A Matrix‐Calibrated Species‐Area Model for Predicting Biodiversity Losses Due to Land‐Use Change

Abstract: Application of island biogeography theory to prediction of species extinctions resulting from habitat loss is based on the assumption that the transformed landscape matrix is completely inhospitable to the taxa considered, despite evidence demonstrating the nontrivial influence of matrix on populations within habitat remnants. The island biogeography paradigm therefore needs refining to account for specific responses of taxa to the area of habitat “islands” and to the quality of the surrounding matrix. We incorporated matrix effects into island theory by partitioning the slope (z value) of species–area relationships into two components: γ, a constant, and σ, a measure of taxon‐specific responses to each component of a heterogeneous matrix. We used our matrix‐calibrated model to predict extinction and endangerment of bird species resulting from land‐use change in 20 biodiversity hotspots and compared these predictions with observed numbers of extinct and threatened bird species. We repeated this analysis with the conventional species–area model and the countryside species–area model, considering alternative z values of 0.35 (island) or 0.22 (continental). We evaluated the relative strength of support for each of the five candidate models with Akaike's information criterion (AIC). The matrix‐calibrated model had the highest AIC weight (w_i = 89.21%), which means the weight of evidence in support of this model was the optimal model given the set of candidate models and the data. In addition to being a valuable heuristic tool for assessing extinction risk, our matrix‐calibrated model also allows quantitative assessment of biodiversity benefits (and trade‐offs) of land‐management options in human‐dominated landscapes. Given that processes of secondary regeneration have become more widespread across tropical regions and are predicted to increase, our matrix‐calibrated model will be increasingly appropriate for practical conservation in tropical landscapes.     

好氧堆肥微生物代谢多样性及其细菌群落结构

好氧堆肥是农业废弃物无害化处理和资源化利用的一条有效途径.为了探究好氧堆肥过程中微生物群落的代谢特征和细菌群落演替现象,了解起关键作用的微生物菌群,通过筛选强降解菌种改善堆肥工艺、提高堆肥效率,采用Biolog法和宏基因组法分析了玉米秸秆和牛粪联合好氧堆肥过程中微生物的碳源代谢能力和细菌群落多样性.结果表明:在第2次翻堆（第14天）时,微生物利用碳源的能力最强,初次建堆时（0 d）和其余翻堆时（第8、20、26天）次之,发酵结束时（第34天）最弱.Simpson、Shannon-Wiener和McIntosh多样性指数表明,建堆时及翻堆时的菌群优势度、丰富度和均匀度均极显著优于好氧堆肥结束.不同好氧发酵时间的微生物群落对同一碳源代谢有差异,同一好氧发酵时间微生物群落对不同碳源的利用率不同.糖类、酸类和醇类是区分好氧堆肥不同时间微生物碳源利用差异的敏感碳源.好氧堆肥不同时间细菌的种类和丰度不同,共享的优势菌门有厚壁菌门（Firmicutes）、变形菌门（Proteobacteria）、拟杆菌门（Bacteroidetes）、绿弯菌门（Chloroflexi）、放线菌门（Actinobacteria）和浮霉菌门（Planctomycetes）,在第0、8、14、20、26、34天这6个时间内它们的相对丰度之和分别达90.27%、90.34%、94.26%、84.21%、84.31%和77.61%,且6种门类在不同发酵时间的丰度表达存在消长变化状态.研究显示,参与好氧堆肥不同时间的微生物群落在碳源代谢能力上存在多样性,在细菌菌群的种类和丰度上也存在多样性.      

