紫胶林-农田复合生态系统地表甲虫多样性——以云南绿春为例

为揭示紫胶林-农田复合生态系统地表甲虫多样性, 于2006-2007年在云南省绿春县牛孔乡采用陷阱法调查了天然紫胶林、人工紫胶林和旱地的地表甲虫群落。共采集标本1 678头, 分别隶属于24科120种, 其中步甲科(Carabidae)和金龟科(Scarabaeidae)种类最丰富, 均占全部种类的12.50%。拟步甲科(Tenebrionidae)个体数量最丰富, 占个体总数的64.48%; 金龟科次之, 占个体总数的17.58%。大多数科的物种数和个体数在不同土地利用生境中的分布没有显著差异, 而步甲科、隐翅甲科(Staphylinidae)、叩甲科(Elateridae)、拟步甲科、瓢虫科(Coccinellidae)和小蠧科(Scolytidae)在不同土地利用生境中的分布有显著差异。天然紫胶林地表甲虫个体数量最少, 物种较丰富, 优势度最低, 多样性最高; 人工紫胶林个体数和物种数均丰富, 优势度和多样性居中; 旱地个体数量最多, 物种最贫乏, 优势度最高, 多样性最低。种级水平的聚类分析体现出人工紫胶林与旱地之间在种类组成上距离较近; 而科级水平的聚类反映出人工紫胶林和天然紫胶林更接近。结果提示, 紫胶林-农田复合生态系统具有区域内土地利用方式多样化的特点; 天然紫胶林在维持地表甲虫多样性水平上具有重要作用, 而人工紫胶林虽具有积极作用, 但仍需进一步恢复。     

Ecosystem function and species loss – a microcosm study

There are too many kinds of organisms to be able to study and manage each, yet the loss of a single species can sometimes unravel an ecosystem. Such `fusewire species'– critical in the same sense that an electrical fuse can cut out a whole circuit – would be a rewarding focus for research and management effort. However, this approach can only be effective if these `fusewires' represent but a small proportion of the number of species in the system.  

Aim

To demonstrate methods for measuring what proportion of the species in a system are critical to ecosystem function.  

Methods

The prevalence of fusewire species was measured in manipulative experiments on an aquatic microcosm.  

Results

No single genus deletion caused changes in key characteristics of the system.  

Main conclusions

Comparison of these results with other published studies shows that the proportion of critical fusewire species varies amongst different ecosystems. The oxidation pond microcosms were shown to contain no single species indispensable to system function. They appear to be ill-suited to a management strategy which focuses on priority eukaryote species. However, a single study provides no evidence that this result is general or even typical of other kinds of ecosystems; it is presented here as an empirical model. Other methods of investigation are available; they are less experimentally rigorous but more practical. These could provide important guidance in planning an approach to management in a particular ecosystem.     

Degraded or just different? Perceptions and value judgements in restoration decisions

An underlying premise of ecological restoration is that it focuses on the recovery of degraded systems. While this is an apparently straightforward aim, there is in fact considerable variation in how the term “degraded” is defined, used and assessed. In addition, there is a notable subjective component to decisions regarding what is degraded and what isn't, and this often relates to the values and goals being considered. There is likely to be little argument over highly degraded systems where damage and loss of valued characteristics are evident. But where system change is less stark and the changes have mixed benefits and disbenefits, the decision on whether the system is degraded and hence in need of restoration becomes more difficult. As systems continue to change in the face of ongoing climate, land use and other environmental changes, decisions become more difficult regarding which systems are degraded and which are merely different from what was there before. Difference does not necessarily equate to degradation. Effective use of scarce management resources relies on an improved ability to openly debate and resolve such issues.     

