Modeling of oak pollen dispersal on the landscape level with a mesoscale atmospheric model

We present the extension and application of the mesoscale atmospheric meteorology model METRAS for dispersion of oak pollen. We incorporated functions for pollen emission, pollen viability and pollen deposition into METRAS and simulated pollen dispersal on a scale of up to 200 km. The basis of the simulations is a real landscape structure that includes topography, land use, and the location and size of oak stands. We simulated the oak pollen dispersion of one single oak stand with an estimated annual pollen production of 1 billion pollen grains/m² forest surface on two exemplary days of the flowering season in 2000. Depending on the meteorological situation of the simulated days, a pollen cloud with about 10 pollen/m³ may extend up to 30 km from the source. Downstream of the oak stand, approximately 1,000 pollen/m² deposited up to a distance of 25 km, and lower amounts of pollen deposited up to 100 km away. These values of pollen concentration and deposition lay within the range of published field studies. Overall, it is shown that mesoscale atmospheric models are applicable to simulate pollen dispersal on the landscape level.     

在中国发展环境会计的局限性分析

建立和发展环境会计是中国贯彻可持续发展战略的必然选择和重要保障。环境会计产生并形成于西方国家，目前中国尚未形成适合中国国情的环境会计体系，环境会计的研究在中国仍处于理论探讨阶段，无法在实践中运用。环境会计研究需要在引进西方国家研究成果的基础上不断的自我创新，自我完善。因此应该结合中国的国情和环境会计的学科特点，从环境会计产生的理论基础，传统会计的局限性，企业对环境责任履行不足三个方面分析环境会计在中国的发展创新受到限制的原因。只有正视这些阻碍环境会计在中国发展的局限性，环境会计才能在理论上进一步完善，在实践中真正运用。     

关于风景评价中心理物理学方法局限性的探讨

由于对西方风景评价理论和方法缺乏足够的了解和深入的研究，现今国内对其中的心理物理学方法及其作用产生了一些误解。本文在扼要介绍了心理物理学派的主要方法思路之后，着重对该学派所存在的重大理论缺陷和方法局限性做了较深入的分析。     

铜对污染区和非污染区海州香薷光合作用差异

在铜胁迫下,以水培的方法,对污染区、非污染区海州香薷的净光合速率(Pn)、气孔导度(Gs)、胞间CO2浓度(Ci)、气孔限制值(Ls)、叶绿素(Chl)等进行比较研究。结果表明,15μmol/L和45μmol/L铜处理下,污染区、非污染区海州香薷Pn均显著下降,但是污染区Pn下降了16%~27%,非污染区Pn下降了56%~62%。此外,非污染区海州香薷Gs、Ci均明显下降,Ls明显上升,Chla、Chlb含量没有明显变化(15μmol/L铜的Chla含量除外),表明其净光合速率下降的主要原因是气孔限制;但是,污染区海州香薷Gs、Ci、Ls上升或轻微变化,Chla、Chlb含量均明显下降,表明其光合作用可能不存在气孔限制,同时Chl含量明显下降可能是其净光合速率下降的原因之一。此研究揭示了金属型植物光合作用差异及其气孔和非气孔限制,可为进一步查明其生长限制因子提供科学依据。     

Airborne myxomycete spores: detection using molecular techniques

Myxomycetes are organisms characterized by a life cycle that includes a fruiting body stage. Myxomycete fruiting bodies contain spores, and wind dispersal of the spores is considered important for this organism to colonize new areas. In this study, the presence of airborne myxomycetes and the temporal changes in the myxomycete composition of atmospheric particles (aerosols) were investigated with a polymerase chain reaction (PCR)-based method for Didymiaceae and Physaraceae. Twenty-one aerosol samples were collected on the roof of a three-story building located in Sapporo, Hokkaido Island, northern Japan. PCR analysis of DNA extracts from the aerosol samples indicated the presence of airborne myxomycetes in all the samples, except for the one collected during the snowfall season. Denaturing gradient gel electrophoresis (DGGE) analysis of the PCR products showed seasonally varying banding patterns. The detected DGGE bands were subjected to sequence analyses, and four out of nine obtained sequences were identical to those of fruiting body samples collected in Hokkaido Island. It appears that the difference in the fruiting period of each species was correlated with the seasonal changes in the myxomycete composition of the aerosols. Molecular evidence shows that newly formed spores are released and dispersed in the air, suggesting that wind-driven dispersal of spores is an important process in the life history of myxomycetes. This study is the first to detect airborne myxomycetes with the use of molecular ecological analyses and to characterize their seasonal distribution.     

