有机污染物对杭州湾海域浮游细菌群落的影响

杭州湾海域剧烈的人为干扰及大量的陆源输入,导致有机物污染严重,是我国近海污染最严重的海域之一.微生物在污染物降解过程中发挥着关键作用并能作为评价污染程度的生物标记,但对于浮游细菌群落如何响应有机污染物尚不清楚.因此,本研究从杭州湾采集了13个站点的表层水样(水表下0.5 m),并采集了邻近外海8个站点的水样作为对照,利用Illumina Mi Seq测序技术测定细菌16S rRNA基因,研究不同有机污染程度对浮游细菌群落的影响.结果表明杭州湾有机污染值A(13.2±1.6)显著(P0.001)高于邻近外海(5.4±3.0),且两区域浮游细菌分布和多样性存在显著差异.杭州湾浮游细菌群落优势菌群为γ-变形菌纲(γ-Proteobacteria,24.4%±5.5%)、α-变形菌纲(α-Proteobacteria,16.5%±7.7%)和浮霉菌门(Planctomycetes,13.9%±8.6%),邻近海域主要优势菌群为蓝细菌(Cyanobacteria,20.1%±7.5%)、拟杆菌(Bacteroidetes,18.4%±1.5%)、放线菌门(Actinobacteria,17.5%±4.2%)、γ-变形菌纲(16.6%±1.2%)和α-变形菌纲(14.3%±1.7%).多元回归树(multivariate regression tree,MRT)分析表明:悬浮颗粒(suspended particulates,SP)、亚硝酸盐(NO-2)、油污(oil)、有机污染是影响浮游细菌群落多样性的最主要因素,分别解释了22.0%、6.5%、6.0%和5.5%的多样性变异.冗余分析(redundancy analysis,RDA)表明:驱动浮游细菌群落变异的环境因子有机污染、化学需氧量(COD)、叶绿素a(Chla)、总氮(TN)、硝酸盐(NO-3)和盐度对物种分布的总解释量为71.0%,而有机污染作为单因子控制了6.5%的群落变异,高于其它单一因子.此外,采用指示值方法共挑选出了35个敏感物种,这些物种相对丰度与有机污染显著相关,可用来指示近海有机污染水平.综上,浮游细菌群落对环境污染敏感,为评价海洋有机污染水平提供了敏感的生物学指标.     

贵州百花水库浮游藻类功能群时空分布特征及影响因子分析

为了探究百花水库浮游藻类功能群时空分布特征及其环境影响因子,于2012年11月（枯水期）、2013年4月（平水期）和2013年7月（丰水期）对浮游藻类群落结构与水环境理化指标进行采样分析.基于浮游藻类功能群、综合营养状态指数、Shannon-Wiener指数、RDA（冗余分析）等方法,分析浮游藻类功能群的群落组成和时空分布特征.结果表明:①共鉴定浮游藻类7门67属58种,其可划分为21个功能群.浮游藻类丰度从枯水期→平水期→丰水期递增,分别为131.99×104、592.27×104、53 140.81×104 L-1.②根据浮游藻类丰度,B功能群小环藻（Cyclotella sp.）,J功能群栅藻（Scenedesmus sp.）、盘星藻（Pediastrum sp.）、空星藻（Coelastrum sp.）,P功能群颗粒直链藻（Melosira granulate）、鼓藻（Penium sp.）,S1功能群湖泊假鱼腥藻（Pseudanabaena limnetica）、湖丝藻（Limnothrix sp.）为优势功能群;浮游藻类功能群季节变化明显,其时空分布特征（枯水期→平水期→丰水期,下同）为P+B+J→J+P→S1.在垂直层面上,枯水期以硅藻组成的P、B功能群在各采样点底层藻类丰度达到最大,中层和底层丰度远高于表层,与P、B类群耐受低光的因素有关;平水期以绿藻组成的J功能群在各采样点15 m藻类丰度达到峰值,与J类群耐受低光的因素有关;丰水期以蓝藻组成的S1功能群在各水层表层藻类丰度达到最大,与S1适宜较高水温的因素有关.③RDA分析结果表明,WT（水温）是影响百花水库浮游藻类时空分布的主要环境因子.研究显示,根据浮游藻类绝对优势功能群（P、B、J、S1）以及不同季节生长策略（R/CR/CR→CR/R→R）可以判定百花水库处于中-富营养化状态.      