物种多样性与生态系统功能：影响机制及有关假说

本文主要介绍了有关物种多样性对生态系统功能的影响机制及有关假说,包括冗余种假说、铆钉假说、不确定假说、无效假说、补偿／关键种假说、非线性假说、单调／驼峰模型假说等。尽管这些假说的提出都有一定的理论或实验研究基础,但到目前为止,还没有一种假说被普遍认为反映了两者之间关系的实际情形（如果确实存在这样一种普适机制）。通过分析,我们发现在这些假说之间存在一定的内在联系,它们或者互相包含,或者互相补充,并且都可以归结到冗余种假说有关。     

生物多样性与生态系统功能:进展与争论

生物多样性与生态系统功能的关系已成为当前人类社会面临的一个重大科学问题,生物多样性的空前丧失,促使人们开展了大量研究工作来描述物种多样性-生态系统功能关系,并试图揭示多样性与系统功能关系的内在机制,本文将多样性对生态系统功能作用机制的有关假说分为统计学与生物学两大类：前者是从统计学角度来解释观察到的多样性-系统功能模式,包括抽样效应,统计均衡效应等;而后者是基于多样性的生物学效应给出的,包括生态位互补,种间正相互作用,保险效应等,本文较为详细地介绍了该领域内有代表性的实验工作,包括“生态箱”实验,Cedar Creek草地多样性实验,微宇宙实验,欧洲草地实验,以及在这些实验结果解释上的激烈争论。     

Optimal Investment in Multi-species Protection: Interacting Species and Ecosystem Health

This article uses an ecological-economic approach to study optimal investment in multi-species protection when species interact in an ecosystem. The analysis is based on a model of stochastic species extinction in which survival probabilities are interdependent. Individual species protection plans can increase a species survival probability within certain limits and contingent upon the existence or absence of other species. Protection plans are costly and the conservation budget is fixed. It is assumed that human well-being depends solely on the services provided by one particular species, but other species contribute to overall ecosystem functioning and thus influence the first species survival probability. One result is that it may be optimal to invest in the protection of those species that do not directly contribute to human well-being, even if biological conservation decisions are exclusively derived from such a utilitarian framework. Another result is that the rank ordering of spending priorities among different species protection plans, as obtained under the assumption of independent species, may be completely reversed by taking species interaction into account. The conclusion is that effective species protection should go beyond targeting individual species, and consider species relations within whole ecosystems as well as overall ecosystem functioning. Ecosystem health is identified as a necessary prerequisite for successful species protection in situ.     

Co-occurrence of prairie and barrens butterflies: applications to ecosystem conservation

Abundance indices from transect surveys for species restricted to prairies and barrens were correlated to test the degree to which these species of conservation concern co-occur. In 56 pair-wise tests among 15 species by subregion, 29 (52%) correlated significantly, all but one positively, and only 17 (37%) of 46 tests involving samples of >60 individuals for each species were non-significant. The species producing the most significant interspecific correlations in prairie were Speyeria idalia (five of ten tests) and Atrytone arogos (four of six tests); in barrens, Euchloe olympia (seven of eight tests) and Hesperia l. leonardus (six of eight tests). Lycaeides melissa samuelis, the butterfly receiving the most conservation attention in these habitats, produced few significant correlations. To explicate these patterns of co-occurrence, case histories were compiled for these species at sites of comparable vegetation by subregion. No management type was clearly favourable for all specialists of a given habitat, although some managements were favourable for more species than others (e.g. haying vs. burning in prairie). Analysis of variance of management at these sites produced more results with significant effects than did correlations of the species' abundance indices with habitat patch size. These results were inconsistent with prevailing ecological theory about the natural maintenance of these habitats; conversely, a single unified (alternative) theory of ecosystem management could not be inferred from these results. These patterns of butterfly co-occurrence suggest an alternative approach to ecosystem conservation that focuses on subsets of species native to a particular ecosystem. These smaller species assemblages significantly co-occur in range, habitat, and management tolerance, and may be amenable to monitoring with indicator species.     

