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581.
梅园昆虫群落的时间结构及动态 总被引:4,自引:0,他引:4
采用物种多样性、均匀性、优势度指标测定梅园昆虫群落的时间结构变化.结果表明,梅园昆虫群落物种数、多样性指数、均匀性指数随季节推移而增加,优势种群也随季节而变化.主成分分析表明,食叶性昆虫及刺吸性昆虫在群落中具有重要作用,刺吸性昆虫与捕食性昆虫发生发展趋势相同;根据群落的相似系数进行聚类和排序分析发现,9月、10月、11月和12月份的昆虫群落最为相似,其次是4月、5月、6月和7月份昆虫群落,再者3月份的昆虫群落,最后是8月份的昆虫大群落.图3表3参17 相似文献
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Abstract: Evaluating logging systems to determine which are most compatible with the maintenance of biodiversity is of prime importance if tropical forests are to be managed in a sustainable way. Bats are model taxa for this purpose. Two different logging systems are used in the natural forest of the Victoria-Mayaro Forest Reserve in Trinidad: open range and periodic block. Open range is a continuous harvesting system and, in common with most methods used to log tropical forests worldwide, has few harvest controls other than girth limits for selected species. Periodic block is a polycyclic system, with felling based on ecological criteria assumed to be compatible with the maintenance of biodiversity. To compare the effects of periodic block and open-range systems on biodiversity, we determined bat species richness and abundance in each system and in primary forest. We caught bats in mist nets set at ground level and in the canopy and in harp traps. In total 1959 individuals representing 38 species were captured. Species richness was similar among primary forest and logged forest habitats, although bat diversity was lower in logged forest. The distributions of bat species abundance did not differ significantly between logged forest and primary forest. We found, however, that both logging systems lead to a decrease in gleaning animalivores and an increase in frugivores. The increase in frugivores was likely the result of an increase in the abundance of bat-dispersed pioneer fruiting plants in logged forest. Bats of periodic-block-managed forest were more similar to those of primary forest than those of forest logged using the open-range system, indicating that the periodic-block system is more compatible with the maintenance of bat diversity. Our results support the suggestion that the measured use of tropical forests can largely be compatible with biodiversity conservation. 相似文献
585.
A traditional method of summarizing spatial distribution of species is the observed species-area curve. Often the observed species-area curve is surprisingly close to the expected species-area curve under the hypothesis of random placement of individuals. This has been used as evidence supporting the hypothesis. In this paper, we argue that using the observed species-area curve to test the general random placement hypothesis is highly inefficient. We present a testing method based on the classical 2 test for over-dispersion which is not only more efficient but also applicable to situations where complete abundance information are unavailable. We also discuss three alternatives of the hypothesis. The focus of this paper is on these and other general issues relevant to communities of different types. No applications are included in this paper. 相似文献
586.
《环境科学学报(英文版)》2023,35(4):275-286
Preparing materials for simultaneous remediation of anionic and cationic heavy metals contamination has always been the focus of research. Herein a biochar supported FeMnMg layered double hydroxide (LDH) composites (LB) for simultaneous remediation of copper and arsenic contamination in water and soil has been assembled by a facile co-precipitation approach. Both adsorption isotherm and kinetics studies of heavy metals removal by LB were applied to look into the adsorption performance of adsorbents in water. Moreover, the adsorption mechanisms of Cu and As by LB were investigated, showing that Cu in aqueous solution was removed by the isomorphic substitution, precipitation and electrostatic adsorption while As was removed by complexation. In addition, the availability of Cu and As in the soil incubation experiments was reduced by 35.54%–63.00% and 8.39%–29.04%, respectively by using LB. Meanwhile, the addition of LB increased the activities of urease and sucrase by 93.78%–374.35% and 84.35%–520.04%, respectively, of which 1% of the dosage was the best. A phenomenon was found that the richness and structure of microbial community became vigorous within 1% dosage of LB, which indirectly enhanced the passivation and stabilization of heavy metals. These results indicated that the soil environment was significantly improved by LB. This research demonstrates that LB would be an imaginably forceful material for the remediation of anionic and cationic heavy metals in contaminated water and soil. 相似文献
587.
居民社区用水用能的碳排放与行为选择和技术水平有关,且随时间波动性强。通过智能监测、实地调研、问卷调查等多种方法,自下而上构建了涵盖居民社区水能消费行为和基础设施相关的碳排放核算方法并评估其影响。通过对北京市海淀区某社区的案例研究发现,该社区夏季、春秋季、冬季碳排放量分别为18.2~20.8、19.3~21.5、58.5~63.8 t/d(以二氧化碳计),不同季节周末日均碳排放量约为工作日的1.0~1.2倍,由于采暖等因素造成冬季碳排放是其他三季的3.0~3.1倍。从全年来看,社区基础设施端共排放二氧化碳6.98×103 t/a,居民消费端排放4.94×103 t/a,占比分别为58.7%和41.3%;案例社区的温室气体核算体系范围1(能源直接碳排放,即气耗)碳排放量为8.98×103 t/a,范围2(能源间接碳排放,即电耗和水耗)碳排放量为2.92×103 t/a,占比分别为75.4%和24.6%。研究结果表明,推动燃气设备等基础设施升级改造、倡导居民生活器具和行为方式节能化等途径是推动居民社区减碳和绿色低碳转型的重要手段。
相似文献588.
Toward Sustainable Management of National Parks in Japan: Securing Local Community and Stakeholder Participation 总被引:4,自引:0,他引:4
Hiwasaki L 《Environmental management》2005,35(6):753-764
Japan’s national park system constitutes a potentially viable mechanism for securing local community participation and building stakeholder consensus for sustainable park management, although the potential of this system is yet to be fully maximized. This article gives an overview of the system of protecting natural resources in Japan, focusing on the national park system. Parks are managed by zoning and regulation, which is unique in that land is not “set aside” for nature conservation, but designated as national park wherever the need to preserve “scenic beauty” has been recognized, regardless of land ownership or land use. Although resource conservation under this system has been problematic, it has advantages, especially in terms of community participation. This article demonstrates that in order to reach the system’s potential, the park authority must act as coordinator of stakeholders and facilitator of bottom-up approaches to decision-making. In order to do this, steps that must be taken include the following: identifying the various stakeholders in park management and defining the “local community”; clarifying the roles and responsibilities of each stakeholder; and supporting consensus-building among stakeholders regarding the objectives and long-term vision of each park. By taking these steps, it would be possible to build a park management system that overrides government boundaries and involves local communities. This will enable the park authority to address the challenges facing Japan’s complex system of conserving natural resources, and move towards sustainable management of natural resources in Japan. 相似文献
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本文详细分析了高职院校学生中非正式群体产生的心理原因、类型、特征和功能,提出了切实可行的教育对策. 相似文献