排序方式: 共有188条查询结果,搜索用时 15 毫秒
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John Paul Schmit Gregory M Mueller Juan Luis Mata Yonging Huang 《Biological conservation》2005,121(1):99-110
Attempts to understand and conserve biodiversity are hampered by a lack of information about many taxonomic groups, particularly those groups that are the most species rich. Although fungi are ubiquitous and play an important role in decomposition, nutrient cycling and nutrient uptake, little is known about fungal diversity, as fungi are usually cryptic and ephemeral. Based on a meta-analysis of macrofungal diversity studies, we show that tree diversity is a promising surrogate for macrofungal diversity at large spatial scales. We present evidence that trees species richness can be used to predict macrofungal species richness and that on the global scale, the distribution of individual tree and macrofungal species notably differs. Additionally our findings provide support for the use of “ratio estimates” to estimate fungal species richness. 相似文献
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Assessing the utility of indicator groups for the conservation of South American terrestrial mammals
Marcelo F. Tognelli 《Biological conservation》2005,121(3):409-417
Because data on the distribution of most species are limited, prioritizing sites for conservation requires the use of indicator groups to represent overall diversity. The purpose of this study is to assess the utility of different subsets of the South American mammal fauna in representing the overall diversity of South American terrestrial mammals, percentage of endangered and restricted-range species, and the percentage of monotypic genera. Particularly, I assess the effectiveness and efficiency of explicitly selected indicator groups at two spatial scales - continental South America and the country of Brazil. Results show that all indicator groups were more effective than a random selection of cells. However, when compared with sets of randomly selected species, only one indicator group outperformed these sets. An indicator group composed of geographically rare species was more effective and efficient at both spatial scales, protecting a higher percentage of the total number of species, as well as higher percentages of endangered and rare species, and total number of monotypic genera. 相似文献
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The potential as indicators of species richness were investigated for 178 species belonging to six ecologically defined species groups (epiphytic bryophytes on nutrient-rich bark, epiphytic macrolichens on nutrient rich bark, pendant lichens on conifer trees, bryophytes on siliceous rocks, bryophytes on dead conifer wood, and polypore fungi on dead conifer wood), using species data from 0.25 ha plots from three different coniferous forest areas (ca. 200 ha each). A species was defined as a potential indicator species for a species group within a study area if its distribution was statistically significantly nested within the species-plot matrix ranked according to species richness, and if the plot frequency of the species was less than 25%.Only two species were identified as potential indicators within all three areas and on average ≈80% of the potential indicator species were lost from one area to another. The results indicate that inconsistency between areas in the species’ frequency distributions and their position in nested hierarchies may strongly reduce the general predictive power of indicator species of species richness, even if significantly nested patterns are found at the community level. We suggest that indicators related to amount and quality of habitats may be an alternative to lists of indicator species of species richness. 相似文献
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Assessment of groundwater storage depletion by overexploitation using simple indicators in an irrigated closed aquifer basin in Iran 总被引:1,自引:0,他引:1
