湖北省极小种群野生植物在原生群落中的竞争地位及保护建议

Competition status and conservation suggestions for Wild Plant with Extremely Small Populations in primary communities in Hubei Province

极小种群野生植物是亟需保护、最为濒危的植物,研究极小种群野生植物物种重要值和竞争格局对保护与恢复具有重要实践意义。本文通过野外群落调查,研究了湖北省分布的7种极小种群野生植物大别山五针松(Pinusfenzelianavar.dabeshanensis)、水杉(Metasequoia glyptostroboides)、峨眉含笑(Michelia wilsonii)、小勾儿茶(Berchemiella wilsonii)、长果秤锤树(Sinojackia dolichocarpa)、黄梅秤锤树(S.huangmeiensis)和庙台槭(Acer miaotaiense)的重要值及改进后的Hegyi竞争指数。结果表明:从重要值来看,水杉、长果秤锤树在各自所属的群落中具有较高的重要值及较低的变异系数,为群落中的优势种;庙台槭和黄梅秤锤树重要值较高,为群落中的亚优势种;大别山五针松、峨眉含笑、小勾儿茶重要值较低,为群落伴生种。从改进后的Hegyi竞争指数来看,湖北省7种极小种群野生植物受到的竞争压力的来源和强度存在较大差异,大别山五针松、峨眉含笑、小勾儿茶、黄梅秤锤树主要受到种间竞争,而水杉、长果秤锤树、庙台槭主要受到种内竞争,因此在制定保护措施前要充分考虑物种间的竞争情况,才能采取更有针对性的保护措施。

Aims:Wild Plant with Extremely Small Populations(WPESP)are plant species that are primarily at the risk of extinction and require urgent protection.It is of great practical significance to protect and recover WPESP through researching species importance value(IV)and competition patterns.Methods:Based on the extensive field survey,we analyzed the species importance value and improved Hegyi competition index of the seven WPESP in Hubei Province,including:Pinus fenzeliana var.dabeshanensis,Metasequoia glyptostroboides,Michelia wilsonii,Berchemiella wilsonii,Sinojackia dolichocarpa,S.huangmeiensis and Acer miaotaiense.Results:The results of the importance value indicated that M.glyptostroboides and S.dolichocarpa were the dominant species in the natural communities with a high importance value and a low variable coefficient in their respective communities,S.huangmeiensis and A.miaotaiense were the sub-dominant species with a relatively higher importance value,and P.fenzeliana var.dabeshanensis,M.wilsonii and B.wilsonii were the accessory species in the community with a relatively low importance value.According to the improved Hegyi competition index,there are big differences in competition density and source of competition among seven WPESP in Hubei Province.Pinus fenzeliana var.dabeshanensis,M.wilsonii,B.wilsonii and S.huangmeiensis are primarily subject to interspecific competition while M.glyptostroboide,S.dolichocarpa and A.miaotaiense are primarily subjected to intraspecific competition.Conclusion:The interspecific and intraspecific competitions of WPESP should be fully considered before implementing conservation measures so that more precise conservation measures can be taken.