功能多样性——生物多样性与生态系统功能关系研究的新视角

生物多样性与生态系统功能的关系是近年来生态学研究的重点.功能多样性是目前反应生态系统功能最好的预测因子,因为它决定了物种多样性与生态系统功能关系的强度和形式.在查阅大量文献的基础上,介绍了功能多样性的概念和研究方法,并比较了不同功能多样性指数的使用特点.同时,论述了功能多样性与传统生物多样性重要指数——物种丰富度之间的关系以及影响因子,功能多样性与生态系统功能的关系以及影响因子,功能多样性研究在实践中的应用,并对功能多样性的研究趋势进行了展望.     

如何保护中国东北的草地资源生物多样性

根据中国东北草地的自然状况，生物多样性和现状以及已有的研究成果，从生态系统、物种和基因三个水平就如何保护中国东北的草地资源生物多样性提出一些建设性意见，包括保护的范围，原则，方法及指标等。     

放牧对荒漠草原群落多样性的影响

退化草地生态系统中物种多样性的严重丧失及其后果,至今仍缺乏有代表性的实验结论.放牧是人类施加于草原生态系统最主要的干扰因素,从荒漠草原群落多样性、植物功能群多样性以及物种多样性与生产力的关系3个方面综述相关研究进展.提出不同放牧制度对荒漠草原群落多样性、植物功能群多样性的影响过程和作用机制是研究荒漠草原利用与保护平衡的...     

广东罗浮山土壤动物多样性垂直变化特征

垂直地带性是重要的地理学空间格局问题,不同的垂直带具有不同的生态系统结构及功能过程.本研究在罗浮山300 m、730 m、990 m和1 246 m海拔高度,分别对土壤动物群落及土壤性质进行调查.结果发现,随海拔升高,土壤酸度愈来愈强,有机质及全氮含量越来越高.罗浮山不同海拔土壤动物个体数量、类群与生物多样性指数变化趋势基本一致:除300 m海拔外,随海拔增加土壤动物各项指标逐步减少;土壤环境因子的主成分分析及灰色关联度分析表明,pH值对土壤动物总数量、类群、多样性指数影响最大.通过本研究,阐明罗浮山土壤动物群落具有垂直分布性,而土壤酸度是影响土壤动物生物多样性、个体数量及类群丰富度的关键因子;同时,揭示了罗浮山低海拔处强烈的人为干扰对该区域生物多样性已造成较大负面影响.     

三江源区高寒草甸生物多样性影响因子分析——以称多县珍秦乡高寒草甸为例

文章以三江源区玉树州称多县珍秦乡围栏禁牧高寒草甸和围栏鼠害治理高寒草甸为研究对象,进行高寒草甸生物多样性影响因子的研究,研究结果表明:1.围栏禁牧和围栏(适牧)鼠害治理对提高草地群落生产力有一定效果;2.围栏禁牧对于草地生物多样性丰富度的增加效果不明显,围栏鼠害治理的同时进行适度放牧有利于草地生物多样性增加;3.高寒草甸草地生物多样性的主要限值因子是温度,而不是水份.     

青藏铁路工程对高寒草地生态系统的影响

分析了青藏铁路冻土区段高寒生态系统主要分布类型及其变化背景，利用对青藏公路工程的类比调查数据，研究了不同高寒生态系统对工程扰动的抗干扰能力和受损后的自然恢复能力，以及不同生态系统与冻土环境的相互关系。综合考虑干扰场地土壤环境，冻土条件以及不同生态系统对干扰的抵抗与恢复能力等要素，提出了评价青藏铁路对生态环境影响的综合干扰度方法和定量评价模型，基于未来不同气候演变情境及其与人类工程活动耦合下冻土环境变化及其对高寒生态系统的影响。结合青藏铁路施工方案，定量评价了青藏铁路工程对高寒生态系统的可能影响。结果表明：大部分严重干扰施工地带对高寒草甸草地只有中等程度影响，影响区高寒草地植被覆盖度将维持在50％以上，高寒草原区重工程扰动地带除了局部有明显影响外，大部分地区只有中等至轻度影响，而中度与轻度工程扰动区域，工程对高寒生态系统的影响轻微。     

青藏高原草地鼠害的生态释义及控制

首先详细阐述了鼠害涵义及对生态系统的危害.针对我国草原尤其青藏高原草地的严重鼠害状况,一方面,较系统地总结了鼠害对草原植被与土壤、生态系统稳定性,以及草地畜牧业生产的影响;另一方面,着重强调了草地中啮齿动物的生态功能——"生态系统工程师"及维持生物多样性的关键种作用.最后,提出了青藏高原草地鼠害的控制思路及途径,指出今后需要特别开展草地啮齿动物种群暴发,即鼠害发生的阈值的研究,并据此采取生态系统的适应性管理,以及其他人工控制技术来抑制鼠害发生.该文对于草地鼠害研究与控制具有重要的理论与实践意义.     

