Sensitivity of conservation planning to different approaches to using predicted species distribution data

The main role of conservation planning is to design reserve networks to protect biodiversity in situ. Research within the field of conservation planning has focused on the development of theories and tools to design reserve networks that protect biodiversity in an efficient and representative manner. Whilst much progress has been made in this regard, there has been limited assessment of the sensitivity of conservation planning outcomes to uncertainty associated with the datasets used for conservation planning. Predicted species distribution data are commonly used for conservation planning because the alternatives (e.g. survey data) are incomplete or biased spatially. However, there may be considerable uncertainty associated with the use of predicted species distribution data, particularly given the variety of approaches available to generate a dataset from such predictions for use in conservation planning. These approaches range from using the probabilistic data directly to using a threshold identified a priori or a posteriori to convert the probabilistic data to presence/absence data. We assess the sensitivity of conservation planning outcomes to different uses of predicted species distribution data. The resulting reserve networks differed, and had different expected species representation. The choice of approach will depend on how much risk a conservation planner is willing to tolerate and how much efficiency can be sacrificed.     

The pedogenic effects of different species and vegetation types and the implications of succession

The paper surveys the changes in pH, organic matter type and degree of podzolization of poorly buffered, freely drained, siliceous soils in Britain caused by the predominant plant species and semi-natural vegetation types. Changes in vegetation with succession, especially with varying grazing and burning regimes, and also with stand regeneration, are outlined, and their implications for soil change noted. Many cyclic changes in species a bundance seem to occur naturally which cause an alternation of contrasting trends in soil acidity and podzolization, thus tending to maintain a long term equilibrium.     

杭州西湖山区不同植被类型植物多样性比较研究

对杭州西湖山区常绿阔叶林(EBLF)、落叶阔叶林(DBLF)和针叶阔叶混交林(NBLMF)3种植被类型的群落多样性指数进行比较.结果表明:落叶阔叶林具有较高的物种多样性,针叶阔叶混交林物种多样性较低;在垂直结构物种多样性比较中,常绿阔叶林和针叶阔叶混交林为灌木层>乔木层>草本层,而落叶阔叶林为灌木层>草本层>乔木层;枯立木在常绿阔叶林中主要存在于6～10 m高度,而落叶阔叶林和针叶阔叶混交林中主要存在于3～4 m高度.与其他各地植被类型相比,常绿阔叶林和落叶阔叶林群落物种多样性随纬度增加而减少.     

Phenol compounds in solutions of soils of different types in the central forest state biosphere reserve

The interannual, seasonal, and daily dynamics of the contents of phenol compounds in the soil solution of a peat-podzolic-gleyic soil in the southern taiga are considered. The concentrations of phenol compounds in the studied soil remain relatively stable. In the solutions obtained from different soil types, the main limiting factor is the degree of hydromorphism, which manifests itself via the biological factor—the intensity of the microorganisms activity and the composition and quality of the forest litters.     

The representation and functional composition of carabid and staphylinid beetles in different field boundary types at a farm-scale

At the farm-scale, hedgerow, degraded hedgerow and fence field boundary types were sampled for overwintering carabid and staphylinid beetles. Distinct beetle assemblages were evident and the structural and botanical characteristics of the boundary types were good explanatory factors of the differences. Each field boundary type supported unique species not found elsewhere; nine species were contributed by hedgerows alone and six species each from degraded hedgerows and fences. Using a systematic complementary site selection method we determined that all field boundary types were of equal importance for full representation of carabid and staphylinid species at the farm-scale. Additionally, fence habitats supported generalist predators of crop pests in greatest densities, whilst degraded hedgerows were most valuable in providing refuge to species vulnerable to disturbance and habitat fragmentation. Contrary to expectation, woodland species were not more evident in hedgerows than either degraded boundaries or fence habitat. This study provides empirical evidence that some components of biodiversity and sustainable farming are best maintained by retaining habitat heterogeneity, including features currently considered of limited conservation value.     

