生物多样性对生态系统功能及其稳定性的影响

生物多样性导致生态系统功能优化学说、组分有机体功能特点决定生态系统功能观点及一些中间观点的提出使生态学界对生物多样性与生态系统功能之间关系的研究结果各异,但关键种的丧失会严重损害生态系统功能是肯定的。对结构多样性的生态系统来说,关键种能稳定生态系统功能,并在一定程度上缓冲波动带来的压力。生物多样性与生态系统稳定性间关系的研究亦未形成共识,一般看法是生物多样性降低会导致生态系统稳定性下降。但也有与之不同的看法,认为多样性与稳定性间无任何关系。对局部多样性、区域多样性及全球范围内生物多样性改变及其相应保护措施的研究比较后认为,应为不同物种提供适合其繁殖条件的局部试验地块,用个体小的物种来控制区域生物多样性及通过各种自然试验方法增加不同范围内的生物多样性。     

森林植被不同尺度的碳水过程及耦合机制研究进展

[目的]陆地生态系统中的碳循环和水循环是陆地生态系统物质和能量循环的核心,也是连接地圈、生物圈和大气层的纽带。森林植被是陆地生态系统的重要组成部分,是表征陆地碳-水循环的重要变量,在维持生物圈和大气圈的动态平衡中发挥着重要作用。目前,对陆地生态系统中碳-水循环的耦合关系和机制缺乏系统的分析和总结。[方法]从森林植被碳与水过程及其相互作用、植被水分利用和耦合机制的角度,综述了森林植被碳与水循环过程及其相互作用的研究与进展,以及不同空间尺度(叶片到区域/全球尺度)碳-水耦合的定义、方法、进展和展望。[结果]新兴的技术和方法实现了不同尺度碳水过程的高频观测,WUE等耦合指标体系推动了碳水耦合机制的研究和发展。[结论]通过系统阐述植被碳水耦合关系的多尺度整合和碳水耦合机理,为系统认识森林碳水耦合机理和水资源管理提供了理论基础,对未来植被经营管理决策具有重要的科学支撑意义。     

气候变化对土壤有机碳库分子结构特征与稳定性影响研究进展

气候变化与土壤碳库之间的相互作用及耦合机制一直是学术界研究的热点与难点。虽然目前在群落—生态系统、区域—全球等不同尺度上开展了大量研究,然而在分子尺度上探究气候因子波动对土壤有机碳库化学结构特征影响机制方面却鲜有研究。本文综述了近年来气候因子变化及其导致的环境、生态因子变化与土壤有机碳库分子结构特征的关系。气温升高不仅将改变土壤中源自植物部分的有机碳来源特征,同时也会将加速土壤木质素等碳组分分解,排水或者旱化引起有机质分解加速,土壤中C=O键增加。植被演替、土壤动物及微生物等与气候变化密的切相关的生态因子则会影响输入土壤植被残体性质,加速糖类、脂类及木质素分解、并改变有机碳结构的生物分子标志物;土壤中有机碳稳定性与分子结构特征密切相关,土壤中具有高的苯环结构(芳香族化合物)及O-烷基碳通常表明土壤碳库具有更高的稳定性,而之前认为较为稳定的木质素等结构在气候变暖背景下可能并不稳定。未来研究中应着重关注与土壤有机碳分子标志物的识别与生态意义判读、生物对土壤有机碳分子结构转换过程的调控作用及机制、大尺度环境/生态过程与碳库分子结构转变的耦合机制及新的土壤有机碳分子结构辨识技术及判读等方面的研究。     

