土壤资源信息共享的WEBGIS实现

如何使用和共享现有的土壤科学数据一直是一个重要问题。为提高土壤资源信息的共享和利用效率,文章阐述了在因特网环境下实现土壤资源信息发布的体系结构及关键技术,讨论了其实现方法。采用WebGIS技术,以ARCIMS为平台,以广东省土壤系列图件为基础,构建土壤信息共享系统,通过WEBGIS进行土壤资源信息的发布和共享,并介绍了系统的主要功能。     

中国土壤学会第十一届全国会员代表大会暨第七届海峡两岸土壤肥料学术交流研讨会通知

土壤资源是人类的生存平台和粮食生产基地,其重要性不言而喻。我国人均耕地、林地、牧草地数量均远远低于世界人均数量,并且整体质量偏低、退化沙化现象较为严重,加之近年城市化的扩张,非农占用耕地大量增加,土壤资源与社会发展之间的矛盾日益突出。为加强我国土壤资源领域的交流,推动对土壤科学与社会可持续发展的学术研究,     

GIS系统在城市大气污染控制与能源结构优化中的应用

通过对GIS系统与能源结构优化模型和大气污染物控制模型的集成研究，开发出具有较强应用价值的GIS优化控制系统。该系统具有数据采集系统、分析系统和决策系统，可用于城市能源结构优化研究，大气污染控制研究，并可促进城市的可持续性发展。     

土壤信息系统数据采集中坐标变换模型及应用

要建立土壤信息系统，数据是其根本。多年来有大量以纸类为媒介的土壤空间数据地图，通过数字化能很容易地将它们转化成土壤信息系统的空间数据。文章就土壤资源建库的地图数字化过程中，仿射变换和相似变换模型在数字化结果坐标校正、地图配准时的应用进行探讨；提出了在GIS软件环境下，选择适当的变换模型对数字化结果实现坐标变换的方法。     

基于GIS的广东省土壤资源信息系统构建研究

研究应用地理信息系统构建广东省土壤资源信息系统的总体模式,建立了土壤资源信息系统的基本功能构成;探索了土壤资源空间信息与文献资料的Internet网络化这一土壤研究新领域,并实现了土壤资源空间信息Internet网络化.     

计算机技术在环境保护信息系统中的应用

结合国内外实际环境系统信息的调研成果和客户需求分析以及环境领域自身的科学规律，论述了7种计算机技术(3S技术、在线监测技术、模型技术、多媒体和可视化技术、人工智能技术、仿真技术和互联网技术)在环境保护信息系统中的应用前景。具有辅助决策功能的综合环境保护信息系统的主要功能包括：(1)信息获取与显示；(2)信息查询；(3)环境信息的分析；(4)环境信息的表达。用计算机技术实现环境保护信息系统的主要功能关键问题在于：(1)系统的有效管理；(2)3S技术与环境模型的融合和集成；(3)专家系统(ES)与3S技术的融合；(4)仿真系统与3S技术的融合：(5)在线监测技术与3S技术的融合；(6)环境系统与Intranet/Internet的融合。     

从施肥和耕作制看耕地的可持续利用

加强农业基础地位，实现农业的可持续发展，是关系到国计民生的大事。耕地是农业的基础，耕地的可持续利用是农业可持续发展的关键。近年来，有些地方盲目追求经济效益，实行连年种植一种经济作物，重化肥，轻土杂肥及环境污染等因素，造成土壤酸化，肥力下降，土壤资源遭受破坏。如何保护好耕地，防止土壤退化，实现耕地的可持续利用，是农业生产中急待解决的问题。东莞市从1984年冬开始，对全市所有耕地进行分类，选取8个有代表性的土壤地力监测点，进行地力跟踪，至今已有15年。经过15年的监测，发现合理的施肥和耕作制，有利于保护土壤…     

