内蒙古白音锡勒典型草原区鼠类群落多样性的研究

在草原生态系统中,鼠类既是消费者又是次级生产者,因此这个类群在草原生态系统中占有重要的地位。 鼠类群落结构是生态系统结构的一部分,它的存在是地理的、生态的和进化的诸因素共同作用的结果。鼠类群落的多样性,反映了同一地区各群落之间的相似程度,也反映了群落与其外界条件的关系,它作为群落的结构参数,是群落特征的重要方面,日益受到生态学工作者的重视。 1979年7-9月,我们曾对内蒙古白音锡勒典型草原区的鼠类群落空间配置及其结构进行研究(钟文勤等,1981)。本文将通过分析这些群落的多样性,进一步探讨鼠类群落与植被、土壤等条件的关系。     

荒漠啮齿动物群落与植物群落的对应分析

动物与其生存环境变量之间的关系一直是生态学家们广泛关注的问题.啮齿动物作为荒漠生态系统中重要的功能群,其数量大小和生态功能对生态系统的平衡和稳定具有重要意义.生境中的植被为啮齿动物提供赖以生存的食物资源和栖息地,了解啮齿动物群落与植被特征之间的关系对于理解动物群落变动规律具有重要意义.不同植被条件下啮齿动物群落的结构不同,Hernández等(2005)研究发现北美Chihuahuan荒漠的灌木生境中啮齿动物密度高于草地生境.     

库布其沙漠及其毗邻地区鼠类群落的结构分析

根据库布其沙漠及其毗邻地区生境和鼠类分布的差异,应用系统聚类法,将该地区的鼠类划分为５个群落：（１）沙漠鼠类群落;（２）半荒漠区沙地鼠类群落;（３）荒漠鼠类群落;（４）荒漠化草原鼠类群落;（５）干草原鼠类群落。５个群落可聚为３个群落组。（１）沙地群落组;（２）半荒漠和荒漠群落组;（３）干草原群落组。同时对鼠类群落的多样性、均匀度等进行了初步分析。     

金华北山啮齿类的生态研究

本文论述了金华北山啮齿类的区系组成、数量季节消长和垂直分布。依据不同生境中鼠种和数量的组成,划分了7个鼠类群落。进而对比和分析了各鼠类群落的组成和空间配置、多样性及生物量的分配。通过以人工针叶林为主的北山与具良好次生林植被的天目山自然保护区之间的比较,表明鼠类组成方面有着明显的差异,并探讨了造成这种差异的部分原因。     

青藏高原高寒生境中丛枝菌根真菌研究进展

极端生境往往蕴藏着具有特殊生理生态功能的生物类群。海拔高、温度低、生长季节短的青藏高原高寒草原生态系统是典型的极端生境之一,目前有关该生境中分布的丛枝菌根真菌(Arbuscular mycorrhizal fungi,AMF)研究已引起广泛关注。本文从青藏高原高寒生境中AM真菌的研究概况入手,论述青藏高原高寒生境中AM真菌的群落组成、物种多样性与分布特征、菌根侵染发育状况及高寒生境对AM真菌的影响。指出高寒生境中AM真菌群落结构研究方面存在的问题,探讨解决这些问题的可能途径及其研究发展前景,以期为青藏高原高寒草原生态系统稳定性的维持与受损生态系统的恢复提供理论依据。     

甘肃河西走廓不同生境中鼠类群落结构初步研究

本文对河西走廓不同生境中鼠类群落的物种组成和多样性进行了初步研究,在6种生境中进行了定量调查和采集,共获13种标本,隶于6（亚）科9属,其中古北界种类占优势。多样性分析结果表明：6种生境的物种丰富度指数RMargaler在.6139-1.9689之间。Shannon-Wiener指数（H')为1.0695-1.5607,Pielou旨数（J')和Simpson指数（D）分别为0.7242-0.9735和0．2768－0．4683,不同生境的丰富种数量（N1)变化趋势与H'相似,而非常丰富种数量（N2）的变化趋势为：半莫荒灌丛生境＞山地草原生境＞戈壁荒漠生境＞农田生境＞森林生境＞山地半荒漠灌丛生境。降水对不同生境类型中鼠类群落物种组成和多样性起直接的限制作用,同时海拔和人类干扰也是影响的因素。     

