Abstract

In recent years, in the arid regions of Russia, there has been a catastrophic increase in the area and frequency of fires in the steppes. At the same time, the entire above-ground part of phytocenoses burns out, which significantly reduces the reserves of the live above-ground phytomass, the productivity of communities, and changes the structure and composition of steppe phytocenoses. The purpose of our work was to study the effect of the pyrogenic factor on the stocks of the live aboveground phytomass and determine the timing of its recovery. In the Burtinskaya Steppe area of the Orenburgsky State Nature Reserve six monitoring sites were laid in 2015 after a fire, each included a control (unburnt) site and a burnt site. To identify the features of the dynamics of the stocks of live aboveground phytomass, standard geobotanical methods and the method of cutting areas were used. The studies were carried out in the 2015–2020 period. As a result of studying the effect of the pyrogenic factor on the vegetation cover of the steppes, it was found that the reserves of live aboveground phytomass (g/m²) reach the value of the control communities in the second year of the study. The seasonal dynamics of live phytomass stocks from 3–4 years after the fire depends more on the composition and type of the community and not on whether it was exposed to a pyrogenic factor. Over the entire period of the study the share of live phytomass reserves in the total aboveground phytomass of burned communities approached the values of control phytocenoses; however, there was always more in the control, which indicates incomplete restoration of the structure of the aboveground phytomass in the burnt areas.

中文翻译：

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火灾后草原植物群落中地上活植物群存量的长期动态（以 Orenburgsky 保护区的 Burtinskaya 草原遗址为例）

摘要

近年来，在俄罗斯的干旱地区，草原火灾的面积和频率都出现了灾难性的增加。同时，植物群落的整个地上部分都枯竭了，这显着降低了地上活植物群的储量、群落的生产力，并改变了草原植物群落的结构和组成。我们工作的目的是研究致热因子对地上活植物群存量的影响，并确定其恢复的时间。在 Orenburgsky 国家自然保护区的 Burtinskaya 草原地区，2015 年一场火灾后铺设了六个监测点，每个监测点包括一个对照（未烧毁）点和一个烧毁点。为了确定地上活植物群的动态特征，使用了标准的地理植物学方法和切割区域的方法。这些研究是在 2015-2020 年期间进行的。热源因子对草原植被覆盖度影响的研究结果表明，地上活植物量的储量（g/m² ) 在研究的第二年达到对照群落的值。火灾后 3-4 年活植物群存量的季节性动态更多地取决于群落的组成和类型，而不取决于它是否暴露于热源因素。在整个研究期间，活植物量储备在被烧毁社区的地上总植物量中所占份额接近对照植物群落的值；然而，控制中总是有更多，这表明烧毁区域地上植物群的结构未完全恢复。