Ambient noise, motor fatigue, and serial redundancy in chaffinch song

Many animal signals are performed in a highly redundant manner as in some bird species where males sing several renditions of one song type before switching to another. However, differences in signal redundancy between contexts and between individuals are only poorly understood. We found that chaffinches (Fringilla coelebs) in noisier areas (i.e., close to waterfalls and torrents) sang longer bouts of the same song type before switching to a new type, suggesting that they use increased serial redundancy to get the message across in noisy conditions. This is the first evidence of a noise-dependent adjustment of signal redundancy in a songbird. In addition, we found that song types with faster trills were sung in shorter bouts suggesting that the performance of highly redundant song series is probably limited by motor constraints. Thus, in noisy environments, serial redundancy in bird song may reflect a trade-off between successful signal transmission and preventing motor fatigue.     

Effects of Local Disturbance of Tropical Forests on Frugivores and Seed Removal of a Small-Seeded Afrotropical Tree

Abstract:  Small-scale, local disturbance of tropical forests, for example from selective logging, is widespread, but its effects on biodiversity and ecosystem function have rarely been studied. In 3 East African tropical rainforests, we investigated the effect of different levels of local forest disturbance on the frugivore community and on tree visitation and fruit removal rates of the small-seeded tree Celtis durandii. We quantified birds and primates in little and heavily disturbed sites, distinguishing between forest specialists, forest generalists, and forest visitors. We quantified frugivorous tree visitors and seed removal rates of C. durandii trees in the same sites. Forest disturbance reduced the species richness and density of the frugivore community and of forest specialists. Frugivorous species and individuals visiting the study trees were reduced significantly, which led to a marginally significant decline in fruit removal by all frugivores and a significant reduction in removal by forest specialists. Reduction in fruit removal by forest specialists was not compensated for by increases in removal by forest generalists or visitors. Results did not differ among the 3 rainforests, which suggests they were consistent at a regional scale. So local forest disturbance led to a loss of frugivores and their seed removal services. This suggests that large-seeded tree species and trees with small fruits are losing seed dispersers. Thus, local forest disturbance appears to have a more general negative impact on frugivores and their seed dispersal services than anticipated previously.     

不同水源补给河流浮游植物群落结构特征及其与环境因子的关系

为探究不同水源补给河流浮游植物群落结构的差异,于2019年5~11月对北京市北运河水系和永定河水系7条河流进行逐月采样调查,分析不同水源补给河流浮游植物群落结构特征,并采用相关性分析和冗余分析（RDA）探究浮游植物群落与环境因子之间的关系.结果表明,7条河流共监测到9门127种浮游植物,硅藻、绿藻和蓝藻为优势种群,分别占种类总数的40.94%、34.65%和10.24%.浮游植物密度介于（0.24~169.14）×10⁶ cell·L^-1之间,均值为38.20×10⁶ cell·L^-1,生物量介于0.21~78.50 mg·L^-1之间,均值为16.49 mg·L^-1.浮游植物种类、密度和生物量均表现为：混合水源补给组>完全再生水补给组>无再生水补给组.浮游植物生物多样性指数H''均值介于1.56~2.18之间,均匀度指数J均值介于0.47~0.67之间,H''和J均表现为：无再生水补给组>混合水源补给组>完全再生水补给组.RDA排序结果表明,影响混合水源补给组浮游植物优势种的主要环境因子为DOC、pH、Chla、DO和TP,影响无再生水补给组和完全再生水补给组优势种的主要环境因子为TN、NH₄⁺-N、N/P和ORP.     

