Taxonomist survey biases and the unveiling of biodiversity patterns

Basic and applied studies based on biodiversity data need accurate information on the distribution of species. However, several studies clearly show that this information is frequently biased, mainly as a consequence of aggregated survey patterns in which taxonomists repeatedly select localities with specific characteristics. In this study, we have constructed three different but simple virtual species richness scenarios to simulate the capacity of random, aggregated or regular survey designs to reveal the true biodiversity pattern. We are specifically interested in the effect of taxonomist insistence on surveying those localities that guarantee success in the collection of as many species as possible (species richness bias), and on the coordinated or uncoordinated character of the efforts carried out by the whole community of taxonomists. In all simulated species richness scenarios, a survey directed towards those localities that were previously recognized as having a higher species richness value is not recommended if the aim is to recover the true geographical pattern of species richness in a given territory. This aggregated process of allocating survey localities is probably caused by the primary aim of taxonomists, which is to acquire specimens of rare species and/or as many species as possible. However, an increase in taxonomist curiosity towards non-surveyed localities near those previously identified as the richest allows one to obtain better results, provided that the species richness pattern is not too patchy and the effort for discovering the true map is not too difficult. Our results suggest that planned survey designs are necessary when most of the data comes from studies not specifically designed to reveal the distribution of biodiversity. The capacity of this data to represent the real geographical pattern of biodiversity may depend on the capacity of the taxonomist community to be self-motivated.     

Replacement cost: A practical measure of site value for cost-effective reserve planning

Conservation needs are often in direct competition with other forms of land-use, and therefore protection of biodiversity must be cost-efficient. While common reserve selection algorithms address this problem, quantitative planning tools often suggest an optimal set of sites that is not necessarily convenient for practical conservation. Besides cost-effective solutions we require flexibility if land-use conflicts are to be effectively resolved. We introduce a novel concept for site value in quantitative reserve planning. Replacement cost refers to the loss in solution value given that the optimal cost-efficient solution cannot be protected and alternative solutions, with particular sites forcibly included or excluded, are needed. This cost can be defined either in terms of loss of biological value or in terms of extra economic cost, and it has clear mathematical definitions in the context of benefit-function-based reserve planning. A main difference with the much-used concept of irreplaceability is that the latter tells about the likelihood of needing a site for achieving a particular conservation target. Instead, replacement cost tells us at what cost (biological or economic) can we exclude (or include) a site from the reserve network. Here, we illustrate the concept with hypothetical examples and show that replacement-cost analysis should prove useful in an interactive planning process, improving our understanding of the importance of a site for cost-efficient conservation.     

Regional climate change adaptation strategies for biodiversity conservation in a midcontinental region of North America

Scenario planning should be an effective tool for developing responses to climate change but will depend on ecological assessments of broad enough scope to support decision-making. Using climate projections from an ensemble of 16 models, we conducted an assessment of a midcontinental area of North America (Minnesota) based on a resistance, resilience, and facilitation framework. We assessed likely impacts and proposed options for eight landscape regions within the planning area. Climate change projections suggest that by 2069, average annual temperatures will increase 3 °C with a slight increase in precipitation (6%). Analogous climate locales currently prevail 400–500 km SSW. Although the effects of climate change may be resisted through intensive management of invasive species, herbivores, and disturbance regimes, conservation practices need to shift to facilitation and resilience. Key resilience actions include providing buffers for small reserves, expanding reserves that lack adequate environmental heterogeneity, prioritizing protection of likely climate refuges, and managing forests for multi-species and multi-aged stands. Modifying restoration practices to rely on seeding (not plants), enlarge seed zones, and include common species from nearby southerly or drier locales is a logical low-risk facilitation strategy. Monitoring “trailing edge” populations of rare species should be a high conservation priority to support decision-making related to assisted colonization. Ecological assessments that consider resistance, resilience, and facilitation actions during scenario planning is a productive first step towards effective climate change planning for biodiversity with broad applicability to many regions of the world.     