中国土壤资源特点与粮食安全问题

土壤资源是粮食生产的基础，也是粮食安全的核心。文章在研究我国土壤资源特点的基础上，系统阐述我国粮食安全正面临着耕地减少、粮食减产的挑战。提出要解决我国耕地土壤和粮食安全问题，必须实施“藏粮于土”的行动计划，全面提高我国土壤资源的综合生产能力，其主要内容是：稳定耕地面积和粮食播种面积，实施基本农田严格保护机制；开发土壤潜力，提高粮食综合生产能力；加强生态环境建设，建立有弹性有应变能力的种植制度；防治土壤污染，保障粮食安全；适度开荒复垦，充分利用非耕地资源。     

土壤学与广东持续农业的发展

持续农业是关于建立资源、生态、地力、经济效益等各个方面均可持续发展的农业制度的一种思想．水土流失、土地退化、耕地锐减、环境污染，制约着广东农业的持续发展．土壤学应围绕持续农业开展研究工作．目前应加强土壤生态环境的保护，防治土地退化，提高土壤肥力，保证耕地生产力的持续发展．应开展土壤资源的动态变化研究，为合理开发和利用土壤资源提供科学依据．     

基于遥感与GIS的土壤侵蚀强度快速估测方法

针对土壤侵蚀问题,提出了一种基于遥感数据、气象数据、土壤数据的区域土壤侵蚀快速估测方法。首先,通过对土壤侵蚀问题形成原因和影响因素的分析,确定土壤侵蚀敏感性因子;其次,利用遥感(RS)、GIS技术提取土壤侵蚀敏感性因子信息;然后,在GIS系统支持下,运用主成分分析方法,进行土壤侵蚀强度分级;以北京密云水库周边区域为例,进行了土壤侵蚀估测方法的应用,并对该区域的土壤侵蚀空间特征进行分析。研究结果表明:(1)区域土壤侵蚀快速估测方法与实际情况有较好的一致性;(2)密云水库周边地区土壤侵蚀以微度和轻度侵蚀为主,所占面积比例为67.51%,中度以上侵蚀仅占面积的1.46%;(3)土壤侵蚀受坡度、地貌影响明显,中度侵蚀主要发生在低山、丘陵区以耕地为主的土地利用上以及坡度在大于25°的阳坡地带。     

Rapid,recurring, structured survey versus bioblitz for generating biodiversity data and analysis with a multispecies abundance model

A bioblitz inexpensively and quickly generates biodiversity data, but bioblitzes are often conducted with haphazard, unreplicated sampling. Results tend to be taxonomically, geographically, or temporally biased, lack metadata, and consist of lists of observed taxa that do not enable further analyses or correction for imperfect detection. A rapid, recurring, structured survey (RRSS) uses a structured sampling design and temporal and spatial replication to survey randomly selected sites on a conservation property. We participated in a loosely structured bioblitz and a subsequent RRSS at Big Canoe Creek Nature Preserve in Springville (St. Clair County), Alabama (USA) to compare observed richness derived from the 2 survey approaches. The RRSS data structure enabled us to fit models that accounted for imperfect detection to estimate abundances, occupancy probabilities, and habitat associations. The loosely structured bioblitz data could not be used in such models. We present a new integrated multispecies abundance model that we applied to avian RRSS data. Our model extension enables estimation for the community, employs data augmentation to estimate the number of undetected species, and incorporates covariates. The RRSS generated a more comprehensive and less biased list of observed taxonomic richness than the loosely structured bioblitz (e.g., 73 vs. 45 bird species and 104 vs. 63 insect families from the RRSS vs. loosely structured bioblitz, respectively). Models fit to the RRSS data identified seasonal patterns in avian community composition and allowed for estimation of habitat–occupancy relationships for insect taxa. The RRSS protocol has potential for broad transferability as a standardized, quick, and inexpensive way to inventory biodiversity and estimate ecological parameters while providing an outreach opportunity.     