江苏大丰麋鹿国家级自然保护区互花米草对水盐梯度的生态响应

为探究江苏滨海湿地环境因子与互花米草生态特征的关系及水分梯度和盐分梯度对互花米草生态特征的影响,于2020年10月,选取江苏大丰麋鹿国家级自然保护区滨海湿地互花米草为研究对象,测定了互花米草的株高、生物量、密度、盖度及土壤水分、土壤盐分、pH、土壤容重.结果 表明:①土壤水分和土壤盐分是影响互花米草生态特征的重要环境因...     

Recruitment of Hornbill-Dispersed Trees in Hunted and Logged Forests of the Indian Eastern Himalaya

Abstract:  Hunting of hornbills by tribal communities is widespread in logged foothill forests of the Indian Eastern Himalaya. We investigated whether the decline of hornbills has affected the dispersal and recruitment of 3 large-seeded tree species. We hypothesized that 2 low-fecundity tree species , Chisocheton paniculatus and Dysoxylum binectariferum (Meliaceae) bearing arillate fruits, are more dispersal limited than a prolifically fruiting drupaceous tree Polyalthia simiarum (Annonaceae), which has potential dispersers other than hornbills. We estimated the abundance of large avian frugivores during the fruiting season along transects in 2 protected and 2 disturbed forests. We compared recruitment of the tree species near (<10 m) and far (10–40 m) from parent trees at protected and disturbed sites. Median abundance of Great ( Buceros bicornis ), Wreathed ( Aceros undulatus ), and Oriental Pied Hornbills ( Anthracoceros albirostris ) were significantly lower in disturbed forests, but sites did not differ in abundances of the Mountain Imperial Pigeon ( Ducula badia ). Overall, tree species showed more severely depressed recruitment of seedlings (77% fewer) and juveniles (69% fewer) in disturbed than in protected forests. In disturbed forests, 93% fewer seedlings of C. paniculatus were beyond parental crowns, and a high number of all seedlings (42%) accumulated directly under reproductive adults. In contrast , D. binectariferum and P. simiarum were recruitment rather than dispersal limited, with fewer dispersed seedlings surviving in disturbed than in protected forests. Results are consistent with the idea that disturbance disrupts mutualisms between hornbills and some large-seeded food plants, with the caveat that role redundancy within even small and specialized disperser assemblages renders other tree species less vulnerable to loss of regular dispersal agents.     

长期施用有机和无机肥对黑土nirS型反硝化菌种群结构和丰度的影响

利用末端限制性片段长度多态性(T-RFLP)和实时荧光定量PCR(real-time quantitative PCR,Q-PCR)技术,结合反硝化潜势(DEA)和土壤理化性质的测定,探索了长期施用有机和无机肥对公主岭黑土nirS型反硝化细菌的群落结构和丰度的影响.试验设不施肥(CK)、单施有机肥(OM)、单施无机肥(NPK)以及有机肥和无机肥混施(MNPK)等4个处理.结果表明,长期施用有机肥显著增加了土壤的DEA,其中OM、NPK和MNPK处理分别为CK处理的5.92、1.81和6.03倍,而NPK和CK间无差异.有机肥处理增加了黑土nirS型反硝化细菌的丰度,OM、NPK和MNPK处理中nirS基因的拷贝数分别为CK的2.73、1.30和3.98倍;NPK处理对nirS基因的拷贝数影响不显著.T-RFLP图谱显示施用有机肥改变了nirS反硝化细菌的群落结构;相比于非有机肥处理,有机肥处理中增加了一类79 bp的片段类型,显著降低了84 bp的片段类型,并完全抑制了一类99 bp的片段类型,而有机肥处理间和非有机肥处理间的nirS群落结构分别相似.系统发育分析表明:黑土中nirS型反硝化菌主要由α、β和γ-变形菌纲及一些尚未培养的微生物组成,79 bp的片段类型与γ-变形菌纲的假单胞菌科(Pseudomonadaceae)和β-变形菌纲的伯克氏菌目(Burkholderiales)相似,84 bp片段类型与Burkholderiales和红环菌目(Rhodocyclales)相似.相关性分析表明,pH、全磷(TP)、全氮(TN)、总有机碳(TOC)、硝态氮(NO3--N)和铵态氮(NH4+-N)依次与nirS型反硝化细菌的种群丰度(r为0.724～0.922,P<0.05)和DEA(r为0.453～0.938,P<0.01)显著相关,DEA与nirS型反硝化细菌的种群丰度显著线性正相关(r=0.85,P<0.01);冗余度分析表明,除含水量外,TN、TP、pH、TOC、NH4+-N和NO3--N(r为0.440～0.862,P<0.01)依次与nirS型反硝化细菌群落结构的变化显著相关,DEA的变化和nirS型反硝化细菌群落结构的变化亦显著相关(r=0.863,P<0.01).本研究表明相比于无机肥处理,公主岭黑土中nirS型反硝化菌的群落结构与丰度对有机肥处理有更显著的响应,且其群落结构的改变与种群丰度的增加与DEA的提高显著相关.     

