Abstract
The effects of forest management on carbon (C) sequestration are poorly understood, particularly in the Three Gorges Reservoir area. We aimed to identify the effects of forest management on C sequestration in Pinus massoniana plantations. An intact control forest (CK), a site undergoing regular shrub cutting with the simultaneous removal of residues (SC), a site under low-intensity thinning (LIT), and a site under high-intensity thinning (HIT) were compared for soil labile organic carbon (LOC), related enzyme activities, and soil characteristics. Soil organic carbon (SOC) significantly decreased in the HIT treatment as compared with that in the CK treatment. Soil EOC, DOC, MBC contents in treated plots were higher than those in the CK treatment; particularly, the HIT treatment significantly increased those values in 0–10 cm layer. Thinning resulted in a decrease in cellulase and amylase activities, but an increase in invertase activity. In addition, the SOC content was significantly correlated with four enzymes activities and LOC components, which suggested that the soil LOC components and enzymes activities were sensitive to the changes of SOC. Our results suggest that high-intensity thinning treatment in Pinus massoniana plantation could significantly decrease the SOC content and lead to an increase of LOC components.
Highlights
The effects of forest management on carbon (C) sequestration are poorly understood, in the Three Gorges Reservoir area
Soil total nitrogen (TN), total phosphorous (TP), available potassium (AK), NH4+–N, and NO3−–N contents decreased with increasing soil depth while soil pH increased with increasing depth, significant difference were only observed in the soil TN content and pH among the soil layers (p < 0.05)
This study demonstrates the distribution of chemical properties of soil, labile organic carbon (LOC) fractions, and enzyme activities, and provides insight into their relationships in Pinus massoniana plantations under different forest management approaches
Summary
The effects of forest management on carbon (C) sequestration are poorly understood, in the Three Gorges Reservoir area. The activities of enzymes related to the soil C cycle (e.g., invertase, amylase, and cellulase) participate in the SOC decomposition and indicate the status of the available C resources These enzyme activities can contribute to our understanding of the variations in SOC in response to forest management[13,14]. Short-term studies have revealed that thinning consistently decreases aboveground C26,29, indicating that low densities of small trees do not fully offset the loss of C30 It is still unclear whether forest management strategies are compatible with the purpose of increasing forest C storage for climate change mitigation. Exploring the effects and mechanisms affecting forest management strategies on SOC sequestration is a key research area in both forestry and C cycling science, while relatively less attention was paid to the effect of short-term forest management activities on soil LOC fractions[31]. In recent years, recreating forest structures and optimizing the use of soil by forest management activities were a major focus of the sustainable management of Pinus massoniana aimed at maintaining ecosystem sustainability and soil productivity[12]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