生态农业景观与生物多样性保护及生态服务维持*

现代集约化的农业生产极大地改变农业景观生物多样性状况及生态系统服务功能,进而影响到农业可持续发展。大量研究显示,农业生态系统中物种多样性维持、害虫控制、传花授粉等生态系统服务功能受到景观结构的影响,仅仅改变集约化的生产方式,并不足以促进生物多样性的恢复及生态系统服务的维持,尚需考虑景观结构的调整和管理。从不同尺度上优化景观要素的空间配置和景观管理方式、建设生态农业景观成为促进农业景观生态系统服务功能维持、保护生物多样性和农业可持续发展的重要措施,具体包括:1)在区域和景观尺度上合理规划和配置种植区域和非种植区域以确保生态安全与稳定性;2)在地块间尺度保护、建设和管理甲虫带、野花带等生态设施,为农业生产提供必要生态系统服务;3)在地块内尺度通过多样化的种植和优化管理措施以获取农业生产和自然保护之间的平衡;4)整合景观规划设计与生态循环工程以促进农业景观资源的高效利用。     

陆地生态系统碳-氮-水循环的关键耦合过程及其生物调控机制探讨

陆地生态系统碳循环、氮循环和水循环是全球变化科学研究的三大主题,而陆地生态系统碳氮水耦合循环过程及其生物调控机制则是全球变化生态学研究的前沿性科学问题。目前,对陆地生态系统碳氮水耦合循环过程及其调控机制认识的不足是制约评估陆地增汇/减排效果,预测分析全球变化对生态系统生产力和固碳功能影响的瓶颈性问题。本文在综合分析陆地生态系统碳氮水循环的耦合过程基础上,论述了制约生态系统碳氮水循环空间格局耦联关系的生物地理学机制,制约典型生态系统碳氮水循环耦合关系的生物生理生态学机制,以及典型生态系统碳氮水耦合循环的关键生物物理和生物化学过程。重点评述了生态系统碳氮水耦合循环的主要过程及其生物调控机制研究进展,包括:(1)植物叶片冠层生物学过程和根系冠层生物学过程及其对生态系统碳氮水耦合循环控制机制,以及二者之间的关联与互作关系;(2)土壤微生物功能群网络及其对碳氮循环过程的影响;(3)生态系统碳氮水交换通量的时空变化规律,以及生态系统的生态化学计量学理论与实践。本文最后还简要介绍了国家基金委重大研究项目"森林生态系统碳氮水耦合循环的生物控制机制"的研究思路及其主要研究内容。期望能够通过这些探讨对推动我国该研究领域的基础理论建设和新技术发展有所贡献。     

农业景观异质性对生物多样性及其 生态系统服务的影响

农业景观中生物多样性具有特殊重要的意义,本文首先综述了农业景观异质性的组成和特征。农业景观的异质性不仅包括空间组成和构型异质性以及时间异质性,更应包括基于物种或功能类群认识的农业景观功能异质性,这对于讨论景观异质性与生物多样性的关系十分关键。纵览景观空间异质性和时间异质性对生物多样性的多尺度影响发现,很多研究证实非农生境对于维持农业景观中生物多样性十分必要,由非农生境斑块和农田基质组成异质性较高的农业景观往往促进生物多样性,不同生物类群对景观异质性的响应尺度不同。景观结构和种间作用的复合影响是异质性农业景观维持生物多样性的机制。景观异质性通过生物多样性的组成和分布进而影响其提供的生物控制、授粉和物质循环等生态系统服务。结合黄河中下游平原农业景观异质性特征及其对生物多样性影响系列研究结果,在联产承包责任制下小田块管理的农业景观中,未来相关研究应基于功能景观的时空异质性深入讨论农业景观对生物多样性及其生态系统服务的影响机制,为可持续农业景观的构建提供科学依据。     