三峡水库大宁河支流浮游植物演变过程及其驱动因素

基于大宁河不同水文期(2012-04-27~2013-01-19)的监测数据,运用数理统计分析手段,探索三峡水库支流浮游植物不同水文期演替模式及其影响因素.结果表明:1研究期间表层叶绿素浓度和藻类细胞密度最大值均出现在汛限期,依次是蓄水期、泄水期和高水位运行期.基于生态功能组原理,不同水文期大宁河的浮游植物演替模式为:CR-R(高水位运行期)-CS(泄水期)-CR/CS(汛限期)-R-CR(蓄水期).2丰富度指数最大值出现在蓄水期,最小值出现在高水位运行期和泄水期;均匀度指数最大值出现在汛限期,最小值出现在高水位运行期和泄水期;多样性指数最大值出现在汛限期,最小值出现在蓄水期和泄水期;演替速率最高值出现在蓄水期,最低值出现在泄水期.3利用数理统计分析方法,高水位运行期,浮游植物生物量与生境参数并不存在显著的相关关系,水动力参数(RSCW)和光热参数(Et和Ef*)是影响浮游植物群落结构的关键要素;泄水期,Et和Ef*均与浮游植物生物量呈显著正相关,营养盐参数(TP)与浮游植物生物量呈显著负相关关系,营养盐参数(TP)和光热参数[Deu(λPAR)/Dmix]是影响浮游植物群落结构的关键要素;汛限期,光热参数(Ef*)与浮游植物生物量呈显著正相关,营养盐参数(TP)与浮游植物生物量呈显著负相关关系,光热参数([Deu(λPAR)/Dmix]、Et和Ef*)和营养盐参数(TP)是影响浮游植物群落结构的关键要素;在蓄水期,TP与Chl-a浓度呈极显著正相关关系,光热参数[Deu(λPAR)/Dmix]是影响浮游植物群落结构的关键要素.     

市政污泥接种焦化废水好氧降解能力及微生物群落演替的响应分析

焦化废水是毒性很大的典型工业废水,生物处理过程中需要微生物具备很强的适应能力.以探讨焦化废水对微生物的毒性抑制以及微生物对焦化废水的适应过程为目的,通过于焦化废水原水中接种市政污泥,在考察COD、苯酚、氨氮和硫氰化物等主要污染物指标降解的基础上,运用Illumina高通量测序平台分析降解过程微生物群落组成及多样性变化的响应关系.结果表明,接种了市政污泥的焦化废水培养16 h后COD开始下降,40 h时苯酚降解了97.14%,72 h时硫氰化物开始降解,96 h时硫氰化物浓度低于检测限,氨氮浓度随着硫氰化物的降解而升高.群落测序分析表明,不同培养阶段污泥中微生物表现出群落结构及丰度上的差异:在苯酚降解阶段,苯酚优势降解菌Acinetobacter、Pseudomonas的丰度增大,48 h总相对丰度为13.04%;在硫氰化物降解阶段,Sphingobacterium、Brevundimonas、Lysobacter、Chryseobacterium为主导菌属,96 h时其总相对丰度为16.13%;在144 h阶段,优势菌属则变为Fluviicola、Stenotrophomonas和Thiobacillus,总相对丰度为22.45%.由此认为,市政污泥克服了焦化废水中毒性成分的抑制作用之后能迅速适应环境,表现出微生物群落结构随着废水降解成分的变化而改变,环境因子和降解功能菌之间的竞争是群落结构演变的主要因素.     

黄河三角洲新生湿地3种柽柳灌丛对土壤有机碳空间分布的影响研究

研究河口湿地不同类型柽柳灌丛土壤有机碳的空间分布规律,探讨植被演替对土壤有机碳的影响,有助于了解河口湿地生态保护及土壤改良的科学规律.以黄河三角洲新生湿地为研究对象,选择柽柳-碱蓬(Tamarix-Suaeda)、柽柳(Tamarix chinensis)和柽柳-禾草(Tamarix-Gramineae)3种灌丛群落类...     

