Transferring Research to Endangered Species Management

ABSTRACT In the natural resource and wildlife profession, we face difficulties in the production, diffusion, and transfer of rigorously tested science, especially when facing entrenched management paradigms. We present 3 case studies to illustrate the challenges in changing entrenched management paradigms for endangered species. Here we examine specifically what factors helped or hindered the adoption of management practices through the theoretical framework developed for the dissemination of technologies. An examination of 3 case studies suggests that active communication and advocacy of scientific findings, along with simple, visible results, will aid researchers in the acceptance and adoption of their research. Management agencies that increase openness and communication with outside experts, reduce bureaucratic procedures, and localize decision making increase the likelihood that new scientific ideas will be adopted by the agency. We also suggest adaptive resource management as a strategy for endangered species management may foster many of the characteristics that aid in the adoption of scientific ideas into management activities.     

On the nature of the species problem and the four meanings of 'species'

Present-day thought on the notion of species is troubled by a mistaken understanding of the nature of the issue: while the species problem is commonly understood as concerning the epistemology and ontology of one single scientific concept, I argue that in fact there are multiple distinct concepts at stake. An approach to the species problem is presented that interprets the term 'species' as the placeholder for four distinct scientific concepts, each having its own role in biological theory, and an explanation is given of the concepts involved. To illustrate how these concepts are commonly conflated, two widely accepted ideas on species are criticized: species individualism and species pluralism. I argue that by failing to distinguish between the four concepts and their particular roles in contemporary biological theory, these ideas stand in the way of a final resolution of the species problem.     

Estimation of local extinction rates when species detectability covaries with extinction probability: is it a problem?

Estimating the rate of change of the composition of communities is of direct interest to address many fundamental and applied questions in ecology. One methodological problem is that it is hard to detect all the species present in a community. Nichols et al. presented an estimator of the local extinction rate that takes into account species probability of detection, but little information is available on its performance. However, they predicted that if a covariance between species detection probability and local extinction rate exists in a community, the estimator of local extinction rate complement would be positively biased.
Here, we show, using simulations over a wide range of parameters that the estimator performs reasonably well. The bias induced by biological factors appears relatively weak. The most important factor enhancing the performance (bias and precision) of the local extinction rate complement estimator is sampling effort. Interestingly, a potentially important biological bias, such as the covariance effect, improves the estimation for small sampling efforts, without inducing a supplementary overestimation when these sampling efforts are high. In the field, all species are rarely detectable so we recommend the use of such estimators that take into account heterogeneity in species detection probability when estimating vital rates responsible for community changes.     

Testing for local species saturation with nonindependent regional species pools

Identifying the factors controlling local community structure is a central problem in ecology. Ecologists frequently use regression to test for a nonlinear saturating relationship between local community richness and regional species pool richness, suggesting that species interactions limit the number of locally coexisting species. However, communities in different regions are not independent if regions share species. We present a Monte Carlo test for whether an observed local-regional richness relationship is significantly different from that expected when regions are nonindependent and species interactions do not limit community membership. We illustrate this test with data from experimental microcosm communities. A conventional F -test suggests a significant saturating relationship between realized community richness and species pool richness. However, the Monte Carlo test fails to reject the null hypothesis that species interactions do not affect community richness. Strong species interactions do not necessarily set an absolute upper limit to the number of locally coexisting species.     

Biological invasions in forest ecosystems: a global problem requiring international and multidisciplinary integration

The world’s forests are crucial biological resources that provide a variety of ecosystem services such as nutrient cycling and provisioning of resources to society. But forests are particularly affected by biological invasions, with regions around the world experiencing invasions by species from virtually every kingdom. Many of these species have severely disrupted forest ecosystem processes, thereby interrupting the provisioning of ecosystem services that societies depend upon. The problem of biological invasion in forests has many facets, and a large diversity of scientific disciplines addresses these issues. To make progress in solving the problems forest invasions pose, developing interdisciplinary collaborations is crucial because the causes of invasions and many of the measures for prevention or management require expertise in biology, economics, and social sciences. The goal of this special issue is to compile a series of articles summarizing various biological, sociological, and policy subject areas associated with forest invasions from a global perspective. These papers were prepared by the task force, “Forests and Biological Invasions,” organized by the International Union of Forest Research Organizations. Publication of this special issue is intended to advance the integration of scientific knowledge and development of solutions to this very serious and growing problem.     