植被恢复的土壤固碳效应：动态与驱动机制

植被恢复是影响土壤有机碳库动态变化的关键过程之一,阐明植被恢复过程中土壤有机碳的固持动态及其驱动机制,是全球变化下碳循环研究的热点和前沿问题。本文综述了近年来国内外关于植被恢复过程中土壤有机碳固定动态及其驱动机制方面的研究,剖析植被恢复中土壤有机碳固持动态及其影响因素,探讨植物碳输入对土壤有机碳动态变化的影响机制,揭示植被恢复中土壤有机碳固定的物理、化学和微生物驱动机制,并对目前研究中存在的问题进行总结,进而提出关于植被恢复的土壤固碳效应研究,亟需在土壤有机碳组分的动态、微生物结构和功能,以及植物—土壤—微生物对土壤有机碳固持的协同作用机制等方面进一步加强。本综述可为植被恢复与土壤固碳稳定机制研究指明未来的方向,进而为促进我国植被恢复的土壤碳循环研究,科学评价生态系统土壤固碳潜力和有效实施生态系统碳汇管理提供科学参考。     

气候变化和人类活动对流域水文恢复力影响的研究进展

水文恢复力是流域或生态系统维持水文稳定性的重要参考指标,深入研究植被结构和水文恢复力之间的关系是未来在全球变化背景下生态水文学的重要方向.但目前水文恢复力对气候变化与人类活动等不同干扰方式的响应机制还缺乏系统的研究,水文恢复力的形成机制及其与植被结构的关系也尚无全面的认识.系统总结了当前水文恢复力的主要概念,从水分利用...     

河岸植被缓冲带生态水文功能研究进展

河岸植被缓冲带是河岸生态系统的重要组成部分,对河岸生态系统的生态及水文过程具有重要的影响。世界上许多国家已将河岸植被缓冲带列为河岸生态系统管理的一个重要内容,并在一些国家被作为控制农业流域非点源污染的最佳管理措施。河岸植被缓冲带的生态水文功能体现在控制河岸侵蚀、截留地表径流泥沙和养分、保护河溪水质、调节水温、为水陆动植物提供生境、维护河溪生物多样性和生态系统完整性以及提高河岸景观质量等多个方面。本文综述河岸植被缓冲带生态水文功能方面的研究进展,总结了一些研究中提出的不同河岸植被缓冲带功能发挥所需要的宽度,同时指出由于河岸生态系统保护的目标,侧重的功能,研究区域土壤、地形、植被、排水特征等因素各异,河岸植被缓冲带生态水文功能发挥所要求的实际宽度也有所不同。     

土壤微生物生物地理学：国内进展与国际前沿

土壤微生物生物地理学是研究土壤中微生物空间分布格局及其随时间变化的一门科学,是土壤微生物学和微生物生态学等领域的研究前沿。近年来,尽管土壤微生物生物地理学研究取得了巨大进展,目前仍面临诸多难题与挑战。本文简要回顾了土壤微生物生物地理学的发展历程,重点介绍近年来我国在森林、草地和农田生态系统中土壤微生物生物地理学研究的主要进展。同时进一步阐述了目前土壤微生物生物地理学研究的国际前沿方向,包括微生物群落空间分布及其驱动机制、群落构建过程与共存网络、微生物地理分布与生态系统功能的关联以及预测微生物群落对全球变化的响应。最后,对土壤微生物生物地理学未来的研究方向进行了展望,强调了清晰的微生物物种定义、微生物群落的时间动态、多组学与合成生物学技术以及高精度的预测模型在土壤微生物生物地理学研究中的重要性。     

Biological crusts as a model system for examining the biodiversity-ecosystem function relationship in soils