2015~2020年洪泽湖浮游植物群落结构及其环境影响因子

洪泽湖是南水北调东线工程的重要调蓄湖泊,在气候调节、防洪防汛等方面起着重要的作用.为研究洪泽湖浮游植物群落结构演替及与环境因子的关系,了解“十年禁渔”前洪泽湖生态系统状况,于2015～2020年进行了逐月监测.研究期间,总氮(TN)年平均浓度从2017年之后呈显著下降趋势,总磷(TP)和化学需氧量(COD)总体呈下降趋势,水温无明显变化趋势,水深和透明度从2015～2018年上升,之后显著下降.调查期间共鉴定有浮游植物8门102属310种,浮游植物优势门类主要包括绿藻门和硅藻门,其次为蓝藻门和甲藻门.主要优势属为栅藻(Scenedesmus)、直链藻(Aulacoseira)、隐藻(Cryptomonas)、小环藻(Cyclotella)、四角藻(Tetraedron)、微囊藻(Microcystis)和长孢藻(Dolichospermum).非度量多维尺度分析方法(NMDS)表明,洪泽湖浮游植物群落结构组成在不同年份、不同季节和不同采样区域有显著差异,其变化主要是浮游植物的优势种属间再分配.NMDS分析结果显示,洪泽湖浮游植物群落结构变化与水温、 TN、 TP、水深和透明度等因素有关...     

黄土高原次生林演替过程土壤有机碳库及其化学组成响应特征

为探明黄土高原次生林演替过程中土壤有机碳库及其化学组成演化特征,选取陕北黄土高原黄龙山林区次生林演替初级阶段(山杨林)、过渡阶段(山杨、辽东栎混交林)和顶级阶段(辽东栎林)样地为研究对象,分析不同土层深度(0～10、 10～20、 20～30、 30～50和50～100 cm)土壤有机碳含量、储量和化学组成变化特征.结果表明：(1)土壤有机碳含量和储量随次生林演替过程显著增加(P<0.05),土壤有机碳含量随土层深度增加显著降低,土壤有机碳储量从初级阶段的64.8Mg·hm^-2增加至顶级阶段的129.2Mg·hm^-2,增加了99%.(2)次生林演替过程中,表层(0～30 cm)土壤有机碳中结构简单、相对易分解的脂肪族碳组分相对含量减少,结构复杂、相对难分解的芳香族碳组分相对含量增加,表明表层土壤有机碳化学组成稳定性随次生林演替过程显著提高,而深层(30～100cm)土壤有机碳化学组成稳定性表现为先增加后降低,即过渡阶段>顶级阶段>初级阶段.(3)次生林演替过程中,初级阶段和过渡阶段土壤有机碳化学组成稳定性随土层深度增加显著增...     

Changes in Species Diversity of Rove Beetles (Coleoptera,Staphylinidae) Depending on the Age of Pine Plantations in Central Belarus

Trends of changes in species richness and dominance in staphylinid communities depending on the age of pine plantations have been analyzed. The species richness of these communities is high in the plantations of age classes 1 and 2 (11 and 28 years, respectively) but decreases in the plantations of age class 3 (60 years). The highest and lowest indices of species diversity are observed in the plantations of age classes 2 and 3, respectively. Four groups of rove beetles have been distinguished by the criterion of their dominance in pine plantations of different ages.__________Translated from Ekologiya, No. 4, 2005, pp. 306–313.Original Russian Text Copyright © 2005 by Derunkov.     

Characteristics of Cajander Larch (<Emphasis Type="Italic">Larix cajanderi</Emphasis> Mayr) on Dredging Waste Dumps in the Amur Region

Former dredging sites were studied in the taiga zone of the Amur region (in Khabarovsk Krai). The involvement of Larix cajanderi in plant succession on dredging waste dumps was revealed. Some morphological-anatomical parameters of L. cajanderi needles were compared in trees growing on the dumps and in adjacent open larch stands on waterlogged peaty soils.__________Translated from Ekologiya, No. 4, 2005, pp. 259–263.Original Russian Text Copyright © 2005 by Osipov, Burundukova.     

Vegetation restoration dynamics in the forest-steppe system of the middle Volga region

The current dynamics of ecosystems of the forest-steppe system is most adequately described via determining the probable trajectories of changes in its elements in a simple Markov chain. The obtained data have made it possible to determine the direction of succession and draw its scheme. Theoretically possible series of community development are presented. The succession of community restoration from the spread of shrubs over steppificated fallow lands to the formation of low forests of European bird cherry has been analyzed. The restoration cycle of ecosystem dynamics is described by eight age stages.