火烧后亚高山草甸恢复过程中物种组成和群落特征变化规律的研究

为了解火烧对植物群落结构和植被恢复速度的影响，本研究以甘肃省皇城羊场亚高山草甸为研究对象，于2017年5月进行了火烧试验，并分别在2017，2018及2019年的5月（返青期）、7月（生长期）和9月（生长末期）测量了该区域火烧样地和原生样地的植被覆盖度、群落多样性和裸地百分比等指标。结果表明：2019年5月后火烧样地与原生样地间植物群落多样性指数（Margalef指数、Shannon-Wiener指数、Simpson指数和Pielou指数）间差异不显著；火烧后引起的植物结构变化是短暂的，并随着时间的推移逐渐减少甚至消失，恢复时间大约16个月左右；同时火烧改变了物种组成，其中在火烧样地中甘肃马先蒿（Pedicularis kansuensis）和锐果鸢尾（Iris goniocarpa）逐渐消失，而鳞叶龙胆（Gentiana squarrosa）和火绒草（Leontopodium leontopodioides）逐渐出现。本研究说明春季火烧对亚高山草甸植物组成和结构有一定的调节作用，可作为亚高山草甸管理的有效措施。

Study on the Species Composition and Community Characteristics of Subalpine Meadow during Restoration after a Fire

In order to understand the effects of fire on plant community structure and vegetation recovery,a burning experiment was conducted in May 2017,in Huang Cheng Sheep Farm in Gansu Province. This study measured vegetation coverage,community diversity and percentage of bare ground in burnt sample plot and unbrunt sample plot in May (regreening stage),July (growing stage),and September (mature stage) from 2017 to 2019 respectively. The results showed that there was no significant difference in diversity index of plant communities (Margalef index,Shannon-Wiener index,Simpson index,and Pielou index) between the burned plot and the original plot after May 2019. The change of plant structure was short-lived,and gradually decreased or even disappeared over time,and the recovery time was about 16 months. At the same time,the fire changed the species composition. In the fire site,Pedicularis kansuensis and Iris goniocarpa gradually disappeared,while Gentiana squarrosa and Leontopodium leontopodioides gradually appeared. These results indicated that the spring fire had some regulating effect on vegetation composition and structure of subalpine meadow grassland,and can be used as an effective measure for management of subalpine meadow.