Short term effects of thinning on soil organic carbon fractions, soil properties, and forest floor in Cunninghamia lanceolata plantations

Abstract

Forest management impacts on the soil carbon pool and soil properties. This study analyzed the changes of soil organic carbon (SOC) fractions, soil properties, and forest floor in a Chinese fir (Cunninghamia lanceolata) plantation after two years of thinning in Eastern China. The experiment consisted of three thinning treatments: unthinned, moderate thinned (stand stem density reduced by approximately 21%), and heavy thinned (stand stem density reduced by approximately 36%) stands. Concentrations of soil dissolved organic carbon (DOC), light fraction carbon (LFOC), and total SOC in the topsoil (0 to 20 cm) increased in the heavy thinned stands, and no significant effect for heavy fraction carbon (HFOC) was detectable in the soil profile. Some soil properties were also altered after thinning, which included a decrease in soil bulk density (BD), and an increase in soil temperature (ST), soil organic matter (SOM), total nitrogen (TN), available nitrogen (AN), available phosphorus (AP), available potassium (AK), and pH. The change of these soil properties mainly occurred in the topsoil layers (0 to 20 cm) in the heavy thinned treatment. The SOC and soil labile carbon fractions were positively correlated with ST, TN, AN, AP, and AK. Moreover, the increase of SOC fractions and the availability of soil nutrients maybe due to the increased input from an abundant well-decomposed forest floor after thinning. These results suggest that a 36% of thinning operations had a marked impact on the soil labile carbon pool and soil fertility in the topsoil in a Chinese fir plantation during a shorttime period. Thus, changes to soil carbon stability and soil fertility should be considered when developing forest management plans.

Enhancing Forest Sustainability: A Comprehensive Exploration of Thinning Practices and their Effects on Soil Chemical and Biochemical Properties

“…Thinning intensity, as studied by Cheng et al [45], exhibited a considerable impact on soil organic carbon (SOC), labile carbon fractions, and soil physical and chemical properties over a short period (2 years). SOC, dissolved organic carbon (DOC), and light fraction organic carbon (LFOC) significantly increased in the heavily thinned plots (36%) compared to unthinned plots.…”

Human disturbance influences occupancy of Altai wapiti in Mongolia

“…Thinning signifi cantly infl uences forest soil, aff ecting root density, microbial communities, organic matter turnover and nutrient budgets, that aff ects tree growth, understory vegetation composition and the whole forest ecosystem (Tian et al, 2010;Qiu et al, 2012;Kim et al, 2016). Thinning can change soil environments by aff ecting soil temperature and moisture, bulk density, and soil organic carbon (Barg & Robert, 1999;Rawls et al, 2003;Benjamin et al, 2008;Xiangrong et al, 2018). The decreased density in and below forest canopies, generated by thinning, leads to improved light intensity conditions in forest stands, which in turn speed up litter decomposition rates (Son et al, 2004;Zhao et al, 2014); it aff ects growth of understory vegetation due to changes in environmental factors such as wind, microclimate and insolation (Bailey et al, 1998;Dodson et al, 2008).…”

The Effect of Forest Thinning on Soil Microbial Community Structure and Function

“…Many studies have investigated the effect of thinning on soil organic carbon [21,22], however, the regulation of soil microbial community on soil carbon with thinning treatment is still not well understood. After thinning treatment, soil organic carbon is altered following the variation in microbial community [23,24]. Therefore, studying the effect of microbial community structure on functions, as well as the microbial effect on soil carbon properties, is necessary for better understanding the belowground processes affecting carbon dynamics [25,26].…”