Factors Mediating Co‐Occurrence of an Economically Valuable Introduced Fish and Its Native Frog Prey

Habitat characteristics mediate predator–prey coexistence in many ecological systems but are seldom considered in species introductions. When economically important introduced predators are stocked despite known negative impacts on native species, understanding the role of refuges, landscape configurations, and community interactions can inform habitat management plans. We measured these factors in basins with introduced trout (Salmonidae) and the Cascades frog (Rana cascadae) to determine, which are responsible for observed patterns of co‐occurrence of this economically important predator and its native prey. Large, vegetated shallows were strongly correlated to co‐occurrence, and R. cascadae larvae occur in shallower water when fish are present, presumably to escape predation. The number of nearby breeding sites of R. cascadae was also correlated to co‐occurrence, but only when the western toad (Anaxyrus boreas) was present. Because A. boreas larvae are unpalatable to fish and resemble R. cascadae, they may provide protection from trout via Batesian mimicry. Although rescue‐effect dispersal from nearby populations may maintain co‐occurrence, within‐lake factors proved more important for predicting co‐occurrence. Learning which factors allow co‐occurrence between economically important introduced species and their native prey enables managers to make better‐informed stocking decisions. Factores que Median la Co‐Ocurrencia de un Pez Introducido con Valor Económico y su Presa, una Rana Nativa     

Correlation and persistence of hunting and logging impacts on tropical rainforest mammals

Humans influence tropical rainforest animals directly via exploitation and indirectly via habitat disturbance. Bushmeat hunting and logging occur extensively in tropical forests and have large effects on particular species. But how they alter animal diversity across landscape scales and whether their impacts are correlated across species remain less known. We used spatially widespread measurements of mammal occurrence across Malaysian Borneo and recently developed multispecies hierarchical models to assess the species richness of medium‐ to large‐bodied terrestrial mammals while accounting for imperfect detection of all species. Hunting was associated with 31% lower species richness. Moreover, hunting remained high even where richness was very low, highlighting that hunting pressure persisted even in chronically overhunted areas. Newly logged sites had 11% lower species richness than unlogged sites, but sites logged >10 years previously had richness levels similar to those in old‐growth forest. Hunting was a more serious long‐term threat than logging for 91% of primate and ungulate species. Hunting and logging impacts across species were not correlated across taxa. Negative impacts of hunting were the greatest for common mammalian species, but commonness versus rarity was not related to species‐specific impacts of logging. Direct human impacts appeared highly persistent and lead to defaunation of certain areas. These impacts were particularly severe for species of ecological importance as seed dispersers and herbivores. Indirect impacts were also strong but appeared to attenuate more rapidly than previously thought. The lack of correlation between direct and indirect impacts across species highlights that multifaceted conservation strategies may be needed for mammal conservation in tropical rainforests, Earth's most biodiverse ecosystems. Correlación y Persistencia de los Impactos de la Caza y la Tala sobre los Mamíferos de los Bosques Tropicales     

Benefits to poorly studied taxa of conservation of bird and mammal diversity on islands

Protected area delineation and conservation action are urgently needed on marine islands, but the potential biodiversity benefits of these activities can be difficult to assess due to lack of species diversity information for lesser known taxa. We used linear mixed effects modeling and simple spatial analyses to investigate whether conservation activities based on the diversity of well‐known insular taxa (birds and mammals) are likely to also capture the diversity of lesser known taxa (reptiles, amphibians, vascular land plants, ants, land snails, butterflies, and tenebrionid beetles). We assembled total, threatened, and endemic diversity data for both well‐known and lesser known taxa and combined these with physical island biogeography characteristics for 1190 islands from 109 archipelagos. Among physical island biogeography factors, island area was the best indicator of diversity of both well‐known and little‐known taxa. Among taxonomic factors, total mammal species richness was the best indicator of total diversity of lesser known taxa, and the combination of threatened mammal and threatened bird diversity was the best indicator of lesser known endemic richness. The results of other intertaxon diversity comparisons were highly variable, however. Based on our results, we suggest that protecting islands above a certain minimum threshold area may be the most efficient use of conservation resources. For example, using our island database, if the threshold were set at 10 km² and the smallest 10% of islands greater than this threshold were protected, 119 islands would be protected. The islands would range in size from 10 to 29 km² and would include 268 lesser known species endemic to a single island, along with 11 bird and mammal species endemic to a single island. Our results suggest that for islands of equivalent size, prioritization based on total or threatened bird and mammal diversity may also capture opportunities to protect lesser known species endemic to islands. Beneficios de los Taxa Poco Estudiados para la Conservación de la Diversidad de Aves y Mamíferos en Islas     

