淡水鱼类功能生态学研究进展

在全球变化和人类活动的影响下,生物多样性正以前所未有的速度丧失,全球生物正经受第六次生物多样性危机。淡水生态系统是最脆弱的生态系统之一。淡水鱼类作为淡水生态系统的重要组成部分,承受着日趋严重的气候变化、栖息地退化、生物入侵和过度捕捞等压力,面临巨大的威胁。在此背景下,如何准确评估鱼类种群和群落对环境变化的响应,以及鱼类群落结构和功能的变化对生态系统功能的影响是淡水鱼类多样性和淡水生态系统保护的关键问题。近年来,淡水鱼类功能生态学的快速发展为解答这一问题提供了一个框架。系统地介绍了淡水鱼类功能生态学主要研究内容、方法、进展及其应用,并着重介绍了淡水鱼类功能特征及其与环境的关系、环境变化下的功能生态学响应研究。据此提出了淡水鱼类功能生态学未来的重点研究方向,指出了其在鱼类多样性保护和资源利用等领域的应用前景。     

Ecologie des coléoptères saproxyliques dans les forêts de l’étage montagnard des Alpes du nord françaises

Ecology of the saproxylic beetles in mountain forests of the northern French Alps. Both saproxylic beetles and deadwood stocks were studied in order to detect special deadwood features important for these organisms, and to better understand their ecology. A total of 37 window traps were used in ten stations covering four mountain forests in the French northern Alps. In the same time, the deadwood stocks were inventoried in the ten stations. 181 m³ of deadwood (1219 fragments) were measured and 4268 individuals belonging to 235 saproxylic species were trapped. The deadwood volume ranges from 21.1 to 233.6 m³/ha and the number of beetle species from 27 to 113. A positive relation was observed between the stand age, the whole volume of deadwood and the species richness of saproxylic beetles. However, in some deadwood rich sites the beetle diversity is not as high as expected. This was explained by the negative influence of the management history of the forest. The compositions of saproxylic communities depend also of some characteristics of the deadwood stocks. Xylophagous and zoophagous species prefer “not lying and recently dead softwood” while the mycophagous and saproxylophagous species are strongly dependent on fungi growing on hardwood, respectively under “large surfaces of barks” and in “large woody debris”. Surprisingly, the majority of the saproxylic beetles living on softwood does not depend on the most represented resinous deadwood type: the “decayed and lying softwood”.     

Can metabolic traits explain animal community assembly and functioning?

All animals on Earth compete for free energy, which is acquired, assimilated, and ultimately allocated to growth and reproduction. Competition is strongest within communities of sympatric, ecologically similar animals of roughly equal size (i.e. horizontal communities), which are often the focus of traditional community ecology. The replacement of taxonomic identities with functional traits has improved our ability to decipher the ecological dynamics that govern the assembly and functioning of animal communities. Yet, the use of low-resolution and taxonomically idiosyncratic traits in animals may have hampered progress to date. An animal's metabolic rate (MR) determines the costs of basic organismal processes and activities, thus linking major aspects of the multifaceted constructs of ecological niches (where, when, and how energy is obtained) and ecological fitness (how much energy is accumulated and passed on to future generations). We review evidence from organismal physiology to large-scale analyses across the tree of life to propose that MR gives rise to a group of meaningful functional traits – resting metabolic rate (RMR), maximum metabolic rate (MMR), and aerobic scope (AS) – that may permit an improved quantification of the energetic basis of species coexistence and, ultimately, the assembly and functioning of animal communities. Specifically, metabolic traits integrate across a variety of typical trait proxies for energy acquisition and allocation in animals (e.g. body size, diet, mobility, life history, habitat use), to yield a smaller suite of continuous quantities that: (1) can be precisely measured for individuals in a standardized fashion; and (2) apply to all animals regardless of their body plan, habitat, or taxonomic affiliation. While integrating metabolic traits into animal community ecology is neither a panacea to disentangling the nuanced effects of biological differences on animal community structure and functioning, nor without challenges, a small number of studies across different taxa suggest that MR may serve as a useful proxy for the energetic basis of competition in animals. Thus, the application of MR traits for animal communities can lead to a more general understanding of community assembly and functioning, enhance our ability to trace eco-evolutionary dynamics from genotypes to phenotypes (and vice versa), and help predict the responses of animal communities to environmental change. While trait-based ecology has improved our knowledge of animal communities to date, a more explicit energetic lens via the integration of metabolic traits may further strengthen the existing framework.     

