中文摘要：

云南松（Pinus yunnanensis）林是我国西南地区最为广布的针叶林。火烧是云南松林常见的一种自然（或人为）干扰，但对云南松林火后更新群落的物种多样性特征很少研究。该研究以云南禄丰县勤丰镇2013年“4．13”火灾后云南松混交林火烧迹地更新早期群落草本层为研究对象，设置了47条1000m^2样带进行群落和环境因子调查，探讨火烧后更新早期群落草本层的物种构成与丰富度的空间格局及其影响因素。结果表明：火后更新草本层按物种构成可分为4个群落类型：草本层物种丰富度受地形和火前群落冠层的影响显著，与立木生物量和地形坡度正相关，而与坡位和海拔负相关，但与火烧强度没有显著的相关性。样带内草本群落β多样性与火前立木胸面积及火烧强度显著正相关，而与海拔和坡位负相关。总体上，生境地形特征、火前冠层和火烧强度构成了火烧后早期群落草本层物种构成与丰富度变化的主要控制因子。此外，一年生和多年生草本物种的更新格局及其对环境的响应存在显著差异。

英文摘要：

Aims Herb layer plays an important role in maintaining ecosystem functioning of forests. The aims of this study were to determine the pattern of species diversity in early post-fire regeneration of the herb layer in mixed Yunnan pine forests and to identify the effects of topography, fire severity, pre-fire vegetation and herb species life-history feature on post-fire regeneration. Methods We conducted field investigations of post-fire regeneration by randomly setting 47 transects of 10 m - 100 m in a burned forest stand in Qinfeng Township, Lufeng County, Yunnan Province, from September to October, 2013. The Two-Way Indicator Species Analysis （TWlNSPAN） was used to classify the herb community types from the 47 transects, and species richness and two indexes offl-diversity were used to analyze herb species diversity and compositional change within sampling transects. Generalized linear model and hierarchical variation partitioning were applied to estimate factors affecting the pattern of herb species diversity of the post-fire communities. lmportantfindings Four herb community types were identified for the 47 transects, which are differentiated by topographic features and fire severities. The species richness in the herb layer of early post-fire regeneration was primarily affected by elevation, topography, fire severity and the pre-fire forest canopy. Specifically, the species richness decreased with increasing elevation, and was positively correlated with biomass of the standing trees and steepness of site slope and negatively correlated with slope position. However, the species richness of herbs was not correlated with fire severity significantly. The within community β-diversity of the post-fire herb layer had a positive correlation with both basal area of pre-fire canopy trees and fire severity. Moreover, the β-diversity was lower at higher elevations. The results also highlighted the differences between annual and perennial species in their distribution pattems.