each hypothesis through research and monitoring. We demonstrate this approach using the objectives of 3 U.S. federal land acquisition programs that focus on migratory bird management. We used a comprehensive literature review, expert elicitation, and professional judgement to evaluate 11 hypotheses about the effect of climate change on migratory birds. Based on our results, we provide a list of priorities for future research and monitoring to reduce uncertainty and improve land acquisition decisions for the programs considered in our case study. Reducing uncertainty about how climate change will influence the spatial distribution of priority species and biotic homogenization were identified as the highest priorities for future research due to both the value of this information for improving land acquisition decisions and the feasibility of reducing uncertainty through research and monitoring. Research on how changes in precipitation patterns and winter severity will influence migratory bird abundance is also expected to benefit land acquisition decisions. By contrast, hypotheses about phenology and migration distance were identified as low priorities for research. By providing a rigorous and transparent approach to prioritizing research, we demonstrate that qualitative value of information is a valuable tool for prioritizing research and improving management decisions in other complex, high‐uncertainty cases where traditional quantitative value of information analysis is not possible. Given the inherent complexity of ecological systems under climate change, and the difficulty of identifying management‐relevant research priorities, we expect this approach to have wide applications within the field of natural resource management.     

Soil organic carbon changes as influenced by agricultural land use and management: a case study in Yanhuai Basin, Beijing, China

The effects of agricultural land use and management practices on soil organic carbon (SOC) are of great concern. In this study, SOC changes were investigated in sandy loam soils (Ustochrepts, USDA Soil Taxonomy) under orchard, vegetable, corn (Zea maize L.), and soybean (Glycine max L.) cultivation in northern China. The corn fields were further classified into three categories based on their inputs, i.e. high-input, mid-input, and low-input corn fields. In April 2005, a total of 197 soil samples were collected from 42 soil sites within 100 cm soil depth in Yanhuai Basin, Beijing, China. SOC contents were determined using rapid dichromate oxidation, and ANOVA statistical analysis was used to test the significances between land use and management practices at p<0.05. The results showed that: (1) the effects of land use and management practices on SOC primarily occurred within the topsoil (0–25 cm), and the SOC contents sharply decreased with the increase in soil depth. (2) SOC content and density values of orchard, vegetable, and high-input corn fields were higher than those of soybean, mid- and low-input corn fields.     

Soil organic carbon changes as influenced by agricultural land use and management: a case study in Yanhuai Basin, Beijing, China

The effects of agricultural land use and management practices on soil organic carbon (SOC) are of great concern. In this study, SOC changes were investigated in sandy loam soils (Ustochrepts, USDA Soil Taxonomy) under orchard, vegetable, corn (Zea maize L.), and soybean (Glycine max L.) cultivation in northern China. The corn fields were further classified into three categories based on their inputs, i.e. high-input, mid-input, and low-input corn fields. In April 2005, a total of 197 soil samples were collected from 42 soil sites within 100 cm soil depth in Yanhuai Basin, Beijing, China. SOC contents were determined using rapid dichromate oxidation, and ANOVA statistical analysis was used to test the significances between land use and management practices at p<0.05. The results showed that: (1) the effects of land use and management practices on SOC primarily occurred within the topsoil (0–25 cm), and the SOC contents sharply decreased with the increase in soil depth. (2) SOC content and density values of orchard, vegetable, and high-input corn fields were higher than those of soybean, mid- and low-input corn fields.     

老工业搬迁区土地利用变化时空特征及其驱动力——以沈阳市铁西老工业区为例

基于QuickBird遥感影像数据,在GIS支持下,分析2000-2010年沈阳市铁西老工业区土地利用变化的时空特征及驱动力.结果表明:研究期间,铁西老工业区工矿仓储用地格局变化最大,由“南宅北厂”历史格局逐渐演变为以居住用地为主的土地利用格局.其中,居住用地面积增加9%,主要来自于建设大路以北地区工矿仓储用地的搬迁转化;工矿仓储用地面积减少20%;商业服务业设施用地、公共管理与公共服务用地面积都有不同程度的增加,分别增加1.3%和3.1%;建设用地是变化幅度较大的土地利用类型,总体变化率达76.9%.研究区2000-2005年的土地利用变化率高于2005-2010年.国家发展战略和政策、区域发展规划、行政体制改革、产业升级等是铁西老工业区土地利用变化的主要驱动力.     