塔里木河下游植物群落的物种数量变化与生态系统动态研究

物种多样性是指物种及其集合体的生物学多样性。物种多样性研究的核心是物种的数量变化和物种的生物学多样性程度。本文根据野外采集的数据 ,运用Simpson指数、McIn tosh指数以及Margalef指数 ,对塔里木河下游英苏、阿布达勒、喀尔达依、阿拉干、依干不及麻等地区的物种多样性指数分别进行了计算 ,并根据计算得到的生物多样性指数探讨了干旱区退化生态系统的物种多样性以及在干旱区物种多样性与生态系统稳定性之间的关系。结果表明 ,塔里木河下游从英苏至依干不及麻 ,Simpson多样性指数的变化范围为 0 82～ 0 2 6 ,McIn tosh均匀度指数的变化范围为 0 6 0～ 0 1 8,Margalef丰富度指数的变化范围为 1 4 7～ 0 38,物种数的变化范围是 9～ 2。分析表明塔里木河下游生态系统退化十分严重 ,并据此讨论了塔里木河下游生态系统退化的特征、演替动态及稳定性     

中国濒危的多孔菌

1992-2009年在全国范围内对中国多孔菌进行了系统调查,基于对多孔菌生境是否受到威胁,初步将48种中国多孔菌列为濒危种,占中国多孔菌总数的8%;分布于20个省和自治区,其中绝大部分生长于原始森林中,主要在倒木和腐朽木上;它们几乎不能在人为干扰的林分内生存;38种为木材白色腐朽菌,9种为褐色腐朽菌,1种为树木菌根菌。对每种的基本形态学、生长基质和生态习性进行了简要论述。     

Hierarchical reliability in experimental plant assemblages

Aims: The mechanism by which species richness affects variation inecosystem functioning both within and among ecosystems remainsa key question at the interface of community and ecosystem ecology.Statistical averaging (the smoothing of average system performancevia consideration of additional components) and the insuranceeffect (reduced variation in system performance by inclusionof asynchronously varying components) predict that more diversecommunities should vary less both between replicates and internally.We experimentally tested these theories in small plant assemblages. Methods: We constructed plant assemblages modeled after old-field plantcommunities. We varied species richness, species compositionand initial densities while holding functional group richnessconstant in replicate assemblages under glasshouse conditions. Important findings: The inverse of the coefficient of variation of aboveground biomassproduction, a proxy measure of reliability, increased with higherdiversity when examined at the level of the assemblage (i.e.among-replicate assemblages) but not at the levels of functionalgroup or species. These stabilizing processes were weakest inlow-diversity, low-density assemblages. This experiment demonstratesthe utility of hierarchical analysis of ecosystem reliabilityat the assemblage, functional group and species level.     

Beyond the single index: Investigating ecological mechanisms underpinning ecosystem multifunctionality with network analysis

Ecosystems simultaneously deliver multiple functions that relate to both the activities of resident species and environmental conditions. One of the biggest challenges in multifunctionality assessment is balancing analytical simplicity with ecosystem complexity. As an alternative to index‐based approaches, we introduce a multivariate network analysis that uses network theory to assess multifunctionality in terms of the relationships between species'' functional traits, environmental characteristics, and functions. We tested our approach in a complex and heterogeneous ecosystem, marine intertidal sandflats. We considered eight ecosystem function, five macrofaunal functional trait groups derived from 36 species, and four environmental characteristics. The indicators of ecosystem functions included the standing stock of primary producers, oxygen production, benthic oxygen consumption, DIN (ammonium and NOx efflux) and phosphate release from the sediments, denitrification, and organic matter degradation at the sediment surface. Trait clusters included functional groups of species that shared combinations of biological traits that affect ecosystem function: small mobile top 2 cm dwellers, suspension feeders, deep‐dwelling worms, hard‐bodied surface dwellers, and tube‐forming worms. Environmental characteristics included sediment organic matter, %mud, %shell hash, and %sediment water content. Our results visualize and quantify how multiple ecosystem elements are connected and contribute to the provision of functions. Small mobile top 2 cm dwellers (among trait clusters) and %mud (among environmental characteristics) were the best predictor for multiple functions. Detailed knowledge of multifunctionality relationships can significantly increase our understanding of the real‐world complexity of natural ecosystems. Multivariate network analysis, as a standalone method or applied alongside already existing single index multifunctionality methods, provides means to advance our understanding of how environmental change and biodiversity loss can influence ecosystem performance across multiple dimensions of functionality. Embedding such a detailed yet holistic multifunctionality assessment in environmental decision‐making will support the assessment of multiple ecosystem services and social‐ecological values.     