Compliance with and ecosystem function of biodiversity offsets in North American and European freshwaters

Land-use change via human development is a major driver of biodiversity loss. To reduce these impacts, billions of dollars are spent on biodiversity offsets. However, studies evaluating offset project effectiveness that examine components such as the overall compliance and function of projects remain rare. We reviewed 577 offsetting projects in freshwater ecosystems that included the metrics project size, type of aquatic system (e.g., wetland and creek), offsetting measure (e.g., enhancement, restoration, and creation), and an assessment of the projects’ compliance and functional success. Project information was obtained from scientific and government databases and gray literature. Despite considerable investment in offsetting projects, crucial problems persisted. Although compliance and function were related to each other, a high level of compliance did not guarantee a high degree of function. However, large projects relative to area had better function than small projects. Function improved when projects targeted productivity or specific ecosystem features and when multiple complementary management targets were in place. Restorative measures were more likely to achieve targets than creating entirely new ecosystems. Altogether the relationships we found highlight specific ecological processes that may help improve offsetting outcomes.     

A palaeo-hydrogeological model for arsenic contamination in southern and south-east Asia

An argument is presented in which areas of natural arsenic contamination of modern groundwaters throughout Asia have a common origin. Arsenic originally accumulated in oceanic ferro-manganoan sediments of the eastern Palaeo-Tethys. This was further concentrated through oceanic crustal extinction in what later became the south-east Chinese accreted mineralised terrain. Proto-Himalayan uplift of this area created the palaeo-drainage systems of the Ganges – Brahmaputra, Irrawaddy, Mekong, and Red Rivers, with consequent headwater erosion of arsenic-rich sediments. Their downstream deposition as immature and easily redistributed Neogene sandstones, silts, and iron-rich clays has created secondary and tertiary reservoirs of adsorbed and authigenic arsenic, from which the current arsenic-rich groundwaters have evolved. Considering river basins within the above palaeo-hydrogeological framework provides a basis for assessing the risk of arsenic in groundwater basins of south and south-eastern Asia.     

Cost‐effective conservation of an endangered frog under uncertainty

How should managers choose among conservation options when resources are scarce and there is uncertainty regarding the effectiveness of actions? Well‐developed tools exist for prioritizing areas for one‐time and binary actions (e.g., protect vs. not protect), but methods for prioritizing incremental or ongoing actions (such as habitat creation and maintenance) remain uncommon. We devised an approach that combines metapopulation viability and cost‐effectiveness analyses to select among alternative conservation actions while accounting for uncertainty. In our study, cost‐effectiveness is the ratio between the benefit of an action and its economic cost, where benefit is the change in metapopulation viability. We applied the approach to the case of the endangered growling grass frog (Litoria raniformis), which is threatened by urban development. We extended a Bayesian model to predict metapopulation viability under 9 urbanization and management scenarios and incorporated the full probability distribution of possible outcomes for each scenario into the cost‐effectiveness analysis. This allowed us to discern between cost‐effective alternatives that were robust to uncertainty and those with a relatively high risk of failure. We found a relatively high risk of extinction following urbanization if the only action was reservation of core habitat; habitat creation actions performed better than enhancement actions; and cost‐effectiveness ranking changed depending on the consideration of uncertainty. Our results suggest that creation and maintenance of wetlands dedicated to L. raniformis is the only cost‐effective action likely to result in a sufficiently low risk of extinction. To our knowledge we are the first study to use Bayesian metapopulation viability analysis to explicitly incorporate parametric and demographic uncertainty into a cost‐effective evaluation of conservation actions. The approach offers guidance to decision makers aiming to achieve cost‐effective conservation under uncertainty.     