吉林蛟河阔叶红松林谱系多样性和功能多样性对采伐干扰的响应

阔叶红松林是东北森林的典型代表,由于受到历史采伐干扰的影响,导致生态系统功能严重退化,威胁东北地区生态安全。生物多样性是生态系统功能形成和维持的重要基础,阐明采伐前后生物多样性的变化对于评估采伐干扰的影响、理解森林恢复过程具有重要意义,能够为森林生态修复与重建提供理论支持。谱系多样性和功能多样性是生物多样性的两个重要维度,然而传统的研究仍停留在物种数量层面,难以全面反映采伐干扰的影响。以吉林蛟河阔叶红松林采伐样地为对象,依托连续四次的样地清查数据,同时结合植物的系统发育和功能性状信息,探讨了不同强度采伐干扰对谱系多样性和功能多样性的影响,具体采伐设置包括：未采伐（对照）,采伐15%胸高断面积（轻度采伐）,采伐30%胸高断面积（中度采伐）以及采伐50%胸高断面积（重度采伐）。结果显示：（1）中、高强度的采伐干扰显著降低了森林谱系多样性和功能多样性,并且高强度干扰条件下森林多样性的恢复要更加困难;（2）采伐还影响着群落功能性状组成,随着采伐强度的增加,群落木质密度加权平均值上升而最大树高下降;（3）相较于采伐强度和采伐木断面积,保留木断面积与生物多样性的联系更加紧密,表明采伐后森林所达到的密度状态是影响生物多样性恢复的关键,当保留木断面积在18m²/hm²附近时,其与谱系多样性的关系出现显著拐点,应在阔叶红松林经营管理过程中受到更多重视。综上所述,谱系多样性和功能多样性为评价采伐的影响提供了新的视角,有助于更加全面地反映采伐干扰对生物多样性的影响,为阔叶红松林生态修复与多样性保护提供科学参照。     

Functional diversity of crustacean zooplankton communities: towards a trait-based classification

1. While studies of phytoplankton and terrestrial plant communities have increasingly emphasised the use of functional traits in ecological research, few have yet to apply this approach to zooplankton communities.
2. This study reviews laboratory and observational studies on zooplankton feeding and life history and provides a series of functional trait tables for the North American freshwater zooplankton. Qualitative and quantitative trait tables highlight areas where data were more scarce and point to which types of studies could fill in gaps in our knowledge of zooplankton niches.
3. Data were most complete for the Cladocera across most traits, while feeding information for cyclopoids was most sparse. Qualitative data that distinguished congeneric species were lacking for most groups.
4. A regional community dendrogram for common north-eastern North American zooplankton species was generated and shows that taxonomic differences between species do not capture fully functional differences based on the traits of body length, habitat, trophic group and feeding type.
5. The data collected here, combined with readily measurable species attributes, can be used to generate a multivariate measure of the functional niche of each species found in a community. Armed with this information, functional relationships that are useful for ecological studies of lake ecosystems can be more easily conducted.     

Global patterns in peatmoss biodiversity

DNA sequence data from the nuclear ribosomal internal transcribed spacers (ITS) and the trnL-trnF chloroplast DNA regions were used to quantify geographical partitioning of global biodiversity in peatmosses (Sphagnum), and to compare patterns of molecular diversity with patterns of species richness. Molecular diversity was estimated for boreal, tropical, Neotropical, nonboreal (tropical plus Southern Hemisphere), Old World and New World partitions, based on a total of 436 accessions. Diversity was partitioned among geographical regions in terms of combined nuclear and chloroplast sequence data and separately for the ITS and trnL-trnF data sets. Levels of variation were estimated using phylogenetic diversity (PD), which incorporates branch lengths from a phylogenetic tree, and the number of polymorphic nucleotide sites. Estimates of species richness suggest that peatmoss diversity is higher in New World than Old World regions, and that the Neotropics constitute a "hotspot" of diversity. Molecular estimates, in contrast, indicate that peatmoss biodiversity is almost evenly divided between New and Old World regions, and that the Neotropics account for only 20-35% of global peatmoss diversity. In general, levels of tropical and boreal peatmoss molecular diversity were comparable. Two species, S. sericeum from the Old World tropics and S. lapazense from Bolivia, are remarkably divergent in nucleotide sequences from all other Sphagna and together account for almost 20% of all peatmoss diversity, although they are represented by only three of the 436 accessions (0.7%). These species clearly demonstrate the nonequivalence of species biodiversity value.     