基于特征选择和GA-BP神经网络的多源遥感农田土壤水分反演

土壤水分是影响水文、生态和气候等环境过程的重要参数,而微波遥感是农田地表土壤水分测量的重要手段之一.针对微波遥感反演农田地表土壤水分受植被覆盖影响较大的问题,该研究提出了一种基于特征选择和GA-BP神经网络(Genetic Algorithm-Back Propagation neural network)的多源遥感农...     

重庆市茶园蚂蚁物种多样性及空间分布格局

为筛选茶园害虫的蚂蚁类天敌,采用样地调查法研究了重庆主要产茶区(海拔371~1 068 m)茶园蚂蚁物种多样性特征与空间分布格局。在重庆主要产茶区茶园,设置3条垂直带,每条垂直带划分为低海拔(300~500 m)、中海拔(500~700 m)和高海拔(700 m以上)3个水平带,每个水平带设置3~4块样地,调查茶园的蚂蚁物种组成、群落多样性及空间分布特点。在物种多样性方面:共采集到蚁科昆虫4亚科,39种。各水平带物种丰富度为7~13种,Shannon-Wiener多样性指数0.55~1.25,Pielou均匀度指数0.08~0.16,Simpson优势度指数为0.26~0.65;各水平带蚂蚁群落多样性指数差异不显著,表明其多样性水平比较一致。群落相似性指数为0.22~0.48,多数处于中等不相似水平。在群落优势种方面:不同海拔茶园蚂蚁优势种数目1~3种,常见种最多达6种,最少仅1种;稀有种最多17种,最少5种;从重庆范围来看,重庆主要产茶区茶园蚂蚁群落共有7种优势种。在蚂蚁空间分布方面:有17种蚂蚁具有较宽的垂直空间分布,活动范围涵盖土壤、地表和树冠,有作为天敌昆虫资源的可能。仅有9种蚂蚁在不同水平带的茶园中均有分布。结合群落相似性与多样性分析结果,重庆茶园生境破碎,蚂蚁群落间物种交流受阻,不利于茶园生物多样性水平的稳定与提高。     

东北平原不同类型土壤有机质含量高光谱反演模型同质性研究

土壤有机质含量是反映土壤肥力的重要特征,利用高光谱技术对耕层土壤有机质（OM）含量进行定量化反演可为土壤信息化管理和精准施肥提供重要的依据。本文利用ASD FR 2500高光谱仪在室内条件下测定了风干土壤样品的可见近红外光谱,分析了东北平原不同土壤类型土壤光谱反射率曲线形状变化及土壤有机质含量的光谱反演模型,结果表明,根据土壤光谱反射率曲线变化特点可以初步将东北平原的几种土壤类型划分为三类,其主要区别在于460～1350nm范围内曲线斜率变化的差异。通过相关分析进一步确定了土壤有机质敏感波段为650～750nm,建立了不同土壤类型的有机质含量回归预测模型,并且对不同模型的回归系数和截距进行了方差同质性检验。结果显示,黑土和黑钙土、黑土和暗棕壤的模型没有显著差异,即可以分别构建同质性模型来简化有机质的预测,但是预测精度有所降低。     

Simulating the effects of different disturbance regimes on Cortaderia selloana invasion

Disturbances favour plant invasions because they provide a pulse of resources for seedling establishment and growth. However, little attention has been paid to the importance of the different disturbance regimes in the extent of invasion. In this paper we asked to what extent invasion depends on spatial and temporal patterns of disturbance. By using the spatially explicit model Fateland, we simulated how Cortaderia selloana, a large-wind dispersed perennial grass invading Mediterranean grasslands, responds to different medium-term (up to 55 years) disturbance regimes. The different scenarios combine disturbance frequency, extent of disturbance and temporal and spatial disturbance variability, and they roughly mimic real situations of habitat management and disturbances in cultural landscapes.The model predicted that the proportion of invaded area would increase with disturbance frequency. The extent of the disturbance overcame the importance of frequency. Aggregated disturbances randomly distributed in space had a more positive effect on invasion than scattered disturbances at repeatedly fixed locations. Whether the disturbances regularly occurred in time or were irregularly distributed did not influence the percentage of invaded landscape. Our simulation analysis unambiguously supports the hypothesis that disturbances are essential for the persistence and expansion of Cortaderia sellona. The high amount of seed rain from a few individuals (e.g., gardens) make this species very sensitive to landscape changes produced by different disturbance patterns (e.g., land abandonment, habitat management or rubbish dumping). Our results can contribute to redirect land management options.     

