How Does Forest Management Affect Soil Dynamics?

Forest management practices can have both positive and negative effects on the dynamics of soil properties and can significantly influence the soil structure, nutrient cycling, organic matter content, and microbial activity. Sustainable management approaches aim to minimize soil disturbance, maintain soil fertility, and promote long-term ecosystem health and resilience.

This Special Issue presents a collection of nine papers—seven based on original data and two comprehensive reviews. The publications collected in this “How does Forest Management affect Soil Dynamics?” Special Issue address these challenges comprehensively and in an interdisciplinary manner. The studies were carried out in a wide range of locations such as Taiwan, China, Chile, and Romania. They present results derived from experimental studies on important topics such as the insights into how roots anchor plants within soil matrices, the influence of plants’ introduction into an agroforestry system on the microbial resource limitations, the effects of thinning infected trees and cultivating resistant pines on soil microbial diversity and function, the impact of acid rain and vegetation clearing on soil biological function, the effects of natural regeneration following severe disturbance, changes in soil microbial communities in extreme desert areas due to various long-term management techniques, improving microbial carbon dynamics in pine forests, and how enzyme stoichiometry highlights microbial nutrient relief through nitrogen fertilization. Further, the Special Issue presents two review papers that contribute to our understanding of the forest soil carbon responses to timber harvesting and prescribed burns and of the microbial networks in forest soils (a 20-year research review).

Fan et al. [1] investigated the soil reinforcement capabilities of the Pachi bamboo root system through in situ shear and pullout tests. They determined that the root diameter is positively correlated with the tensile strength and elastic modulus. Pachi bamboo, which grows in dense clusters with deep clumping roots, significantly enhances the slope stability—especially at shallow depths—due to its extensive root network. The study confirmed that root reinforcement is closely linked to the number, size, and cross-sectional area of bamboo culms in a cluster. Simple formulas were developed to estimate the root resistance based on these culm characteristics. Over a 10-year span, the culm density within clusters increased, further improving the soil stabilization. These results highlight the practical potential of Pachi bamboo for slope protection and in ecological engineering.

In a complex study, Zhang et al. [2] highlighted how different interventions impact soil microbes and provided valuable insights for sustainable pine forest ecosystem management following nematode infestation. After pine forests were affected by pine wood nematode, different management strategies—removing infected trees (sanitation-thinned plots) or planting disease-resistant species (Pinus thunbergii and Pinus taeda)—led to notable differences in the soil microbial communities. The disease-resistant pine plots showed higher enzyme activities and distinct bacterial and fungal community structures compared to the sanitation-thinned plots. The soil moisture, pH, and potassium levels were key factors influencing the microbial community composition. Additionally, wood-decomposing and ectomycorrhizal fungi were more abundant in the resistant pine plots. The authors developed formulas to quantify the microbial community changes based on these environmental factors and management practices.

Another study examined how simulated acid rain and the removal of understory vegetation affected the soil biological activity in a Cinnamomum camphora plantation. He et al. [3] determined that acid rain significantly changed the soil organic carbon, CO₂ emissions, enzyme activity, and microbial community structure. Removing understory vegetation reduced the soil moisture and nutrient availability, disrupted the enzyme balance, and shifted microbial communities. The bacterial diversity increased but with decreased stability, while fungal communities were more resilient, due to their metabolic traits. The study revealed that bacterial instability was linked to carbon limitation, whereas fungal stability related to phosphorus limitation. Overall, the findings highlight the crucial role of understory vegetation in maintaining soil health and emphasize the need for integrated forest management to protect soil ecosystems in subtropical plantations.

Ortiz et al. [4] determined that passive post-disturbance management of native Nothofagus forests in south-central Chile led to similar nutrient levels, water cycling capacity, and a decline in soil carbon sequestration over 45 years. The dominance of the opportunistic grass Chusquea sp. limits understory diversity and ecosystem recovery despite providing soil protection. The soils showed resilience, but active scarification and agroforestry are recommended to enhance regeneration and productivity. The authors highlighted that further research is needed on the carbon dynamics and microbial communities to better understand soil carbon stabilization.

Soil microbiome transition areas were analyzed by Zhang et al. [5] in relation to different long-term management methods over a period of 13 years. The research was oriented to respond to vegetation loss due to extreme management through excessive cutting or plant burning. Both bacterial and fungal communities were influenced by soil organic carbon, while the microbial community structure exhibited shifts from the control to floodwater irrigation. The results reinforce the need for the application of carefully regulated cutting and burning practices, to optimize plant regeneration and soil enrichment with nutrients from organic matter decomposition by microorganisms, which will ensure long-term resilience and productivity in dessert ecosystems.

Rui et al. [6] studied soil extracellular enzyme activity and stoichiometry in a complex experiment on the cultivation of Panax notoginseng (Sanqi) within the Pinus armandii forest. Their research aimed to explore the impact of P. armandii monoculture and the Sanqi–P. armandii agroforestry system in terms of the soil quality and the interactive effects of the season, plant introduction, soil compartments, and nutrient limitation on soil microorganisms. Their findings showed that N, rather than P, restricts the microbial metabolism under both cultivation systems. Based on the results, the authors recommend the application of organic fertilizers to support the sustainable development of Sanqi–P. armandii agroforestry system and to alleviate microbial N limitations.

The microbial activity in the soil of a Moso bamboo forest under a gradient of N application was the focus of research conducted by Chu et al. [7]. The results showed that the application of N fertilizer alleviated the C and N limitation of microorganisms. Another important aspect was that N application altered the soil nutrient resources and modulated the microbial strategy for nutrient acquisition. Their findings provide a good theoretical base for the development of new fertilizer application strategies based on microbial nutrient requirements, to obtain sustainability in the management of Moso bamboo forests.

A global meta-analysis on the impact of clearcutting, thinning, and prescribed burning on soil carbon dynamics was conducted by Ono and Noormets [8]. The authors analyzed a database of 414 observations from 110 studies to quantify the impact of the management type on soil respiration and its associated biophysical and soil variables. Both clearcutting and prescribed burning produced a decline in soil respiration, although acting in a different manner—through the removal of crowns, which reduces the carbon supply, and through detritus combustions, which also kill roots and microorganisms. Thinning does not significantly affect the soil respiration components, due to its minor impact on belowground compartments and the compensatory growth of the remaining trees. Long-term field experiments are important for future research, to increase the understanding of carbon stabilization.

A review of the key research from 2003 to 2023 was conducted by Oneț et al. [9], aiming to respond to a series of questions related to the forest soil microbiome and its responses to ecological disturbances. Their findings show that forest microbiomes are shaped by both the soil and plant type. The high impact on microbial community assemblage is related to the nutrient levels, soil fertility, successional stages of the forest, and disturbance patterns. The forest microbiome presents variable dynamics in relation to seasonal conditions, applied management on forest species, and long-term environmental shifts. For a deeper understanding of the complex soil microbiome, the authors propose long-term interdisciplinary studies to forecast the shifts in microbial communities due to environmental and anthropogenic disturbances.

We would like to thank all the authors for their contributions to these important topics. Understanding microbial systems, community structures, and responses to management interventions is essential for gaining a deeper understanding of ecosystem functioning. It is our expectation that this Special Issue of Forests will offer a robust platform for future scholarly inquiry into this vital area of research.