【作者】 秦卫华；

【导师】 张金池；

【作者基本信息】 南京林业大学 ， 生态学， 2013， 博士

【摘要】 湖北石首天鹅洲长江故道湿地区域是历史上中国麋鹿的主要栖息地之一，为让野生麋鹿重新回归家园，国家1991年在这里建立了石首麋鹿自然保护区，随着麋鹿数量增多，生境质量逐渐退化，麋鹿食源植物种类和生物量逐渐减少，而以接骨草为代表的麋鹿不采食植物数量不断增多，其中保护区内杨树林下接骨草群落面积已达200hm2，约占保护区总面积的12.8%，对天鹅洲生境中的麋鹿就地保护造成巨大威胁。2010年保护区发生了麋鹿感染病原菌大量死亡的突发事件，有专家推测可能与保护区内异常分布的大面积接骨草群落有关系。因此，本文以天鹅洲麋鹿生境中的接骨草为主要研究对象，分别在保护区内选择开阔草地、人工意杨林、堤坝坡地和道路旁4种生境，共设置了16个接骨草固定调查样地，从2011年9月至2012年11月，共进行了4次系统调查，对接骨草及其伴生植物的生物多样性指数、生态重要值、生态位宽度、生态位重叠值等进行了分析，同时研究了接骨草的化感作用，还分析了天鹅洲生境中接骨草及其伴生动物的相互关系，最后针对天鹅洲生境麋鹿就地保护中存在的威胁因素，为管理部门提出了相关建议对策。这些研究结果均为首次报道。1.接骨草群落的生态位研究研究发现：(1)共记录接骨草伴生植物34科、76属、84种，约占保护区植物总数的32.2%。四种生境类型中，接骨草、牛鞭草、葎草、狗牙根、牛膝、荩草、爵床、窃衣、天胡荽、水芹、大巢菜、求米草、透茎冷水花、蹄盖蕨、鹅观草和狗尾草等16种植物的生态重要值最高；生态位宽度最高的为接骨草、葎草、牛膝、附地菜、鹅观草、薹草属、鸡矢藤和苍耳8种；与接骨草生态位重叠程度最高的主要为葎草、附地菜、苍耳、鸡矢藤、牛膝、薹草属、水芹等7种。(2)天鹅洲麋鹿生境接骨草群落中仍然分布有种类不少的麋鹿可采食植物，一定程度下麋鹿仍然可以利用接骨草群落生境作为觅食场所，而不仅仅是作为产仔隐蔽场所。(3)由于保护区采取了较强的人工生境干预与调控措施，导致天鹅洲麋鹿生境中植被的演替具有不规律性，从生态位实验结果来看，除葎草生态位宽度有所下降外，接骨草和豨薟等麋鹿不采食的植物的生态位宽度基本没有明显的变化，显示目前的人工干预措施效果不明显。2.接骨草对5种农作物种子的化感作用本文首次测定了接骨草水提液对萝卜、小白菜、黄瓜、玉米和小麦5种农作物种子发芽率、幼苗生长及生物量方面的影响情况。结果发现：总体上接骨草对于普通农作物具有较为显著的化感抑制效应，并且随着接骨草水提液浓度的升高，化感效应也随之逐渐增强。在种子发芽率方面，接骨草水提液对5种供试农作物的化感作用程度不同，萝卜和小白菜最敏感，随着处理浓度升高，抑制效应显著增强；其次是玉米，抑制作用比较显著；仅在高浓度时对黄瓜种子有显著抑制作用；对小麦种子发芽无抑制作用。在幼苗茎(叶)长方面，接骨草水提液对萝卜在低浓度时具有显著促进作用，高浓度时具有显著抑制作用；对玉米在低浓度时具有促进作用，高浓度时无影响；对小麦叶长无影响。在生物量方面，接骨草水提液对萝卜影响显著，随着处理浓度升高，生物量显著降低；对玉米在低浓度时具有显著促进作用，高浓度时具有显著抑制作用；对小麦影响不显著。由于无法获取成熟度均匀、发芽率一致的野生麋鹿食源植物种子，本试验仅探讨了接骨草对5种农作物种子的化感作用，未对麋鹿食源植物进行实验，也未对接骨草化感物质进行分离鉴定，存在一定的局限性，这些都有待于后续的深入研究。3.接骨草及其伴生动物关系分析本文首次调查了天鹅洲生境中接骨草伴生动物的种类，并分析了接骨草与伴生动物的关系。结果发现：天鹅洲麋鹿生境中与接骨草群落有关的伴生动物种类至少在36种以上，其中绝大多数为昆虫，共有33种，占总数的91.7%，其他为蜗牛类和蜘蛛类。接骨草伴生动物可划分为取食者、传粉者和互惠共生者3大类，其中取食者至少在16种以上，为专性有害关系；传粉者至少在12种以上，为专性有益关系；互惠共生者至少在8种以上，为兼性有益关系。本文首次报道了接骨草的伴生动物种类、生活习性、相互关系、遇见率与优势程度等，可以为综合分析接骨草在天鹅洲麋鹿生境中的地位提供支持。但由于受到野外调查时间与频次的限制，使得研究结果具有一定的局限性，包括接骨草伴生动物种类实际情况可能要远大于实地观察记录结果(36种)，针对具体的伴生动物未统计数量、停留时间、拜访频率等定量数据，这些不足还有待于后续的深入研究。本文从群落中种间关系入手，系统查明了天鹅洲麋鹿生境中接骨草所处的生态位，并综合探讨了接骨草与麋鹿食源植物、接骨草与其他伴生植物、接骨草与伴生动物、接骨草与麋鹿生存繁衍等之间的关系，科学分析了接骨草对于天鹅洲麋鹿生境退化的作用，为恢复天鹅洲生态环境质量，实现麋鹿健康、可持续发展提供了基础资料，也为相关管理部门进行决策提供了技术支撑。更多还原

【Abstract】 The wetland of Yangtze River in Tian’ezhou, Hubei Province is one of the main habitats ofPere David’s deer in history. The Chinese government established the Shishou Milu naturereserve in1991, and1567hm2reed marsh grassland are under strict protection by the fence, tohelp the wild Pere David’s deer return and live in their hometown. Now, this nature reservesupport the largest population of wild Pere David’s deer in central China. However, habitatquality in the Tian’ezhou is degrading because of the increased Pere David’s deer. In addition,species number and biomass of edible plants for the deer reduced gradually, and the inedibleplants increased, especially for Sambucus chinensis. Actually, the area of Sambucus chinensiscommunity under Populus canadensis forests in the nature reserve has reached~200hm2,accounted~12.8%of the total area of the nature reserve, which has threatened the deercommunity. It’s noted that lots of deer died in2010due to bacterial infection, and some expertsspeculated that the extensively distributed Sambucus chinensis community in the nature reserveprobably associated with their death. Under these circumstances, the Sambucus chinensiscommunities in Tian’ezhou were studied, and16fixed