采用不同监测数据组合反演饱和均质石英砂水热运移参数

土壤及含水层的水力参数与热参数对于定量描述土壤水、地下水迁移规律及其伴生的热运移过程十分重要。为探讨不同监测数据类型组合对多孔介质水热参数估计的影响,该研究基于热示踪方法,开展了3种不同粒径条件下的饱和均质石英砂的热示踪试验,并结合HYDRU-2D模型对介质的饱和导水率、导热系数和纵向、横向热弥散度进行反演。参数估计时分别设置3种情景对介质水热参数进行估计：仅采用观测点温度（R1）、观测点温度+水流通量（R2）、观测点温度+水流通量+热量损失（R3）。并对R1情景设置3种不同参数反演组合,即同时对2组参数（饱和导水率和导热系数）、3组参数（饱和导水率、纵向和横向热弥散度）和4组参数（饱和导水率、导热系数、纵向和横向热弥散度）进行估计。研究结果表明：同时对介质饱和导水率、导热系数与热弥散度进行估计,有利于提高介质水热参数的估计精度;对导热系数的合理估计可减小R1情景中介质饱和导水率的估计误差。4组参数中饱和导水率是敏感性最高的参数,增加用于参数反演的水流运动和热量传递信息时,粗砂、中砂、细砂的累积流量相对误差分别减少了9.74、6.65和12.53个百分点,显著提高了介质饱和导水率的反演精度。饱和导水率的估计值随介质粒径增大而增大,而纵向热弥散度随粒径的变化则呈相反的变化规律,横向热弥散度估值基本不变。增加水流和热量传递信息还能显著提高中砂的导热系数反演精度,导热系数的估计值随着介质孔隙度增大而逐渐降低。研究可为基于不同数据类型的均质介质参数反演提供。     

Incorporating uncertainty about species’ potential distributions under climate change into the selection of conservation areas with a case study from the Arctic Coastal Plain of Alaska

This analysis presents a conservation planning framework for decisions under uncertainty and applies it to the Arctic Coastal Plain of Alaska. Uncertainty arises from variable distributional shifts of species’ ranges due to climate change. The planning framework consists of a two-stage optimization model that selects a nominal conservation area network in the first stage and evaluates its performance under the climate scenarios in the second stage. The model is applied to eleven at-risk species in Alaska including the threatened Spectacled Eider and Steller’s Eider sea ducks and the polar bear. The 109th United States Congress and 2008 federal budget proposed opening for oil and gas development the “1002 Area” of the Arctic National Wildlife Refuge, which intersects the Plain. This analysis finds that, if Arctic Alaska experiences 1.5 °C of warming by 2040 (as predicted by the Intergovernmental Panel on Climate Change’s A2 scenario), then potential habitat will decrease significantly for eight of these at-risk species, including the polar bear. This analysis also shows that there is synergism between oil and gas development and climate change. For instance, climate change accompanied by no development of the 1002 Area results in an increase of potential habitat for Steller’s Eider. However, if development accompanies climate change, then there is a 20% decrease in that area. Further, this analysis quantifies the tradeoff between development and maintenance of suitable habitat for at-risk species.     

Applying species distribution modelling for the conservation of the threatened saproxylic Stag Beetle (Lucanus cervus)