In arid and semi-arid regions irrigation is usually needed to provide enough water for crop growth in cultivated areas. As surface waters are scarce, especially in summertime when the water is needed, groundwater is heavily used to supply the water demand. Overexploitation of the aquifer in dry years causes depletion of the groundwater storage and systematical lowering of the piezometric levels. This is a particular problem in aquifers developed in closed basins where lateral inflow is nearly absent and replenishment is constrained by rainfall recharge. In this paper, simple indicators derived from meteorological data, abstraction rates and piezometric time series are compared with the groundwater storage depletion as obtained from a calibrated groundwater flow model. Application of the method to the overexploited Shahrekord basin in Iran shows that for the simulated period 1989-2003 an accumulative index of the difference of aquifer recharge, as calculated by a soil moisture balance method, and groundwater abstraction has a correlation coefficient of nearly one with model calculated storage. Indicators based on the filling index derived from piezometric time series or on the ratio of aquifer discharge to recharge have slightly lower correlations. The accumulated index indicator can be used to follow aquifer storage in the future without the need to run the full groundwater flow model. This simple approximation is restricted to aquifer systems with a limited lateral inflow and outflow. 相似文献
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为了揭示中、低适宜区域橡胶种植地的生物多样性状况,及选择有益于保护生物多样性的种植模式,使用陷阱法于2015年9月和2016年8月调查了钝叶黄檀-玉米地(对照)、橡胶纯林(Ⅱ)、橡胶-茶树混农林(Ⅲ)、橡胶-咖啡混农林(Ⅳ)中地表层和树冠层蚂蚁物种多样性、群落结构差异及指示物种,以研究不同类型种植模式间蚂蚁群落间的差异。结果表明:4种类型样地中,地表层蚂蚁中多度、物种丰富度、ACE值均存在显著差异(P0.05),大小排序为橡胶-茶树混农林橡胶纯林钝叶黄檀-玉米地橡胶-咖啡混农林;树冠层蚂蚁群落多度存在显著差异(P0.05),大小排序为橡胶纯林橡胶-茶树混农林橡胶-咖啡混农林钝叶黄檀-玉米地,物种丰富度和ACE值不存在显著差异(P0.05)。地表层和树冠层蚂蚁群落结构样地类型间均存在极显著差异(P0.01),其中橡胶-茶树混农林的蚂蚁群落结构与其余样地存在较高的相似性。4种类型样地中均存在1种指示物种,钝叶黄檀-玉米地为棒刺大头蚁(Pheidolespathifera),橡胶林为黑头酸臭蚁(Tapinomamelanocephalum),橡胶-茶树混农林为环纹大齿猛蚁(Odontomachuscirculus),橡胶-咖啡混农林为缅甸细长蚁(Tetraponera birmana)。从本研究来看,橡胶-茶树混农林是当地橡胶复合农林系统中既具经济效益,又能较好保护蚂蚁多样性的种植模式。 相似文献
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R. F. Hogervorst H. A. Verhoef N. M. van Straalen 《Biology and Fertility of Soils》1993,15(3):189-195
Summary A comparative field study was conducted to study the correlation between forest vitality and the abundance of soil microarthropods. During 5 years the vitality of six pine forests within the Veluwe area, the Netherlands, was estimated by the number of needle year-classes, while soils were sampled and extracted for various soil microarthropod groups. Within sites the number of needle year-classes in the forest stands fluctuated over the 5 years, while the collembolan family Sminthuridae showed a trend towards a decreasing population density and the density of the cryptostigmatid mite Platynothrus peltifer Koch increased. Among sites there was a significant positive correlation between the number of needle year-classes and the relative abundance of P. peltifer. The results imply that soil microarthropods may indicate changes in physical and chemical factors in relation to soil fertility and vitality of the trees. 相似文献
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紫胶玉米混农林模式对地表蚂蚁多样性及功能群的影响 总被引:3,自引:1,他引:2
为了揭示紫胶玉米混农林对地表蚂蚁群落多样性及功能群的影响,采用陷阱法调查了云南省绿春县紫胶林、紫胶玉米混农林和玉米旱地3种类型样地的地表蚂蚁物种组成、物种多样性、群落结构相似性、指示物种和功能群等。结果显示,紫胶玉米混农林模式具有较高的地表蚂蚁物种数和稀有物种数,与玉米旱地相比,紫胶玉米混农林的蚂蚁物种数增加41%,稀有物种数增加85%。紫胶玉米混农林与紫胶林具有更高的蚂蚁多样性,其物种丰富度和ACE估值均显著高于玉米旱地,而紫胶玉米混农林的多度显著高于紫胶林和玉米旱地。地表蚂蚁物种组合在3种类型样地中有差异,与紫胶林和紫胶玉米混农林相关联的物种与玉米旱地不同。3种样地的指示物种不同,玉米旱地的指示种为扁平虹臭蚁和伊大头蚁,紫胶玉米混农林为凹头臭蚁、西昌刺结蚁和中华小家蚁,紫胶林为费氏盘腹蚁、立毛举腹蚁、阿普特铺道蚁、贝卡盘腹蚁和西氏拟毛蚁。紫胶玉米混农林蚂蚁功能群组成比例介于玉米旱地和紫胶林之间,其中机会主义者(OPP)、从属弓背蚁族(SC)、隐蔽物种(C)及气候特化种(CS)的蚂蚁物种数、多度及比例明显高于玉米旱地。紫胶玉米混农林生境较为复杂,对地表蚂蚁多样性保护具有积极作用,是平衡环境保护和经济可持续发展的较好模式。 相似文献
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