人为不同干扰条件下荒漠啮齿动物群落格局的动态特征——动物与植物群落的典型相关分析

群落的格局和动态是群落牛态学和生态系统生态学研究中的基础问题,也是揭示群落结构和功能的核心问题。为了深入了解生态系统的结构与功能,研究啮齿动物群落格局在人为不同干扰下的动态特征,特别是研究荒漠区的脆弱生态系统中啮齿动物群落格局在人为不同干扰下的动态特征,是揭示人为干扰下荒漠生态系统结构和功能变化特征的基础。2002～2004年在内蒙古阿拉善典型荒漠区,选择了4种不同干扰条件的生境,分别为禁牧区、过牧区、轮牧区和开垦区,研究了人为不同干扰下啮齿动物群落格局的变动趋势,应用典型相关方法分析了啮齿动物群落与植物群落在不同干扰条件下的相互关系。结果表明,在两种观察尺度域上（标志样地和线路样地）动物群落变量与植物群落变量的相关关系表现为：动物群落变量与植物群落变量中的草本关系最为突出,在分析的两个尺度的8个样地中,除标志样地的过牧区外,其它7个样地均与草本关系密切,且绝大多数样地动物群落变量与草本的盖度和地上生物量呈负相关关系。这说明荒漠生态系统中,在4种干扰条件下,草本的特性,特别是草本的盖度和地上生物量对啮齿动物群落格局及其动态变化起到关键作用,其值越大,啮齿动物群落组成种的丰富度（数量）和生物量就越小。就同一种干扰条件下的两种尺度域上的情况看,动物群落和植物群落的相关性较突出的特点是：在禁牧区和开垦区,喜湿的种类（黑线仓鼠和草原黄鼠）与植被的相关性显著,在轮牧区和过牧区,喜旱的种类（小毛足鼠和三趾跳鼠）与植被的相关性显著,且均与草本呈负相关关系。     

延安林区地栖鼠类组成及优势度分析

延安林区共有地栖鼠类8种,分属2科6属。密度和生物量在反映不同生境鼠类作用大小方面并不一致,本文利用密度和生物量综合决定的重要值来表示鼠类优势度,分析了该区地栖鼠类组成及作用大小,并对不同生境中鼠类的优势度水平进行了比较。指出中华鼢鼠是该林区的优势种类,并提出了针对该鼠的造林建议。     

吐鲁番沙漠植物园及其周围地区鼠类群落结构调查

2005年4月15日~2005年6月3日对中国科学院吐鲁番沙漠植物园及其周围地区的鼠类群落进行了调查,采用样线铗捕法,共捕获鼠类373只,隶属于3科3属4种。用种类(S)、多样性指数(H′)、均匀性指数(E)、优势度(D)等4个指标对灌木林、园林、沙地、废弃耕地、农田等5种不同生境类型的鼠类群落进行统计分析和对比。结果发现,不同生境类型的鼠类群落在群落组成、多样性、均匀性和优势度等方面存在着明显的差异;废弃耕地多样性和均匀性最高而优势度最低;园林多样性最低,农田均匀性最低,灌木林优势度最高。红尾沙鼠(Meriones libycus)和子午沙鼠(M.meridianus)分别占以上5种类型鼠类群落总生物量的59.5%和37.5%,可以确定为吐鲁番沙漠植物园及其周围地区鼠类群落的优势种。     

不同恢复措施对内蒙古乌拉特中旗荒漠草原植物群落的影响

处于干旱地区的内蒙古荒漠草原，在防风固沙、生物多样性保育等方面发挥着重要的生态功能。近年来由于人类活动的干扰及气候变化的影响，内蒙古荒漠草原生态系统发生了严重的退化。如何有效恢复荒漠草原的生态功能是当前亟待解决的问题，科学合理地进行人为定向培育是荒漠草原植物群落恢复与重建的重要措施。本研究以乌拉特中旗荒漠草原为对象，通过控制实验探讨了不同退化程度下植物群落结构及地上生物量对不同恢复措施的响应。结果表明：在重度退化的荒漠草原生态系统，短期封育提高了杂类草的相对盖度，使群落地上生物量增加2.11倍；添加有机肥提高了禾草物种丰富度，使群落地上生物量提高了3.97倍；补播显著提高了植物群落的盖度、密度，使群落地上生物量提高了9.76倍。在重度沙化区，补播显著提高了群落的盖度、密度、地上生物量，但对物种多样性无显著影响。在中度退化区，添加复合肥显著降低了短花针茅群落杂类草物种数，提高了禾草及植物群落的地上生物量；添加复合肥显著提高了柠条锦鸡儿-丛生禾草群落中禾草物种丰富度，但对植物群落盖度、密度及地上生物量无显著影响；喷施叶面肥显著降低了藏锦鸡儿-灌丛化禾草群落杂类草的盖度和密度，提高了禾草的地...     