Despite its size and attractiveness, many Lucanus cervus sites remain undetected in NW Europe because of its short flight period and its nocturnal activity. Therefore, present-day designated conservation areas for L. cervus are probably insufficient for a sustainable conservation of the species. We applied eight species distribution modelling techniques (artificial neural networks, classification tree analysis, generalised additive models, generalised boosting models, generalised linear models, mixture discriminant analysis, multiple adaptive regression splines and random forests) to predict the distribution of L cervus in Belgium using 10 randomly generated calibration and evaluation sets. We used AUC, sensitivity (% correctly predicted presences in the evaluation set) and specificity (% correctly predicted absences in the evaluation set) and Kappa statistics to compare model performances. To avoid the incorporation of only marginally suitable woodland sites into the Natura 2000 network, we, conservatively, considered the species as being present only in grid cells where all 10 randomly generated model sets predicted the species as such. Model performance was, on average, good allowing to predict the potential distribution of L. cervus accurately. According to the predicted distribution using the more robust prevalence threshold, only 5731 ha (11% of the potentially suitable area) is protected under the Natura 2000 scheme in Belgium. Subsequently, we categorised the potentially suitable woodlands into three conservation priority categories based on their surface area and the already designated Natura 2000 area. Including the most suitable L. cervus woodlands previously not included in the Natura 2000 sites within such network would require protecting an area of 15,260 ha. Finally, we discuss the implications of using species distribution modelling for nature policy decisions in designating conservation networks.     

Biological soil crust and surface soil properties in different vegetation types of Horqin Sand Land,China

Physical and chemical properties (including coverage, thickness, hardness, moisture, particle size distribution, organic matter and nutrient contents etc.) of biological soil crust and 0–5.0 cm surface soil under the crust in three types of vegetation (semi-shrub Artemisia frigida, shrub Salix gordejevii and tree Populus simonii) were surveyed in 2005 and 2006 in Horqin Sand Land to understand the effects of different vegetation types on development of soil crust and surface soil properties under crust. The results showed that 1) no physical soil crust or biological soil crust (BSC) formed on mobile dunes without vegetation, though most ground surface in originally mobile dunes had been covered by BSC fifteen years after planted vegetation was established; 2) BSC development was best in shrub S. gordejevii sites, second in semi-shrub A. frigida sites, and weakest in tree P. simonii sites; 3) development of BSC was better in moss crust distributed mainly beneath or near plant canopies than in lichen crust distributed mainly between plant canopies in all three vegetation types; 4) surface soil properties 0–5.0 cm under BSC were improved significantly in all three vegetation types compared to those in mobile sand land. The magnitude of improvement was greater in S. gordejevii sites than in A. frigida and P. simonii sites, and greater in moss crust sites than lichen crust sites, but the magnitude of improvement decreased significantly with increasing surface soil depth; 5) based on the above-mentioned results, we suggest that S. gordejevii should be favored in future planting in Horqin Sand Land.     

重庆缙云山不同土地利用类型坡面产流对暴雨的响应

 为给三峡库区理水调洪型植被建设提供一定依据,在三峡库区重庆缙云山5种典型土地利用类型(混交林,阔叶林,楠竹林,灌木林及农地)建立坡面径流小区,从产流量、产流历时和产流过程来研究坡面产流对暴雨的响应。结果表明:在相同暴雨条件下,楠竹林地表径流深分别为混交林的2．7倍,为灌木林的3．7倍,为农地的4．5倍,为阔叶林的5．7倍。混交林和阔叶林的地下径流深比其他土地利用类型大一个数量级,为其他土地利用类型的 8-10倍。混交林坡面径流产流历时可延长248min,农地最少,仅为33 min。混交林地下产流历时可延长59 h;阔叶林居次,为50 h;农地产流历时缩短近11h。楠竹林坡面径流峰值约为混交林和灌木林的2倍,为阔叶林和农地的3倍。阔叶林和混交林地下径流峰值比楠竹林大2个数量级,比灌木林和农地大1个数量级。因此,重庆缙云山各土地利用类型中,混交林和阔叶林理水调洪功能最强,楠竹林理水调洪功能最差。     

Plant species affect the concentration of free sugars and free amino acids in different types of soil

Substantial amounts of low molecular weight organic compounds (LMWs) such as sugars and amino acids are transferred from plant roots into soil. These substances are released due to decomposition processes or leaching (exudation). Afterwards they can be metabolized by soil microorganisms into different compounds, or they can be partially re‐absorbed by the plants. The aim of this study was to clarify the influence of five wild plant species on the composition and pool sizes of LMWs extractable from three different soils. Four of the five species caused significant changes in soil LMW pools. In Chernozem, the sugar concentrations of soil with plants were up to 60 % higher than those of the bulk reference soil, and amino acids increased by as much as 207 %. The relative abundance of free amino acids in roots did not correlate with the relative abundance of amino acids in soil after six weeks of plant growth. The relative abundance of soil amino acids, that increased after plant growth, was strongly dependent on the type of soil and on the plant species present. We suggest that rather than rhizodeposition being dependent on soil type, it reflects differential microbial metabolization of amino acids in the respective soils.     

