甘肃皋兰县荒漠草原植物群落数量分类及植被特征研究

Quantitative classification and vegetation characteristics of plant communities of Desert Steppe inGaolan County

摘要:

【目的】 研究皋兰县荒漠草原植物群落的数量分类及植被特征，分析影响群落分布的主要环境因子，了解该区植被资源现状，为该区植被恢复及物种多样性的保护提供理论依据。【方法】 基于研究区30 个网格的植被特征调查数据，以物种重要值为指标，采用双向指示种法（TWINSPAN）和典范对应分析法（CCA）进行数量分类与排序，研究皋兰县植物群落组成及影响群落分布的主导因子。【结果】 TWINSPAN 分类将皋兰县荒漠草原植物划分为7 类：群落Ⅰ（红砂+细叶亚菊群落）、群落Ⅱ（盐爪爪+滩地韭群落）、群落Ⅲ（红砂+蓍状亚菊群落）、群落Ⅳ（盐爪爪+栉叶蒿群落）、群落Ⅴ（锦鸡儿+短花针茅群落）、群落Ⅵ（红砂+长芒草群落）和群落Ⅶ（中亚紫菀木+长芒草群落）；不同群落间物种组成差异较大，各群落的高度和盖度较低；群落Ⅰ和群落Ⅲ的物种组成最丰富，物种相似性最高，且群落Ⅲ物种均匀度最高，分布范围最广。植被生活型谱以地面芽、一年生植物为主；CCA 排序显示，最冷月最低温和温度季节性变化标准差对群落的分布影响最大，其次是昼夜温差月均值和年均温。【结论】 皋兰县境内主要优势种为红砂、细叶亚菊、蓍状亚菊，温度是影响该区植物群落分布最重要的环境因子，该区植物群落类型单一，结构简单，物种多样性和丰富度较低，政府应加强该区植物的管理和保护，以确保该区的生态安全和可持续发展。

Abstract:

【Objective】 This research takes quantitative classification and vegetation characteristics of plant com ‐munities for desert steppe in Gaolan County，and explores the main environmental factors affecting community distribution，so as to understand the current status of vegetation resources and provide vital information for ecological restorationand species diversity protection.【Method】 Based on the vegetation characteristics survey data of 30 grids in thestudy area，the bidirectional indicator species method （TWINSPAN） and canonical correspondence analysis （CCA）were used to quantitatively classify and sort the plant community composition and the dominant factors affecting thecommunity distribution in Gaolan County.【Result】 30 grids were divided into7 categories by TWINSPAN quantitativeclassification method： Community I（ Reaumuria songarica+Ajania tenuifolia），Community II（ Kalidium folia-tum+ Allium oreoprasum），Community III （R. songarica+ Ajania achilleoides），Community IV （K. foliatum+Neopallasia pectinate），Community V （Caragana sinica+ Stipa breviflora），Community VI （R. songarica+ Stipabungeana） andCommunity VII （Asterothamnuscentraliasiaticus +S. bungeana） respectively. There were significantdifferences in species composition among different communities，and the height and coverage of each community werelow. In these communities，Community I and Community III had the richest species composition and the highest speciessimilarity，while Community III had the highest uniformity index and widest distribution range. The vegetationlife-form spectrum was mainly composed of hemicryptophytes and therophytes. The CCA ranking showed that thedistribution of communities was most affected by Minimum Temperature of Coldest Month and Temperature Seasonality，followed by Mean Monthly Temperature Range and Annual Mean Temperature.【Conclusion】 The main dominantspecies in Gaolan County were R. songarica，A. tenuifolia and A. achilleoides. Temperature is the most importantenvironmental factor affecting the distribution of plant communities in this area. The community type was single，the structure was simple and the species diversity and richness were low. The government should strengthen the managementand protection of plants in this area to ensure ecological security and sustainable development.Key words：Desert Steppe；TWINSPAN；CCA；quantitative classification of community；vegetation