Diversity and Abundance of Biological Soil Crust Taxa in Relation to Fine and Coarse-Scale Disturbances in a Grassy Eucalypt Woodland in Eastern Australia

Over the last 200 years the box woodlands of eastern Australia have been considerably altered by European farming practices. These changes have been accompanied by a reduction in the size and number of patches of vegetation as well as the quality of the understorey vegetation and underlying soil surface. We measured diversity and abundance of soil crust taxa in relation to habitat complexity, remnant area and width, diversity of vascular plants as well as the number, size and separation of patches of vegetation and grass butts (coarse-scale patchiness), and an index of surface stability derived from measures of seven soil surface features of small microsites (patches of bare/crusted, litter- or grass-covered soil; micro-scale) on both coarse- and fine-textured soils at 35 sites in south-eastern Australia. Fifty taxa were recorded from the 35 sites, and there were more taxa from sites with fine-textured soils (12.7) compared with coarse-textured soils (4.4). The soil crust community was dominated by a few relatively common species, with many species occurring at only a few sites. Half the number of species accounting for <1% of total abundance. Bare and crusted microsites supported more species and greater cover compared with grassy microsites. Crust diversity declined with increasing coarse-level disturbances (i.e. declines in habitat complexity, remnant area and width, and diversity of vascular plants) but the results were not consistent between soil types. No measures of fine-scale disturbance were related significantly to any of the crust diversity or abundance measures, and there was no evidence of a recent grazing effect on crust composition. The fact that few sites had many species (and visa versa) suggests to us that many sites are probably required to conserve soil crust taxa in these highly fragmented landscapes     

Biophysical and human influences on plant species richness in grasslands: Comparing variegated landscapes in subtropical and temperate regions

A survey of grassy woodlands in the Queensland subtropics was conducted, recording herbaceous species richness at 212 sites on three properties (2756 ha). A range of habitats typical of cattle grazing enterprises was sampled and site variables included lithology, slope position, tree density, soil disturbance, soil enrichment and grazing. Results were compared with a previously published survey of temperate grasslands. Lithology, slope position and tree density had relatively minor effects on plant species richness, although in both surveys there was some evidence of lower species richness on the more fertile substrates. Soil disturbance and soil enrichment significantly reduced the richness of native species in both surveys, while exotic species were insensitive (subtropics) or increased (temperate) with disturbance. Rare native species were highly sensitive to disturbances, including grazing, in the temperate study. Although some trends were similar for rare species in the subtropics, the results were not significant and there were complex interactions between grazing, lithology and slope position. Grazing did not have a negative effect on native species richness, except in the closely grazed patches within pastures, and then only on the most intensively developed property. At the scale recorded (30 m²), the native pastures, roadsides and stock routes sampled in the subtropics appear to be among the most species‐rich grasslands ever reported, both nationally and globally. Native species richness was approximately 50% higher than the temperate survey figures across all the comparable habitats. While there are no clear reasons for this result, potential explanations are proposed.     

Sampling soil wood charcoals at a high spatial resolution: a new methodology to investigate the origin of grassland plant communities

Questions: (i) Can sampling of soil wood charcoals at high spatial resolution produce new evidence concerning the presence of chalk grassland before or during the Neolithic, Bronze and Iron Ages? (ii) Are there correlations between vegetation history and archeological data during these periods at this particular site? Location: The chalk hillsides of Saint‐Adrien in the lower Seine Valley, Upper Normandy, northwest France. Methods: The study was carried out at a high spatial resolution in chalk grassland using soil wood charcoal analysis, in which charcoals found in the soil were identified and dated in an area of several hundred square meters. Results: Late‐successional woody species (Fagus sylvatica, Quercus sp.) were still present in the study site in an area inconsistent with the existence of large chalk grassland herbaceous plant communities (several hectares) in the Neolithic (6500–3800 BP) and Bronze Age (3800–2700 BP). Conclusions: The presence of late‐successional woody species on the studied hillside suggests that fires in the Neolithic were linked to forest clearance for pastoral activities, as already demonstrated for similar ecosystems in eastern France and Germany. Nevertheless, our methodology clearly demonstrates that palaecological studies need to take into account the spatial organisation of plant communities as a complementary element to validate their potential existence in former times.     