sample sites for Sambucus chinensiswere set up, which covered four major habitat types in the nature reserve, including grassland,forest, slope, and roadside area.The Sambucus chinensis communities were investigated four times during September2011~November2012. This project aimed to:1) determine the biodiversity index, ecologicalimportance values, niche breadth and niche overlap for Sambucus chinensis and its accompanyplants;2) allelopathic effects of Sambucus chinensis; and3) identify the companion animals ofSambucus chinensis in Tian’ezhou. Finally, some useful suggestions were proposed for thegovernment and land administrator, to help solving the existed threats for the deer inTian’ezhou. All the research findings are reported for the first time.1. Niche of the Sambucus chinensis communityBased on the4times investigation in Tian’ezhou habitat during two years, The results showthat：Eighty-four companion plants of Sambucus chinensis were noted, which belonged to34families and76genera, accounted for32.2%of the total plant species in the nature reserve.In the four habitat types (i.e. grassland, forest, slope and roadside), sixteen species had thelargest ecological importance values, including Sambucus chinensis, Hemarthria altissima,Humulus scandens, Cynodon dactylon,Arthtaxon lanceolatu, Oplismenus undulatifolius, Pileapumila, Achyranthus bidentata, Rostellularia procumbens, Torilis scabra, Hydrocotylesibthorpioides, Qenantha javanica, Vicia sativa, Athyrium filixfemina, Roegneria kammoji andSetaria viridis. Eight species had the highest niche breadth, including Sambucus chinensis,Humulus scandens, Achyranthus bidentata, Trigonotis peduncularis, Roegneria kammoji, Carexspp，Xanthium sibiricum and Paedeia scandens. Seven species had the highest niche overlap values with Sambucus chinensis, i.e. Humulus scandens, Trigonotis peduncularis, Xanthiumsibiricum, Paedeia scandens, Achyranthus bidentata, Carex spp and Qenantha javanica.Someedible plants still distributed in the Sambucus chinensis communities in Tian’ezhou, and PereDavid’s deer could make use of these sites not only as shelters but foraging sites.The vegetationsuccession is irregular in Tian’ezhou, probably because of intensive human intervention andcontrol measurements in the nature reserve. Regarding the results of niche experiment, theniche breadth of some inedible plants for the deer, such as Sambucus chinensis andSiegesbeckia orientalis, did not have significant variations, except for Humulus scandens,whose niche breadth declined. Therefore, the impacts of human intervention are not veryeffective in the nature reserve.2. Allelopathic effects of Sambucus chinensis on five crop speciesSambucus chinensis is a traditional medicinal plant in China, and its medicinalcomposition and values are research hotspots for current studies. In this project, allelopathiceffects of Sambucus chinensis on seed germinations of five crop species, including pakchoi(Brassica rapa), turnip (Raphanus sativus), cucumber (Cucumis sativus), wheat (Triticumaestivum) and maize (Zea mays), were studied for the first time by using filter paper method.The allelopathic effects on stem (leaf) length and biomass of three crops were also studied,inclding wheat, turnip and maize.The inhibitory effects