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991.
四川小寨子沟自然保护区地表甲虫多样性 总被引:8,自引:0,他引:8
采用样线法,调查了四川省小寨子沟自然保护区地表甲虫群落。通过8条样线调查共采到标本2893头,分属27科。以隐虫科的标本数量占绝对优势,占标本个体总数的77.74%,其次是步行虫科,占标本个体总数的14.52%,这两科为该地区的优势类群;而金龟科和牧场金龟科为该地区的常见类群,分别占本次标本收获量的1.69%,其余甲虫均为稀有类群。通过多样性指数研究发现,以凌冰沟、白水沟以及尚武的地表甲虫多样性最高,花桥、鸡湾、竹林沟的多样性最低。相似性研究表明,所有样线间的相似性程度较低,仅鸡湾和竹林沟两条样线的地表甲虫群落极为相似,相似性系数达0.75。另外,尝试性引入DG指数来评判科级水平上的多样性指数,并把它与惯用的Shannon-W iener多样性指数做了比较,结果显示,DG指数在科级水平上得出的多样性指数与丰富度具有较高的一致性,而Shannon-W iener多样性指数有时会得出与实际颠倒的结果。所以建议在地表甲虫科级多样性分析时采用DG指数也许比较合适。研究表明,人为活动的适度干扰,导致了栖息环境的空间异质性,利于多种地表甲虫的生存,过低或过高的人为活动都会降低地表甲虫的多样性。 相似文献
992.
根据川西卧龙地区林线位置岷江冷杉(Abies faxoniana)的年轮宽度资料, 分析了该地区树木年轮宽度与气候要素的关系, 并重建了该地区1850年以来夏季(6-8月份)温度的变化历史。结果表明: 川西卧龙地区在过去159年来的温度变化上, 最为明显的特征是20世纪40年代以来的显著变暖趋势, 而在20世纪40年代以前的温度明显偏低, 主要的低温时期在1850-1870年和1890-1930年。该温度序列的冷暖期与附近地区的冰芯、冰川进退资料, 以及对于夏季温度响应敏感的树轮年表都有着较好的对应关系, 这表明重建序列记录了可靠的区域尺度的温度信号。对重建温度序列的小波分析表明, 较为明显的有2-8年和10-16年的周期, 而这些周期可能与厄尔尼诺-南方涛动气候系统和太阳活动周期有一定的关系。 相似文献
993.
994.
湖北星斗山自然保护区国家重点保护野生植物调查研究 总被引:7,自引:0,他引:7
据调查统计,湖北星斗山自然保护区共有国家级保护植物33种,其中I级保护植物8种,Ⅱ级保护植物25种。本文分析这些植物的分布现状及特点,提出相应的保护对策。 相似文献
995.
Case studies on Poisson lognormal distribution of species abundance have been rare, especially in forest communities. We propose a numerical method to fit the Poisson lognormal to the species abundance data at an evergreen mixed forest in the Dinghushan Biosphere Reserve, South China. Plants in the tree, shrub and herb layers in 25 quadrats of 20 m×20 m, 5 m×5 m, and 1 m×1 m were surveyed. Results indicated that: (i) for each layer, the observed species abundance with a similarly small median, mode, and a variance larger than the mean was reverse J-shaped and followed well the zero-truncated Poisson lognormal;(ii) the coefficient of variation, skewness and kurtosis of abundance, and two Poisson lognormal parameters (σ andμ) for shrub layer were closer to those for the herb layer than those for the tree layer; and (iii) from the tree to the shrub to the herb layer, the σ and the coefficient of variation decreased, whereas diversity increased. We suggest that: (i) the species abundance distributions in the three layers reflects the overall community characteristics; (ii) the Poisson lognormal can describe the species abundance distribution in diverse communities with a few abundant species but many rare species; and (iii) 1/σ should be an alternative measure of diversity. 相似文献
996.