Success criteria and adaptive management for a large-scale wetland restoration project

We are using a 20+ year photographic history of relatively undisturbed and formerly diked sites to predict the restoration trajectories and equilibrium size of a 4,050 ha salt marsh on Delaware Bay, New Jersey (USA). The project was initiated to offset the loss of finfishes from once-through cooling at a local power plant. We used a simple food chain model to estimate the required restoration size. This model assumed that annual macrophyte detritus production and benthic algal production resulted in production of finfishes, including certain species of local interest. Because the marsh surface and intertidal drainage system are used by many finfishes and are the focal points for exchange of detrital materials, the restoration planning focused on both vegetational and hydrogeomorphological parameters. Recolonization bySpartina spp. and other desirable taxa will be promoted by returning a natural hydroperiod and drainage configuration to two types of degraded salt marsh: diked salt hay (Spartina patens) farms and brackish marsh dominated byPhragmites australis. The criteria for success of the project address two questions: What is the bound of expectation for restoration success, and how long will it take to get there? Measurements to be made are macrophyte production, vegetation composition, benthic algal production, and drainage features including stream order, drainage density, channel length, bifurcation ratios and sinuosity. A method for combining these individual parameters into a single success index is also presented. Finally, we developed adaptive management thresholds and corrective measures to guide the restoration process.Corresponding editor: R.E. Turner     

Current status of the threatened amphibians and reptiles of Japan

This article compares amphibian and reptile components of the original and revised versions of the Red List of Japan, and analyzes geographic patterns of, and major threats to, species and subspecies now assigned to the threatened categories. The numbers of both amphibians and reptiles categorized as threatened in the Red List of Japan have increased greatly through its revision as a result of recent progress in the taxonomy of these groups in Japan, the introduction of new criteria for risk assessment, and unexpectedly rapid declines in the status of several taxa. Threatened taxa of amphibians and reptiles in the revised list tend to be concentrated in the Ryukyu Archipelago, where deforestation seems to be the major ultimate cause of declines. Reduction in the quality and quantity of inland water environments seems to be the major cause of declines in several endemic amphibians from the main islands of Japan. The importance of conservation was emphasized in the revised list by progress in taxonomy, by new insights and data on the estimation of temporal dynamics of population density or habitat size for threatened taxa, and by the impacts of and need to prevent further deforestation in the Ryukyus and of the ongoing destruction of inland water habitats on the main islands of Japan. Received: May 6, 1999 / Accepted: October 26, 1999     

中国木兰科植物爱威胁的状况及其保护措施

木兰科（Magnoliaceae)植物是原始的被子植物,中国是木兰科植物的起源中心,在地史上木兰科植物有过广泛分布,木兰科植物有重要经济作用。近年来,由于各地森林遭受强度破坏和碎化,许多种类的生存受到严重威胁。本文主要探讨中国木兰科植物的地理分布和区系性质,受威胁现状和保护措施,以及木兰科植物的开发利用等。     

Summer aridity rather than management shapes fitness‐related functional traits of the threatened mountain plant Arnica montana

Semi‐natural mountain grasslands are increasingly exposed to environmental stress under climate change. However, which are the environmental factors that limit plants in these grasslands? Also, is the present management effective against these changes? Fitness‐related functional traits may offer a way to detect changes in performance and provide new insights into their vulnerability to climate change. We investigated changes in performance and variability of functional traits of the mountain grassland target species Arnica montana along a climate gradient in Central German low mountain ranges. This gradient represents at its lower end climate conditions that are expected at its upper end under future climate change. We measured vegetative, generative, and physiological traits to account for multiple ways of plant responses to the environment. Using mixed effects and multivariate models, we evaluated changes in trait values among individuals as well as the variability of their populations in order to assess performance under changing summer aridity and different management regimes. Fitness‐related performance of most traits showed strongly positive associations with reduced summer aridity at higher elevations, while only specific leaf area and leaf dry matter content showed no association. This suggests a higher performance level at less arid montane sites and that the physiological traits are less sensitive to this climate change factor. The coefficient of variation of almost all traits declined steadily with decreasing site aridity. We suggest that this reduced variability indicates a lower environmental stress level for A. montana toward its environmental optimum at montane elevations, especially because the trait performance increased simultaneously. Surprisingly, management factors and habitat characteristics had only low influence on both trait performance and variability. In summary, summer aridity had a stronger effect to shape the trait performance and variability of A. montana under increased environmental stress than management and other habitat characteristics.     