Eight questions about invasions and ecosystem functioning

I pose eight questions central to understanding how biological invasions affect ecosystems, assess progress towards answering those questions and suggest ways in which progress might be made. The questions concern the frequency with which invasions affect ecosystems; the circumstances under which ecosystem change is most likely; the functions that are most often affected by invaders; the relationships between changes to ecosystems, communities, and populations; the long-term responses of ecosystems to invasions; interactions between biological invasions and other anthropogenic activities and the difficulty of managing undesirable impacts of non-native species. Some questions have been answered satisfactorily, others require more data and thought, and others might benefit from being reformulated or abandoned. Actions that might speed progress include careful development of trait-based approaches; strategic collection and publication of new data, including more frequent publication of negative results; replacement of expert opinion with hard data where needed; careful consideration of whether questions really need to be answered, especially in cases where answers are being provided for managers and policy-makers; explicit attention to and testing of the domains of theories; integrating invasions better into an ecosystem context; and remembering that our predictive ability is limited and will remain so for the foreseeable future.     

Interactions between almond plantations and native ecosystems: Lessons learned from north‐western Victoria

Five years of research on interrelationships between fauna use of almond plantations and native vegetation in north‐western Victoria shows that almond plantations have a strong influence on fauna dynamics and in some cases may provide important habitat for threatened species.     

长期施肥对黄土高原典型草原群落稳定性的影响及机制研究

施肥是当前草地生态系统最常见的人为干扰方式之一,可导致草地生物多样性和生态系统稳定性发生显著变化.该研究以黄土高原典型草原为研究对象,通过连续8年的氮肥(尿素)野外添加试验,分析不同氮肥处理(分别为0、5、10、20、40和80 g·m-2)对草地群落稳定性的影响,并分析检验可能影响群落稳定性的四个潜在机制(物种多样性...     

Répartition des rotifères dans deux lacs-tourbières du Massif Central (France)

In rotifer communities of two french peat-bogs, characteristic species associations can be described for each stage in the formation of this ecosystem. The oligotrophic lowmoor with Sphagnum angustifolium has the highest proportion of characteristic species.The affinity between the open water fauna (used as a standard) and the Sphagnum fauna decreases with a gradient in water content. The latter was a dominant factor in the distribution of rotifer species in the peat-bog.

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Répartition des rotifères dans deux lacs-tourbières du Massif Central (France)

     

Ecosystem‐level effects of keystone species reintroduction: a literature review

The keystone species concept was introduced in 1969 in reference to top‐down regulation of communities by predators, but has expanded to include myriad species at different trophic levels. Keystone species play disproportionately large, important roles in their ecosystems, but human‐wildlife conflicts often drive population declines. Population declines have resulted in the necessity of keystone species reintroduction; however, studies of such reintroductions are rare. We conducted a literature review and found only 30 peer‐reviewed journal articles that assessed reintroduced populations of keystone species, and only 11 of these assessed ecosystem‐level effects following reintroduction. Nine of 11 publications assessing ecosystem‐level effects found evidence of resumption of keystone roles; however, these publications focus on a narrow range of species. We highlight the deficit of peer‐reviewed literature on keystone species reintroductions, and draw attention to the need for assessment of ecosystem‐level effects so that the presence, extent, and rate of ecosystem restoration driven by keystone species can be better understood.     

