长江流域农作物起源及其与生物多样性特征的关联

长江流域的农耕文明是中华文明的重要组成部分。作为世界著名的农作物起源中心之一, 长江流域拥有丰富的生物多样性, 孕育了大量的栽培植物。本文梳理了起源于长江流域的农作物的资料以及新石器时代文化遗址的植物遗存信息; 结合对长江流域的自然环境特征与全新世以来植被变化的总结, 尝试厘清长江流域对植物资源利用的动态变化, 探讨本地栽培植物与生物多样性的关联。结果表明长江流域农耕文明以稻作为最主要的生产方式, 驯化了大量果树与水生蔬菜, 反映出对本地亚热带常绿阔叶林与湿地的依赖与适应。与其他流域相比, 长江流域具有相对优越的生态要素配置, 其驯化作物类型表现出典型的亚热带湿润森林植被区特征。研究长江流域农作物驯化相关的自然与人类因素, 有助于我们更好地把握长江流域农耕文明的起源。本文不但可为长江流域植物遗传资源的保护与开发提供参考, 而且对于推进长江流域的生态文明建设和可持续发展具有指导作用。     

沉水植被的重建与消失对原生动物群落结构和生物多样性的影响

利用建在武汉东湖的中型围隔来研究沉水植被的重建一消失对原生动物群落的影响。结果表明：沉水植被重建后,一些原已消失的种类重又出现,原生动物种类增加,密度降低,多样性指数增高,优势种类由固着种类取代浮游种类。沉水植被的消失引起原生动物优势种类的明显变化,周丛种类大量丧失,但密度显著增高。     

翅果油树群落结构多样性

群落结构多样性的研究可以为实施更加有效的生物多样性监测、保护与持续利用提供科学依据。采用扩展形式的Shannon指数和基于方差的结构多样性指数(STVI)对山西省翅果油树群落进行了结构多样性研究。结果表明:两个结构多样性指数表现出较为一致的变化趋势,均可反映山西翅果油树群落的结构多样性差异;群落类型、物种组成、空间结构,以及生境条件、环境因子和人为干扰强度等是影响翅果油树群落结构多样性的主要因素;STVI结构多样性指数克服了在计算多样性时将直径和高度划分等级时的主观性,并且能更好地描述一个较大的结构序列,因此运用价值更大。     

关于微生物多样性的思考

从微生物的物种、遗传、代谢和生态类型等4个方面讨论了微生物多样性问题,提醒人们在关注动植物多样性的同时,要加强对微生物多样性的认识,从而更全面地认识生物的多样性,为解决人类目前面临的诸多问题提供更多的途径。     

岳麓山蕨类植物生物多样性研究

目的:为湖南植物区系的研究提供基础资料.方法:进行野外调查、标本采集、鉴定并结合相关资料进行统计,对岳麓山蕨类植物多样性进行了初步研究.结果:①分布有蕨类植物共23科,包括40属73种.②蕨类植物的优势科、优势属均表现明显,优势科为鳞毛蕨科、蹄盖蕨科和金星蕨科;优势属为鳞毛蕨属、凤尾蕨属和铁角蕨属.③分布区类型以亚热带为主,属中国-日本区系.结论:岳麓山蕨类植物区系地理成分复杂,是东亚植物区系的一个关键地区.     