长江山区航道剖面能见度分析及局地影响因素初探

为了分析三峡航道不同区域能见度基本特征,比较不同垂直剖面、沿江距离对局地能见度的影响,基于中国气象局沿江、剖面布设的12个能见度监测点近3 a观测资料,对比分析了三峡航道涪陵、万州、宜昌3组区域12个监测点的能见度时空分布特征,并对能见度的局地差异做了初步讨论。结果表明：涪陵区雾情对航运安全影响最大,万州和宜昌区其次。涪陵区和万州区雾日的月际变化趋势一致,5、6月和11、12月为大雾高发时期。不同剖面能见度的日变化分析表明早晨至上午时间为大雾高发时段,午后至傍晚前为大雾低发时段。通过能见度与局地因子的关系模型验证,三峡航道能见度局地差异大部分源于监测点的海拔高度及可能的水体影响等,同组区域内,高海拔点、临近水域点平均能见度明显偏低,雾情频次也相对较高     

土地利用对典型喀斯特河流溶解性有机质的直接和间接影响

土地利用可向河流直接输送陆源有机质直接影响河流溶解性有机质（DOM）丰度,也可通过增强河流营养负荷间接加强DOM的本地生产.研究基于紫外-可见光吸收光谱（UV-VIS）和三维荧光-平行因子分析（EEM-PARAFAC）技术研究雨季（7月）芙蓉江河流DOM组分特征和空间分布,并采用相关分析和偏最小二乘路径模型（PLS-PM）辨析和量化多尺度下土地利用对DOM的直接和间接影响.结果表明,土地利用对DOM的直接影响普遍强于间接影响.不同DOM组分对水体营养状况和土地利用的响应各异,溶解性有机碳（DOC）和有色溶解性有机质（CDOM）更易受水体营养状况影响,荧光溶解性有机质（FDOM）则对土地利用更为敏感.土地利用对DOC和CDOM的直接影响强度随空间尺度略有波动,但总影响强度无明显的空间尺度差异,对FDOM的直接影响强度在河段500 m缓冲区尺度最大,且随尺度增大而降低.旱地、城镇用地、其它建设用地、斑块密度（PD）、边缘密度（ED）和香农多样性指数（SHDI）为增加河流DOM丰度的典型土地利用指标,水田、灌木林、最大斑块指数（LPI）和聚合度指数（AI）为有效减少DOM丰度的典型土地利用指标.总氮（TN）、硝态氮（NO₃^--N）和溶解性总磷（DTP）与土地利用和DOM密切相关,即氮、磷元素在"土地利用-河流DOM"中有着重要的"中介"作用.FDOM可作为衡量近河段土地利用直接向河流输入陆源有机质强弱的指示参数.     

人工增雨（雪）的环境效应及评价方法

随着全球气候变暖,水资源短缺问题表现得日趋突出,实施人工增雨（雪）技术开发空中云水资源已引起人们的广泛关注,对人工增雨（雪）的环境效应及评价方法进行深入研究具有重要的理论意义与实践价值。从大气、土壤、水体等方面,对人工增雨（雪）所引起的环境效应进行阐述,并归纳总结了人工增雨（雪）的评价方法。包括物理学方法、天气学方法、统计分析方法和数值模拟方法等。旨在科学合理地开发空中云水资源,降低人工增雨（雪）的作业成本。     