新疆山盆系统绿洲经济生物圈保护区模式探讨

研究指出新疆“三山夹两盆”山盆系统景观带谱决定其荒漠绿洲生物圈保护区的逆序组织模式 ,人工绿洲必须实施岛国经济外向发展模式 ,其发展途径为内部生态经济优化和发展外向型经济。并提出建立阿尔泰山、天山与昆仑山水源和生物多样性保护区 ,古尔班通古特沙漠和塔克拉玛干沙漠自然保护区以及退耕还牧、发展高效生态农业模式的建议。     

滨海重盐碱地人工栽植柽柳生长动态及生态效应

柽柳(Tamarix chinensis)是盐碱地土壤改良和植被构建的先锋物种,但仅靠柽柳的自然扩散难以在滨海重盐碱地形成灌木优势群落,对盐碱地的改良作用不明显,因此探索重盐碱地人工栽植柽柳的生态效应有重要意义。本研究以撂荒地为对照,对不同树龄的人工柽柳群落的个体生物量、碳储量动态、植物物种组成及其重要值和土壤特性进行分析,以评估重盐碱地栽植柽柳的生态效应。结果显示:3年生、5年生和7年生柽柳个体单株生物量逐渐增加,群落的植被碳密度分别为4.78 t(C)·hm 2、5.56 t(C)·hm 2和6.89 t(C)·hm 2,而对照撂荒地碳密度只有0.98 t(C)·hm 2;与对照地相比,栽植柽柳显著降低了土壤表层的含盐量,对照地土壤0～10 cm的平均盐分含量高达10.53 g·kg 1,而3年生、5年生和7年生0～10 cm土壤平均含盐量分别为3.35g·kg 1、1.86 g·kg 1和5.54 g·kg 1。栽植柽柳后土壤有机质和有效氮呈增高趋势,有效钾含量显著增加,7年生柽柳土壤0～5 cm和5～15 cm的有效钾含量分别比对照地高出65.59%和28.90%。随着柽柳树龄增加群落中草本植物的丰富度逐渐升高,对照地的草本物种只有8种,7年生柽柳群落达到15种;耐盐物种在群落中的重要值随着栽植的时间逐渐降低,盐地碱篷的重要值由34.8下降到0.7,以种子兼营养繁殖的植物如獐毛和苦荬菜的优势度逐渐增大。这证明,重盐碱地人工栽植柽柳可以快速构建灌木优势群落,固碳作用明显;同时栽植柽柳为生态系统提供了进展演替的动力,灌草结合的群落结构和稳定的群落环境不仅促进盐碱地土壤表层盐分含量的降低,也促进了物种多样性的增加和群落的进展演替,是提高滨海重盐碱地利用率的有效途径。     

The potential value of indicator groups in the selection of marine reserves

Efforts to systematically select networks of marine reserves to conserve biodiversity may be constrained by limited information on the distribution of biodiversity. A potential solution is the use of surrogates, such as indicator groups, that effectively represent other elements of biodiversity. The potential of macroalgae and molluscs to act as indicator groups for all species in the selection of intertidal marine reserves was tested for a sample of rocky shore locations in south-east Australia. Fifteen locations were surveyed between November 1999 and January 2000, and reserve selection for each of the potential indicator groups and for all species was undertaken using richness-based and rarity-based algorithms. The sets of locations chosen by both algorithms to conserve each of the indicator groups included around 95% of all species. There was 54% spatial correspondence of the sets of locations chosen for each of the indicator groups. Molluscs appeared to be a reliable indicator for areas of reservation ranging from 6.7 to 73.3% of the locations surveyed, including a similar percentage of all species as the locations selected for all species. Unlike macroalgae, locations chosen for molluscs included significantly more species than a set of locations chosen at random, and more species than the set of locations chosen for randomly selected subsets of species of the same richness as molluscs. There is significant scope for further research into the value of indicator groups in reserve selection in marine systems.     