贡嘎山海拔梯度上不同植被类型土壤甲烷氧化菌群落结构及多样性

甲烷是仅次于CO₂的第二大温室气体.森林表层土壤中甲烷好氧氧化作用是大气甲烷重要的汇,在碳循环和减缓全球变暖方面起着重要作用.研究不同植被类型土壤中甲烷氧化菌的群落结构及多样性,有助于更好地理解植被演替、人为干扰和不同土地利用背景下甲烷氧化菌群落组成和多样性变化与地上植被之间的相互关系.本研究在贡嘎山东坡海拔梯度上的4种不同植被类型中采集了92个土壤样品,利用Miseq测序技术和生物信息学方法评估了甲烷氧化菌群落组成及多样性在4种不同植被类型间的变化,并探讨了其变异的潜在原因.结果表明: 常绿阔叶林和针阔叶混交林土壤中甲烷氧化菌的群落结构较为相似,暗针叶林和灌丛草甸土壤甲烷氧化菌的群落结构较为相似.4种不同植被生态系统中,针阔叶混交林土壤中的甲烷氧化菌α多样性显著高于其他3种植被生态系统(P＜0.001),且暗针叶林和灌丛草甸土壤中甲烷氧化菌β多样性显著高于常绿阔叶林和针阔叶混交林(P＜0.001).Spearman相关分析表明,不同类型甲烷氧化菌的相对丰度对环境变化的响应模式不同.造成α多样性差异的主要因子可能是土壤总氮、电导率和土壤温度.偏Mantel检验分析和冗余分析(RDA)表明,常绿阔叶林和针阔叶混交林土壤甲烷氧化菌多样性受环境因子的影响较大,而暗针叶林和灌丛草甸土壤中甲烷氧化细菌多样性变化可能存在其他潜在的影响因素或者机制.降水可能是造成低海拔常绿阔叶林和针阔叶混交林与高海拔暗针叶林和灌丛草甸土壤甲烷氧化细菌群落结构差异的主要原因.贡嘎山海拔梯度上不同植被类型土壤中甲烷氧化菌的群落结构和多样性变化可能主要是由于土壤理化性质和气候变化综合作用的结果.     

鄂尔多斯台地拟步甲多样性

为了解拟步甲多样性及其对生境的指示作用,选取鄂尔多斯台地的北部的石龙庙、石灰庙、新街镇和杭锦旗,以巴氏罐诱法采集拟步甲。群落多样性分析显示,物种数和个体数量最丰富的是杭锦旗;多样性指数以石灰庙最高,石龙庙最低;物种丰富度指数以石灰庙最高,石龙庙最低;优势度指数以石龙庙最高,新街镇最低;均匀度指数以新街镇最高,杭锦旗样地最低。研究结果表明,降水梯度对拟步甲物种多样性有很大影响,物种多样性指数和均匀度指数分别与降水梯度存在不显著和显著的正相关关系;个体数量与降水梯度存在显著的负相关关系。     

鄂尔多斯台地拟步甲多样性

为了解拟步甲多样性及其对生境的指示作用,选取鄂尔多斯台地的北部的石龙庙、石灰庙、新街镇和杭锦旗,以巴氏罐诱法采集拟步甲。群落多样性分析显示,物种数和个体数量最丰富的是杭锦旗;多样性指数以石灰庙最高,石龙庙最低;物种丰富度指数以石灰庙最高,石龙庙最低;优势度指数以石龙庙最高,新街镇最低;均匀度指数以新街镇最高,杭锦旗样地最低。研究结果表明,降水梯度对拟步甲物种多样性有很大影响,物种多样性指数和均匀度指数分别与降水梯度存在不显著和显著的正相关关系;个体数量与降水梯度存在显著的负相关关系。     

等熵方程与生物熵限方程

本文分析了等熵方程;推导出核酸序列的熵限方程,率先提出了生物进化过程中核酸序列选择的熵原则;绘制了分析核酸序列熵变的等熵图．     

陕南秦巴山区药用植物群落物种多样性研究

采用样方法对陕南秦巴山区药用植物群落物种多样性进行了研究。结果显示,该地区药用植物共计105科268属361种,其中药用裸子植物5科6属7种,药用被子植物92科254属344种,药用蕨类植物7科8属10种;含1属的科、含2~5属的科和含1种的属的药用植物数量较多,所占比例较高;该地区各植被类型的物种多样性变化各具特点,其中,物种丰富度指数(S)、Shannon-Wiener多样性指数(H)及Simpson 多样性指数(D)表现为:乔木层最小、灌木层较大、草本层最大,但Pielou物种均匀度指数(J)的变化较为复杂;药用植物群落总的物种丰富度、乔木层物种丰富度和草本层物种丰富度均随海拔的升高表现出先升高后下降的趋势,且物种丰富度最大值出现在海拔1000~1200 m的山地常绿落叶阔叶林和温性针阔混交林的过渡区域,但灌木层物种丰富度与海拔之间无相关关系。本研究结果为阐明山地物种多样性的分布格局提供了基础资料,也为该区域药用植物的保护和管理提供参考。     

Recovery of ciliate communities from an oligotrophic mountain stream after a catastrophic wind damage