Despite that soils may be the greatest repository of biodiversity on Earth, and that most terrestrial ecosystem functions occur in the soil, research on the role of soil biodiversity in ecosystem function has lagged behind corresponding research on aboveground organisms. Soil organisms pose special problems to biodiversity-function research, including the fact that we usually do not know their identity nor what they do in soil ecosystems, cannot easily estimate their biodiversity, and cannot culture the majority of the organisms for use in manipulative experiments. We propose here that biological soil crusts (BSCs) of deserts and many other ecosystems may serve as a useful model system for diversity-function research because the species concept is relatively well-defined within BSC organisms, their functional attributes are relatively well-known, and estimation and manipulation of biodiversity in experiments are feasible, at least within some groups of BSC biota. In spite of these features, there is a pronounced lack of research on biodiversity-function using these organisms. At least two complementary approaches are possible: experiments using artificially-constructed BSCs, and observational studies which statistically control for the effects of other factors which are likely to covary with biodiversity. We applied the latter to four observational datasets collected at multiple spatial scales in Spain and the United States using structural equation models or path analysis using ecosystem function indicators relating to hydrology, trapping and retention of soil resources, and nutrient cycling. We found that, even when total BSC abundance and key environmental gradients are controlled for, direct and approximately linear relationships between species richness and/or evenness and indicators of ecosystem functioning were common. Such relationships appear to vary independently of region or spatial scale, but their strength seems to differ in every dataset. Functional group richness did not seem to adequately capture biodiversity-function relationships, suggesting that bryophyte and lichen components of BSC may exhibit low redundancy. More research employing the multi-trophic, multi-functional, and manipulable BSC system may enable more rapid understanding of the consequences of biodiversity loss in soils, and help enable a biodiversity-function theory that is pertinent to the numerous ecosystem services provided by soil organisms.     

基于文献计量分析的生态系统恢复力研究进展

该文基于VOSviewer和Histcite文献计量方法,以CNKI数据库和Web of science核心合集中生态系统恢复力研究文献为对象,通过对文献数量、高频关键词的分析,总结国内外恢复力研究的脉络和内容演变。研究发现:1)生态系统恢复力研究领域发表的文章数量总体上呈上升趋势,文献主要来源于美国;2)国际恢复力研究经历了从基础理论到政策管理及技术应用,各个方向存在相互的引证关系,分析研究热点的时序演化发现,2000年前,以恢复力的内涵和基础理论为研究重点;2001-2010年间,珊瑚礁的测度模型及提升路径成为热点;近10 a来,恢复力研究领域进一步扩大,研究方法更加多样化;3)与其他国家相比,中国的恢复力研究起步较晚,侧重于应用基础研究,集中于恢复力的工程措施、调查监测手段以及影响因素的探讨。     

Scale effect of climate on soil organic carbon in the Uplands of Northeast China

Purpose  

Climate factors, considered significant factors in regulating soil organic carbon (SOC), are not equally important at all spatial scales. However, the scale which provides the optimal relationship between climate and SOC and how that relationship varies at multiple scales are still unclear. Thus, it is crucial to study the relationship between climate factors and SOC at multiple scales when attempting to accurately predict the SOC pool and evaluate the influence of climate change on global carbon cycling. The objective of this research is to examine the scale effect of climate factors on SOC content in the Uplands of Northeast China.     

Spatial heterogeneity of a microbial community in a sandy soil ecosystem

A fieldwork was carried out in Caesarea sand dunes, Israel, to determine the influence of fine-scale landscape-patch abiotic-factor heterogeneity on microbial activity in a Mediterranean region. Soil organisms in terrestrial systems are unevenly distributed in time and space, and are often aggregated. Spatio-temporal patchiness in the soil environment is thought to be crucial for the maintenance of soil biodiversity, providing diverse microhabitats that are tightly interwoven with resource partitioning. Determination of a ‘scale unit’ to help understand ecological processes has become one of the important and most debatable problems in recent years. To better understand the distribution of soil microbial communities at multiple spatial scales, a survey was conducted to examine the spatial organization of the community structure in two sandy soil ecosystems. One-hundred forty-four soil samples were collected from two patches 4000 m apart from each other. Basal respiration (CO₂ evolution without the addition of any external substrate), microbial biomass, functional diversity, and community-level physiological profile (CLPP) in soil were measured with a MicroResp? system. Soil abiotic analysis was performed by soil standard analytical methods. The results demonstrated that bacterial distributions can be highly structured, even within a habitat that appears to be relatively homogeneous at the plot and field scale. Different subsets of the microbial community were distributed differently across the plot. This is due to spatial heterogeneity associated with soil physical, chemical, and biological properties. Although spatial variability in the distribution of soil microorganisms is generally regarded as random, this variability often has a predictable spatial structure. This study provided evidence that a spatially explicit approach to soil ecology can enable the identification of factors that drive the spatial heterogeneity of populations and activities of soil organisms, at scales ranging from meters to hundreds of meters. Furthermore, there is increasing evidence that spatial soil ecology can yield new insights into the factors that maintain and regulate soil biodiversity, as well as on how the spatial distribution of soil organisms influences plant growth and plant community structure.     

