广西不同气候条件下马尾松人工林木本植物组成及多样性特征

马尾松Pinus massoniana人工林广泛分布于我国南部,为了理解马尾松人工林在不同气候条件下的响应特点和分布特征,以中国广西中亚热带、南亚热带和北热带不同气候条件下马尾松人工林的幼龄林、中龄林和过熟林阶段为研究对象,比较分析不同气候条件下马尾松人工林木本植物物种组成及多样性特征。结果表明:(1)所研究的7个林分类型中,共记录到木本植物229种,隶属56科127属,随着中亚热带气候条件向北热带气候条件过渡,马尾松人工林林下热带分布物种占比增大,温带分布树种逐渐减少;(2)在幼龄林阶段,与南亚热带气候条件相比,中亚热带气候条件下马尾松人工林林下灌木层及木本群落整体的物种丰富度相对较高,在中龄林阶段和过熟林阶段,北热带气候条件下马尾松人工林林下木本群落物种丰富度和物种多样性最高,但优势种集中性较低;(3)在幼龄林阶段,南亚热带与北热带气候条件马尾松人工林林下物种差异性最大,在中龄林阶段,中亚热带与北热带气候条件马尾松人工林林下物种相似程度最高。气候条件变化对林下乔木层建群种有着明显影响,而且由于生境条件差异,不同气候条件下物种构成明显不同,在幼龄林阶段不同气候条件对林下木本群落影响最大。

Composition and Diversity of Woody Plants of Pinus massoniana Plantations under Different Climatic Conditions in Guangxi

Pinus massoniana plantations are widely distributed in southern China.In order to understand the response characteristics and distribution characteristics of P.massoniana plantations under different climate conditions,the young,middle-aged and over-mature forest stages of P.massoniana plantation under different climatic conditions in the mid-subtropical zone,south subtropical zone and north tropical zone of Guangxi,China were taken as the research objects.The species composition and diversity characteristics of woody plants under different climate conditions were compared and analyzed.The results showed that:(1) Among the 7 forest types studied,a total of 229 woody plants were recorded,belonging to 56 families and 127 genera.With the transition from the mid-subtropical climate to the northern tropical climate,the proportion of tropical distribution species of the P.massoniana plantation forest increased,and the temperate distribution of tree species gradually decreased.(2) At the young forest stage,the species richness of undergrowth shrub layer and woody community of P.massoniana plantations in mid-subtropical climatic conditions was relatively high compared with that of south subtropical climatic conditions.At the middle-aged forest stage and over-mature forest stage,the species richness and species diversity of undergrowth woody community in P.massoniana plantations under northern tropical climate were the highest,but the concentration of dominant species was lower.(3) At the young forest stage,the difference between understory species of P.massoniana plantation under the southern subtropical and northern tropical climates was the largest.At the middle-aged forest stage,the similarity degree of undergrowth species of P.massoniana plantations under sub-tropical and northern tropical climates was the highest.Changes in climatic conditions had a significant impact on the species under tree layers,and due to differences in habitat conditions,the species composition under different climatic conditions was significantly different.Different climatic conditions at the young forest stage had the greatest impact on the understory woody forest communities.