We studied the recovery of ciliate taxoceonoses in a mountain stream after a catastrophic windstorm that strongly affected mountainous regions of Slovakia in 2004. To this end, we analyzed changes in the community structure of ciliate assemblages from the Zubrovica stream in the Low Tatra Mts during the time frame between 2003 and 2008 by various statistical methods, including diversity and similarity indices, hierarchical clustering, multidimensional scaling, and PCA. The climax ciliate communities were characteristic for oligotrophic running waters, i.e., they were equitable (E_H = 0.75–1.00) and harbored a comparatively low number of species (2–9) with typically low abundances (10–125 ind./ml). However, the community structure changed dramatically after the devastating windstorm. There was a significant increase of species number (10–30) and abundance (260–1480 ind./ml), concomitant with a decrease of the equitability (E_H = 0.43–0.83). These changed quantitative and qualitative community parameters wore off comparatively quickly, i.e., about six months after the catastrophic windstorm, the ciliate taxocoenoses had reached a community structure similar to that before the wind damage. The present observations and those from terrestrial habitats indicate that ciliate communities have a good capability to comparatively quickly reach a climax even after a strong disturbance.     

中国生物多样性适应气候变化策略研究

全球气候变化不仅给人类社会可持续发展带来严峻挑战,而且严重威胁到生物多样性及生态安全。我国是生物多样性最为丰富的国家之一,气候变化已经在对动物分布、行为和迁移,植物物候、植被和群落结构等方面造成了影响,并增加了珍稀濒危物种的灭绝风险,同时对生态系统的功能方面也造成了明显影响。未来气候变化将成为生物多样性丧失的主要驱动力之一。世界很多国家都在制定生物多样性适应气候变化的策略和采取适应行动,加强生物多样性的保护。本文在分析国外适应策略的基础上,结合中国生物多样性的现状,提出了适应气候变化的策略建议,包括制定生物多样性适应气候变化的国家战略,开展气候变化对生物多样性的影响监测和评估,针对敏感物种的就地保护和迁地保护,针对气候变化将导致退化生态系统开展恢复与重建,重点关注生物多样性适应气候变化优先区的保护,通过科学研究和国际合作,促进生物多样性适应气候变化技术的提高,期望为我国生物多样性保护和应对气候变化提供支持。     

European Policy Review: Biodiversity and climate change

Climate change and its impacts on biodiversity have gained much political and scientific interest over the past decade. In order for the right policy measures to be taken on adaptation and mitigation, research and stakeholder involvement has a strong role to play to support decision makers. This paper provides an overview of recent developments and research needs in Europe.     

Climate change, conservation and management: an assessment of the peer-reviewed scientific journal literature

Recent reviews of the conservation literature indicate that significant biases exist in the published literature regarding the regions, ecosystems and species that have been examined by researchers. Despite the global threat of climatic change, similar biases may be occurring within the sub-discipline of climate-change ecology. Here we hope to foster critical thought and discussion by considering the directions taken by conservation researchers when addressing climate change. To form a quantitative basis for our perspective, we assessed 248 papers from the climate change literature that considered the conservation management of biodiversity and ecosystems. We found that roughly half of the studies considered climate change in isolation from other threatening processes. We also found that the majority of surveyed scientific publications were conducted in the temperate forests of Europe and North America. Regions such as Latin America that are rich in biodiversity but may have low adaptive capacity to climate change were not well represented. We caution that such biases in research effort may be distracting our attention away from vulnerable regions, ecosystems and species. Specifically we suggest that the under-representation of research from regions low in adaptive capacity and rich in biodiversity requires international collaboration by those experienced in climate-change research, with researchers from less wealthy nations who are familiar with local issues, ecosystems and species. Furthermore, we caution that the propensity of ecologists to work in essentially unmodified ecosystems may fundamentally hamper our ability to make useful recommendations in a world that is experiencing significant global change.     

