群落中物种多度格局的研究综述

物种多度格局是群落结构的重要内容，但在目前的生态学研究中对其重视不够；多度格局研究早在３０年代就开始，在过去的数十年中得到了重要发展；现已建立了多种多度格局模型，它们各有所长；多度格局与物种多样性指数结合，对群落结构研究更具意义；在多度格局研究中也有一些问题值得讨论。     

Species abundance estimation using point-to-plant sampling in a design-based setting

A new species abundance estimator is proposed when point-to-plant sampling is adopted in a design-based framework. The method is based on the relationship between each species abundance and the probability density function of the relative squared point-to-plant distance. Using this result, a kernel estimator for species abundance is provided and the nearest neighbor method is suggested for bandwidth selection. The proposed estimator requires no assumptions about the species point patterns nor corrections for sampling near the edges of the study region. Moreover, the estimator shows suitable statistical properties as well as good practical performance as is shown in a simulation study.     

南黄海鯷鱼产卵场大型底栖生物次级生产力研究

根据2001至2003年南黄海鯷鱼产卵期在鯷鱼产卵场33个站考察采集的大型底栖生物定量样品资料，利用Brey’s(1990)的经验公式对调查海区进行了大型底栖生物栖息密度、生物量、次级生产力和P/B值的研究计算，结果表明，该海域大型底栖生物平均栖息密度为194．3ind．m^-2，平均生物量以去灰干重计，为4．08gm^-2，平均次级生产力以去灰干重计，为4．09gm^-2a^-1，研究表明，生物量和次级生产力受水深的影响，平均P／B值在研究海域为1．32a^-1，对研究结果与整个南黄海、渤海和东海的结果进行了比较与讨论，证明生产力随水深的加大而降低，P／日值随水漏升高而升高，图2表1参25     

博斯腾湖浮游动物的调查研究

通过1987年7月至1989年9月的野外调查和实验室测试,对新疆博斯腾湖大湖区域五个小区浮游动物种群结构、数量和优势种进行了研究.查明浮游动物58属103种,以原生动物和轮虫占优势,年平均数量 776个/ L.博斯腾湖可列为中营养湖泊.     

Determination of Fish Community Composition in the Untempered Regions of a Thermal Effluent Canal – The Efficacy of a Fixed Underwater Videography System

High flows and deep waters associated with thermal dischargecanals invoke safety concerns and preclude the use of conventional fish sampling methodologies. Despite these challenges, it is critical that assessments of thermal effectsfrom power generation do not rely solely on data collected in the plume, but also focus on fish living in the canal, particularly in regions above the zone of tempering influence. We deployed a fixed underwater videography apparatus to monitor the community composition and abundance patterns of fish in the Nanticoke thermal generating discharge canal on the north shore of Lake Erie from February 1, 1999 until July 31, 1999. We also compared the number of species observed using video to angling surveys, visual observations through the air/water interface and two modified netting procedures. Our results indicate that videography permitted the detectionof the most species and the highest number of individuals. Variable visibility was the largest limitation of this approach. The addition of infrared lighting for low light conditions and a series of cameras positioned at several depths would be a cost effective, safe, and efficient method ofassessing community structure and behaviour of fish in thermal discharge canals.     

Influence of benomyl and prometryn on the soil microbial activities and community structures in pasture grasslands of Slovakia

The effects of pesticides (a herbicide and a fungicide) on the microbial community structure and their activity were analyzed in soil from four alpine pasture grasslands in Slovakia. Specifically, the effects of the herbicide, Gesagard (prometryn active ingredient), and fungicide, Fundazol 50 WP (benomyl active ingredient), on the microbial respiration activity (CO₂ production), the numbers of selective microbial physiological groups (CFU.g^?1) and the structure (relative abundance) of soil microbial communities [(phospholipid fatty acid (PLFA)] were analyzed under controlled laboratory conditions. All treatments including the treatments with pesticides increased (statistically significantly) the production of CO₂ in all fields during 21 days of incubation and posed a statistically insignificant negative influence on the numbers of the observed physiological groups of microorganisms. The significantly negative influence was evaluated only in the numbers of two physiological groups; spores of bacteria utilizing organic nitrogen and bacteria, and their spores utilizing inorganic nitrogen. A shift in the microbial composition was evident when the PLFA patterns of samples from different sites and treatments were compared by the Principal Component Analysis (PCA). According to the second component PCA 2 (15.95 %) the locations were grouped into two clusters. The first one involved the Donovaly and Dubakovo sites and the second one contained the Velka Fatra and Mala Fatra locations. The PLFA composition of the soils showed important changes after the treatment with pesticides according to PCA 1 (66.06 %). Other treatments had not had a significant effect on the soil microbial community with the exception of the population of fungi. The lower relative abundance (significant effect) of Gram-positive bacteria, actinomycetes and general group of bacteria were determined in samples treated by the herbicide Gesagard. The application of fungicide Fundazol decreased (statistically significantly) the relative abundance of actinomycetes and general group of bacteria and paradoxically increased the population of fungi.     

Ecological and Biological Features of Melic (Melica virgata Turch. ex Trin.) in Transbaikalia

The endangered species Melica virgata was studied with respect to geographic distribution, the recent state of cenopopulations, the characteristics of habitats, phytocenotic relationships, morphology, and specific ecological and physiological features. The data on the introduction, biochemical composition, and economic significance of M. virgata are presented, and measures aimed at species conservation are proposed.     

