Faculty of Life Science and Technology, Central South University of Forestry and Technology, Changsha, Hunan, China; Huitong National Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystems in Hunan Province, Huitong, Hunan, China.
Faculty of Life Science and Technology, Central South University of Forestry and Technology, Changsha, Hunan, China; Huitong National Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystems in Hunan Province, Huitong, Hunan, China; National Engineering Laboratory for Applied Technology of Forestry & Ecology in South China, Changsha, China.
Sci Total Environ. 2023 Jun 15;877:162894. doi: 10.1016/j.scitotenv.2023.162894. Epub 2023 Mar 21.
Thinning is a widely-used management practice to reduce tree competition and improve wood production and quality in forest plantations. Thinning affects the soil ecosystem by changing the microclimate and plant growth, as well as litter inputs above and belowground, with all the resulting consequences for microbial communities and functions. Although many case studies have been carried out, a comprehensive understanding of the thinning effects on soil properties and microbial communities and functions in plantations remains to be explored. In this study, a meta-analysis was performed on 533 paired observations based on 90 peer-reviewed articles to evaluate the general responses of soil (mainly 0-20 cm depth) physicochemical properties, microbial biomass and community structure, and enzyme activities to thinning. Results showed that thinning increased soil temperature (13 %), moisture (8.0 %), electric conductivity (13 %), and the contents of total nitrogen (TN, 4.1 %), dissolved organic carbon (DOC, 9.7 %), nitrate N (NO-N, 27 %) and available phosphorous (22 %). For microbial properties, thinning decreased the fungi to bacteria ratio (F:B, -28 %) and the gram-positive bacteria to gram-negative bacteria ratio (G+:G-, -12 %), while increased microbial biomass C (7.1 %), microbial respiration (13 %), and nutrient-cycle related enzyme activities, including phenol oxidase (14 %), cellobiohydrolase (21 %), urease (10 %), and acid phosphatase (9 %). In particular, moderate thinning (30-60 % intensity) has higher conservation benefits for soil C and nutrients than light and heavy intensity, thus being recommended as the optimal thinning activity. This meta-analysis suggests that thinning consistently altered soil properties, shifted microbial community compositions from K- to-r strategist dominance, and stimulated microbial activities. These results are essential for optimizing plantation thinning management and provide evidence for applying the macro-ecology theory to ecosystem disturbance in soil microbial ecology.
间伐是一种广泛应用的管理措施，用于减少树木竞争，提高人工林的木材产量和质量。间伐通过改变微气候和植物生长，以及地上和地下凋落物的输入，影响土壤生态系统，所有这些都会对微生物群落和功能产生影响。虽然已经进行了许多案例研究，但对于间伐对人工林土壤性质和微生物群落和功能的影响仍需要进行全面的了解。在这项研究中，对基于 90 篇同行评议文章的 533 对观测结果进行了荟萃分析，以评估土壤（主要是 0-20 cm 深度）理化性质、微生物生物量和群落结构以及酶活性对间伐的一般响应。结果表明，间伐增加了土壤温度（13%）、水分（8.0%）、电导率（13%）和总氮（TN，4.1%）、溶解有机碳（DOC，9.7%）、硝态氮（NO-N，27%）和有效磷（22%）的含量。对于微生物特性，间伐降低了真菌与细菌的比值（F:B，-28%）和革兰氏阳性菌与革兰氏阴性菌的比值（G+:G-，-12%），同时增加了微生物生物量 C（7.1%）、微生物呼吸（13%）以及与养分循环相关的酶活性，包括酚氧化酶（14%）、纤维二糖水解酶（21%）、脲酶（10%）和酸性磷酸酶（9%）。特别是，中度间伐（30-60%强度）比轻度和重度间伐对土壤 C 和养分具有更高的保护效益，因此被推荐为最佳间伐强度。这项荟萃分析表明，间伐一致地改变了土壤性质，使微生物群落组成从 K 策略者向 r 策略者转变，并刺激了微生物活性。这些结果对于优化人工林间伐管理至关重要，并为将宏观生态学理论应用于土壤微生物生态学中的生态系统干扰提供了证据。