CHLOROPHYLL-a CONCENTRATION IN THE LOWER KAFUE RIVER AND CHONGWE RIVER BASINS

SUMMARY

The concentration of chlorophyll a was measured in the warm monomictic impoundment, Itezhi-tezhi Lake ([xbar] = 2,00 mg m^?3); in the small, slightly polluted Chongwe Dam ([xbar] = 11,0 mg m^?3); and in the temporary Mungasiya River ([xbar] = 53,4 mg m^?3). The average standing crop of the periphyton of green filamentous algae in the Chongwe River reached 28,3 mg m^?2. The highest concentrations of chlorophyll ([xbar] = 69,6 mg m^?2) were found in the Cyanophyta community of the extreme biotope of Longola Hot Springs.     

Effects and mechanism of plant litter on grassland ecosystem: A review

Plant litter is dead, above and below ground; organic material i.e. leaves barks, needles, twigs and roots. Plant litter plays a key role in nutrient cycling and community organization in grassland ecosystems. Litter can have important consequences on recruitment of plant species through modification of biological, physical, and chemical features of microenvironment. Plant litter offers a major input of organic matter to the soil which modifies soil chemistry, hence impacts nutrient cycling. At early stages of litter decomposition, a particular amount of carbon is transporting to the soil nutrient pool. In terrestrial ecosystems, plant litter regulating biogeochemical cycles, maintain soil fertility, nutrient availability, and therefore influence plant growth, diversity, composition, structure, and productivity. Litter can also impact plant above net plant productivity and below net plant productivity in grassland ecosystem. Plant litter accumulation and decomposition can impact plant species composition and community structure through temperature, light and nutrient availability. The effects of plant litter on vegetation may be negative, positive or neutral due vegetation variability, study duration, habitat, latitude, quantity and quality of litter. These diverse effects of plant litter on grassland ecosystem might be due to, management practice type, management intensity, climate type, timing, precipitation and soil nutrient pool etc. Current review attempts to describe prominent effects of plant litter on vegetation, seed germination, soil fertility, Productivity, species composition, community structure and mechanism in grassland ecosystem.     

Habitat engineering under dry conditions: The impact of pikas (Ochotona pallasi) on vegetation and site conditions in southern Mongolian steppes

Question: Does ecosystem engineering by small mammals have a significant influence on vegetation patterns in the arid steppe vegetation of southern Mongolia? Location: Gobi Altay Mountains, southern Mongolia. Methods: We assessed the impact of the small lagomorph Ochotona pallasi on plant community composition, nutrient levels and biomass production in montane desert steppes. Data were derived from vegetation relevés, harvests of above‐ground standing crop and a bioassay, followed by analyses of soil and plant nutrient contents. Results: Although the local climate is arid with <150 mm annual precipitation, clear evidence of allogenic ecosystem engineering was found. Plant communities on burrows differed from those on undisturbed steppe in that they contained more species of annuals and dwarf shrubs, and a greater abundance of the important fodder grass Agropyron cristatum. Standing crop and nutrient concentrations were higher for plants growing on burrow soil. In situ measurements and a pot experiment showed that this effect was related to increased levels of soil nutrients (P, K, N) rather than moisture availability. Conclusions: The study confirms that O. pallasi positively influences soil nutrient levels on its burrows, which leads to increased grassland productivity even under dry conditions. Thus, O. pallasi does not deteriorate site conditions, and the need for presently applied pest control schemes aimed at this species should be reassessed.     

ECOLOGY OF THE EPIPELIC ALGAL COMMUNITIES IN MARION LAKE,BRITISH COLUMBIA1,2

Studies of the seasonal and spatial distribution of the epipelic algal standing crop and primary productivity were conducted in Marion Lake, British Columbia. Possible biological, chemical, and physical factors controlling the epipelic algal community dynamics were also investigated. The epipelic algal flora of the lake was very diverse, however, it can be generally considered as acidophilic associations of algae. The vertical distribution of the epipelic algae is partially influenced by the amount of light reaching the sediment, but also strongly influenced by the grazing of animals and erosion by wave action. Temperature, light, and grazing by animals all appear to influence the seasonal fluctuations in the algal standing crop. Concentrations of nutrients immediately above the sediment surface appear to be less important as controlling factors. The most important variables influenceing the primary productivity of the epipelic community are temperature, total algal standing crop, and light. Nutrients, again, appear to be less important as controlling factors. The study supports the idea that epipelic algal growth is high in shallow, low nutrient lakes and that the epipelic algal productivity is extremely important to the total energy budget of the lake.     

Indirect estimation of the underground standing crop of individual plant species of natural grassland communities

The estimation of underground standing crop of individual plant species in a natural grassland ecosystem without direct measurement of screened plant material is described. A mathematical formulation techinque has been designed by correlating the variables fresh weight, dry weight, ash weight and also nitrogen, phosphorus, potassium, sodium, calcium, sulphur and magnesium content of the plant species.     

