Results 31 to 40 of about 4,372 (132)
Shuitu Baochi Xuebao, 2008 为了研究榆林地区近13年来土地利用结构变化及其趋势,本文选用1993年、2000年和2006年三期遥感影像,利用Erdas软件和ArcGIS 9.1软件,采用土地利用动态度、开发度和耗损度等指数模型,分析了榆林地区1993-2006年土地利用类型的数量变化和空间变化特征以及各地类的转移情况。结果表明:榆林地区13年来各类土地利用类型综合动态度有下降趋势;各类土地利用类型的增减在空间上变化比较大,通过统计分析显示,草地、耕地变化较快,林地、建设用地呈增长趋势,未利用地、水域面积减少;土地利用动态度 ...
胡振琪 +4 more
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World Medical &Health Policy, Volume 17, Issue 4, Page 823-830, December 2025.ABSTRACT Sepsis is a leading cause of mortality in the United States, with over 350,000 deaths annually, yet the contribution of neighborhood‐level social determinants of health (SDoH) remains underexplored. We conducted a retrospective analysis of 4.4 million hospitalized patients with sepsis, identified using ICD‐10 codes, leveraging de‐identified ...
Ahad Khaleghi Ardabili +3 more
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Conservation Biology, Volume 39, Issue 6, December 2025.Abstract Identifying refugia from emerging threats is vital to ensure the persistence of rare and threatened species, but modeling habitat distribution for these species is challenging and the role of people in refuge management is rarely considered. Myrtle rust is an emerging infectious disease that represents a grave threat to the rare wetland tree ...
Sarah M. Herbert +7 more
wiley +1 more source
Shuitu Baochi Xuebao, 2005 通过对沙质海岸5种植被类型的土壤物理性状和水源涵养功能的研究,结果表明:(1)混交林和草地的土壤物理性状及贮水能力明显优于纯林地的土壤物理性状;(2 ) 5种植被类型土壤的涵养水源能力大小依次为草地>黑松刺槐混交林>黑松纯林>柽柳林>刺槐纯林;表层土壤高于底层土壤;(3)各植被类型枯落物的饱和持水率在10 5 12 % 4 5 3 6 4 % ,水容量在4 5 833 17t/hm2 之间;刺槐纯林枯落物的水源涵养功能最大;(4) 5种植被类型的涵养水源量在14 76 6 6～1870 38t/hm2 ...
王贵霞 李传荣 许景伟 齐清 王月海 王卫东
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Shuitu Baochi Xuebao, 2022 北京主要河流河岸带实施平原造林工程后,对河岸带植被类型及土壤造成不同程度影响。研究河岸带原有及重建植被类型土壤生态化学计量特征,对河岸生态系统土壤碳氮磷平衡及固碳潜力提升提供科学依据。选取北京温榆河昌平段岸边原有植被类型3种样地(乔木林、乔灌林及草地),重建植被类型2种样地(乔木林与灌木林),共15个样方,采集3层(0—10,10—20,20—30 cm)土壤样品,分析并计算碳(C)、氮(N)和磷(P)含量及计量比。结果表明:原有与重建植被类型的土壤有机碳(SOC)、全氮(TN)、全磷(TP ...
王莹 +5 more
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Importance of connectivity for carnivore richness and occupancy in fragmented biodiversity hotspots
Conservation Biology, Volume 39, Issue 6, December 2025.Abstract Structural connectivity affects wildlife movement between habitat patches, contributing to the persistence of wildlife populations and their resilience to human‐induced and environmental changes. However, its importance to wildlife population persistence remains unclear, particularly in fragmented landscapes, where there are additional co ...
Cindy M. Hurtado +12 more
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Shuitu Baochi Xuebao, 2005 北京山区作为典型的干旱半干旱石质山地,土壤瘠薄,水资源严重亏缺,这已成为该地区造林成活率及林木生长最为主要的限制因子。侧柏作为本区的主要造林树种,在保持水土、涵养水源等方面发挥着重大意义,所以分析研究该树种的主要林分类型林地间土壤水分、物理性质及其养分条件显得尤为重要。通过设定标准地和定位观测的方法,研究了北京地区侧柏幼龄林主要林分类型的土壤特征,以便掌握各林分类型侧柏林地的差异。并通过林学措施最大限度地利用有限的天然降水,增加土壤水资源,使林木得以充分利用,为该地区以及干旱半干旱地区在适地适树的前提下,
贾忠奎 马履一 徐程扬 张华 孙盛
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Shuitu Baochi Xuebao, 2021 为研究晋西黄土区退耕还林后不同植被覆盖下土壤的入渗特征及土壤质量评价，采用野外双环入渗法测定土壤的入渗特征，并测定不同地类土壤的容重、孔隙度、有机质、全氮等指标，使用相关性分析研究不同类型植被覆盖下土壤的入渗性能及其与土壤理化性质的相关关系，并将各地类的土壤理化性质进行主成分分析。结果表明：（1）植被类型对于土壤渗透速率影响较大，表现为天然次生林>刺槐×油松混交林>刺槐纯林>油松纯林>灌木林地>苹果园地>荒草地>农田（玉米地）。（2）退耕还林后，不同植被类型的土壤理化性质差异显著（P灌木林地>苹果园地 ...
刘畅 +7 more
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Conservation Biology, Volume 39, Issue 6, December 2025.Abstract Forest cover is positively associated with fish biomass and fisheries yield in the Amazon River floodplain, and many species enter flooded forests to feed, spawn, or seek refuge from predation. Floating macrophyte beds, known as floating meadows, in Amazon floodplains support high fish diversity and serve as nursery habitat for many fishes of ...
Sam Grinstead +6 more
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Global Change Biology, Volume 31, Issue 11, November 2025.This study assessed the potential impacts of climate and land‐use change on soil fungal diversity across four North American biomes. We found that climate change typically caused both diversity losses and gains, particularly in coniferous forests and among arbuscular mycorrhizal fungi, whereas land‐use change mainly reduced diversity, especially in ...
Wenqi Luo +5 more
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