Parasitic wasps orient to green leaf volatiles

Summary Undamaged plants emit low levels of green leaf volatiles (GLVs), while caterpillar-damaged and artificially damaged plants emit relatively higher levels of certain GLVs. Female braconid parasitoids,Microplitis croceipes, oriented to both damaged plants and to individual GLVs in no-choice tests in a wind tunnel, but seldom oriented to undamaged plants. Female ichneumonid parasitoids,Netelia heroica, also oriented to individual GLVs in a wind tunnel. Males of both wasp species failed to orient to the GLVs. These data show that leaf-feeding caterpillars can cause the release of GLVs, and that parasitic wasps can respond to these odors by flying upwind (chemoanemotactic response), which brings the wasps to their caterpillar hosts. This supports the hypothesis that plants communicate with members of the third trophic level,i.e., plants under herbivore attack emit chemical signals that guide natural enemies of herbivores to sites of plant damage. In this interaction, the GLVs serve as tritrophic plant-to-parasitoid synomones. That parasitoids from two different wasp families oriented to GLVs suggests that the response may be widespread among the Hymenoptera.Mention of a commercial or proprietary product does not constitute an endorsement by the U.S. Department of Agriculture     

Potential for Electropositive Metal to Reduce the Interactions of Atlantic Sturgeon with Fishing Gear

Atlantic sturgeon (Acipenser oxyrhynchus) populations have been declared either endangered or threatened under the U.S. Endangered Species Act. Effective measures to repel sturgeon from fishing gear would be beneficial to both fish and fishers because they could reduce both fishery‐associated mortality and the need for seasonal and area closures of specific fisheries. Some chondrostean fishes (e.g., sturgeons and paddlefishes) can detect weak electric field gradients (possibly as low as 5 Μv/cm) due to arrays of electroreceptors (ampullae of Lorenzini) on their snout and gill covers. Weak electric fields, such as those produced by electropositive metals (typically mixtures of the lanthanide elements), could therefore potentially be used as a deterrent. To test this idea, we recorded the behavioral responses of juvenile Atlantic sturgeon (31–43 cm fork length) to electropositive metal (primarily a mixture of the lanthanide elements neodymium and praseodymium) both in the presence and absence of food stimuli. Trials were conducted in an approximately 2.5 m diameter × 0.3 m deep tank, and fish behaviors were recorded with an overhead digital video camera. Video records were subsequently digitized (x, y coordinate system), the distance between the fish and the electropositive metal calculated, and data summarized by compiling frequency distributions with 5‐cm bins. Juvenile sturgeon showed clear avoidance of electropositive metal but only when food was present. On the basis of our results, we conclude that the electropositive metals, or other sources of weak electric fields, may eventually be used to reduce the interactions of Atlantic sturgeon with fishing gear, but further investigation is needed. El Potencial del Metal Electropositivo para Reducir las Interacciones del Esturión Atlántico con Instrumentos de Pesca Bouyoucos, Bushnell & Brill 13–003     

The role of time and species identities in spatial patterns of species richness and conservation

Many conservation actions are justified on the basis of managing biodiversity. Biodiversity, in terms of species richness, is largely the product of rare species. This is problematic because the intensity of sampling needed to characterize communities and patterns of rarity or to justify the use of surrogates has biased sampling in favor of space over time. However, environmental fluctuations interacting with community dynamics lead to temporal variations in where and when species occur, potentially affecting conservation planning by generating uncertainty about results of species distribution modeling (including range determinations), selection of surrogates for biodiversity, and the proportion of biodiversity composed of rare species. To have confidence in the evidence base for conservation actions, one must consider whether temporal replication is necessary to produce broad inferences. Using approximately 20 years of macrofaunal data from tidal flats in 2 harbors, we explored variation in the identity of rare, common, restricted range, and widespread species over time and space. Over time, rare taxa were more likely to increase in abundance or occurrence than to remain rare or disappear and to exhibit temporal patterns in their occurrence. Space–time congruency in ranges (i.e., spatially widespread taxa were also temporally widespread) was observed only where samples were collected across an environmental gradient. Fifteen percent of the taxa in both harbors changed over time from having spatially restricted ranges to having widespread ranges. Our findings suggest that rare species can provide stability against environmental change, because the majority of species were not random transients, but that selection of biodiversity surrogates requires temporal validation. Rarity needs to be considered both spatially and temporally, as species that occur randomly over time are likely to play a different role in ecosystem functioning than those exhibiting temporal structure (e.g., seasonality). Moreover, temporal structure offers the opportunity to place management and conservation activities within windows of maximum opportunity.     