Development pattern and enhancing system of automotive components remanufacturing industry in China

Along with the increasing number of automotive output and End-of-Life vehicles (ELVs) in China, resources shortage and environmental pollution are aggravating, so the tremendous need to reuse automotive components gives birth to the industry. The Chinese government becomes to realize that it is necessary to build a conservation-oriented and environment-friendly harmonious society. As the ultimate form of recycling, remanufacturing will be an effective method to promote the development of Chinese circular economy. The automotive remanufacturing industry in China is just at the preliminary stage, this paper presents some problems before remanufacturing, during remanufacturing and after remanufacturing, and then it points out several barriers, such as restrictive policies and regulations, consumer acceptance, scarcity of technologies, etc. Like many other developed countries, Chinese remanufacturing industry will also experience the primary stage, growth stage and developed stage. while the emphasis of resources input will not be the same. By analyzing the resources input characteristics at different development stages, three development patterns, such as the Government Incenting Pattern, Technology Driving Pattern and Market Leading Pattern, are put forward. At present, the cooperation of the government, industry, universities and research institutes, etc, will jointly construct the enhancing system of automotive components remanufacturing industry in China. Finally, it concludes with a summary and some suggestions in the field.     

互花米草入侵对杭州湾滨海湿地土壤碳氮磷生态化学计量特征的影响

互花米草入侵对滨海湿地生态系统产生极大威胁.选取杭州湾滨海湿地为研究区,采用方差分析研究互花米草入侵下滨海湿地土壤碳氮磷生态化学计量特征,结合冗余分析(RDA)、增强回归树(BRT)和偏最小二乘结构方程模型(PLS-SEM)进一步探讨滨海湿地环境因子与土壤碳氮磷生态化学计量特征之间的驱动耦合关系.结果表明：(1)互花米草入侵后,湿地土壤全氮和氮磷比(N∶P)显著增加;随入侵时间增加,土壤全氮和N∶P显著降低,有机碳、碳氮比(C∶N)和碳磷比(C∶P)显著增加.(2) RDA分析表明,冬季影响表土C∶N∶P生态化学计量特征的主要因子表现为有机碳>电导率>全氮,夏季为有机碳>容重>全氮.(3) BRT分析表明,互花米草入侵下,全氮是影响土壤C∶N和N∶P的关键因子,而有机碳对C∶P影响最强.(4) PLS-SEM分析表明,互花米草入侵下,黏粒和含水率直接影响有机碳,进而影响C∶N和C∶P;黏粒和电导率直接影响全磷,进而影响N∶P和C∶P;电导率直接影响全氮,进而影响C∶N和N∶P.综上,互花米草入侵对研究区土壤C∶N∶P生态化学计量特征影响显著,土壤物理性质和养分含...