A hierarchical framework for classifying seabed biodiversity with application to planning and managing Australia’s marine biological resources

A conceptual hierarchical framework for classifying marine biodiversity on the sea floor, used successfully for continental-scale bioregionalisation and adopted to guide marine resource planning and management in Australia, has wider application at a global scale. It differs from existing schemes for classifying marine biota by explicitly recognizing the overarching influence of large-scale biodiversity patterns at realm (ocean basin and tectonic), provincial (palaeohistorical) and bathomic (depth-related) levels. The classification consists of 10 nested levels within realms, of which the first seven are primarily spatially nested and ecosystem based, and the lowest levels represent units of taxonomic inheritance: 1 - provinces, 2 - bathomes, 3 - geomorphological units, 4 - primary biotopes, 5 - secondary biotopes, 6 - biological facies, 7 - micro-communities, 8 - species, 9 - populations, and 10 - genes. According to this scheme, marine biodiversity is characterised in a systematic way that captures the scale-dependence and hierarchical organization of the biota. Levels are defined with respect to their functional roles and spatial scales, in a manner that directly supports the incorporation of biodiversity information in regional-scale planning by highlighting centres of endemism, biodiversity richness and priority information needs. Whereas species are the fundamental units of biodiversity, biological facies are the smallest practical unit for conservation management at regional scales. In applying the framework we make extensive use of biological and physical surrogates because marine data sets, particularly those of the deep sea, are usually sparse and discontinuous. At each level of the hierarchy, attributes and surrogates are defined to reflect the scale and range of biogeographic and ecological processes that determine the spatial and temporal distribution of marine biodiversity. The Australian experience in applying this framework suggests that it provides a workable systematic basis for defining, managing and conserving biodiversity in the sea.     

Hierarchical systematic conservation planning at the national level: Identifying national biodiversity hotspots using abiotic factors in Russia

National conservation planning should operate with measures of biodiversity similar to those applied globally in order to harmonize national and international conservation strategies. Here we suggest quantitative measures which enable two criteria of the global biodiversity hotspots to be applied on a national level for 74 large countries, and show how these measures can be applied to map national biodiversity hotspots. The plant endemism criteria of global hotspots are captured by quantitative measures of endemism, which are approximately scale-independent and can be corrected to account for a country’s environmental conditions and conservation priorities. The flexible land use criteria for national biodiversity hotspots are defined from percentage of natural vegetation remaining in the global hotspots. The minimum-area-required approach is applied to define the borders of national biodiversity hotspots using data on vascular plants species richness. We show how national biodiversity hotspots can be mapped from the species-energy relationship for vascular plants using climate, topographical and land use data when spatial pattern of species richness is not known. This methodology to map national biodiversity hotspots from abiotic factors is applied to Russia as a case study. Three Russian biodiversity hotspots, North Caucasus, South Siberia and Far East were identified. The resulting hotspot maps cover national-scale environmental gradients across Russia and although they are also identified by Russian experts their actual geographical locations were hitherto unspecified. The large-scale national hotspots, identified for Russia, can be used for further fine scale and more detailed conservation planning.     