标准景观情景方法及其在新农村建设规划中的应用

目前中国新型城镇化规划与新农村建设过程中,决策者急需通过科学的方法来获取对未来充分的认识,以制定合理的规划,为了解决传统趋势外推法的局限性,该文提出了一种标准景观情景方法。该文通过分析传统趋势外推法的优劣特点,在国内外情景学研究的基础之上提出标准景观情景方法,阐述了该方法应用于景观生态领域的优势与特点,构建了方法理论体系,并且将其应用于金井镇案例区,验证了其可行性与实用性。结果表明:通过该研究方法向决策者展示了未来2种不同的景观情景,并与传统趋势外推法模拟结果形成对比,提出了基于不同发展方向的相关政策启示。该方法适用于新型城镇化规划与新农村建设,同时应用到自然资源管理、环境规划、农业政策制定等领域也具有一定的指导意义。     

Workweek Optimization of Experimental Designs: Exact Designs for Variable Sampling Costs

An optimal experimental design combines high-quality parameter estimation with efficient use of resources. This paper proposes a new method for heuristic optimization of experimental designs in the presence of variable sampling costs. The method finds the inexpensive designs with desirable statistical qualities and provides substantial insight regarding the relative importance (in monetary terms) of sampling at specific design points. The method is illustrated within the context of a start-stop exposure study in aquatic toxicology. Fast heuristics enable the analyses of a large range of sensitivity issues and examination of trade-offs between information and cost. The method is described for designs in which replicate sampling is prohibited; a generalization allowing for replicate sampling is provided as an appendix in the online supplemental materials.     

Long-term monitoring of tropical bats for anthropogenic impact assessment: Gauging the statistical power to detect population change

Bats are ecologically important mammals in tropical ecosystems; however, their populations face numerous environmental threats related to climate change, habitat loss, fragmentation, hunting, and emerging diseases. Thus, there is a pressing need to develop and implement large-scale networks to monitor trends in bat populations over extended time periods. Using data from a range of Neotropical and Paleotropical bat assemblages, we assessed the ability for long-term monitoring programs to reliably detect temporal trends in species abundance. We explored the magnitude of within-site temporal variation in abundance and evaluated the statistical power of a suite of different sampling designs for several different bat species and ensembles. Despite pronounced temporal variation in abundance of most tropical bat species, power simulations suggest that long-term monitoring programs (?20 years) can detect population trends of 5% per year or more with adequate statistical power (?0.9). However, shorter monitoring programs (?10 years) have insufficient power for trend detection. Overall, our analyses demonstrate that a monitoring program extending over 20 years with four surveys conducted biennially on five plots per monitoring site would have the potential for detecting a 5% annual change in abundance for a suite of bat species from different ensembles. The likelihood of reaching adequate statistical power was sensitive to initial species abundance and the magnitude of count variation, stressing that only the most abundant species in an assemblage and those with generally low variation in abundance should be considered for detailed population monitoring.     

含分布式发电接入的农村电网多目标规划

分布式发电（distributed generation,DG）接入对农村电网损耗、电压及可靠性有很大影响,为了充分发挥DG接入的经济技术效益,提出了一种多目标分布式电源规划方法。该方法以设备投资成本、系统有功损耗、停电损失及购电费用4个指标最小为目标函数,利用判断矩阵获得各目标函数权重,通过加权将多目标优化转化成单目标优化问题,采用改进遗传算法实现了DG位置及容量的优化配置。为了避免因DG可选布点太多、导致算法计算速度慢的问题,根据配电网损耗、电压及可靠性指标改善效果,提出了一种实用的确定DG候选位置的方法。IEEE33节点系统仿真结果表明,本文提出的DG规划模型和求解方法能够有效提高农村电网的投资效益和性能指标。     

小尺度乡村景观生态评价及重构研究

本文旨在小尺度上对乡村景观进行生态化评价, 辨识乡村景观建设的主要生态环境问题。在北京市大兴区、河北省曲周县和江苏省常熟市各选取1个研究区, 基于高分辨率遥感影像, 通过实地野外调查建立小尺度景观数据库。从景观空间结构和属性两方面进行评价, 采用情景分析研究乡村景观植被建设潜力。研究结果显示, 不同研究区整体上形成高度相似的网格化景观格局。线状景观组成在3个区域间差异显著, 注重田埂、田间路、防护林和沟渠的建设以维持农田景观多样性。农田防护林普遍存在主林带间隔过大的问题。农田基础设施地表过度硬化成为当前建设模式突出的生态问题, 在大兴区和常熟市分别达到28.46%和56.19%。防护林在林木覆盖率与绿量评价上显示出不弱于面状林地的重要性, 但面临结构简单、树种多样性低下、残缺断带率高达18%~38%的不足。情景评价显示线状植被具备较大的建设潜力, 合理规划能有效提升乡村林木覆盖率0.58%~1.16%、增加绿量2.22%~19.59%。本研究表明, 小尺度评价能辨识出乡村景观建设所面临的主要生态环境问题以及生态景观建设方向。     

