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常绿阔叶林恢复过程植物物种多样性的变化   总被引:1,自引:0,他引:1  
Evergreen broad-leaved forest is one of the most important vegetation types in China. Because of the human activities, evergreen broad-leaved forest has been destroyed extensively, leading to degraded ecosystem. It is urgent to conserve and restore these natural forests in China.tn this paper, the tendency and rate of species diversity restoration of the evergreen broad-lea ved forest in Darning Mountain has been studied. The main results are as follows:(a) in subtropical mid-mountain area, species diversity in degraded evergreen broad-leaved forest can be restored. Through analyzing b diversity index of communities in different time and space, it was found that the species composition of communities tend to be the same as that in the zonal evergreen broad-leaved forest. (b) The restoration rate of evergreen broad-leaved forest was very fast. Planting Chinese fir after clear-cutting and controlled burning of the forest 178 species appeared in a 60Om^2, sample area after 20 years““ natural recovering. Among these species, 58 were tree layer and the height of community reached 18m, The survey suggested that it would take only 20 years for the degraded forest to develop into community composed of light demanding broad-leaved pioneer trees and rain-tolerance broad-leaved trees, and it need another 40-80 years to reach the stage consisting of min-tulerance evergreen broad-leaved trees, (c) Species number increased quickly at the early stage (2-20 years) during vegetation recovering process toward the climax, and decreased at the min-stage (50-60 years ), then maintained a relatively stable level at the late-stage (over 150 years).  相似文献
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开矿导致地表植被破坏,并使植物群落结构发生改变。以零星矿井式开采的四川马边白家湾矿区为研究区域,通过群落调查,采用重要值和物种多样性指数,结合除趋势典范对应分析(DCCA)排序和多元回归进行数据分析,研究了开矿对植物多样性格局的影响。结果表明:(1)随着开矿干扰减弱,植物群落分为明显的四个群丛,依次由草本向灌木、乔木顺序演替;(2)开矿干扰与DCCA轴紧密相关,是影响植物多样性的重要环境因素,导致乔木层盖度变化且对多样性有直接影响;(3)群落间相似性与开矿干扰负相关,而物种替代速率与开矿干扰呈U型关系。  相似文献
3.
Since the UNCED Conference in Rio de Janeiro 1992, the need to actively protect biodiversity is universally acknowledged. The UN Convention on Biological Diversity (CBD) defined biodiversity as comprising ecosystem diversity, species diversity and genetic diversity, and decided for the ecosystem level as the basis for describing biodiversity. However, due to conceptual problems as much as to the lack of data, so far no comprehensive measurements of biodiversity have been developed. A single measure quantitatively describing biodiversity even seems out of reach due to the incommensurability of the three levels. This makes it impossible to directly base policy decisions on existing or future estimates of the “total size” of biodiversity. Instead, it is suggested to analyse the pressures threatening biodiversity, which can usually be measured quantitatively, and act as the interface between the socioeconomic driving forces behind them and the biological impacts. The drivers (physical primary drivers, politics and policies causing them as secondary and institutional structures as tertiary ones) do not only affect biodiversity, but a range of sustainability problems. The analysis permits to integrate biodiversity risks with broader environmental and sustainability policies, and thus to mainstream biodiversity preservation.Such an analysis is presented for Europe, naming pressures and driving forces and illustrating the close links between the causes of biodiversity pressures and other environmental problems. This way, it is possible to develop first ideas how the standard set of environmental policies must be modified and extended to cover the issue of biodiversity.  相似文献
4.
识别物种多样性OUV表征指标,对于世界物种多样性类别自然遗产价值的认知、评估与监测具有重要意义。在对国内外物种多样性评价体系中具有普适性价值指标的初步筛选与分类的基础上,以206项自然遗产与35项混合遗产为研究对象,通过分析表征指标的频次、相关性、回归贡献值与多维聚类度,构建了以稀有性、多样性、代表性和重要性为主的四大类含13项特征的世界自然遗产物种多样性OUV表征指标体系。其中,重点指标4项即濒危物种、物种丰富度、物种特有度和重要物种,一般指标7项即物种相对多度、物种密度、旗舰物种、地方性物种、珍稀物种、红色名录指数和标志物种,参考指标2项即古老孑遗物种和关键物种。该表征指标体系的构建对于自然遗产价值的认知与保护,特别是物种多样性类别遗产的研究、申报、规划与管理具有现实意义。  相似文献
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城市植物多样性直接影响着城市生态系统的功能与 稳定性。基于重庆市主城区公园植物的样地调查数据,从生 活型、来源类型2个方面对公园植物多样性开展研究。调查 统计得到107科257属347种植物,表明重庆主城区公园植 物种类丰富。3种生活型植物中,草本植物的物种丰富度、 Shannon-Wiener多样性、功能性状平均距离指数均为最 高,乔木植物的Pielou物种均匀度、功能离散度、Rao二次 熵指数和功能均匀度均为最高。3类生活型植物的功能性状差 异显著。总体上固氮植物占比较低,虫媒、动物传粉植物占比 最高。与乡土植物相比,外来植物仍具有较高的多样性,外来 植物的引入丰富了功能性状、提高了物种数。基于研究结果, 建议重庆市公园建设进一步重视功能性状的选择和应用,提高 乡土植物的功能多样性。本研究的结论和方法为中国城市植物 多样性保护与研究、可持续城市建设提供参考。  相似文献
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