山东省生物多样性的研究现状与发展趋势

生物多样性是人类赖以生存的物质基础。目前,山东省生物多样性下降的总体趋势尚未得到有效遏制,为进一步加强生物多样性保护工作,有必要对山东省的生物多样性研究的相关情况进行总结,提出未来的研究方向。通过查阅近10年的文献,从遗传多样性、物种多样性和生态系统多样性3个方面总结了山东省生物多样性的研究现状,并指出其存在的问题和发展趋势。     

基于GIS的广西北部湾经济区生态系统间接利用价值评估研究

针对目前生态系统间接利用价值评估中缺乏空间表达、对数据要求高、评估效率低等不足,构建了基于GIS的广西北部湾经济区生态系统间接利用价值评估方法.2005 ～ 2010年北部湾经济区间接利用价值呈现上升趋势;按研究区域间接利用价值统计,价值最高的是南宁市辖区,价值最低是北海市辖区;按单位面积间接利用价值统计,上思县价值最高,北海市辖区最低;间接价值较高区域主要分布在较高植被覆盖度的区域,如南宁市辖区、钦州市辖区、灵山县、上思县和防城港市辖区.     

基于GIS二次开发的广西北部湾经济区生态系统服务价值评估

改变传统生态系统服务价值的评估模式,利用GIS对空间数据的高效管理和分析的优势,针对生态环境管理人员对于软件操作简单化和系统开发资金节约的要求,构建了在Visual Studio 2008．NET平台上利用C#语言和ArcGIS Engine组件下的广西北部湾经济区生态系统服务价值评估系统。该系统界面友好,操作方便,可实现GIS的基本功能,可扩展性强,能提高生态系统服务价值的评估效率,为生态环境保护与建设提供决策依据,促进生态系统的可持续发展。     

Estimating daytime subcanopy respiration from conditional sampling methods applied to multi-scalar high frequency turbulence time series

This study presents a new method to estimate daytime respiration from the subcanopy of forests directly from conventional eddy covariance (EC) measurements. The method primarily considers the respiration signal from root, litter and microbial respiration, which are known to be the main components of ecosystem respiration, R_e, as well as decomposition of coarse and fine woody detritus, and respiration from low understory vegetation (forbs, herbs and grasses). The conceptual framework is based on the premise that upward moving air parcels carry a specific and unambiguous signal in their CO₂ and water vapour composition, which can be separated and distinguished into respiration and photosynthesis. The model employed a combination of conditional sampling methods, quadrant analysis and relaxed eddy accumulation with hyperbolic deadbands to identify respiration events and to quantify their flux contribution. Datasets from five sites, most of which had multiple sampling heights, were selected to test this technique among contrasting ecosystems and canopy structures.Respiration signals were successfully identified in daytime data of all sites. A hyperbolic deadband of size H = 0.25 applied to the plane constructed from perturbations of carbon dioxide c and water vapour q densities effectively separated the signals of respiration from photosynthesis. The time fraction of respiration events was ≤10% during daytime. The global correlation coefficient r_c,q was found to be a universal predictor of this time fraction and was therefore used as a filter to identify periods of a meaningful and extractable respiration signal. Coherent structures, defined as ramp-shaped flow pattern observed in time series in and above forest canopies, are likely to be the underlying transport mechanism for these respiration events.Daytime subcanopy R_e estimates derived from the new method agreed with those derived from: (i) the intercept of light-response curves and (ii) soil CO₂ efflux chambers for three of the five sites. Limitations were posed by the dense, multi-layered deciduous canopy and the intense vertical turbulent mixing at one coniferous site. In addition, refixation of respired CO₂ by the understorey (CO₂ recycling) may cause an underestimation of daytime R_e or pose a limitation to the method proposed here. An indicator relating the canopy shear length scale, L_s, to the adjustment length scale, L_d, was proposed to predict the skill of the new method, and found to be useful in four of the five sites. Analysis of vertical coupling in the plant canopy using exchange regimes could explain the failure of the new method for the remaining site.     

Environmental controls on photosynthetic production and ecosystem respiration in semi-arid grasslands of Mongolia

The Mongolian steppe zone comprises a major part of East Asian grasslands. The objective of this study was to separately evaluate the quantitative dependencies of gross primary production (GPP) and ecosystem respiration (R_eco) on the environmental variables of temperature, moisture, radiation, and plant biomass in a semi-arid grassland ecosystem. We determined GPP and R_eco using transparent and opaque closed chambers in a grassland dominated by Poaceae species in central Mongolia during five periods: July 2004, May 2005, July 2005, September 2005, and June 2006. Values of GPP were linearly related to live aboveground biomass (AGB) enclosed by the chamber. The amount of GPP per unit ground area differed among the study periods, whereas GPP normalized by the amount of AGB did not differ significantly among the periods, suggesting that plant production per unit green biomass did not depend on the phenological stage. GPP/AGB fit well a rectangular hyperbolic light–response curve for all the study periods. When the air and soil were dry, considerable reduction in GPP was observed. The GPP/AGB ratio was also expressed as individual functions of air temperature, vapor pressure deficit, and volumetric soil water content. R_eco was exponentially related to the soil temperature and the relationship was modified by soil moisture. The amount of R_eco and its temperature sensitivity (Q₁₀) declined with decreasing soil moisture. Sharp increases of R_eco after rainfall events were observed. The values of R_eco, even including the rain-induced pulses, were expressed well as a bivariate function of soil temperature and soil moisture near the soil surface.     

