海南岛次生低地雨林棕榈藤伴生群落优势种生态位研究

以海南岛甘什岭自然保护区次生低地雨林群落优势种及棕榈藤为试验材料,通过重要值筛选群落优势种,利用生态位宽度、相似性比例和生态位重叠探究棕榈藤与各林层优势种对资源的作用机制,为棕榈藤资源保护和利用提供理论参考。结果显示:(1)青梅(Vatica mangachapoi)和铁凌(Hopea reticulata)为群落建群种,5种棕榈藤在整个群落中具有相对较高的重要值,但差异较大,其中杖藤(Calamus rhabdocladus)最大(0.286),小钩叶藤(Plectocomia microstachys)最小(0.053),其排序为:杖藤大白藤(C.faberii)黄藤(Daemonorops jenkinsiana)白藤(C.tetradactylus)小钩叶藤。(2)5种棕榈藤在群落中具有较大的生态位宽度,其中杖藤最大(Bi和Ba分别为2.900和0.612),且明显大于草本层,但与其他林层优势种差异小。(3)棕榈藤种间与优势种均表现出较低的生态位相似性比例,除黄藤与亮叶鸡血藤(Callerya nitida)外,各林层优势种与所有棕榈藤种相似性比例最高的物种相同,为益智(Alpinia oxyphylla)、百足藤(Pothos repens)、铁凌和青梅;藤种间,杖藤与各其它棕榈藤具有较高的生态位相似性比例,小钩叶藤最小。(4)林层优势种和棕榈藤的Lik和Lki值总体较低,均低于0.1,且生态位宽度大的不一定重叠程度越高;其中0~0.023的重叠数量占总数的63.5%,0.023~0.046为36.0%,0.046的仅占0.5%。研究认为,棕榈藤在群落中具有相对较高的资源利用能力,但种间差异较大,棕榈藤种间及其与优势种间均表现为生态位分化,物种间倾向于资源共享。

Niche Characteristics of Dominant Species of Rattan Accompanying Communityin Secondary Lowland Rain Forest in Hainan Island,China

Dominant species and natural rattan populations in secondary lowland rain forest of Ganshilin Natural Reserve Area in Hainan Island were as test materials. According to contrastively analyzing important values of rattan and dominant species in the community, we conductedto identify utilization and competition relationships of rattan inter species with dominant species at layers,niche breadth, niche proportional similarity and niche overlap to explore the mechanism of rattan and dominant species at forest layer, so as to provide some theoretical references for protection to rattan resource. The results were presented as follows:(1)Vatica mangachapoi and Hopea reticulata were constructive species, 5 kinds of rattan hadrelatively upper IV in community,but there was quite a difference.Calamus rhabdocladus (Cr) had maximum IV, was 0.286. Plectocomia microstachys(Pm)had the minimum, IV equal to 0.053, sorting as follow: Cr> Cf> Dj> Ct>Pm. (2) Rattan had greater niche breadth, in which the greatest one was Cr, B_iand B_awere 2.900 and 0.612, respectively, obviously greater than the species at herb layer and had little difference with other layers. (3)The results of niche proportional similarity were indicated that the lower similarity was showed between rattan and dominant species in layers, only excepted for Dj and Callerya nitida, basically the species at layers of the largest similarity with rattan palms were same, which were Alpinia oxyphylla, Millettia reticulata, V. mangachapoi and H. reticulate. The similarity of Cr had the highest ratio with other rattan, on the contrary, Pm hadthe lowest ratio. (4) L_ik and L_ki between rattan and dominant species in layers were generally lower. All of those were less than 0.1, and niche breadth and overlap were not positively correlated. The value of overlap between 0-0.023 accounted for 63.5%, 36.0% of quantity were focused on 0.023-0.046, only 0.5% left for the rest. The study indicates that rattans in the region have relatively higher resource utilization capacity among the community species. However, great interspecies discrepancies and niche differentiations are showed among rattan interspecies and with dominant species, tending to resource sharing.