不同指标轻小型喷灌机组配置优化

为探究配置方式对喷灌机组整体性能的影响,明晰不同配置方式的特点,在前期调研的基础上,以轻小型灌溉机组4.4CP-45为例,分别以单位面积上资源消耗,如机组能耗、年费用及使用年限内总费用等为评价指标,结合实际使用配置方式,采用遗传算法,讨论平坡条件下配置不同喷头10PXH、15PY、20PY及40PY时的喷头数及管径等最优组合方式,并对每种配置方式的适用范围进行分析。研究结果表明,通过3个优化目标下机组最优配置方式的对比,较好地反映出每种配置方式的优劣,与实际使用方式吻合较好。配置40PY 喷头时,机组单位能耗高,但年费用很低,适于抗旱或大田作物的灌溉;配置15PY 喷头时,优化配置下的机组能耗比初始配置时降低7.3%,比配置20PY降低8.3%,同时各项费用都比较低,灌溉均匀性高,但移动时劳动强度较大,适于经济作物或植物幼苗的灌溉;配置20PY喷头时,机组总费用最低,为6284.8元/hm2,比初始配置降低15.4%。所有配置方式下能耗费、运行费分别占据机组年费用及总费用的主要部分,有必要通过配置优化或采用中低压喷头、改善管理以降低系统能耗。该研究可以为机组的合理设计、喷头选择及应用推广提供参考。     

Assessing replacement cost of conservation areas: How does habitat loss influence priorities?

Replacement cost refers to the loss incurred if the ideal set of conservation areas cannot be protected due to compulsory inclusion or exclusion of some area candidates. This cost can be defined either in terms of loss of conservation value or in terms of extra acquisition cost, and it has a clear mathematical definition as a difference between the value of the unconstrained optimal solution and a constrained suboptimal solution. In this work we for the first time show how replacement cost can be calculated in the context of sequential reserve selection, where a reserve network is developed over a longer time period and ongoing habitat loss influences retention and availability of sites. In case of site exclusion, a question that can be asked is, “if a site belonging to the ideal (optimal) solution cannot be obtained, what expected loss in reserve network value does this entail by the end of the planning period given that the rest of the solution is re-organized in the most advantageous manner?” Heuristically, the proposed method achieves the ambit of combining irreplaceability and vulnerability into one score of site importance. We applied replacement cost analysis to conservation prioritization for wood-inhabiting fungi in Norway, identifying factors that influence replacement cost and urgency of site acquisition. Among other things we find that the reliability of loss rate information is important, because the optimal site acquisition order may be strongly influenced by underestimated loss rates.     

考虑风险价值的不确定性水资源优化配置

保障区域农业用水的可持续发展,对水资源进行优化配置至关重要。由于粮食主产区水资源配置过程中存在许多不确定性因素,在追求最小用水成本时,也存在着较大的风险,因此该文以三江平原涵盖的七台河、佳木斯、双鸭山、鹤岗和鸡西5个重要粮食主产区为研究区域,以区间两阶段随机规划模型为基础,引入风险偏好,构建地表水和地下水优化配置模型。结果表明,双鸭山和鸡西的配水过程中地表水缺水量很大,主要开采利用地下水;佳木斯作为粮食生产面积较大的行政区,需要外来水进行补给;七台河和鹤岗的种植面积较小,综合考虑引水成本和粮食收益,引用较少的外来水来降低成本;最后得出不同来水水平下,各种风险偏好下水资源优化配置的最小成本的变化规律,即在低来水水平下,用水成本从344.2×108~355.4×108元增加到411.5×108~430.7×108元;在高来水水平下,总用水成本从422.5×108~435.3×108元降低到351.7×108~365.3×108元;在中来水水平时,总用水成本则呈现出先增加后减少的规律。该模型兼有区间两阶段和风险价值模型的特点,综合衡量成本和风险,可有效节约用水成本,并能增强水资源系统规避风险的能力,并以佳木斯2014年实际用水为例,计算得到相对误差在15%以内,较为真实地反映水资源优化配置过程中的不确定性和风险性,为提高水资源利用效率和区域水资源规划管理提供依据。     

