野生欧洲李群落物种多样性及种群年龄结构分析

Species Diversity and Age Structure of Wild Prunus domestica Community

欧洲李(Prunus domestica)是重要的野生果树资源,其野生群落在我国仅见于新疆伊犁地区天山野果林区。采用群落取样方法对我国境内已知的唯一天然分布欧洲李群落物种组成、物种多样性和种群的年龄结构进行调查与分析。研究表明,野生欧洲李居群表现为温带落叶阔叶林,成林郁闭度最高可达0.7,群落物种多样性和均匀度均较低,群落内木本植物有7科14属15种,共计712株/丛,以蔷薇科(Rosaceae)为优势科(7种),其个体数占总数的77.95%,乔木层和灌木层的物种组成尤为简单,均以欧洲李为优势种,分别为103株和312株,占总数的59%,相应重要值也最高,分别为116.48和105.45;草本植物25科59属70种,共计2091株/丛,以禾本科(Poaceae)为优势科,共6种,其个体数占总个体数的26.06%,其中鸭茅(Dactylis glomerata)个体数最高,达391丛,占总数的19%,重要值高达37.11;野生欧洲李群落分层明显,乔、灌层物种丰富度显著小于草本层,但在物种均匀度方面,灌木层表现最低,主要受制于上层乔木遮蔽的影响而产生集聚效应;野生欧洲李种群数量稀少,分布区狭窄,只分布在新源县和巩留县的10个分布地,现有野生欧洲李共415株,基于胸径和株高的龄级结构,均表现出种群的繁育层比较发达,幼苗占比在70.12%以上,壮年树及老年树相对较少,种群发育具有一定潜力,但其种群规模狭小且严重破碎化,面临野外灭绝的风险,亟需将原地保护和迁地保护相结合,建立种质资源保育基地。

Prunus domestica L.was one of the most important wild fruit tree resources,and up to date,its wild community has only been found to be distributed in wild fruit forest area of the Tianshan Mountains in Ili region of Xinjiang,China.By the method of quadrat survey,the species composition,diversity and age structure of the only wild P.domestica community were investigated and analyzed.The result showed that P.domestica community was temperate deciduous forest whose crown density of mature forest was up to 0.7,and the species diversity and evenness were low.In the community the individual number of woody plants was totally 712 that contained 15 species belonging to 7 families,14 genera.The dominant family was Rosaceae including 7 species and the number of individuals accounted for 77.95%of the total.In tree layer and shrub layer,species composition was simple.P.domestica was 103 and 312,respectively,accounting for 59%of the total.The corresponding important values were also the highest,at 116.48 and 105.45,respectively.The individual number of herb plants was totally 2 091 that contained 70 species belonging to 25 families,59 genera.The dominant family was Poaceae including 6 species,the number of which accounted for 26.06%of the total individual number.Among them,the dominant species was Dactylis glomerata whose individual number reached 391 clusters,accounting for 19 of the total and the important value was as high as 37.11.The layers of P.domestica community were obvious.The species richness of tree and shrub layer was much less than that of the herb layer,but the species evenness of herb layer was the lowest,which was mainly affected by the influence of the upper layer of trees,resulting in agglomeration effect in the wild P.domestica community.P.domestica population was rare with a narrow distribution area,only found in 10 distribution areas in Xinyuan County and Gongliu County.Currently,a total of 415 P.domestica individuals were found.Based on the age structure of the DBH and the height,the statistics showed that the breeding layer was much highly developed and 70.12%of them were young trees.The mature trees and the old trees were relatively few and the population development had certain potential.However,the community size was small and severely fragmented,which was on the verge of extinction in the wild areas,so it was urgent to protect P.domestica in situ and ex-situ,and also to establish the resource conservation base for the species.