河北坝上草原不同生境对强足通缘步甲的影响

以河北坝上草地优势物种强足通缘步甲Pterostichus fortipes为研究对象,探讨不同生境对该物种多样性的影响.主要研究内容包括:强足通缘步甲的种群时间和空间动态,种群与环境因子的关系等.结果表明:1)强足通缘步甲在不同生境内的数量分布有显著差异;2)强足通缘步甲种群与地表温度、地下5cm地温和立枯物显著正相关;3)适度的干扰能提高该物种多样性,但干扰频度和程度过高或过低却不利于其物种多样性的提高.研究结果明确了环境中主要生物和非生物因子对强足通缘步甲多样性的影响变化,为生态变化指示性物种的确定提供了科学依据.     

草地植物生物多样性的保护

评述了中国，加拿大在草地生物多样性方面给出的定义及其重要性，探讨了保护和持续利用草地资源及生物多样性的利害关系。在中国和加拿大，草地生物多样性的丧失应归咎于将草草地大面积转为农田以及土地的错误管理，两国都已制定了生物多样性保护性国策，并且认识到全球性努力土该领域的必要性，长春研讨会作为一个范例，显示了国际合作在帮助某些国家确定及合理地解决草地生物多样性保护方面的普遍问题。     

森林土壤线虫群落多样性现状与展望

地下生态学是当今生态学研究的热点与前沿.土壤线虫是地下生态系统的重要组成部分,其在森林土壤生态系统土壤有机质转换、养分循环、土壤结构改善等方面发挥重要作用,并能反映对地上植被变化与干扰,如采伐与火干扰对森林土壤生态系统影响,是森林土壤生态系统健康的重要生物指示物种.本文从森林土壤线虫分类及其生态分布、土壤线虫生物多样性在森林生态系统中的作用以及森林土壤线虫研究最新进展三个方面探讨森林土壤线虫群落多样性的现状,对于土壤线虫多样性对土壤环境健康的意义具有重要的指示作用,并结合分子生物学研究方法展望.     

Parasitic plants indirectly regulate below-ground properties in grassland ecosystems

Parasitic plants are one of the most ubiquitous groups of generalist parasites in both natural and managed ecosystems, with over 3,000 known species worldwide. Although much is known about how parasitic plants influence host performance, their role as drivers of community- and ecosystem-level properties remains largely unexplored. Parasitic plants have the potential to influence directly the productivity and structure of plant communities because they cause harm to particular host plants, indirectly increasing the competitive status of non-host species. Such parasite-driven above-ground effects might also have important indirect consequences through altering the quantity and quality of resources that enter soil, thereby affecting the activity of decomposer organisms. Here we show in model grassland communities that the parasitic plant Rhinanthus minor, which occurs widely throughout Europe and North America, has strong direct effects on above-ground community properties, increasing plant diversity and reducing productivity. We also show that these direct effects of R. minor on the plant community have marked indirect effects on below-ground properties, ultimately increasing rates of nitrogen cycling. Our study provides evidence that parasitic plants act as a major driver of both above-ground and below-ground properties of grassland ecosystems.     

Consistent patterns and the idiosyncratic effects of biodiversity in marine ecosystems

Revealing the consequences of species extinctions for ecosystem function has been a chief research goal and has been accompanied by enthusiastic debate. Studies carried out predominantly in terrestrial grassland and soil ecosystems have demonstrated that as the number of species in assembled communities increases, so too do certain ecosystem processes, such as productivity, whereas others such as decomposition can remain unaffected. Diversity can influence aspects of ecosystem function, but questions remain as to how generic the patterns observed are, and whether they are the product of diversity, as such, or of the functional roles and traits that characterize species in ecological systems. Here we demonstrate variable diversity effects for species representative of marine coastal systems at both global and regional scales. We provide evidence for an increase in complementary resource use as diversity increases and show strong evidence for diversity effects in naturally assembled communities at a regional scale. The variability among individual species responses is consistent with a positive but idiosyncratic pattern of ecosystem function with increased diversity.     