Insects affect relationships between plant species richness and ecosystem processes

This study examined whether insects can alter relationships between plant species diversity and ecosystem function in grassland communities, by (i) altering biomass across a plant diversity gradient, (ii) altering relative abundances of plant species, or (iii) altering ecosystem function directly. We measured herbivore damage on seminatural grassland plots planted with 1, 2, 4, 8, or 12 plant species, and compared plant biomass in a subset of these plots with replicates in which insect levels were reduced. Plant biomass and herbivore damage increased with species richness. Reducing insect populations resulted in greater evenness of relative plant species abundances and revealed a strong positive relationship between plant species richness and above-ground biomass. Reducing insects also changed the relationship between plant species richness and decomposition. Plant species mixtures and their relative abundances partially explained plant biomass results, but not decomposition results. These results suggest that insects can alter relationships between plant diversity and ecosystem processes through all three mechanisms.     

Experimental slab salvage and reinstatement after pipeline construction in a threatened grassland community

The protection and management of grasslands is a priority to conserve biodiversity, particularly in fragmented landscapes subject to human‐induced disturbance. We examined the success of salvage and reinstatement of multiple 90 m² slabs of modified temperate grassland in a pipeline construction corridor in south‐eastern Australia and compared it with a reinstated topsoil treatment (i.e. standard pipeline reinstatement practice) and an undisturbed control. Thirty‐six plots (each 9 × 10 m) representing the three treatments were monitored across six locations, pre‐ and postconstruction every 3 months for 2 years. We sampled 18 vegetation/habitat variables to examine the effect of treatments over time. Introduced grass cover was consistently higher than native grasses for both treatments, and the cover of introduced grasses increased over time in both treatments. Conversely, control plots had considerably higher native grass cover than the slab and reinstated topsoil treatments. Native species richness was not negatively affected by the slab reinstatement process. Our results suggest that in this instance, slab replacement was an ineffective way to reinstate native grasslands, as it appeared to confer minimal benefit when compared to the standard practice of reinstating topsoil. This was most likely due to the high degree of disturbance to slabs during the reinstatement process.     

Geochemical parameters of sedimentation and the distribution of Silurian brachiopod communities in Lithuania

Silurian rocks from borehole cores in the Baltic Basic were analyzed for Si, Al, Ti, Fe, Ca and Mg oxide content and chemical data were related to sedimentary environment, lithology and brachiopod community distribution. Evaluation of these relationships enables precise positioning of closely related communities within Boucot's (1975) brachiopod Benthic Assemblages. Preliminary attempts are made to evaluate climatic change based on Al/Ti oxide ratios.     

Impacts of tourism on threatened plant taxa and communities in Australia

Summary Many Australian plant species and communities appear to be threatened by tourism. A review of management plans, recovery plans and a survey of experts found that tourism was considered to be a direct or indirect threatening process for 72 plant taxa. This is one fifth of threatened species for which threats have been identified. In addition, many more species are listed as threatened by weeds, trampling, pathogens, clearing and collecting. These are often indirect impacts of tourism, particularly in conservation reserves where tourism is the only commercial activity permitted. Tourism was also considered to be a threatening process for several plant communities. A lack of recognition of the importance of direct and indirect impacts of tourism may potentially hinder the conservation of plant species and communities both in Australia and overseas. It may also limit the effectiveness of sustainable tourism policies, particularly in conservation reserves.     

Patch distribution and dispersal limitation of four plant species in Swedish semi-natural grasslands

This study examined whether the patch distribution of four plant species Agrimonia eupatoria, Carlina vulgaris, Hypochoeris maculata and Plantago media were affected by dispersal limitation. Analysis of the patch size/isolation relationship was combined with a seed sowing experiment examining the recruitment of the species. Patch size was negatively correlated to isolation in Carlina, Hypochoeris and indicating that dispersal processes might affect the distribution pattern. Patch size of Agrimonia was not correlated, or in one case positively correlated, to isolation. Agrimonia was also the only species among the four where the recruitment not was affected by disturbance treatment or locality. The recruitment of Carlina, Hypochoeris and Plantago was higher in disturbed plots compared to undisturbed, and the latter two species were also affected by locality. This suggests that Agrimonia is less sensitive to isolation (and the ongoing fragmentation of the landscape) compared to the other three species, probably due to better dispersal and recruitment ability. We conclude in a discussion how different management strategies could serve to maintain viable populations of these species. This revised version was published online in August 2006 with corrections to the Cover Date.     