of water extraction of Sambucus chinensis on seed germination weredifferent for the five crops. Turnip and pakchoi were the most sensitive, followed by maize, andthe inhibitory effects significantly increased with the concentration of water extraction ofSambucus chinensis. Cucumber seeds were only inhibited for germination at highconcentrations. For stem (leaf) length, water extraction of Sambucus chinensis had a significantpromotion effects on turnip and maize at low concentrations, but inhibited turnip growth at highconcentrations. Regarding to biomass, water extraction of Sambucus chinensis significantlyinhibited turnip, and the higher the concentration, the lower the biomass. In addition, maizebiomass was significantly promoted at low concentrations and inhibited at high concentrations.There are some limitations for the study. The allelopathic effects of Sambucus chinensiswere only analyzed for five crop species, instead of the wild edible plants for the deer inTian’ezhou, because the seeds of these edible plants that have uniform maturity andgermination rate were hard to collected. Moreover, the specific allelochemicals of Sambucuschinensis have not been identified.3. The inter-relationship of Sambucus chinensis and its companion animalsSambucus chinensis played an important role in the food chain and food web inTian’ezhou, although it could not be used by Pere David’s deer. This project systematicallysurveyed the companion animals of Sambucus chinensis in Tian’ezhou for the first time, andthen preliminary analyzed the inter-relationship between the companion animals and Sambucuschinensis.There were at least36companion animal species of Sambucus chinensis in Tian’ezhou.Thirty-three of them (91.7%) were insects, and the others were snails and spiders. The companion animals could be divided into three types, including predators, pollinators andmutual benefitors. At least16predators,12pollinators and8mutual benefitors were determinedin Tian’ezhou.The companion animals of Sambucus chinensis were reported for the first time, such as thespecific species, life habit, inter-relationship between the companion animals and Sambucuschinensis, encounter rate and their degree of dominance. It is very useful while analyzing theniche of Sambucus chinensis in Tian’ezhou. Because of the limits of census duration andfrequency, companion species of Sambucus chinensis in nature may be far greater than thatdiscovered in this study. Moreover, some important aspects need to be further studied, such astheir population size, residence duration, and visit frequency.This project determined the niche of Sambucus chinensis from the perspective ofinterspecific relationship in Tian’ezhou, where the largest Pere David’s deer lived in centralChina. The relationships between Sambucus chinensis and edible plants, other companionplants and animals, survival and reproduction of Pere David’s deer were analyzed, andexamined the effects of Sambucus chinensis on habitat degradation in Tian’ezhou. This studycan provide some basic information for recovering habitat quality of Tian’ezhou and promotingthe healthy and sustainable development of the deer population. On the other hand, it canprovide some technical supports for the government and decision-makers.更多还原