Pseudoreplication in ecological research: the problem overlooked by Russian scientists

The use of differential statistics to test for treatment effect with data from experiments where either treatments were not replicated (though samples may be) or replicates are not statistically independent leads to serious methodological problem. This problem, discovered by Hurbert (1984), is called pseudoreplication. Due to unknown reasons, pseudoreplication issue was completely overlooked by the Russian ecologists, in spite of the fact that the international scientific community is aware of pseudoreplication for almost twenty years. As the result, up to 47% of the experimental ecological papers, published in six Russian academic journals (Botanicheskij zhurnal, Ekologia, Izvestija RAN Ser. Biol., Lesovedenie, Zhurnal Obshchei Biologii, Zooligicheskij zhurnal) in 1998-2001, are pseudoreplicated; this proportion is nearly twice as high as the proportion of pseudoreplicated studies in international journals during 1960-1980, e.g. before the problem was discovered by Hurlbert (1984). This situation is alarming, especially because a substantial part of pseudoreplication arise from incorrect use of statistics, not from incorrect designing of experiments. By using several examples from the recent papers of Russian ecologists I shortly review the situations where pseudoreplication may occur and discuss some aspects of the experimental design, which are critical for correct processing and interpretation of ecological data.     

井冈山地区莲鱼复合种养模式效益评价

为研究莲鱼复合种养生态系统中的浮游植物群落特征, 及该养殖模式的经济和生态效益, 2019年春季至秋季, 对江西井冈山地区莲鱼种养、莲单种和鱼单养3种种养模式的水质及浮游生物开展了季节调查, 结合当地生产经营, 分析了不同种养模式的经济效益及生态足迹。研究表明, (1)共鉴定出浮游植物7门103种,其中绿藻56种, 蓝藻21种, 硅藻16种, 裸藻3种, 隐藻4种, 金藻2种, 黄藻1种。复合种养模式水体的水质均处于轻污染-无污染状态, 优于单种和单养模式, 且优势种存在季节性差异。(2)冗余分析表明, 水温和溶解氧是影响莲鱼复合种养生态系统浮游植物群落结构的关键环境因子, 总磷(鱼单养模式的主要影响因子)和硝酸氮(莲单养模式的主要影响因子)并不是影响该复合种养模式中浮游植物群落的主要环境因子。(3)莲鱼复合种养经济效益为25200元/公顷, 介于鱼单养和莲单种模式之间, 但其产生每万元利润的生态足迹最低, 为4.48 hm2, 是鱼单养模式的80.9%, 莲单种的33.2%。江西井冈山地区的莲鱼复合种养模式是一种高效益、低生态负荷的综合种养模式, 适宜在当地大面积推广。     

安太堡矿区复垦地植被种间关系及土壤因子分析

为研究安太堡矿区植被复垦过程中不同植物群落类型的种间关系及影响群落稳定性的外部环境因子, 作者对矿区的植物群落和自然生境进行了野外调查。对森林、灌丛和草地3种群落分别在10 m×10 m、 4 m×4 m和1 m×1 m的尺度上, 采用校正的χ2检验、Spearman秩相关分析研究了不同群落类型中出现频率较高的物种之间的联结性, 同时应用灰色关联识别对影响群落稳定性的土壤因子进行了识别。结果表明: 草地群落中物种组成贫乏, 以旱生种为优势类群, 物种间既具有一定的联结性, 又具有相当独立的分布格局。灌丛群落主要种整体呈现正联结, 其组成成分仍以旱生或中旱生物种为主, 部分中生性物种的出现及其与优势种的正相关关系都在一定程度上指示了灌丛群落向正向演替方向进行。森林群落主要种也整体呈现正联结, 表明群落处于植被演替进程中一个相对稳定的过渡阶段。土壤因子与植物群落稳定性的关联顺序为: 有机质> N > P> K> Cu> Mn > pH > Zn>电导率。总的来看, 矿区现有森林群落配置方式是较灌丛群落和草地群落配置方式更适合于矿区特殊生境的群落类型, 而土壤因子中有机质在决定群落稳定性方面发挥重要作用。此研究结果对制定该矿区植被恢复计划具有参考价值。     