Effects of Private‐Land Use,Livestock Management,and Human Tolerance on Diversity,Distribution, and Abundance of Large African Mammals

Successful conservation of large terrestrial mammals (wildlife) on private lands requires that landowners be empowered to manage wildlife so that benefits outweigh the costs. Laikipia County, Kenya, is predominantly unfenced, and the land uses in the area allow wide‐ranging wildlife to move freely between different management systems on private land. We used camera traps to sample large mammals associated with 4 different management systems (rhinoceros sanctuaries, no livestock; conservancies, intermediate stocking level; fenced ranches, high stocking level; and group ranches, high stocking level, no fencing, pastoralist clan ownership) to examine whether management and stocking levels affect wildlife. We deployed cameras at 522 locations across 8 properties from January 2008 through October 2010 and used the photographs taken during this period to estimate richness, occupancy, and relative abundance of species. Species richness was highest in conservancies and sanctuaries and lowest on fenced and group ranches. Occupancy estimates were, on average, 2 and 5 times higher in sanctuaries and conservancies as on fenced and group ranches, respectively. Nineteen species on fenced ranches and 25 species on group ranches were considered uncommon (occupancy < 0.1). The relative abundance of most species was highest or second highest in sanctuaries and conservancies. Lack of rights to manage and utilize wildlife and uncertain land tenure dampen many owners’ incentives to tolerate wildlife. We suggest national conservation strategies consider landscape‐level approaches to land‐use planning that aim to increase conserved areas by providing landowners with incentives to tolerate wildlife. Possible incentives include improving access to ecotourism benefits, forging agreements to maintain wildlife habitat and corridors, resolving land‐ownership conflicts, restoring degraded rangelands, expanding opportunities for grazing leases, and allowing direct benefits to landowners through wildlife harvesting. Efectos del Uso Privado de Suelo, Manejo de Ganado y la Tolerancia Humana sobre la Diversidad, Distribución y Abundancia de Mamíferos Mayores Africanos     

西北煤炭开发生态风险管控区划分及管理策略

为维护我国西北地区生态安全,引导煤炭资源有序开发利用,以甘肃省、青海省、新疆维吾尔自治区为研究区域,结合西北地区典型内陆河流域地下水形成特征及区域生态环境特点,选取与区域煤炭综合开发活动具有重要关联的地下水资源、生态环境等指标,利用专家打分法确定评价指标权重,构建煤炭综合开发生态风险管控评价指标体系,通过对指标体系分级结果的空间转化,划分禁止开发区、限制开发区、适度开发区3个煤炭开发的生态风险管控区.结果表明:①禁止开发区面积约131.6×104 km2,占西北三省（自治区）总面积的46%,主要分布在柴达木、塔里木、准噶尔三大盆地的盆周及周边地区,总体上呈"三环"分布,禁止开发区应禁止一切煤炭开发活动.②限制开发区1区主要分布在新疆维吾尔自治区南部地区及天山北麓以及甘肃省河西走廊的人工绿洲,煤炭开发利用过程中要兼顾保护农田、地下水,维持防风固沙功能方可进行;限制开发区2区主要分布在甘肃省酒泉地区黑河流域,新疆维吾尔自治区阿克苏地区、喀什地区及和田地区的荒漠生态系统内以及环塔里木盆地外围地区,煤炭开发利用过程中需兼顾防风固沙功能及生态系统保护方可进行.③适度开发区分布较为分散,在保护特定生态系统功能的前提下可适度开发.研究显示,需针对上述不同类型的生态风险管控区提出差别化管理要求,重点对限制开发区、适度开发区的煤炭开发提出相应的生态保护要求,提出由限制为主转向优化发展为主的管理方略.      

我国北方四类土壤中氨氧化古菌和氨氧化细菌的活性及对氨氧化的贡献

氨氧化古菌(ammonia-oxidizing archaea,AOA)与氨氧化细菌(ammonia-oxidizing bacteria,AOB)是目前已知的两类好氧氨氧化微生物,广泛分布于各类生态系统中.采用双氰胺(dicyandiamide;DCD)和1-辛炔(1-octyne)抑制剂的方法对我国北方湿地、草原、农田、沙漠4类生态系统的土壤中AOA和AOB的氨氧化速率(ammonia oxidation rate,AR)分别进行定量测定,剖析AOA、AOB对不同土壤中氨氧化的贡献.结果表明:在氨氮含量较高的湿地土壤((32.58±1.38)mg·kg~(-1))中氨氧化速率由AOB主导(ARAOB占AR的86.19%),而在氨氮含量较低的草原土壤((10.40±0.69)mg·kg~(-1))、农田土壤((5.09±0.25)mg·kg~(-1))中氨氧化速率则由AOA主导(ARAOA分别占AR的65.50%、62.20%).氨氮含量是影响AOA、AOB相对活性的主要限制性因素.湿地土壤中氨氧化速率最高,为3.22 mg·kg~(-1)·d~(-1)(以N计),其次是草原土壤和农田土壤,其AR分别为1.11、1.00 mg·kg~(-1)·d~(-1),沙漠土壤中未检测到氨氧化速率.对氨氧化古菌、细菌的amoA基因进行定量分析的结果表明:在氨氮含量最高的湿地土壤和最低的沙漠土壤((1.27±0.05)mg·kg~(-1))中AOA丰度高于AOB丰度,在草原、农田土壤中AOB丰度高于AOA丰度.amoA基因生物多样性分析表明,377个古菌amoA序列以85%相似度可以划分为19个独立操作单元(operational taxonomic unit,OTU),具有较高的生物多样性,其Shannon指数为1.51~1.73.直接通过氨氧化微生物amoA基因丰度来推测AOA、AOB的活性具有一定的缺陷,而依靠AOA、AOB分别的氨氧化速率能够准确地衡量其在不同生态系统中对氨氮去除的相对贡献,对于理解不同生态系统中氨氮去除过程和效应有着重要的意义.