Herb stratum diversity and community structure in Gurez valley of Kashmir Himalaya: application of multivariate techniques in community analyses

In temperate forests, herbs comprise up to 90% of species richness yet received less attention, and their community structure, diversity patterns, and driving mechanisms still remain understudied. We provide a phytosociological overview of herb stratum to develop a vegetation model to characterize and designate vegetation groups and interpret their diversity and species distribution patterns. Multivariate analyses – classification (TWINSPAN) and ordination (indicator species analysis [ISA], non-metric multidimensional scaling [NMDS], and Canonical Correspondence Analysis [CCA]) were applied to data set collected from 32 plots across Gurez valley, Kashmir Himalaya to recognize the understory plant communities, determine the environmental predictors and highlight their significance. Altogether, 131 herbs from 38 families were recorded. TWINSPAN classified understory vegetation into three communities: Tanacetum multicule – Pedicularis pectinata – Aconitum heterophyllum (TPA), Taraxacum officinale – Trifolium repens – Plantago major (TTP), and Impatiens brachycentra – Tussilago farfara – Galium boreale (ITG). Diversity indices and species richness vary significantly, following the trend TTP>TPA>ITG. CCA revealed that disturbances, canopy, altitude, and moisture were the strongest parameters determining species differentiation. The study outlines a methodological workflow based on analytical methods and vegetation-plot data that describe vegetation groups and might be helpful in further in-depth vegetation classification syntheses and decision-making in conservation, global change issues, and management.

在温带森林中，草本植物的物种丰富度占比可达90%，但相关研究却相对匮乏，其群落结构、多样性格局及驱动机制仍未得到充分探索。本研究针对草本层开展植物社会学（phytosociology）概述研究，旨在构建植被模型以表征并界定植被群丛，同时阐释其多样性格局与物种分布规律。研究采用多元分析方法——包括分类分析（双向指示种分类法（TWINSPAN））与排序分析（指示种分析（ISA）、非度量多维标度（NMDS）及典范对应分析（CCA）），对采自克什米尔喜马拉雅地区古雷兹谷32个样地的数据集开展分析，以识别林下植物群落、明确环境驱动因子并阐释其作用意义。本次研究共记录到38科131种草本植物。通过TWINSPAN分析，林下植被被划分为3个群落：菊蒿（Tanacetum multicule）-栉叶马先蒿（Pedicularis pectinata）-异叶乌头（Aconitum heterophyllum）（TPA）、蒲公英（Taraxacum officinale）-白三叶（Trifolium repens）-大车前（Plantago major）（TTP）以及短距凤仙花（Impatiens brachycentra）-款冬（Tussilago farfara）-北极拉拉藤（Galium boreale）（ITG）。各样地的多样性指数与物种丰富度存在显著差异，呈现TTP>TPA>ITG的变化趋势。典范对应分析（CCA）结果显示，干扰程度、冠层覆盖度、海拔与土壤湿度是决定物种分异的最强环境因子。本研究基于分析方法与植被样地数据，构建了一套可用于描述植被群丛的研究方法流程，可为后续更深入的植被分类综合研究，以及在生物多样性保护、全球变化应对与资源管理等领域的决策提供参考。