基于土地利用变化的生态系统服务价值及其改善效果研究——以内蒙古自治区为例

以内蒙古自治区为例,基于土地利用与生态系统服务价值(ESV)的关系,提出将生态改善效果纳入生态服务功能综合评价的分级方法,并分析生态服务功能的空间分布格局,揭示生态改善与生态系统服务价值的对应关系。结果表明:(1)2015年研究区ESV为1.87万亿元,区域整体生态环境质量水平提升;(2)研究区的生态改善具有空间分异特征,高ESV改善区仅集中于大兴安岭等高生态价值区,其余地区生态改善不明显,甚至呈恶化趋势,造成地区间差距不断扩大;(3)生态系统服务的提供程度与生态改善效果具有高关联性,依据各功能和生态改善水平可将研究区划分为北部大兴安岭核心区、中部高覆盖草原区两类高值区,以及西部沙地区、南部沿黄河地区和东部科尔沁地区三类低值区。生态管控措施应综合生态服务功能与生态改善效果的匹配程度,以达到减小区域ESV差距、促进生态环境协调发展的目的。     

Developing a land evaluation model for faba bean cultivation using geographic information system and multi-criteria analysis (A case study: Gonbad-Kavous region,Iran)

This study was carried out to assess the land suitability for rainfed faba bean (Vicia faba L.) cultivation in Gonbad-Kavous region (Golestan province, north of Iran) using geographic information system (GIS) and analytical hierarchy process (AHP), the most common methods for evaluation of land use suitability. Several parameters were considered in this study, including the annual average, minimum and maximum temperatures, annual precipitation, slope, elevation, and some soil properties such as organic matter, pH, EC, texture, phosphorus, potassium, calcium, iron, and zinc. The environmental parameters and the classification system used in the this work are inspired by the United Nations Food and Agriculture Organization (FAO) method dedicated to land suitability. In determining the weights of parameters, expert opinions were consulted and the final land suitability map was generated in five classes. As evidenced by the results, it was estimated that 23.48% of the study area (48,354.5 ha) is highly suitable for faba bean cropping, while 25.38% (52,237.37 ha) is moderately suitable and 25.03% (51,522.85 ha) is marginally suitable. In addition, our results indicated that just 26.11% of total agricultural lands are non-suitable for crop production. The currently non-suitable (49,778.80 ha) and permanently non-suitable (3997.09 ha) classes are located in the north and northwest parts of Gonbad-Kavous township. Soil salinity, low organic matter, low precipitation, high Ca content, and deficiency of P and Fe contents were found to be key limiting factors in this area.     

基于区域城市化LUCC的人类生态过程定量研究——以上海市区典型城市化样带为例

借鉴流域研究的范例,根据上海市1987年、1995年和2003年3期Landsat5 TM遥感影像记录的土地利用／覆被数据和有关的社会经济统计数据,运用Rs和GIS技术在上海市中心西南城市边缘建立典型城市化样带。采用生态足迹法分析该样带内人类的生态供给与需求;提出一城市化区域人类生态过程的新研究方法,得出城市化过程中区域的人类生态质量指数与波动指数,并根据模型计算出的指数值,对样带区域总体及其中城乡区域在城市化中的人类生态状况进行了动态分析,以尝试对区域城市化中人类生态过程进行定量化研究。     

干旱区绿洲土地利用/覆被及景观格局变化特征——以新疆精河县为例

从宏观上运用3S技术,利用1972年MSS、1990年Landsat TM、2001年Landsat ETM+和2005年CBERS 4个时期遥感影像数据,将GIS和景观生态学的数量分析方法相结合,运用ArcGIS以及Fragstats,分析了干旱区绿洲精河县1972～2005年间的土地利用/覆被和景观格局的变化.结果表明:(1)1972～2005年的33a中,精河县LUCC的总体变化趋势是绿洲面积有小幅度扩张,其中人工绿洲面积扩张尤为显著,天然绿洲面积减少.(2)研究区水域面积的变化受艾比湖湖面面积的变化影响较大,变化不显著,但总体上呈缓慢增长的趋势.(3)盐渍地面积的变化经历了先扩张后减小的一个过程.1990年达到最大值,但到2005年面积又有很大程度减少.沙地面积小幅度减小,其他地类的面积始终呈增加趋势.(4)景观在各个研究时段也发生显著变化.总的来说,整个研究区景观的密度持续增大,最大斑块指数先减小后增大,面积加权形状指数减小,形状趋于规则;斑块间的最邻近距离减小.表明1972年时景观中的优势斑块类型的连接性较2005年好,逐渐向具有多种要素的密集格局演变,景观更加破碎.同时不同斑块间的分离度增大,也说明景观破碎化程度加深.从香农多样性指数和香农均度指数的变化可以看出,景观的多样性增加,且均度增强.景观多样性及破碎化程度增加,也反映了土地利用越来越丰富.总之,要实现区域土地资源的可持续发展和景观生态功能的良性发挥,必须注重土地利用格局优化,维护景观生态过程与格局的连续性.