铁锰复合氧化物同时吸附锑镉性能研究

以五价锑（Sb（V））和镉（Cd²⁺）为对象,考察了二者单独存在和共存体系下铁锰复合氧化物（FMBO）对其吸附性能,探讨了Sb（V）（或Cd²⁺）的吸附对Cd²⁺（或Sb（V））吸附的影响.研究发现,单独存在体系下Sb（V）和Cd²⁺的吸附常数K_F分别为0.48和1.13 L·mg^-1,而共存体系下则分别提高至1.88和1.51 L·mg^-1;Elovich动力学模型可较好地描述共存条件下Cd²⁺与Sb（V）在FMBO表面的吸附,表明该体系的吸附为多层吸附且为非均相扩散过程;吸附48 h后Sb（V）和Cd²⁺的最大吸附量分别达到0.32和1.43 mmol·g^-1;Sb（V）在偏酸性而Cd²⁺在偏碱性pH范围具有较好的吸附效果.Sb（V）（或Cd²⁺）通过改变FMBO表面ζ电位和反应平衡pH等机制影响Cd²⁺（或Sb（V））的吸附.此外,XPS和吸附后水相铁锰浓度结果显示,Cd²⁺可能与FMBO体相中Mn²⁺进行晶格置换并促进Mn²⁺的溶出,进而促进了Sb（V）的吸附.     

双酚类化合物的毒理学效应及微生物降解机制的研究进展

双酚类化合物作为重要的有机化工原料,广泛应用于各行各业。然而双酚类化合物是一类内分泌干扰物,毒性评价结果表明其与许多疾病发病率的升高密切相关。伴随双酚类化合物的大量使用,诸多环境样品中都检测出双酚类化合物。由于双酚类化合物的结构稳定,很难在自然界中被完全降解,会不断累积,对生态安全和人体健康产生危害,亟待有效修复。有机污染物的物理化学修复方法易对环境造成二次污染,微生物降解因其获取容易、无二次污染等特点成为双酚类化合物修复的有效途径。本文总结概述了几种典型双酚类化合物的毒性评价及微生物降解机制。     

臭氧与过氧化钙协同降解甲基红废水

对单独臭氧（O₃）、臭氧与过氧化钙（O₃/CaO₂）联用技术降解甲基红染料废水进行了研究,考察了O₃流量、温度、废水初始pH值、CaO₂投加量、处理时间以及不同水基质等因素对甲基红降解效果的影响.结果表明,在O₃流量为48L/h,温度为26℃,初始pH值为6.2的纯水中降解10min,单独O₃处理对甲基红的降解率为86.1%.在此条件下投加CaO₂,投加量为6.9mmol/L时,O₃/CaO₂联用技术对甲基红废水的脱色率可达到94%.水基质中草酸的存在并不会对O₃/CaO₂联用体系的降解作用造成抑制.O₃/CaO₂联用体系在多种复杂水基质中都能达到较好的脱色效果.通过对比试验发现,O₃/CaO₂联用对甲基红的降解起协同作用,CaO₂不仅可以产生H₂O₂促进染料被O₃降解,而且CaO₂的吸附作用也有利于染料和污染物质的氧化去除.该联用工艺可高效地去除印染废水的色度,达到出水水质处理标准.     

哈尔滨市大气细颗粒物污染特征及其毒性效应

为研究哈尔滨市大气细颗粒物的污染特征及其毒效应,分别采集PM_2.5、PM_1.0样品,分析其质量浓度、数浓度的变化分布特征以及对小鼠肺损伤的影响.结果表明：2017年全年PM_2.5、PM_1.0的质量浓度均呈冬高夏低趋势;PM_1.0质量浓度占PM_2.5总质量浓度的62%~85%,PM_1.0数浓度变化趋势为两边高中间低,且其大小与温度呈负相关,与相对湿度无显著相关性;研究大气颗粒物对小鼠肺损伤影响时发现,染毒组小鼠肺组织细胞中LDH、ACP、AKP、ALB增高,说明大气颗粒物PM_2.5和PM_1.0对小鼠肺组织细胞具有毒效应;肺灌洗液中MDA、NO、NOS水平升高,SOD活性下降,说明PM_2.5和PM_1.0都使机体发生氧化损伤,且PM_2.5和PM_1.0质量浓度增加,会使小鼠肺组织细胞毒效应增强,由此引发的机体氧化损伤程度增大.