Reciprocal adjustments between landforms and living organisms: Extended geomorphic evolutionary insights

Whilst biological organisms adapt to the environment, earth surface processes and landforms evolve as a result of physicochemical processes, and as the result of the activity of certain living organisms defined as ‘ecosystem engineers’. The importance of long- and short-term impacts on geomorphic structures and processes by ecosystem engineers appears to be underestimated. Recent recognition of complex abiotic–biotic feedbacks in nature has resulted in a convergence of approaches in ecology and geomorphology. Present biogeomorphic knowledge supports the hypothesis that abiotic–biotic feedbacks create characteristic modulated patterns of earth surface landforms, adjusting according to biological evolution in the long term and to ecological succession in the short term. In this context, natural selection of organisms and ecological successions are considered to have the potential, in some cases, for extension to the physical world, including earth surface landforms. This perspective aims to contribute to the disruption of the ‘classical’ dichotomy between abiotic–biotic compartments because it emphasizes reciprocal adjustments (i.e., feedback mechanisms) between living organisms and abiotic environment dynamics. The extended evolutionary perspective, that is intended to feed back to ecology and evolutionary biology, indicates the potential for change in our deep understanding of geomorphology to reflect evolutionary and ecological succession theories.     

Cutting the lawn − Natural burial and its contribution to the delivery of ecosystem services in urban cemeteries

This article investigates the impact of natural burial on the delivery of ecosystem services (ESs) in urban cemeteries in England that are owned and managed by local authorities. Local authority natural burial sites have received far less attention from researchers than independent sites developed by farmers, charitable trusts, funeral directors and land owners. Here we argue that the local authority hybrid cemeteries that combine natural burial with traditional graves may have a far greater impact in delivering regulatory and cultural ecosystem services than the much larger and frequently more environmentally ambitious natural burial grounds developed by the independent sector. The article presents three case studies of cemeteries, each of which represents a different interpretation of natural burial. Two have retrofitted natural burial into an existing cemetery landscape. The third is a new cemetery where natural burial was included with traditional burial in the original design brief and planning application. The research reveals how natural burial is transforming the traditional cemetery, with its focus on an intensively managed lawn aesthetic, towards a more habitat rich and spatially complex landscape with its own distinctive identity. The research also reveals how natural burial (within the unique constraints of UK burial culture that does not permit the recycling of burial space) is increasing the burial capacity of urban cemeteries by accessing land and grave space that might not be suitable or appropriate for more traditional forms of burial.     

Investigation of environmental and land use impacts in forested permafrost headwaters of the Selenga-Baikal river system,Mongolia - Effects on discharge,water quality and macroinvertebrate diversity

Headwater streams play a major role for provision of ecosystem services, e.g. drinking water. We investigated a high-altitude headwater catchment of the Kharaa River (including 41 1st-order rivers) to understand the impact of land cover (especially forest cover), environment and human usage on runoff, chemical water quality and macroinvertebrate fauna in a river basin under discontinuous permafrost conditions in an arid, sparsely populated region of Mongolia. To verify our hypotheses that different landuses and environmental impacts in permafrost headwaters influence water quality, we investigated 105 sampling sites, 37 of them at intermittent stream sections without water flow. Discharge was positively impacted by land cover types steppe, grassland and forest and negatively by shrubland, forest burnt by wild fires (indicating a reduction of permafrost) and slope. Water quality was affected by altitude, longitude and latitude, shrub growth and water temperature. Shannon diversity of macroinvertebrates was driven by water temperature, iron content of the water, flow velocity, and subbasin size (adjusted R² = 0.54). Sample plots clustered in three groups that differed in water chemistry, macroinvertebrate diversity, species composition and bio-indicators. Our study confirms that steppes and grasslands have a higher contribution to runoff than forests, forest cover has a positive impact on water quality, and diversity of macroinvertebrates is higher in sites with less nutrients and pollutants. The excellent ecological status of the upper reaches of the Kharaa is severely threatened by forest fires and human-induced climate change and urgently needs to be conserved.     

A trait-based characterization of cover plants to assess their potential to provide a set of ecological services in banana cropping systems

Cover plants are one of the means to increase the functional biodiversity of fields and to enhance the ecological functions of the communities. However, the design of cropping systems including cover plants relies largely on expert knowledge. There is a lack of methods to select the best suited cover plants according to their role in the agrosystem. We propose to use functional traits to select cover plants suited to sustain ecological services in the banana agrosystems of the French West Indies. Our objectives were (i) to characterize a collection of cover plants on a trait basis, according to their potential to provide the services expected in a banana agrosystem and (ii) to discuss the potential use of this characterization for the design of innovative multi-species banana cropping systems. In these systems, four main services are targeted, i.e. controlling weeds, controlling plant-parasitic nematodes, improving soil fertility and particularly N availability, and avoiding competition with banana for resource acquisition. Three experiments were conducted, under field and controlled conditions, to evaluate the potential of a collection of 28 tropical cover plants to achieve the functions related to these services. For each cover plant, a functional profile was constructed from a combination of plant traits that are easy to assess experimentally. It described plants’ potential to achieve the functions expected in a banana agrosystem. Functional profiles required for cover plant usages were also identified. The comparison of the plant functional profiles and the functional profiles required for their usages enabled us to select the best suited plants for each usage. However, these functional profiles rarely corresponded, meaning that a cover plant is rarely sufficient to achieve all the functions required for a usage. Functional complementarities obtained by the mixture of different species of cover plants are thus often required. Compared to classical approaches of innovative cropping system design based on the experimental testing of spatial and temporal plant combinations, such a trait-based approach saves time by focusing on a shortlist of cover plants best suited according to their functions in the agrosystem.     

管涔山生物多样性特征研究

从地理位置、地形地貌、气候、土壤与植被和地质特征5个方面阐述了管涔山的自然概况,并从物种多样性、生态系统多样性和遗传多样性3个方面介绍了管涔山的生物多样性特征,最后提出了管涔山生物多样性保护的重要意义。