| 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. |
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