Soil invertebrate fauna enhances grassland succession and diversity

One of the most important areas in ecology is to elucidate the factors that drive succession in ecosystems and thus influence the diversity of species in natural vegetation. Significant mechanisms in this process are known to be resource limitation and the effects of aboveground vertebrate herbivores. More recently, symbiotic and pathogenic soil microbes have been shown to exert a profound effect on the composition of vegetation and changes therein. However, the influence of invertebrate soil fauna on succession has so far received little attention. Here we report that invertebrate soil fauna might enhance both secondary succession and local plant species diversity. Soil fauna from a series of secondary grassland succession stages selectively suppress early successional dominant plant species, thereby enhancing the relative abundance of subordinate species and also that of species from later succession stages. Soil fauna from the mid-succession stage had the strongest effect. Our results clearly show that soil fauna strongly affects the composition of natural vegetation and we suggest that this knowledge might improve the restoration and conservation of plant species diversity.     

Changes in plant community diversity and aboveground biomass along with altitude within an alpine meadow on the Three-River source region

The grassland is an important component of terrestrial ecosystems and plays a significant role in biodiversity and ecosystem functions.In the present study,the changes of plant species diversity and aboveground biomass productivity were examined along with the altitude in natural alpine grassland in the source region of three rivers on the Qinghai-Tibetan Plateau.Eleven experimental locations were selected with altitudes ranging from 3862 to 4450 m above sea level(a.s.l.).The results indicated that Kobresia pygmaea meadow,Kobresia humilis meadow and Salix cupularis shrub meadow had higher indices of diversity and aboveground biomass.The distribution of species diversity,richness and aboveground biomass showed similarly unimodal patterns across the altitude gradient with the highest indices appeared at mid-altitudes locations.The changing trend of species diversity,richness and evenness also showed significant unimodal patterns with total aboveground biomass,and the highest species diversity occurred at intermediate level of productivities.This research would provide a valuable reference for the protection of grassland biodiversity and maintaining of the grazing ecosystem function in the source region of the Three Rivers.     

两种类型人为干扰对城市风景林植物多样性的影响

【目的】城市化对城市森林生态系统产生巨大影响,探讨城市化背景下植物群落物种多样性成为城市生态学研究热点。笔者探究了游客活动干扰和城市园林管理干扰对物种多样性的影响,为徐州泉山保护区的生态保护提供理论基础。【方法】于2018年6月,对泉山保护区的泉山、泰山和云龙山进行野外调查,整理统计54个样方物种数据并进行物种多样性分析。【结果】人为干扰加剧了物种数的减少;两种类型人为干扰对不同层物种数影响不同;游客活动干扰对物种多样性影响显著(P<0.05),城市园林管理干扰则无显著影响(P>0.05);两种类型人为干扰对物种丰富度无显著影响(P>0.05),对均匀度影响显著(P<0.05)。两种类型人为干扰对不同层物种数影响不同,游客活动干扰增强会降低乔木层的物种数,城市园林管理干扰增强则降低灌木层的物种数;游客活动干扰对物种多样性影响显著,中度干扰下物种多样性最小,城市园林管理干扰对物种多样性无显著影响;游客活动干扰和城市园林管理干扰均未影响物种丰富度,但均影响物种均匀度,并且影响结果不同。均匀度随着游客活动干扰增强呈先减小后增加的趋势,而随着城市园林管理干扰增强呈增加的趋势。【结论】游客活动干扰较城市园林管理干扰对植物多样性格局产生更直接显著的影响,在保护中更应警惕游客的行为对植物多样性的负面影响,严格规范游客行为。     

Ecosystem stability and compensatory effects in the Inner Mongolia grassland

Numerous studies have suggested that biodiversity reduces variability in ecosystem productivity through compensatory effects; that is, a species increases in its abundance in response to the reduction of another in a fluctuating environment. But this view has been challenged on several grounds. Because most studies have been based on artificially constructed grasslands with short duration, long-term studies of natural ecosystems are needed. On the basis of a 24-year study of the Inner Mongolia grassland, here we present three key findings. First, that January-July precipitation is the primary climatic factor causing fluctuations in community biomass production; second, that ecosystem stability (conversely related to variability in community biomass production) increases progressively along the hierarchy of organizational levels (that is, from species to functional group to whole community); and finally, that the community-level stability seems to arise from compensatory interactions among major components at both species and functional group levels. From a hierarchical perspective, our results corroborate some previous findings of compensatory effects. Undisturbed mature steppe ecosystems seem to culminate with high biodiversity, productivity and ecosystem stability concurrently. Because these relationships are correlational, further studies are necessary to verify the causation among these factors. Our study provides new insights for better management and restoration of the rapidly degrading Inner Mongolia grassland.     