植物群落的生物多样性及其可入侵性关系的实验研究

 生物入侵已经成为一个普遍性的环境问题,并为许多学者所关注。尽管一些理论研究和观察表明生物多样性丰富的群落不容易受到外来种的入侵,但后来有些实验研究并没能证实两者的负相关性,多样性 可入侵性假说仍然是入侵生态学领域争论比较多的一个焦点。人为构建不同物种多样性和物种功能群多样性（C3 禾本科植物、C4植物、非禾本科草本植物和豆科植物）梯度的小尺度群落,把其它影响可入侵性的外在因子和多样性效应隔离开来,研究入侵种喜旱莲子草(Alternanthera philoxeroides)在不同群落里的入侵过程来验证多样性 可入侵性及其相关假说。研究结果显示,物种功能群丰富的群落可入侵程度较低,功能群数目相同而物种多样性不同的群落可入侵性没有显著性差异,功能群特征不同的群落也表现出可入侵性的差异,生活史周期短的单一物种群落和有着生物固氮功能的豆科植物群落可入侵程度较高,与喜旱莲子草属于同一功能群且有着相似生态位的土著种莲子草(A. sessilis)对入侵的抵抗力最强。实验结果表明,物种多样性和群落可入侵性并没有很显著的负相关,而是与物种特性基础上的物种功能群多样性呈负相关,群落中留给入侵种生态位的机会很可能是决定群落可入侵性的一个关键因子。     

Nature reserve selection problem: a tight approximation algorithm

The Nature Reserve Selection Problem is a problem that arises in the context of studying biodiversity conservation. Subject to budgetary constraints, the problem is to select a set of regions to conserve so that the phylogenetic diversity of the set of species contained within those regions is maximized. Recently, it was shown in a paper by Moulton et al. that this problem is NP-hard. In this paper, we establish a tight polynomial-time approximation algorithm for the Nature Reserve Section Problem. Furthermore, we resolve a question on the computational complexity of a related problem left open in Moulton et al.     

桂西地区南亚热带落叶栎林群落组成及物种多样性研究北大核心CSCD

落叶栎林是桂西地区南亚热带的典型次生林,也是该区域落叶阔叶林的重要群系组。该研究采用典型样方法对桂西地区落叶栎林群落进行调查,分析了该区域落叶栎林群落的物种组成、区系成分、物种多样性特征及其与地形因子的关系,为桂西地区南亚热带植物多样性保护与恢复提供依据。结果显示:(1)研究区落叶栎林群落维管束植物共计269种,隶属80科178属。(2)种子植物区系以热带成分为主,同时表现出一定程度的温带过渡性质。(3)聚类分析表明,调查的落叶栎林群落可分为云南波罗栎林、栓皮栎林、白栎林、麻栎林4种林分类型,其中以白栎林群落的物种多样性最高,且灌木层的物种多样性显著高于乔木层和草本层。(4)RDA分析显示,落叶栎林群落不同层次物种多样性的差异受地形因子的影响,多样性指标与经度、纬度、海拔之间具有明显的相关性(P<0.05),其中乔木层物种多样性主要与经度、纬度呈显著的相关性,灌木层物种多样性与纬度、海拔相关,草本层物种多样性与经度、纬度、海拔之间均有相关性。     

陆地植物群落物种多样性维持机制

从空间尺度和特定生物区系两个尺度对物种多样性的维持机制进行了综述.在大的空间尺度,简述了引起物种多样性存在差异的物理和自然因子的作用,包括植物群落的历史和年龄、梯度变化(纬度梯度、水分梯度、海拔梯度、土壤养分梯度)、面积效应和隔离程度;针对特定生物区系,从生物因素(生产力、种间关系、林隙动态)和非生物因素(演替、干扰及空间异质性、人类活动)方面论述其与物种多样性之间的关系.     

The Principle of Competitive Exception in a Two-Species Community with One Metabolic Regulation Factor

The validity of the competitive exclusion principle (the Gause’s principle) at one metabolic regulation factor is demonstrated for a general model of two-species community. The competitive exclusion principle postulates that a long-term coexistence of species is impossible if their number exceeds the number of density-dependent growth-regulating factors. Previously, this principle was proved for the stationary states in a general model of a community with any number of factors. In the dynamic modes, the number of species in a community may exceed the number of regulating factors. However, under the influence of one factor, only one species survives.     