海岸带沉积物中氮循环功能微生物多样性

海岸带生境类型多样,环境梯度明显,是研究微生物多样性、群落结构与功能关系及调控机制的天然实验场.沉积物是海岸带环境中营养盐再生与转化发生的重要场所,其中多种微生物类群在氮素循环过程中扮演重要角色.本文重点介绍海岸带沉积物中固氮菌、氨氧化菌、厌氧氨氧化菌、反硝化与硝酸盐铵化微生物的基于16SrRNA基因的物种多样性和基于关键酶基因nifH、amoA、narG、nirS、nirK、nosZ、nrfA、hzo、hzs等的功能多样性;总结了在海岸带特有生境(如河口、潮间带、海草藻床、红树林、盐沼、珊瑚礁、浅海等)及污染胁迫、生物扰动等条件下各功能类群的群落组成特征及时空变化规律,并提出今后需要重点关注新的培养技术和方法的开发,以进一步提高微生物的可培养性,将单细胞基因组测序与分析技术、DNA和RNA结合起来研究,以全面了解氮循环微生物多样性、参与介导硝酸盐铵化过程的微生物多样性等方面.     

功能多样性及其研究方法

功能多样性是联系生物多样性和生态系统功能的关键性因素。植物群落内功能多样性的量化描述对于研究生物多样性响应环境变化及其对生物多样性-生态系统功能关系的影响至关重要。由于功能多样性的概念含混不清,使得对其范围的确定、定量描述及其对生态系统功能的作用的评价存在较大的难度。在查阅大量文献的基础上,以植物群落为例,介绍了功能多样性的定义、计算方法及研究中应注意的问题。在植物群落功能多样性指数的选择和测定过程中,对获取相关物种必要的功能特征信息、确定其权重、确定不同物种在群落中的相对丰富度、利用所得的功能多样性指数解释和预测生态系统过程的变化等问题,进行了研究。     

The Conservation of Saproxylic Insects in Tropical Forests: A Research Agenda

Invariably, insects are overlooked when tropical forest management issues are discussed, because there are so many species, they are taxonomically intractable and so poorly known. Often people take the view that if you look after the vegetation and vertebrates, the insects will look after themselves. This may be true for some functional groups, but for saproxylic insects, this seems unlikely. Their study deserves high priority, since they are dependent on the very resource – wood – whose removal from the ecosystem is the usual object of forest management. Given the current international effort to develop 'criteria and indicators' to monitor sustainable forest management for biodiversity values, there is a window of opportunity for sound ecological research on saproxylic insects to influence the formulation of forest policy such that their needs can be taken into account. There is already a large body of knowledge on temperate and boreal region saproxylic insects, and on the effects that logging has on them, but knowledge of the tropical forest situation lags far behind. This paper proposes a research agenda to enable the needs of saproxylic insects to be taken into account in natural forest management in the tropics. Basic questions, such as whether logging has so far had an impact on tropical saproxylic insects, and whether there are workable sampling techniques to investigate this, still remain to be addressed and deserve high priority. The links between the responses of saproxylic insects and more 'charismatic' study species need to be investigated. We also need to know whether there is a correlation between the intensity of logging and the response of saproxylic insects, and, critically, whether we would be justified in measuring some surrogate aspects of forest structure (as potential habitat for saproxylic insects) rather than the saproxylic insects themselves, and modelling this to determine likely impacts of different management regimes. We consider such an ambitious research agenda as justified given the scale of impact that forest use and management is likely to have on tropical forest insects in the future.