外来入侵物种造成的间接经济损失估算模型

外来入侵物种已对我国生态系统功能造成严重破坏.由于没有市场交易和市场价格,采用机会成本、影子价格或影子工程费用估算外来入侵物种对生态系统服务功能造成的经济损失.在分析森林、农田、草原、湿地、草坪等生态系统服务功能价值评估的基础上,根据外来入侵物种对各类生态系统服务功能造成的损害程度,分别建立了外来入侵物种对森林、农田、草原、湿地、草坪等生态系统的间接经济损失评估模型;并在参数估计的基础上,计算了2000年外来入侵物种造成的间接经济损失.     

土地利用变化对高寒草甸植物群落结构及物种多样性的影响

以原生高寒嵩草草甸封育系统为对照,研究了不同土地利用对植物群落结构和物种多样性的影响,检验了不同人工重建措施对植被的相对影响程度.研究结果表明:高寒嵩草草甸草地退化导致植被稀疏、覆盖度下降、群落物种组成减少、群落中各功能群的比例发生变化、物种多样性降低.退化草地封育自然恢复7年后,恢复最快的是一年生杂草,其次是禾草类;重度退化草地改建成人工草地7年后,禾本科植物仍然是群落中的优势类群,但原生植被中的优势功能群--莎草类在任何人工草地中没有出现;经相关分析表明,物种多样性指数与均匀度指数呈极显著正相关(P＜0.01),与物种丰富度呈显著正相关(P＜0.05).不同土地利用条件下,各群落之间种相似性系数的变化表明,退化草地经过多年的封育,或经松耙补播后逐步向原生植被方向演替;人工草地逐步向退化演替方向发展.     

Disturbance and diversity in experimental microcosms

External agents of mortality (disturbances) occur over a wide range of scales of space and time, and are believed to have large effects on species diversity. The "intermediate disturbance hypothesis", which proposes maximum diversity at intermediate frequencies of disturbance, has received support from both field and laboratory studies. Coexistence of species at intermediate frequencies of disturbance is thought to require trade-offs between competitive ability and disturbance tolerance, and a metapopulation structure, with disturbance affecting only a few patches at any given time. However, a unimodal relationship can also be generated by global disturbances that affect all patches simultaneously, provided that the environment contains spatial niches to which different species are adapted. Here we report the results of tests of this model using both isogenic and diverse populations of the bacterium Pseudomonas fluorescens. In both cases, a unimodal relationship between diversity and disturbance frequency was generated in heterogeneous, but not in homogeneous, environments. The cause of this relationship is competition among niche-specialist genotypes, which maintains diversity at intermediate disturbance, but not at high or low disturbance. Our results show that disturbance can modulate the effect of spatial heterogeneity on biological diversity in natural environments.     

Grassland species loss resulting from reduced niche dimension

Intact ecosystems contain large numbers of competing but coexisting species. Although numerous alternative theories have provided potential explanations for this high biodiversity, there have been few field experiments testing between these theories. In particular, theory predicts that higher diversity of coexisting competitors could result from greater niche dimensionality, for example larger numbers of limiting resources or factors. Alternatively, diversity could be independent of niche dimensionality because large numbers of species can coexist when limited by just one or two factors if species have appropriate trade-offs. Here we show that plant coexistence and diversity result from the 'niche dimensionality' of a habitat. Plant species numbers decreased with increasing numbers of added limiting soil resources (soil moisture, nitrogen, phosphorus and base cations), which is consistent with theoretical predictions that an increased supply of multiple limiting resources can reduce niche dimension. An observational field study gave similar results. The niche dimension hypothesis also explained diversity changes in the classic Park Grass Experiment at Rothamsted. Our results provide an alternative mechanistic explanation for the effects of nutrient eutrophication on the diversity of terrestrial, freshwater and marine ecosystems.