The effects of species properties and community context on establishment success

Understanding whether factors important for species establishment in a local community are predictable or context‐ dependent is key for determining the features that affect community stability and species coexistence. A major challenge for scientists addressing this question is that natural systems are complex. This makes it difficult to test multiple properties of species and features of the resident community simultaneously to determine what factors are most important for establishment success of a species into a novel community. We used the model aquatic system inside the leaves of the pitcher plant Sarracenia purpurea to test whether properties predicted to be important for establishment success of a species (initial density, competitive ability, body size) are generalizable across communities varying in resource availability and the presence of a top predator. For intermediate trophic‐level species, we found that both competitive dominance and initial density were important for establishment success. Although a less competitive species was also able to successfully establish in the communities, high resource availability and high initial density were important for its establishment success. Body size of the introduced species, although correlated with competitive ability, was not an important characteristic for establishment success. The presence of a top predator significantly decreased the densities of the introduced species when resources were low, but did not completely inhibit establishment success. The relative importance of each of these factors, and interactions among them, could not have been discerned through single hypothesis testing. The results from this work show the need for detailed experiments that focus on combinations of factors to understand if mechanisms determining community assembly and species establishment can be generalized across systems.     

河北小五台山国家级自然保护区森林群落与环境的关系

植物与环境之间的关系是一个复杂的演变过程,运用数量生态学方法探讨森林群落的物种组成、种群的生态特征、不同植物群落与环境之间的关系,有助于保护该区森林群落的稳定性和生物多样性。根据148个森林群落样方数据,选用双向指示种分析(TWINSPAN)和典范对应分析(CCA)方法,对河北小五台山国家级自然保护区森林群落进行分类和排序研究。结果表明:(1)TWINSPAN将该区的森林群落分为20个类型;(2)CCA排序结果较好地反映出群落分布格局与环境梯度的关系,各个森林群落类型在前两轴分异明显,在11个环境因子中,海拔、坡位、凋落层厚度、土壤导电率、土壤温度、土壤湿度、土壤厚度和干扰程度这8个环境因子对森林群落的分布起较大的作用,影响森林群落的分布格局,形成不同的植被类型。(3)乔木层优势种的CCA二维排序图所揭示的环境梯度与群落类型的分布有很大的相似性;t值双序图阐明了海拔、凋落层厚度、土壤温度、干扰程度等环境因子对森林群落乔木层优势种有着重要影响。采用TWINSPAN分类与CCA排序的方法,较好地解释了森林群落与环境因子的关系,为小五台山地区森林生态系统的科学管理和保护提供了理论依据,研究结果也为同类地区森林生态系统研究及保护提供参考和借鉴。     

Optimizing protection efforts for amphibian conservation in Mediterranean landscapes

Amphibians epitomize the modern biodiversity crisis, and attract great attention from the scientific community since a complex puzzle of factors has influence on their disappearance. However, these factors are multiple and spatially variable, and declining in each locality is due to a particular combination of causes. This study shows a suitable statistical procedure to determine threats to amphibian species in medium size administrative areas. For our study case, ten biological and ecological variables feasible to affect the survival of 15 amphibian species were categorized and reduced through Principal Component Analysis. The principal components extracted were related to ecological plasticity, reproductive potential, and specificity of breeding habitats. Finally, the factor scores of species were joined in a presence-absence matrix that gives us information to identify where and why conservation management are requires. In summary, this methodology provides the necessary information to maximize benefits of conservation measures in small areas by identifying which ecological factors need management efforts and where should we focus them on.     

浙江近海春、夏季蟹类群落结构及其与环境因子的关系

根据2015年4月和7月浙江近岸海域单船底拖网调查资料, 分析了春、夏两个季节浙江近岸海域蟹类的种类组成、优势种及资源密度分布, 采用生态多样性指数和丰度/生物量比较曲线(ABC曲线)分析了群落物种多样性及其动态变化, 同时运用典范对应分析(CCA)研究了蟹类群落变化与海洋环境因子的关系。结果表明: 浙江沿岸海域春、夏季共捕获蟹类28种, 隶属于11科19属, 调查海域蟹类主要以暖水性种类占优势; 春季优势种为双斑蟳(Charybdis bimaculata)、三疣梭子蟹(Portunus trituberculatus)和日本蟳(Charybdis japonica), 夏季优势种为三疣梭子蟹和双斑蟳; 两个季节蟹类平均资源密度分别为244.38 和585.60 kg/km2, 中北部海域资源密度高于南部海域; 种类丰富度指数(D)、物种多样性指数(H′)和种类均匀度指数(J′)三种群落多样性指数均不高, 蟹类群落多样性水平处于较低水平; 根据ABC曲线评估干扰对蟹类群落的影响可得: 春、夏季浙江近岸蟹类群落分别处于严重干扰和中等干扰状态; 典范对应分析结果表明: 在进行对应分析的9个环境因子中, 水深为影响研究海域春夏两季蟹类分布的首要环境因子; 盐度(表层和底层)为影响蟹类分布的次要环境因子, 其他环境因子也均在一定程度上影响蟹类群落分布。     

