Traits,trees and taxa: global dimensions of biodiversity in mammals

Measures of biodiversity encompass variation along several dimensions such as species richness (SR), phylogenetic diversity (PD) and functional/trait diversity (TD). At the global scale, it is widely recognized that SR and PD are strongly correlated, but the extent to which either tends to capture variation in TD is unclear. Here, we assess relationships among PD, SR and TD for a number of traits both across clades and regional assemblages of mammals. We also contrast results using two different measures of TD, trait variance and a new measure we refer to as trait bin filling (the number of orders of magnitude of variation that contain at least one species). When TD is defined as trait variance, PD is a much stronger correlate of TD than SR across clades, consistent with hypotheses about the conservation value of PD. However, when TD is defined as bin filling, PD and SR show similar correlations with TD across clades and space. We also investigate potential losses of SR, PD and TD if species that are currently threatened were to go extinct, and find that threatened PD is often a similar predictor of threatened TD as SR.     

甲真菌病患者分离真菌多样性分析

为了探寻甲真菌病患者病甲部位的真菌多样性,以期对临床治疗提供参考,结合菌种培养的形态学研究和rDNA ITS序列分析的方法,对临床拟诊为甲真菌病患者的病甲分离培养菌株进行物种鉴定,并以丰富性指数(Ma)、多样性指数(H′)、均匀度指数(J)等指标分析指甲和趾甲分离真菌的多样性。2010年2月至9月在北京大学第三医院皮肤科的1 568例拟诊甲真菌病患者中,641例培养阳性,包括趾甲561例和指甲80例。检测到的皮肤癣菌占59.13%(其中红色毛癣菌为96.04%),酵母菌17.00%,其他真菌23.87%。分离自趾甲的Candida galli、Lewia infectoria和Paraconiothyrium hawaiiense,以及分离自指甲的Cyberlindnera jadinii确定为中国新记录种。趾甲分离菌的物种多样性指数H′、丰富度指数Ma和均匀度指数J均高于指甲分离菌。研究结果表明,该医院就诊甲真菌病患者可分离培养的真菌以皮肤癣菌的红色毛癣菌为主要物种,且趾甲分离菌的菌种多样性较指甲的更为明显。     

一种基于公众科学数据的区域性鸟类多样性评价方法

鸟类是理想的生物多样性指示类群。中国观鸟记录中心(以下简称“记录中心”)是目前中国最大的鸟类监测公众科学数据平台, 其记录覆盖94%的全国鸟种和94.3%的县级行政区。本研究基于公众科学数据, 参考《区域生物多样性评价标准》(HJ 623-2011)中的受胁物种丰富度指数, 构建了鸟类丰富度指数(R_{B_A})和珍稀濒危鸟类丰富度指数(R_{TB_A}), 继而提出一种对区域鸟类多样性进行评价的新方法。本研究计算了自2014年起, 各省级、地级、县级行政区(不含市辖区)每年在记录中心的累积记录鸟种数对官方发布鸟种数的覆盖率和省级行政区记录的累积珍稀濒危鸟种数对官方发布数据的覆盖率, 并计算了自2018年起各级行政区每年的R_{B_A}和R_{TB_A}, 以了解各地鸟类丰富度指数的逐年变化情况, 并分析记录中心数据集的发展趋势和两个指数的敏感性。分析结果表明, 记录中心数据对全国各级行政区的鸟种覆盖率自2014年起逐年增加, 在2023年分别有94.1%的省级、59.0%的地级和49.0%的县级行政区(不含市辖区)的鸟种覆盖率超过90%; 记录中心的累积珍稀濒危鸟种数据在省级行政区的覆盖率亦呈上升趋势, 但略低于所有鸟种覆盖率。自2020年起, 全国每年观测到的鸟种数量呈逐年增加趋势, 但其中部分省份每年观测到的鸟种总数在2022年出现下降。自2020年起, 各省级行政区的R_{B_A}和R_{TB_A}整体呈现上升趋势。R_{B_A}范围为0.50-0.96, R_{TB_A}范围为0.45-0.98, 显示R_{TB_A}更为敏感。本研究结果表明, R_{B_A}和R_{TB_A}在本地用户提交记录数量充足的地区有较大的应用价值, 可作为生物多样性评价指标应用。R_{TB_A}对于鸟类多样性的变化更为敏感, 更能体现在地鸟类保护状况。随着记录中心等公众科学平台的发展, 以R_{B_A}和R_{TB_A}为代表的基于公众科学的评价指数在物种多样性评估和物种监测方面有巨大的应用潜力。     

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。     

Ancestor–descendant relationships in evolution: origin of the extant pygmy right whale,Caperea marginata

Ancestor–descendant relationships (ADRs), involving descent with modification, are the fundamental concept in evolution, but are usually difficult to recognize. We examined the cladistic relationship between the only reported fossil pygmy right whale, †Miocaperea pulchra, and its sole living relative, the enigmatic pygmy right whale Caperea marginata, the latter represented by both adult and juvenile specimens. †Miocaperea is phylogenetically bracketed between juvenile and adult Caperea marginata in morphologically based analyses, thus suggesting a possible ADR—the first so far identified within baleen whales (Cetacea: Mysticeti). The †Miocaperea–Caperea lineage may show long-term morphological stasis and, in turn, punctuated equilibrium.     

边缘效应与生物多样性

自从边缘效应提出以来,许多生态学家对它与生物多样性之间的关系进行了研究。大量的事实显示出边缘效应会表现出正效应或负效应,其结果并不完全一致。边缘效应的利用、管理和生物多样性保护是一项有意义而紧迫的工作。     

Regional patterns of diversity and estimates of global insect species richness

The total number of insect species in the world is an important if elusive figure. We use a fresh approach to estimate global insect species richness, based on biogeographic patterns of diversity of well or better documented taxa. Estimates generated by various calculations, all variations on a theme, largely serve to substantiate suggestions that insect species are likely to number around 10 million or less.     

Phylogenetic relationships of nine mullet species (Mugilidae) in the Mediterranean Sea

Phylogenetic relationships among four genera and nine species (Mugil cephalus, Mugil soiuy, Liza ramada, Liza aurata, Liza abu, Liza saliens, Liza carinata, Chelon labrosus, Oedalechilus labeo) of the Mediterranean mullets (Mugilidae) were investigated by means of allozyme electrophoresis using a seven-enzyme system (CK*, GAPDH*, G3PDH*, IDHP*, ME*, MDH*, PGM*) comprising eleven putative loci. The highest genetic divergence was 1.299, detected between M. cephalus and L. aurata and the lowest (0.280) was found between L. carinata and L. saliens. The amount of genetic divergence between the genera Chelon and Oedalechilus did not appear to be high (0.285). In a UPGMA tree, all nine species were grouped in two main branchings. In the first branch, C. labrosus and O. labeo clustered as closest taxa and were sister group to L. ramada. The other four Liza species produced two sub-branching in this group; L. carinata branched together with L. saliens, and L. aurata branched together with L. abu. In the second branch the two species of the genus Mugil, M. cephalus and M. soiuy, clustered together and were clearly isolated from the other three genera.