气候情景下典型开垦与退耕区耕地动态变化的定量模拟

全球气候变化是当前关注的热点问题,研究气候情景下中国典型开垦与退耕区耕地动态变化对保障中国粮食安全具有重要意义。该研究以东北地区作为典型区,基于设计的土地利用规划情景和RCPs（representative concentration pathways）气候情景,采用土地利用变化动态（DLS,dynamics of land system）模型模拟了在规划情景和RCPs气候情景下开垦与退耕区2010－2030年耕地的空间分布格局,分析不同耕地类型未来的变化趋势。研究结果表明：规划情景下水田呈持续减少的态势,而旱田在2000－2010年有小幅增长的态势,而后出现大面积减少;AIM（Asia-Pacific integrated model）气候模式情景下旱田增长趋势也较明显,水田则保持小幅减少的态势;MESSAGE（model for energy supply strategy alternatives and their general environmental impact）气候模式情景下,耕地面积呈减少的态势。从不同用地类型之间的转移分析得出,该区域开垦与退耕相逆的现象在未来情景下仍会延续,但是发生的频率却随时间的推移逐渐降低。该研究为开垦与退耕区应对气候变化,合理进行农业规划和耕地保护提供参考。     

Changes in soil organic carbon in a mountainous French region, 1990–2004

This paper reports spatial and temporal changes at the regional level in soil organic carbon (SOC) using a soil-test database. A total of 23 329 SOC test values recorded between 1990 and 2004 by certified commercial laboratories and collected in a mountainous French region (Franche-Comté) were integrated in a database. Results show a strong trend in organic carbon content, mainly related to elevation. A large loss in SOC was observed over the survey period. This loss correlated with baseline SOC content with greater loss from soils with higher carbon content. This loss is likely to be due to both changes in land use from permanent grassland to cultivation and to an increase in temperature during the survey period. Our study demonstrates that past soil-test results which were not originally intended for monitoring can provide an alternative method for detecting changes in SOC.     

Using a Master Sample to Integrate Stream Monitoring Programs

The need for aquatic resource condition surveys at scales that are too extensive to census has increased in recent years. Statistically designed sample surveys are intended to meet this need. Simple or stratified random sampling or systematic survey designs are often used to obtain a representative set of sites for data collection. However, such designs have limitations when applied to spatially distributed natural resources, like stream networks. Stevens and Olsen proposed a design that overcomes the key limitations of simple, stratified random or systematic designs by selecting a spatially balanced sample. The outcome of a spatially balanced sample is an ordered list of sampling locations with spatial distribution that balances the advantages of simple or stratified random samples or systematic samples. This approach can be used to select a sample of sites for particular studies to meet specific objectives. This approach can also be used to select a “master sample” from which subsamples can be drawn for particular needs. At the same time, these individual samples can be incorporated into a broader design that facilitates integrated monitoring and data sharing.     

水稻精量穴直播机播量监测系统研制

播种量是水稻精量穴直播机的关键技术参数。为了实时监测水稻精量穴直播机的播种量,提高播种作业性能,该文以环形布置安装于排种管的面源式光电传感器为主要监测元件,设计了水稻精量穴直播机播量监测系统。根据型孔式排种器结构与工作原理,确定了面源式光电传感器和旋转编码器的安装方式。采用高速摄像技术建立了水稻种子流通过监测区时种子数量与脉冲宽度之间的数学模型;通过时间分割节点得到穴粒数监测时间窗口,根据监测时间窗口内的脉冲宽度信息得到每穴播种粒数。选用南粳46和象牙香占2种具有代表性的水稻品种,对水稻精量穴直播机播量监测系统进行试验,将人工统计数据与监测系统统计数据进行对比分析,台架试验结果表明:对于南粳46(短粒型品种),平均穴粒数监测误差不超过7.99%,穴数监测误差不超过6.07%;对于象牙香占(长粒型品种),平均穴粒数监测误差不超过24.07%,穴数监测误差不超过5.66%。该系统基本满足不同工作转速下不同粒型的水稻播种量实时监测要求,可为后期实现水稻精量穴直播机大田作业参数监测提供了参考。     

