异质生境对水生型空心莲子草-双穗雀稗共存的影响  

Effects of heterogeneous habitats on the coexistence of aquatic ecotype Alternanthera philoxeroides and Paspalum paspaloides

作　　者：吴昊[1,2] 张三煜 姬秋博 王文浩 肖楠楠 张乐慧 WU Hao;ZHANG San-yu;JI Qiu-bo;WANG Wen-hao;XIAO Nan-nan;ZHANG Le-hui(College of Life Sciences,Xinyang Normal University,Xinyang 464000,Henan,China;Wuhan Botanical Garden,Chinese Academy of Sciences,Wuhan 430074,China)

机构地区：[1]信阳师范学院生命科学学院,河南信阳464000 [2]中国科学院武汉植物园,武汉430074

出　　处：《应用生态学报》2022年第1期85-96,共12页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(31800460);信阳师范学院“南湖学者奖励计划”青年项目(2018B051)资助。

摘　　要：物种共存取决于生物自身属性及生境异质性等多重因素的综合效应。本研究基于较大空间尺度(21°—35°N)的野外调查,比较了水生型入侵植物空心莲子草与其本土共存种双穗雀稗在形态及化学计量特征等方面的差异,并分析了环境因子对二者属性差异的影响。结果表明:空心莲子草盖度和重要值显著大于双穗雀稗(34.3%、104.0%),而双穗雀稗高度显著大于空心莲子草(13.8%)。空心莲子草全氮(TN)、N∶P显著高于双穗雀稗(55.1%、55.8%),而双穗雀稗全碳(TC)、C∶N显著高于空心莲子草(4.1%、83.8%)。空心莲子草盖度随经度增大而增加,其多度随水体硝态氮和经度增大而增加,其重要值随水体铵态氮上升而增加;双穗雀稗盖度、多度和重要值均随铵态氮上升而降低。空心莲子草C∶N随铵态氮上升而降低;随年均温和年均降雨量上升,双穗雀稗C∶N增加,而N∶P降低;两种植物的C∶P均随铵态氮和电导率上升而降低;空心莲子草N∶P基本不受环境影响。这表明空心莲子草具有较高的盖度及N吸收能力,且水体N含量上升会增大空心莲子草的入侵优势度;但双穗雀稗在水热条件优越的生境中可通过提高C同化物储量及采取"生长竞争策略"应对入侵。二者对环境响应的差异性使其可在水生系统中广泛共存。Species coexistence depends on the comprehensive effects of biological properties and habitat heterogeneity.Based on a large-scale field survey(21°—35°N),we compared the differences on morphological and stoichiometric characteristics between the invasive aquatic species Alternanthera philoxeroides and the native co-occurring species Paspalum paspaloides,and examined the effects of environmental factors on such differences.The results showed that the coverage and importance value(IV)of A.philoxeroides were all significantly greater than P.paspa-loides(34.3%and 104.0%,respectively),whereas the height of P.paspaloides was significantly greater than A.philoxeroides(13.8%).Moreover,the total nitrogen concentration(TN)and N:P of A.philoxeroides were significantly greater than those of P.paspaloides(55.1%and 55.8%,respectively),whereas the total carbon concentration(TC)and C:N of P.paspaloides were significantly greater than those of A.philoxeroides(4.1%and 83.8%,respectively).A.philoxeroides coverage increased with the increases of longitude,and its abundance increased with the increases of water nitrate concentration and longitude,while its IV increased with the increases of water ammonium concentration.However,the coverage,abundance,and IV of P.paspaloides decreased with the increases of ammonium concentration.C:N of A.philoxeroides decreased with the increase of ammonium concentration.Increased mean annual temperature and mean annual precipitation increased C:N but decreased N:P of P.paspa-loides.The C:P of both species decreased with the increases of ammonium concentration and electrical conductivity.N:P of A.philoxeroides was little affected by environment.These results indicated that A.philoxeroides had greater coverage and N absorption capacity than P.paspaloides,and that enriched water nitrogen would aggravate the invasion of A.philoxeroides.Meanwhile,P.paspaloides improved its C-assimilate reserves and chose the growth competition strategy for resisting A.philoxeroides invasion under the superior hydrother

关 键 词：生物入侵 水生生态系统 物种共存 化学计量 空心莲子草 

分 类 号：Q948[生物学—植物学]