Palynological investigations on vegetation and climate change in the Late Quaternary of Lake Rukche area,Gorkha Himal,Central Nepal

Palynological data and pedological investigations including stable isotopes and lignin biomarkers (Glaser et al. in press) from a 4 m core of Lake Rukche (3500 m a.s.l.) enhance our palaeoecological knowledge of the time since the LGM in the Gorkha Himal, Central Nepal. Even before 15000 B.P. forest types became established which prove the existence in Central Nepal of a temperate-humid climate with a considerable amount of winter and spring precipitation from westerly disturbances. Lignin input and pollen data point to a patchy vegetation cover around Lake Rukche with meadow-steppes dominated by Poaceae. Around 15000 B.P. Quercus and Pinus roxburghii dominated the lower altitudes while the vegetation around Lake Rukche was more steppe-like (Chenopodiaceae, Artemisia). Subsequently the climate became warmer and drier as winter and spring precipitation decreased while summer rain remained low. Later on more resource-demanding forests became established under improved temperature and precipitation conditions (Engelhardia). Around Lake Rukche coniferous forests (Abies, Picea) occurred beside meadow-steppes. The transition from the Pleistocene to the Holocene is not recorded. In the Holocene alpine Kobresia-meadows stabilised the soil surface causing sand accumulation to end. During the mid-Holocene (7800–2750 B.P.) humid oak forests with demanding elements (Ilex, Coriaria, Myrsine and Engelhardia) dominated the vegetation cover. A charcoal layer and a marked emergence of fire-induced communities with Pinus roxburghii, Poaceae, Ericaceae and Pteridium are proofs of a first strong anthropogenic change in vegetation which coincided with the climatic deterioration at the onset of the Subatlantic. Since 900 B.P. grazing pressure and the frequency of fires increased, resulting in a replacement of Betula utilis-forests by meadows and woods of Juniperus and Rhododendron. While previous anthropogenic influence increased the biodiversity by promoting replacement communities, recent developments have led to a decrease in biodiversity through loss of natural vegetation communities.     

Biased richness and evenness relationships within Shannon–Wiener index values

The purpose of this analysis was to empirically model and graphically illustrate the numerical relationships between richness (S, 4–35 species) and evenness (E) with respect to Shannon–Wiener index (H′, log_e-based) values. Thirty-two richness-based third-order polynomial regression models (R > 0.99, P < 0.001, n = 28–71) were constructed to characterize these relationships. A composite diagram showed richness varied curvilinearly, with steepness increasing and the spacing between curves decreasing with greater evenness and H′. Maximum H′ values for each richness curve were equal to log_e S (when E = 1), whereas minima were approximated by evenness values of ∼1/S (when H′ = 0). It was concluded from multiple and polynomial regression analyses that: (i) evenness contributed more than richness (E:S ≥3:1) to determining H′, based on standardized partial beta-coefficients; (ii) the differential in E:S ratios increased with greater richness; (iii) the patterns of H′ sample variation between maximum unevenness and perfect evenness was convexo-concave shaped; and (iv) richness as an explanatory variable of H′ was likely an artifact of evenness (0–1 scale) being rescaled according to individual H′ maxima. H′ was redefined as a logarithm-weighted measure of evenness at a given level of richness, which means H′ is either an imperfect index of diversity or a biased measure of evenness. It was also found that the fundamental components of the Shannon–Wiener index measure dominance concentration rather than evenness, with the reversal in emphasis due to multiplication of the H′ equation by −1. H′-derived effective species numbers (exp H′, D) increasingly deviated from those of the diversity model D = S × E in response to increasing richness (up to 69% for 35 species), particularly when evenness was between 0.15 and 0.40. Of two cross-validated H′ prediction methods (P < 0.001, n = 325), the collective use of individual richness-based polynomial regression equations (r = 0.954) was better than a single multiple regression model that incorporated a broad spectrum of richness levels (r = 0.882). A simple graphic model was constructed to illustrate patterns of evenness variation as a function of changing richness and H′ values. Based on the identified biases, particularly E:S ratios, it was recommended that use of H′ be discontinued as a basis for assessing diversity in ecological research or, at the very least, accompanied by independent analyzes of richness and evenness.     

景观基因组学方法在保护生物学研究中的应用与前景

生物多样性是人类生存与发展的基础,全球气候的快速波动正对生物多样性造成严重威胁。保护生物学旨在研究全球生物多样性面临的危机及如何更加有效地进行生物多样性保护。景观基因组学（Landscape genomics）研究通过解析基因型与环境因子之间的关联性,揭示物种响应气候变化的适应性遗传变异与适应性进化,推动了保护生物学的快速发展。本文简要阐述了景观基因组学解析物种适应性遗传变异空间分布格局的主要研究方法,总结了近年来景观基因组学方法在动植物保护研究中的应用案例,并针对景观基因组学方法在保护生物学研究中存在的问题及未来研究方向提出了建议。