四川千佛山自然保护区的鸟类资源 总被引:6,自引:0,他引:6
通过2002年10月和2003年5月对保护区鸟类的集中调查,结合历史文献,确认保护区有鸟类13目35科160种.其中国家I级保护鸟类2种,Ⅱ级保护鸟类19种,完全或主要分布于我国的鸟类种类20种.保护区鸟类以留鸟和夏候鸟为主,有留鸟91种,夏候鸟48种,而冬候鸟、旅鸟分别只有13种和8种.鸟类区系组成为:古北界种类有30种,东洋界种类90种,广布种19种,以东洋界种类占优势,同时兼具西南区和华中区的特点.保护区鸟类主要分布在阔叶林和灌丛生境,其次是针阔混交林生境.保护区内鸟类水平分布的情况和垂直分布的情况都差异明显. 相似文献
997.
David Carnicero Martiniano Fernández-Valverde Librada M Cañedo Carmen Schleissner José M Luengo 《FEMS microbiology letters》1997,149(1):51-58
Pseudomonas putida U grown in a chemically defined medium containing octanoic acid as the sole carbon source accumulated a homopolymer of poly(3-hydroxyoctanoate) as intracellular reserve material, and metabolized the polymer during the late exponential phase of growth. Kinetic measurement of the uptake of [1-14C]octanoic acid by cells at 34°C in 85 mM phosphate buffer, pH 7.0 showed linear uptake for at least 2 min and the calculated Km and Vmax were 100 μM and 9 nmol min−1 respectively. This transport system is constitutive, energy-dependent, and is strongly inhibited by structural analogs of octanoic acid, by various fatty acids with a carbon length higher than C5 and by certain phenyl derivatives. 相似文献
998.
Patricia Galina-Tessaro Aradit Castellanos-Vera Enrique Troyo D. Gustavo Arnaud F. Alfredo Ortega-Rubio 《Biodiversity and Conservation》2003,12(7):1321-1334
Lizard assemblages were surveyed in eight selected habitats in the Vizcaino Biosphere Reserve in Baja California Sur, Mexico. We compared the species composition and relative abundance among habitats, considering habitat characteristics, such as vegetation type, vegetation ground coverage, and soil types. Thirteen lizard species were recorded. The most abundant species in almost all habitats was Uta stansburiana, accounting for 59% of all observations. Cnemidophorus tigris was the second most abundant species, accounting for 12% of all observations. The richest habitat was the rocky lower elevations of the Sierra de San Francisco (nine species). However, the habitat with the highest diversity value was Scammon's dunes. Implications of our findings for lizard conservation in this biosphere reserve are discussed. 相似文献
999.
Biodiversity conservation in Changbai Mountain Biosphere Reserve, northeastern China: status, problem, and strategy 总被引:2,自引:0,他引:2
The Changbai Mountain Biosphere Reserve (CMBR) is the largest and one of the earliest natural reserves established in China. The continuous losses of species and ecosystems in the reserve since its establishment have raised numerous concerns within China and beyond, which also leads some people to question the function and efficiency of natural reserves in protecting biological and ecological resources. By collecting the published data, conducting field investigation, and interviewing local people, we present the current status of biological and ecological diversity/resources in the reserve and analyze the major factors causing biodiversity loss in the reserve in an ecological and socio-economic context. We found that the high human population pressure, mismanagement practices of resources, a poor resource evaluation system which underestimates the ecological value of the natural reserve, an inappropriate economic development policy, and rapid expansion of the tourist industry were the major causes leading to the biodiversity loss in the reserve in the past few decades. In order to manage the biological resources and biodiversity in the CMBR in a sustainable way, we recommend some strategies and measures which include balancing economic development and biological/ecological conservation, controlling human population in the reserve, encouraging collaboration within and outside the reserve, especially the areas around the reserve, enhancing governmental assistance and subsidy to the local residents, and promoting scientific research and biodiversity education in the local communities. 相似文献
1000.
中国西双版纳蚋类纪要及一新种(双翅目,蚋科) 总被引:2,自引:1,他引:1
记载西双版纳自然保护区蚋类16种,隶属于蚋属Simulium的3亚属,其中包括1个中国新纪录种和3个待定种,并记述1新种,版纳绳蚋S.(G.)bannaense sp.nov.。该新种蛹具10条呼吸丝,与其已知4个近缘种即重庆绳蚋S.(G)chongqingense以及产白爪哇的S.(G.)batoense、产自印尼的S.(G.)atratoides和产自菲律宾的S.(G.)bi-colense等在形态学上有明显的种间差异。 相似文献