Results 81 to 90 of about 1,486,775 (187)

古田山10种主要森林群落类型的α和β多样性格局及影响因素

open access: yes, 2019
古田山国家级自然保护区地处中亚热带,地形复杂,森林群落类型丰富。我们在保护区内10种主要森林群落类型中网格化布置并调查了79个20 m×20 m样地,分析了不同群落类型内及相互间的α(Shannon-Wiener指数)、β(Horn-Morisita相异性指数)多样性分布格局及其影响因素。结果表明:(1)α多样性主要受到群落类型、海拔和坡向的影响。α多样性在不同群落类型间差异显著,并且随海拔升高、坡向从南到北,α多样性增大。(2)β多样性主要受到群落类型和海拔的影响,受空间距离的影响不显著 ...
陈声文   +7 more
core  

Resource Substitution: Local Governments' Issue Attention and Policy Reinvention

open access: yesPolicy Studies Journal, EarlyView.
ABSTRACT Research on policy reinvention, where a government modifies rather than replicates policy innovations introduced by other governments, has progressed significantly, but how it is influenced by the government's issue attention has not been thoroughly examined.
Yingxin Zhang, Yixue Yao, Kaifeng Yang
wiley   +1 more source

张家界荷花国际机场鸟类群落的时空变化

open access: yes野生动物学报, 2017
研究机场及其周边地区鸟类群落的时空变化规律可为鸟击防范提供科学依据。为了评估鸟击风险等级和制定有针对性的鸟击防范措施,2012年3月~2013年2月,我们采用样线法(共设置8条涵盖净空区树林、水域、农田、村落和灌草丛5种生境类型的样线),对张家界荷花国际机场净空区不同季节的鸟类资源进行了实地调查,并通过比较5种生境中鸟类的物种多样性指数、均匀度指数、物种数和种群密度,分析机场鸟类物种多样性与群落结构时空特征。在荷花机场净空区共记录到92种鸟类,隶属于14目、30科,其中候鸟比例接近50%。春 ...
王海燕 张志强 李益得 李中原 程 军 杨道德
doaj  

Integrating Human Rights Into Food Systems Policy to Progress the Fulfillment of the Right to Adequate Food—Enablers, Barriers, and Windows of Opportunity

open access: yesWorld Food Policy, Volume 12, Issue 2, November 2026.
ABSTRACT Prevailing levels of hunger, malnutrition, and food insecurity—driven by conflict, global economic crises, and ecological destruction—are threatening fulfillment of the right to adequate food. The integration of human rights in food systems policies can address these challenges; however, progress in the adoption of human rights–based ...
Ellen Johnson   +4 more
wiley   +1 more source

哈尔滨市城市化建设对鸟类群落的影响

open access: yes野生动物学报, 2015
近年来,城市化对鸟类的影响受到生态学家的广泛关注。于2014年3~5月对哈尔滨市区7块城市绿地中鸟类的分布和数量进行了调查,同时选取4个城市化指标以确定影响哈尔滨市区鸟类群落的主要城市化因子,并进一步分析哈尔滨城市化与鸟类群落的关系。调查共记录到鸟类121种隶属于14目38科。在7个样地中,鸟类群落多样性指数显示为:H群力湿地公园>H植物园>H太阳岛>H东北林业大学林场>H兆麟公园>H四季上东小区>H儿童公园; 均匀性指数E群力湿地公园>E植物园>E东北林业大学林场>E太阳岛>E四季上东小区>E兆麟公园>
王 舒 童玉平 王志洁 姚依晨 刘力榕 李 枫
doaj  

Evaluating the Effectiveness of Open‐Source LLMs for Automated Analysis of Multilingual Consultation Feedback: A Swiss Case Study

open access: yesPolicy Studies Journal, Volume 54, Issue 4, November 2026.
ABSTRACT Public consultations are a cornerstone of democratic policymaking, yet the sheer volume and heterogeneity of submissions often overwhelm traditional analysis. Emerging large language models (LLMs) offer new opportunities for making sense of such data, but their performance in contexts with high linguistic and technical diversity remains ...
Edgar Mathevet, Lauriane Cailleux
wiley   +1 more source

Predictive evolutionary genomics: principles, validation, and practice

open access: yesNew Phytologist, Volume 252, Issue 1, Page 36-48, October 2026.
Summary Climate change and habitat loss are driving rapid evolutionary responses in populations world‐wide, which creates an urgent need for evolutionary forecasting in conservation and agriculture. Such forecasting can be categorized into three time scales: trait‐based models that use multivariate quantitative genetic equations to project correlated ...
Daniel Ortiz‐Barrientos   +5 more
wiley   +1 more source

中国裸子植物的物种多样性格局及其影响因子

open access: yes, 2018
物种多样性的大尺度空间格局是宏观生态学和生物地理学研究的核心问题之一。本文利用中国裸子植物分布数据,结合气候、地形等环境信息,分析了中国裸子植物物种多样性的大尺度格局及其影响因素,比较了不同类群之间物种多样性格局和主导因子的差异,并探讨了裸子植物在植物区系中所占比重的地理格局。结果表明,中国裸子植物的物种多样性总体上呈现南高北低的趋势,物种多样性在横断山区最高。在裸子植物的三个主要类群中,松柏亚纲的物种多样性格局与整体相似,买麻藤亚纲的多样性高值区则出现在中国西北部的干旱地区,苏铁亚纲的分布区较为狭窄 ...
吕丽莎   +4 more
core  

滇西北高山微水体与溪流生境底栖动物多样性和环境特征

open access: yes, 2019
高山微水体由于面积微小且通过地表径流形成串联结构常常被认为与高山溪流具有类似的生境,然而由于这两类生境中环境因子与底栖动物多样性存在差异,它们在生态系统中的作用可能完全不同。滇西北地区是全球生物多样性热点区域之一,境内高山微水体和高山溪流分布密集,在区域底栖生物多样性维持方面具有重要的功能,然而目前对这两类高山淡水生态系统的研究较少。为了比较这两类生境环境因子的异同及其对底栖动物多样性的维持作用, 2015年6月,作者在云南省怒江州贡山县的高山峡谷内,对27个高山微水体和同区域分布的1条高山溪流 ...
谭路   +10 more
core   +1 more source

Neutral interactions among non‐native plants are common

open access: yesNew Phytologist, Volume 252, Issue 1, Page 292-309, October 2026.
Global distribution of studies and overall effect of co‐invasion for all metrics of non‐native plant performance combined. Summary Globalization has accelerated the establishment of non‐native plant species, increasing the prevalence of multispecies co‐invasions; yet interactions among co‐invaders remain poorly understood.
Feng He   +7 more
wiley   +1 more source

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