A comment on Hubbell's zero-sum ecological drift model

In Hubbell's model of zero-sum ecological drift, loss of species from communities by stochastic change in population size is balanced by the production of new species by processes analogous to mutation or to the fission of populations. Large regional metacommunities contain so many individuals that species are lost slowly and infrequent speciation events can maintain high diversity. However, validation of Hubbell's model requires that community size, diversity, and species life spans match up, and this is shown to be a problem with both the mutation and fission mechanisms of speciation. In the first case, most species are rare and ephemeral and would fail to be recognized by traditional taxonomic practices. In the second case, species life spans are so long that diversity builds to unrealistic levels. Thus, the problem confronting community drift probably is not the maintenance of diversity but rather its control, requiring such mechanisms as environmental change or occasional evolution of competitively superior species that sweep the metacommunity. Testing the community drift model will require close attention to community size and species life spans.     

Exclusion effects on vegetation characteristics and their correlation to soil factors in the semi-arid rangeland of Mu Us Sandland,China

Exclusion has been applied as a main measure for re-vegetation all over the world.This paper,by comparing the results of year-round exclusion,seasonal exclusion,and non-exclusion,quantified the vegetation variations under three different exclusion measures and their correlation to soil factors.The analysis results for community species component and plant diversity using multi-response permutation procedures (MRPPs)showed that exclusion did change the species component and increase plant diversity remarkably,while the period of exclusion had no significant influence on these two community features.The indicator species analysis and calculation of similarity indices indicated that community for year-round exclusion were becoming xerophytization and unpalatability,and showed highly spatial heterogeneity of plant species distribution,whereas community for seasonal exclusion was under stable non-equilibrium condition.Detrended correspondence analysis (DCA)and detrend canonical correspondence analysis (DCCA)results of relationship between plant species and soil variables demonstrated that soil moisture was a controlling factor for plant species component,microbiotic soil crust cover,soil organic matter,and soil bulk density had significant effects on soil moisture,among which microbiotic soil crust was a leading factor owing to its limitation to rainfall infiltration on the one hand,and its constraints to entrance of herbaceous seeds into soil or to germination of soil seeds on the other hand.As a result of long-term removal of animal grazing,crust kept intact in year-round exclusion community,which was a main reason of community xerophytization.It was also obvious from ordination results that some important environmental factors,such as tempo-spatial change of rainfall and corresponding tempo-spatial change of soil moisture,were neglected during direct gradient analysis.In addition,biodiversity was close related to soil nutrients as well as to soil moisture condition (soil water content and crust cover),and it had positive relation to available N,and negative relation to available P.Higher soil N had advantage to non-leguminous plants growth on nutrition-poor sand land definitely.The impact of P to community component was unclear and should be studied from plant physiology.Further researches on nonequilibrium theory in semi-arid rangeland will provide a scientific and flexible animal development paradigm for being implementing livestock fen-raising and grazing-forbidden policies in China.     

Mechanisms underpinning community stability along a latitudinal gradient: Insights from a niche-based approach

At large scales, the mechanisms underpinning stability in natural communities may vary in importance due to changes in species composition, mean abundance, and species richness. Here we link species characteristics (niche positions) and community characteristics (richness and abundance) to evaluate the importance of stability mechanisms in 156 butterfly communities monitored across three European countries and spanning five bioclimatic regions. We construct niche-based hierarchical structural Bayesian models to explain first differences in abundance, population stability, and species richness between the countries, and then explore how these factors impact community stability both directly and indirectly (via synchrony and population stability). Species richness was partially explained by the position of a site relative to the niches of the species pool, and species near the centre of their niche had higher average population stability. The differences in mean abundance, population stability, and species richness then influenced how much variation in community stability they explained across the countries. We found, using variance partitioning, that community stability in Finnish communities was most influenced by community abundance, whereas this aspect was unimportant in Spain with species synchrony explaining most variation; the UK was somewhat intermediate with both factors explaining variation. Across all countries, the diversity–stability relationship was indirect with species richness reducing synchrony which increased community stability, with no direct effects of species richness. Our results suggest that in natural communities, biogeographical variation observed in key drivers of stability, such as population abundance and species richness, leads to community stability being limited by different factors and that this can partially be explained due to the niche characteristics of the European butterfly assemblage.