Effects of thinning intensity on understory vegetation and soil microbial communities of a mature Chinese pine plantation in the Loess Plateau

Slope Position Rather Than Thinning Intensity Affects Arbuscular Mycorrhizal Fungi (AMF) Community in Chinese Fir Plantations

“…Previous studies have proven that thinning could enhance the growth of reserved trees by improving growth space and light transmittance in stands, as well as the development of the understory, which increases litter decomposition, available soil nutrients, and soil microorganisms [12,18,19]. However, thinning may affect soil properties in the long term due to changes in litter decomposition and nutrient status [1,15]. Hence, in our study, changes in soil properties over a short time (two years after thinning) were not significant and resulted in quite similar AMF despite the thinning intensity used.…”

“…This is because most plantations were initially planted at high density and have not been efficiently managed with thinning [1,5,6]. In addition, these plantations may exhibit other problems associated with monocultures [3,7], such as simple community structure, lack of biological stability, litter decomposition tardiness, and soil nutrient and land fertility losses [4,8,9], which seriously affect the long-term productivity and sustainable management of the plantations [8,10,11].Thinning, as an important silvicultural practice, affects forest characteristics directly and indirectly, such as overstory, understory, soil properties [1,12,13], and microbial communities [14,15]. Several studies have shown that the development of understory after thinning results in an increasing proportion of rapidly decomposable litter, which could supplement the available soil nutrients [16][17][18] and ultimately affect the soil microorganisms because of the variety of litter, plant roots, and exudates [12,[19][20][21].…”

“…In turn, soil microorganisms may influence the growth of plants by altering elements in the rhizosphere soil and improving nutrient acquisition by plants [20,22]. Hence, it is necessary to understand the changes of soil microorganisms and the relational soil factors in forest thinning practice [15,[23][24][25].Slope position, as an important topographical factor, is responsible for the heterogeneity of the microenvironment by changing the light, temperature, and water [26]. Slope position affects soil structure and development [27,28], soil nutrient redistribution and availability by gravity and hydraulic power [29,30], and diversity and distribution of vegetation [31][32][33] and soil microbes [34][35][36].…”

“…Thinning, as an important silvicultural practice, affects forest characteristics directly and indirectly, such as overstory, understory, soil properties [1,12,13], and microbial communities [14,15]. Several studies have shown that the development of understory after thinning results in an increasing proportion of rapidly decomposable litter, which could supplement the available soil nutrients [16][17][18] and ultimately affect the soil microorganisms because of the variety of litter, plant roots, and exudates [12,[19][20][21].…”

“…In turn, soil microorganisms may influence the growth of plants by altering elements in the rhizosphere soil and improving nutrient acquisition by plants [20,22]. Hence, it is necessary to understand the changes of soil microorganisms and the relational soil factors in forest thinning practice [15,[23][24][25].…”