摘要
利用天目山自然保护区内设立的典型亚热带常绿落叶阔叶混交林1 hm^2固定样地为基础,分别对1996年和2012年(时间跨度为16年)的实地调查监测数据进行综合处理分析,包括优势种的生态位宽度、生态位重叠、种间联结和生物量等方面对其群落演替特征进行深入探讨。结果表明:1996年到2012年中,优势种生态位宽度指数下降的有青钱柳(Cyclocarya paliurus)和缺萼枫香(Liquidambar acalycina),而上升较明显的有小叶青冈(Cyclobalanopsis myrsinifolia)和东南石栎(Lithocarpus harlandii);并且2012年优势种相比于1996年生态位重叠程度更高;1996年和2012年胸径(DBH)≥10 cm的乔木树种的总生物量分别为151.03 t和148.53 t,而2012年优势种胸径5—10 cm幼树的总生物量达到10.03 t,增长潜力较大。结果总体上与天目山常绿落叶阔叶混交林演替趋势相吻合,并以此揭示天目山亚热带常绿落叶阔叶混交林群落演替规律提供数据支撑与借鉴。
Characterization of the spatial distribution of tree species within forest stands is a focus of global research in forest ecology. The tree arrangement provides forestry ecologists significant information on ecological processes such as competition,facilitation,mortality,and dispersal,which tend to follow specific types of spatial patterns in a forest stand.Assessment of inter-and intraspecific interactions of tree species in forest stands that reduce growth and induce mortality,or enhance establishment and growth,has important consequences for both forest dynamics and management. In addition,the biomass ratio distribution of various dominant tree species is a synthetic reflection of the community structure and function in interspecific relationships,niche differentiation,and population dynamics. The objective of this study was to reveal spatial associations of dominant tree species in a subtropical evergreen deciduous broad-leaved forest in southeast China,and to quantitatively identify their ecological relationships and explain possible causes for their successful coexistence in these forest ecosystems. To accomplish the objective,niche breadth,niche overlap,and interspecific associations were used to analyze the inter-and intra-specific interactions of trees based on field data collected from forest permanent plots（ 1 hm^2）in the National Nature Reserve of Mount Tianmu,Zhejiang Province. Furthermore,the biomass structure of the stand wasstudied at the community level. Field surveys of the forest permanent plots were conducted in 1996 and 2012,respectively.Field measurements showed that the niche breadth index of the dominant species Cyclocarya paliurus and Liquidambar acalycina decreased; on the contrary,that of Cyclobalanopsis myrsinifolia and Lithocarpus harlandii increased. Moreover,the niche overlap degree of the dominant species in 2012 was higher than that in 1996,which showed that the sharing and utilization of resources was higher in 2012. Species with similar biological features,ecological adaptability to the habitat,or a higher degree of niche overlap tended to be positively related,whereas those with different biological features,adaptability to the habitat,or existing interspecies competition tended to be negatively related. The test showed that positive correlations of the majority of the dominant species-pairs in 1996 and 2012,accounting for 48. 48 and 71. 21%,respectively,were followed by negative correlations of dominant species pairs accounting for 31.82% in both 1996 and 2012. Only some species pairs displayed no correlations in 1996. The results showed that all the dominant species showed similarity and niche overlap adaptability to the community environment and the ecological characteristics of the subtropical evergreen deciduous broadleaved forest were affected by niche breadth,proportional similarity,and overlap in vegetation succession. The biomass of the trees in which diameter at breast height（ DBH） was ≥ 10 cm decreased from 151. 03 Mg in 1996 to 148. 53 Mg in2012. The biomass of the dominant species in which DBH was 5—10 cm in 2012 was 10. 03 Mg,which suggested considerable potential growth. Our results explained the successful coexistence of dominant tree species at the study site and highlighted detailed tree-tree interactions of the species in the subtropical evergreen deciduous broad-leaved forest.
出处
《生态学报》
CAS
CSCD
北大核心
2017年第20期6761-6772,共12页
Acta Ecologica Sinica
基金
浙江省重点科技创新团队项目(2011R50027)
关键词
常绿落叶阔叶混交林
优势种
生物量
群落演替
天目山
evergreen and deciduous broad-leaved mixed forest
dominant species
biomass
community succession
Tianmu mountain