植物多样性对土壤动物影响的研究进展

生物多样性与生态系统功能一直是生态学研究的一个热点。近些年来的研究表明,植物多样性除了影响陆地生态系统地上部分的初级生产力等生态系统功能,还会间接影响地下生物多样性及土壤生态系统过程。本文概述了植物多样性对土壤动物的影响及其主要机制,归纳了植物多样性通过改变输入土壤中的资源数量与资源多样性、微生境结构、土壤环境因子等影响土壤动物的途径。目前关于土壤动物群落对植物多样性的响应仍存在很多问题和争议,本文总结了需要进一步深入研究的方向,特别指出了要加强研究影响植物多样性与土壤动物关系的生物与非生物因子、后续的生态效应和反馈、不同机制和途径的贡献定量化等。     

Estimating effective soil depth at regional scales: Legacy maps versus environmental covariates

Soil depth reflects the quantity and ecosystem service functions of soil resources. However, there is no universal standard to measure soil depth at present, and digital soil mapping approaches for predicting soil depth at the regional scale remain immature. Using observation of soil profile morphology, we compared the soil depth nomenclatures from the World Reference Base for Soil Resources, Chinese Soil Taxonomy, and Soil Taxonomy. For this study, shallow soils were defined as those with an effective soil depth < 100 cm. Based on legacy data and field soil survey, the spatial distribution of shallow soils in Xinjiang, China, and the main controlling environmental factors were explored. Results showed that shallow soils in Xinjiang are mainly distributed in high altitude regions such as the Tian Mountains. At the regional scale, significant correlations were observed between soil depth and climate factors, as well as between soil depth and vegetation fractional coverage. Contrary to previous conclusions at small spatial scales, terrain attributes could not explain soil depth variation at the regional scale. This study addressed knowledge gaps on soil depth prediction at regional scales while elucidating climate‐vegetation‐soil coevolution.     

基于土壤生物空间异质性分析的空间土壤生态学研究

土壤生物以不同的方式改变着土壤的物理、化学和生物学特性。了解土壤生物的空间异质性是很关键的。土壤生态学和空间生态学结合的新的研究领域─空间土壤生态学关注空间在土壤生物种群结构及动态中的重要性。本文通过对土壤生物空间异质性的分析,内容包括空间土壤生态学的提出、土壤生物空间异质性研究的意义、研究方法,重点综述了影响土壤生物分布格局的因素、尺度,土壤生物空间分布对植被-土壤系统的影响,土壤生物空间异质性的作用,其中包括土壤生物空间异质性与多样性的关系、土壤生物对局部干扰的响应、土壤生物空间格局对植被的影响。     

多尺度高分辨率全球土地覆被遥感产品相对一致性比较

国家及区域尺度的土地覆被信息对于解决环境演变、生物多样性保护、生态系统评价及环境建模等一系列问题起着至关重要的作用。该文从国家及区域尺度分别比较了当前全球2种最高分辨率的土地覆被遥感产品,以便解释两者在空间及专题上的一致性和异质性。结果表明,GLOBCOVER和MODIS2种产品在国家尺度上具有较好的一致性,但在区域尺度上仍有较明显的差异,特别是在中国东北和西南地区;2种产品在林地、灌木、耕地和草地间存在严重的混淆现象;总体精度和Kappa系数在全国尺度和区域尺度有着较大的差异,总体精度值从全国尺度的56.35%降为区域尺度的27.01%,Kappa系数值从全国尺度的47.09%降为区域尺度的16.57%。在全国尺度上东北区域有着最好的一致性,四川盆地的总体一致性最差;MODIS产品的类别均质性百分比明显优于GLOBCOVER,类别一致性百分比与空间一致性之间存在显著的相关性,其决定系数R2为0.724,说明产品间的类别均质性百分比差异越小,两者的空间一致性越高。该研究可为遥感产品的使用者提供准确可信的信息分布,为产品生产者有针对性改进分类算法提供科学合理依据。