Toxic potential of different types of sewage sludge as fertiliser in agriculture: ecotoxicological effects on aquatic,sediment and soil indicator species

Purpose

Treated and processed sewage sludges (biosolids) generated during the treatment of wastewater usually contain substantial concentrations of nutrients, especially phosphorus, which is essential for plant growth. Sewage sludge therefore can be used as an alternative fertiliser in agriculture. But since sewage sludge could also contain pollutants, analysis and ecotoxicological tests on affected soil and stream water organisms are necessary in order to guarantee its harmless use.

Materials and methods

Three test species were chosen to cover the environmental compartments, water, sediment and soil. The following test species and parameters were applied to evaluate the acute effects of three sewage sludge samples: Lemna minor (growth inhibition, discolouration and colony breakup), Gammarus fossarum (mortality, behaviour) and Eisenia fetida (avoidance behaviour). Chemical assessment included nutrients, organic pollutants and heavy metals.

Results and discussion

The assessment of a non-dewatered sludge (S1) sample resulted in an inhibition of growth of L. minor starting from 0.6 g total solid (TS)?l^?1 after 7 days (EC₅₀ 1.2 g TS l^?1). G. fossarum displayed significantly decreased movement activity at 0.5 and 1.2 g TS l^?1 sludge concentration during an exposure time of 2 days, leading to decreased survival after 4 days of exposure in 0.5 g TS l^?1 (LC₅₀ 0.5 g TS l^?1). After 2 days, E. fetida exhibited an increased avoidance behaviour of contaminated soil from 0.2 g TS kg^?1 sewage sludge (EC₅₀ 0.4 g TS kg^?1). The dewatered sludge samples (S2 and S3) had a lower toxic effect on the test organisms. G. fossarum was the most sensitive test species in the applied test setups. The realistic application amounts of the tested sewage sludge samples of approximately 6.0 g TS kg^?1 (maximum allowed application amount of sewage sludge) and approximately 3 g TS kg^?1 (maximum agronomical relevant application amount) in worst case studies are higher than the analysed EC₅₀/LC₅₀ values of S1 and of the LC₅₀ (G. fossarum) of S2 and S3.

Conclusions

All three tested sewage sludge samples have to be classified as toxic at high concentration levels under laboratory conditions. Realistic output quantities of S1 will negatively influence soil invertebrates and freshwater organisms (plants and crustacean), whereas the dewatered sludge samples will most likely not have any acute toxic effect on the test organisms in the field. Test with environmental samples should be conducted in order to support this hypothesis.

     

延边烟区不同土壤的根际土壤微生物生态效应研究

为揭示烤烟根际微生物数量及酶活性的变化规律,阐明烤烟-土壤-微生物之间的协同作用机理,在延边烟区采集不同土壤类型的烤烟根际土壤,研究了烤烟根际土壤微生物生态效应.结果表明:不同土壤条件下烤烟各时期根际微生物区系和微生物生理菌群数量存在着较大的差异,其中暗棕壤黏土和暗棕壤黑砂土比白浆土更适合细菌和解钾菌的生长,白浆土真菌数的变化幅度较大可能是引起烟叶质量变差的原因之一,暗棕壤黏土和暗棕壤黑砂土在烤烟生育期内放线菌数量的变化较大,明显大于白浆土;自生固氮菌在移栽后 60 天前数量均较低,60 天后急剧升高,100 天时暗棕壤黏土和暗棕壤黑砂土自生固氮菌数量显著高于白浆土;氨化菌生长的最适宜期出现的早晚顺序为:暗棕壤黏土＞暗棕壤黑砂土＞白浆土;生育期内根际土壤解磷菌数变化较大,暗棕壤黏土烟株在旺盛生长时期的解磷菌数显著高于其他 2 种类型土壤.过氧化氢酶活性的变化规律很大程度上受土壤类型的影响,而转化酶和多酚氧化酶变化受土壤类型影响较小,但两者的大小受土壤类型的影响.