Shredder–tadpole facilitation of leaf litter decomposition in a tropical stream

1. Leaf litter decomposition is one of the most important ecosystem processes in streams. Recent studies suggest that facilitation, in which litter is processed by a succession of species with differing abilities and requirements, may be important in making the nutrients bound in litter available to the stream assemblage.
2. We predicted that stream invertebrates that feed on terrestrial leaf litter (shredders) and tadpoles would facilitate leaf litter decomposition by changing the quality of leaf material directly via physical contact or indirectly via nutrient release. We experimentally examined the ability of shredders and tadpoles to break down leaves, independently and together, in artificial streams beside a natural forest stream.
3. The decomposition rate was greater when shredders and tadpoles were together than was expected from rates in single-species treatments, indicating that facilitation occurred. This facilitation operated in one direction only: the rate of leaf breakdown by tadpoles was higher when leaves had been partly processed by shredders, but there was no similar effect when leaves previously occupied by tadpoles were processed by shredders. We did not detect facilitation caused by indirect nutrient release.
4. Shredders may have benefited tadpoles by roughening leaf surfaces, making them easier for the tadpoles to consume and enhancing leaf breakdown in the presence of both taxa. This indicates that the loss of a single species can have impacts on ecosystem functioning that go beyond the loss of its direct contribution.     

The impacts of invasive ecosystem engineers in freshwaters: A review

1. Invasive species are a key stressor in freshwater ecosystems. When these species are also ecosystem engineers, their impacts are exacerbated because they modulate resource availability for a wide range of other species. The aim of this review is to synthesise existing knowledge of the impacts of invasive ecosystem engineers in freshwaters and identify knowledge gaps requiring further research.
2. The four questions explored in this review are: (1) What are the trends in research into invasive ecosystem engineers? (2) What are common negative effects of invasive ecosystem engineers in freshwater? (3) Do all impacts of invasive ecosystem engineers have negative consequences for biodiversity? (4) What happens when multiple ecosystem engineers interact? Four literature searches in Web of Science have been used to identify articles for the review and to estimate relative research effort between terrestrial, marine and freshwater ecosystems.
3. The number of research articles focusing on ecosystem engineers across all ecosystem types is increasing. Despite well-known examples of ecosystem engineer species in freshwaters (e.g. beaver), more research has focussed on terrestrial environments and invasive species.
4. The effects of invasive ecosystem engineers in freshwater systems are varied and often context dependent. Their effects on biodiversity or native ecosystem engineers are often shown to be negative; however, not all effects associated with these species are deleterious to native species. For instance, some invasive ecosystem engineers support native species through the provision of food or refuges.
5. Although freshwater ecosystems are often influenced by multiple species of ecosystem engineers (including native, invasive or both), little is known about interactions between these species or the combined effects of multiple ecosystem engineers. More research is also needed that relates the results of laboratory experiments to the field and develops methods for measuring factors that govern the impact of engineers on ecosystems. Understanding the spatial variability of the impacts of invasive ecosystem engineers as well as their interaction with anthropogenic stressors (e.g. hydrologic modification) is also necessary.
6. The lag in research surrounding invasive ecosystem engineers in freshwater compared to other biomes is concerning, as freshwater ecosystems support biodiversity disproportionate to the area they occupy. Creating predictive models of the impacts of freshwater ecosystem engineers would help anticipate the effects of invasive ecosystem engineers in freshwater and add to the broader understanding of their effects in other biomes.

     

北京城区花粉致敏植物种类、分布及物候特征

为了解北京城区花粉致敏植物的种类、分布格局和物候特征,结合文献调研及专家访问,对北京5环以内的花粉致敏植物进行了调查.结果表明:1)北京城区五环内共有致敏花粉植物19科32属99种,其中北京本地种52种,占总数的52.5%,国内其他地区引进种和国外引进种各占总数的26.3%和21.2%;2)北京城区32属花粉致敏植物以北温带成分为主,占40.6%,其次是世界性分布与泛热带分布;3)公园内的花粉致敏植物种数最多,行道树种中花粉致敏植物的比例最高.北京城区各功能区中花粉强致敏草本的盖度,从大到小的顺序是城市废弃地>体育中心及机关单位>道路绿地>公园>居民区>学校>广场;4)北京城区木本花粉致敏植物的花期主要集中在3—4月,草本在7—9月.