半干旱区湿地-干草原群落交错带边缘效应研究

以宁夏盐池四儿滩湿地为例,于2005年和2006年7~8月份沿湿地—干草原生境梯度按东、东北、西、西北4条样线进行实地植被调查,并采用TWINSPAN数量分类和植物群落结构指数计量研究湿地—干草原交错带边缘效应。结果表明:(1)四儿滩湿地生态系统植物群落分为沼泽植被、草甸植被、干草原植被3个类型。(2)四儿滩湿地植物群落结构指数除群落均匀度指数外,生态优势度、丰富度和物种多样性均是交错带最大,其次是旱生带,湿生带最小。(3)四儿滩湿地—干草原交错带不同方向群落结构差异较大,各项植物群落结构指数均是东北样线最大,西北样线最小。造成不同样线间边缘效应差异的主要因素是人为干扰程度和地形抬升程度不同。     

高寒草地土壤温室气体排放对放牧的响应研究进展

高寒草地生态系统具有独特的地理环境和气候特征,对放牧干扰十分敏感,在全球温室气体通量中贡献突出,研究高寒草地放牧对土壤温室气体排放的影响机制具有重要意义。本文总结高寒草地温室气体源/汇特征、不同放牧方式对土壤微环境和微生物群落结构的影响,发现高寒草地主要是CO₂源、CH₄汇、N₂O源。放牧通过家畜选择性采食、践踏和排泄物返还等多重机制作用于地上植物、土壤结构、温度、湿度和养分,进而影响地下微生物及温室气体通量。本文旨在为高寒草地生态系统健康发展和管理及缓解全球气候变化提供科学依据,并对未来研究方向进行展望。     

香港芒萁群落养分的研究

本文研究香港芒萁群落养分的分配、季节动态和循环。研究结果表明：(1)N、P、K浓度在活物质大于死物质,地上部分大于地下部分。(2)植物的养分贮量是活物质大于死物质,地下部分大于地上部分。(3)当年生芒萁地上部养分贮量随生物量的增加而增加,但是,干物质生产率超过养分吸收率,使得N、P、K浓度由于生物量的增加而降低。(4)虽然芒萁群落的净第一性生产力大于其邻近的草地和灌木林,但其净第一性生产量中的N和P量却小于灌木林。(5)以土壤中的总N和总P来计算,生态系统中的N和P主要贮存于土壤库中,但以土壤有效K来计算,则有大约36％～50％的K贮存于植被中。(6)在研究期间,立枯体和死地被物中的N、P、K贮量逐渐增加,这表明在火灾后生态系统的立枯体和死地被物养分库有一个累积过程。(7)N、P、K通过枯枝落叶的归还量分别占它们在地上部净第一性生产量中的49.1％、30.8％和13.1％,而地上部净第一性生产量中的N和P的31.2％和46.6％来自于养分的内部循环。     

Invertebrate,not small vertebrate,herbivory interacts with nutrient availability to impact tallgrass prairie community composition and forb biomass

The effects of herbivores and their interactions with nutrient availability on primary production and plant community composition in grassland systems is expected to vary with herbivore type. We examined the effects of invertebrate and small vertebrate herbivores and their interactions with nutrient availability on grassland plant community composition and aboveground biomass in a tallgrass prairie ecosystem. The abundance of forbs relative to grasses increased with invertebrate herbivore removals. This increase in forb abundance led to a shift in community composition, where invertebrate removals resulted in greater plant species evenness as well as a divergence in composition among plots. In contrast, vertebrate herbivore removals did not affect plant community composition or aboveground biomass. Nutrient additions alone resulted in a decrease in plant species richness and an increase in the abundance of the dominant grass, but the dominant grass species did not greatly increase in abundance when nutrient additions were combined with invertebrate removals. Rather, several subdominant forbs came to dominate the plant community. Additionally, the combined nutrient addition and invertebrate herbivore removal treatment increased forb biomass, suggesting that invertebrate herbivores suppress the responses of forb species to chronic nutrient additions. Overall, the release of forbs from invertebrate herbivore pressure may result in large shifts in species composition, with consequences for aboveground biomass and forage quality due to altered grass:forb ratios in grassland systems.     

钱塘江河口滩涂围垦区人口迁居与农田小兽群落的关系

1987年8月和1989年8月,作者对钱塘江河口滩涂围垦区人口迁居与农田小兽群落的关系进行了调查。在6种类型的人群居住区内,4种家栖小兽中以臭鼩为优势种。随着人口和建筑物增多,食虫类数量超过家鼠,处于优势地位,因而在家鼠与食虫类之间有一定程度的负相关。同时还探讨了家栖小兽群落与农田小兽群落之间的迁移和扩散的关系。