Phylogeography and Limited Genetic Connectivity in the Endangered Boring Giant Clam across the Coral Triangle

Abstract: The Coral Triangle is the global center of marine biodiversity; however, its coral reefs are critically threatened. Because of the bipartite life history of many marine species with sedentary adults and dispersive pelagic larvae, designing effective marine protected areas requires an understanding of patterns of larval dispersal and connectivity among geographically discrete populations. We used mtDNA sequence data to examine patterns of genetic connectivity in the boring giant clam (Tridacna crocea) in an effort to guide conservation efforts within the Coral Triangle. We collected an approximately 485 base pair fragment of mtDNA cytochrome c oxidase 1 (CO1) from 414 individuals at 26 sites across Indonesia. Genetic structure was strong between regions (φ_ST=0.549, p < 0.00001) with 3 strongly supported clades: one restricted to western Sumatra, another distributed across central Indonesia, and a third limited to eastern Indonesia and Papua. Even within the single largest clade, small but significant genetic structure was documented (φ_ST=0.069, p < 0.00001), which indicates limited gene flow within and among phylogeographic regions. Significant patterns of isolation by distance indicated an average dispersal distance of only 25–50 km, which is far below dispersal predictions of 406–708 km derived from estimates of passive dispersal over 10 days via surface currents. The strong regional genetic structure we found indicates potent limits to genetic and demographic connectivity for this species throughout the Coral Triangle and provides a regional context for conservation planning. The recovery of 3 distinct evolutionarily significant units within a well‐studied taxonomic group suggests that biodiversity in this region may be significantly underestimated and that Tridacna taxa may be more endangered than currently recognized.     

A methodological approach to develop “contaminant migration–population effects” models

The main aim of the present work is to discuss the methodological approaches that underpin the “contaminant migration–population effects” models for the evaluation of the detriment to populations of moving organisms in environmental systems with spatial and time dependent pollution levels. A technique to couple the equations controlling the population dynamics and the pollutant dispersion is described and discussed. The domain of application and the limitations of the methodology are analysed and illustrated by some examples. Possible alternative approaches are briefly presented.     

Effects of Growth Form and Functional Traits on Response of Woody Plants to Clearing and Fragmentation of Subtropical Rainforest

The conservation implications of large‐scale rainforest clearing and fragmentation on the persistence of functional and taxonomic diversity remain poorly understood. If traits represent adaptive strategies of plant species to particular circumstances, the expectation is that the effect of forest clearing and fragmentation will be affected by species functional traits, particularly those related to dispersal. We used species occurrence data for woody plants in 46 rainforest patches across 75,000 ha largely cleared of forest by the early 1900s to determine the combined effects of area reduction, fragmentation, and patch size on the taxonomic structure and functional diversity of subtropical rainforest. We compiled species trait values for leaf area, seed dry mass, wood density, and maximum height and calculated species niche breadths. Taxonomic structure, trait values (means, ranges), and the functional diversity of assemblages of climbing and free‐standing plants in remnant patches were quantified. Larger rainforest patches had higher species richness. Species in smaller patches were taxonomically less related than species in larger patches. Free‐standing plants had a high percentage of frugivore dispersed seeds; climbers had a high proportion of small wind‐dispersed seeds. Connections between the patchy spatial distribution of free‐standing species, larger seed sizes, and dispersal syndrome were weak. Assemblages of free‐standing plants in patches showed more taxonomic and spatial structuring than climbing plants. Smaller isolated patches retained relatively high functional diversity and similar taxonomic structure to larger tracts of forest despite lower species richness. The response of woody plants to clearing and fragmentation of subtropical rainforest differed between climbers and slow‐growing mature‐phase forest trees but not between climbers and pioneer trees. Quantifying taxonomic structure and functional diversity provides an improved basis for conservation planning and management by elucidating the effects of forest‐area reduction and fragmentation. Efectos de la Forma de Crecimiento y Atributos Funcionales en la Respuesta de Plantas Leñosas al Desmonte y Fragmentación de Bosque Lluvioso Subtropical     

扬尘污染防治理论初探

针对扬尘污染问题,进行了扬尘污染防治理论探讨,明确了扬尘的概念和特点;提出相对起尘量的概念,定量地分析了城市不同类型下垫面对扬尘污染的影响;建立了城市下垫面生态等级的划分方法;提出通过提高生态域等级及制定道路积尘量限定标准这两类措施来治理扬尘污染;建立了这两类扬尘污染防治措施的环境效益评估方法体系。     

氮沉降下西南亚高山针叶林生长的养分限制特征

长期氮(N)沉降及其诱导的N、磷(P)养分平衡性对森林生长与生产力的生态反馈效应已成为当前森林生态学研究的前沿与热点,但目前大多研究主要基于已有文献数据整合分析,而缺乏野外原位系统性研究与试验证据.以西南亚高山两种典型人工针叶林——云杉(Picea asperata)林和华山松(Pinus armandii)林为对象,...