Main nutrient compounds in food bodies of Mexican <Emphasis Type="Italic">Acacia</Emphasis> ant-plants

Summary. Myrmecophytic plants use obligate ant mutualists as a constitutive indirect defence mechanism. These plants often produce cellular food bodies (FBs) to nourish their resident ants. Lipids, proteins, and even highly specialised compounds such as glycogen have been reported from FBs, but detailed chemical analyses of FB composition have so far been presented only for Southeast Asian Macaranga and Central American Piper myrmecophytes. Here we report the chemical composition of FBs of five myrmecophytic Acacia (Fabaceae) species from Mexico using HPLC (carbohydrates and proteins) and GC-MS (lipids). Feeding experiments revealed no hints on any use of external food sources by the inhabiting Pseudomyrmex ants. These ants obviously rely completely on FBs and extrafloral nectar provided by their hosts. The total content of nutrients in Acacia FBs was 15-25% of FB dry mass, being much lower than in Macaranga or Piper FBs. Proteins were dominating (8-14 % dm) in Acacia FBs and thus were present in higher amounts than in Macaranga FBs, yet in lower amounts than in Piper. Lipids contributed 1-9 % of dry mass, showing a lower proportion than in FBs of Macaranga or Piper. Carbohydrates made up 3-11 % dm, reaching in most Acacia species the same range as observed in Macaranga and in Piper FBs. Water content was 18-24 % of FB fresh mass, and structural tissue obviously made up a much higher proportion in Acacia FBs than in Macaranga or Piper FBs. Both characters might represent an adaptation to producing FBs unprotected at the leaf tips under dry conditions. Acacia FBs contain all amino acids and all fatty acids that are considered essential for insects, and their contents of lipids and proteins are higher than in the leaves from which they are ontogenetically derived. This indicates a putatively adaptive enrichment of nutritionally valuable compounds in structures functioning as ant-food.     

Examining the uncertain origin and management role of martens on Prince of Wales Island,Alaska

Conservation biologists are generally united in efforts to curtail the spread of non‐native species globally. However, the colonization history of a species is not always certain, and whether a species is considered non‐native or native depends on the conservation benchmark. Such ambiguities have led to inconsistent management. Within the Tongass National Forest of Alaska, the status of American marten (Martes americana) on the largest, most biologically diverse and deforested island, Prince of Wales (POW), is unclear. Ten martens were released to POW in the early 1930s, and it was generally believed to be the founding event, although this has been questioned. The uncertainty surrounding when and how martens colonized POW complicates management, especially because martens were selected as a design species for the Tongass. To explore the history of martens of POW we reviewed other plausible routes of colonization; genetically and isotopically analyzed putative marten fossils deposited in the late Pleistocene and early Holocene to verify marten occupancy of POW; and used contemporary genetic data from martens on POW and the mainland in coalescent simulations to identify the probable source of the present‐day marten population on POW. We found evidence for multiple routes of colonization by forest‐associated mammals beginning in the Holocene, which were likely used by American martens to naturally colonize POW. Although we cannot rule out human‐assisted movement of martens by Alaskan Natives or fur trappers, we suggest that martens be managed for persistence on POW. More generally, our findings illustrate the difficulty of labeling species as non‐native or native, even when genetic and paleo‐ecological data are available, and support the notion that community resilience or species invasiveness should be prioritized when making management decisions rather than more subjective and less certain conservation benchmarks.