基于能值的陆域受威胁和濒危物种价值估算——以福建省厦门市为例

开展受威胁和濒危物种价值评估是生物多样性研究的关键问题之一。当前受威胁和濒危物种研究正处于濒危等级界定和保护优先性确定阶段,存在不同保护等级交叉管理、价值评估方法欠缺及重复性计算等多方面问题。利用IUCN濒危等级和中国特有种等级名录确定厦门市不同濒危等级物种数,在此基础上利用能值转换率和修正的中国能值/货币比率对厦门市陆域受威胁和濒危物种价值进行估算。结果显示,通过多途径整理纳入估算的厦门市陆域野生动植物物种数为1444种,其中受威胁和濒危物种数为318种;2015年厦门市物种能值价值约为3.53×10~(11)元,2010年约为3.08×10~(11)元,其中两期受威胁和濒危物种能值价值均占物种总价值的88.31%;中国特有种等级对价值贡献最大达73.25%,其次是IUCN濒危等级达23.24%。研究表明,能值评估法能够客观凸显受威胁和濒危物种价值,研究结果可为生物多样性及物种保育的管理决策提供技术支撑。     

复合污染尾矿废水中真菌群落多样性及其驱动机制

金属尾矿废水中含有重金属以及多种有机和无机污染物, 然而在该极端生境中仍然有大量微生物存在。为了揭示碱性尾矿废水中真菌群落的组成模式和多样性格局及其维持机制, 本文利用ITS1区rDNA基因扩增子测序和qPCR技术对山西中条山十八河尾矿库废水中5个不同采样点真菌群落的组成、丰度和分布格局进行了研究。通过主坐标分析(PCoA)比较不同采样点间群落结构的差异性; 通过冗余分析(RDA)探讨了水体理化因子对真菌群落结构的影响; 通过零模型分析了影响群落结构的主要因素; 通过网络图分析了真菌类群之间的种间相互作用。结果表明, 布勒掷孢酵母属(Bullera)、Schizangiella、支顶孢属(Acremonium)和亚罗酵母属(Yarrowia)是主要的优势属, 真菌群落在不同采样地点从门到属水平的相对丰度均有明显变化。真菌群落丰度沿水流方向逐渐增加且与有机碳(TOC)浓度呈显著正相关。真菌群落的α-多样性与pH、重金属(As和Cu)、无机碳(IC)和铵态氮(NH₄⁺)浓度显著相关。真菌群落的空间结构在不同采样点具有明显差异, 这种差异性与理化因子没有显著关系; 不同采样点真菌群落的零偏差值均大于零, 且不同物种之间存在复杂的种间相互作用。以上结果说明, 在尾矿废水中环境因子只对真菌群落的α-多样性有显著影响, 而群落的β-多样性主要受种间相互作用关系的影响, 表明在碱性铜尾矿废水中存在比较复杂的真菌群落动态模式。     

Managing for change: wetland transitions under sea‐level rise and outcomes for threatened species

Aim Global sea‐level rise (SLR) could be as much as 1.8 metres by 2100, which will impact coastal wetland communities and threatened species. We evaluated the likely outcomes of SLR for wetland communities using a process‐based simulation model and coupled this with a metapopulation model for a threatened native rodent (Xeromys myoides). Furthermore, we tested the amplified impacts of SLR, urban growth and introduced predators on X. myoides persistence. Location South‐east Queensland, Australia. Methods We adapted the Sea Level Affects Marshes Model to subtropical Australia. We used LiDAR elevation data, field data to parameterize surface accretion and shallow subsidence, and local knowledge to configure wetland transitions. SLR was simulated based on the IPCC B1 and A1FI scenarios, as well as the maximal limit of 1.8 m by 2100. Further, we coupled our demographic model to projected shifts in wetland habitat, and estimates of future wetland loss to urban expansion and feral cat (Felis catus) predation. Results Our models project a general decline in wetland communities under SLR, with a noted exception of mangroves. Under the A1FI scenario, SLR allows mangroves to migrate inland, with urban development acting as an obstruction in some areas. Mangrove expansion provides an unexpected benefit for dependent X. myoides populations, although the inclusion of predation and habitat loss due to urban development still suggests extirpation in c. 50 years. Main conclusions Through this case study, we illustrate the usefulness of process‐based SLR models in understanding outcomes for wetland communities and dependent species. Our models will underscore decision‐making in a dynamic system, with global applications for urban planning, conservation prioritization and wildlife management.