基于ZigBee技术的粮库监测系统设计

针对大型粮库设施粮食存储环境相关参数监测点分散的现状,设计出了一种层次型网络拓扑结构的无线传感器网络中央监测系统。以承载ZigBee技术的CC2430芯片为无线节点的检测与信息处理核心,结合温度、湿度传感器模块,构成无线传感器网络终端检测子节点,对现场环境实时检测,并通过路由节点将数据上传;路由节点模块设计,采用无线或RS-485标准的方式与中心节点进行信息通讯,使现场循环检测数据能实时传送给中央监控计算机,实现深入粮仓内部的多点检测、实时监测。结果表明,系统功能扩展方便、布网灵活、施工成本低,为大型粮库设施现代化管理奠定了基础。     

Outliers in collaborative studies: coping with uncertainty

An overview is given of the options available in detecting and dealing with outliers in collaborative studies. The fundamental points of agreement and disagreement are highlighted. The common sense approach of just looking at the data is emphasized. The importance is stressed of making a harmonized choice of outlier treatments, even though such a choice may not be optimal for all circumstances.     

农村能源综合规划方法的改进

总结了“六五”以来农村能源综合规划方法,在此基础上,根据我国建设社会主义市场经济的形势和实现可持续发展战略的要求,提出了以发展农村能源产业支持农村能源建设,综合考虑能源供应、经济发展和环境影响相互作用的农村能源综合规划方法。该方法在“九五”百县农村能源综合建设项目中得到了广泛应用。     

生猪养殖污水水质指标相关性分析与建模

生猪养殖污水成分复杂且对环境存在较大的污染风险,常规实验室监测法准确性高但效率低且时效性差,自动监测法速度快但成本高。为寻求一种能兼顾两种方法优点的监测方案,该研究以一家规模生猪养殖场的排放污水为研究对象,对衡量污水水质的7个主要指标的变化特征、相关性和其中2个指标的回归建模进行了研究。通过对不同季节及不同气候条件下30组随机样本的检测与相关性分析,发现氨氮、总氮和电导率有相似的变化趋势且彼此之间均存在强相关性,相关系数分别为0.772、0.775和0.920。基于相关性分析结果,对氨氮和总氮分别进行了一元和多元回归分析建模,并确定了相对最佳的适合于氨氮的"多项式回归模型"和总氮的"综合模型"。经验证,两个模型的决定系数分别为0.855和0.953,可较好地用于评价生猪养殖污水中氨氮和总氮2个指标的浓度大小。基于这2个模型,生猪养殖污水需直接检测的主要指标的数量可有效减少、检测难度和成本均明显降低。因此,模型可为生猪养殖污水高效、低成本的自动监测方案的建立提供重要的理论基础。     

Conservation cornerstones: Capitalising on the endeavours of long-term monitoring projects

Ecological monitoring is widely used to measure change through time in ecosystems. The current extinction crisis has resulted in a wealth of monitoring programs focussed on tracking the status of threatened species, and the perceived importance of monitoring has seen it become the cornerstone of many biodiversity conservation programs. However, many monitoring programs fail to produce useful outcomes due to inherent flaws. Here we use a monitoring program from south-eastern Australia as a case study to illustrate the potential of such endeavours. The threatened carnivorous marsupial, the brush-tailed phascogale (Phascogale tapoatafa), has been monitored at various locations between 2000 and 2010. We present strong evidence for a decline in relative abundance during this period, and also describe relationships with environmental variables. These results provide insights likely to be valuable in guiding future management of the species. In the absence of the monitoring program, informed management would not be possible. While early detection of population declines is important, knowledge of the processes driving such declines is required for effective intervention. We argue that monitoring programs will be most effective as a tool for enhanced conservation management if they test specific hypotheses relating to changes in population trajectories. Greater emphasis should be placed on rigorous statistical analysis of monitoring datasets in order to capitalise on the resources devoted to monitoring activities. Many datasets are likely to exist for which careful analysis of results would have benefits for determining management directions.