Effect of coppice conversion into high forest on soil organic C and nutrients stock in a Turkey oak (Quercus cerris L.) forest in Italy

Recover of Soil Microbial Community Functions in Beech and Turkey Oak Forests After Coppicing Interventions

Forest management influences the occurrence of tree species, the organic matter input to the soil decomposer system, and hence, it can alter soil microbial community and key ecosystem functions it performs. In this study, we compared the potential effect of different forest management, coppice and high forest, on soil microbial functional diversity, enzyme activities and chemical-physical soil properties in two forests, turkey oak and beech, during summer and autumn. We hypothesized that coppicing influences soil microbial functional diversity with an overall decrease. Contrary to our hypothesis, in summer, the functional diversity of soil microbial community was higher in both coppice forests, suggesting a resilience response of the microbial communities in the soil after tree cutting, which occurred 15-20 years ago. In beech forest under coppice management, a higher content of soil organic matter (but also of soil recalcitrant and stable organic carbon) compared to high forest can explain the higher soil microbial functional diversity and metabolic activity. In turkey oak forest, although differences in functional diversity of soil microbial community between management were observed, for the other investigated parameters, the differences were mainly linked to seasonality. The findings highlight that the soil organic matter preservation depends on the type of forest, but the soil microbial community was able to recover after about 15 years from coppice intervention in both forest ecosystems. Thus, the type of management implemented in these forest ecosystems, not negatively affecting soil organic matter pool, preserving microbial community and potentially soil ecological functions, is sustainable in a scenario of climate change.

Holm oak (Quercus ilex L.) cover: A key soil-forming force in controlling C and nutrient stocks in long-time coppice-managed forests

In forest ecosystems, soil-plant interactions drive the physical, chemical, and biological soil properties and, through soil organic matter cycling, control the dynamics of nutrient cycles. Parent material also plays a fundamental role in determining soil's chemical properties and nutrient availability. In this study, eight long-time coppice-managed Holm oak forests under conversion to high forest, located under similar climatic conditions in Tuscany and Sardinia Regions (Italy), and grown on soils developed from three different lithologies (limestone, biotite granite, and granite with quartz veins) were evaluated. The research aimed to a) estimate the amount of C and nutrients (total N and potentially available P, Ca, Mg, and K) stored both in the organic, organo-mineral, and mineral horizons and at fixed depth intervals (0-0.3 and 0.3-0.5 m), and b) assess the dominant pedological variables driving elemental accumulation. The soils were described and sampled by genetic horizons and each sample was analyzed for its C and nutrient concentration in both the fine earth and skeleton fractions. Despite the different parent materials from which the soils had evolved, the physicochemical properties and the C and nutrient stocks for the 0-0.3 and 0.3-0.5 m layers did not show substantial differences among the eight soils. Conversely, some differences were observed in the stocks of potentially available P and Ca per 0.01 m of mineral horizons. The findings show that over time, plant-induced pedogenic processes (acidification, mineral weathering, organic matter addition, and nutrient cycling) almost obliterated the influence of parent materials on soil properties. This resulted in the upper soil horizons that showed similar characteristics, even though derived from different lithologies. However, among the study sites, some differences occurred due to lithology, as in the case of the soils derived from calcareous parent materials that had high concentrations of exchangeable Ca in the mineral horizons and, likely, to environmental variables (e.g., exposure), which possibly influenced litter degradation and the release of nutrients such as N and available P.

Depth-to-Water Maps to Identify Soil Areas That Are Potentially Sensitive to Logging Disturbance: Initial Evaluations in the Mediterranean Forest Context

Scientific research on reduced-impact logging has been addressed to develop effective approaches and methodologies to limit soil disturbance caused by forest operations. In recent years, the development of soil trafficability maps based on soil wetness indices is the approach that has been extensively used in the context of the Boreal forests. In particular, the depth-to-water (DTW) index has been identified as an interesting solution for the identification of areas particularly sensitive to soil disturbance. This study aimed to evaluate the cost-benefit factor of DTW maps for the identification of soil-sensitive areas in the Mediterranean context. In particular, a DTW map was developed for two oak coppice areas located in Italy and harvested over a period of 2–4 years with different mechanisation levels. Soil surveys concerning soil moisture, physico-chemical properties (bulk density, penetration resistance, shear resistance, organic matter), and biological properties (soil microarthropods community measure via soil biological quality (QBS-ar) index) were carried out in these forests, checking for significant differences between the zones at DTW index ≤1 (which should be more sensitive to soil disturbance) and the other areas of the forest soil. The results obtained revealed the efficiency of a DTW index in potential areas at a higher level of soil moisture. On the other hand, the values of soil physico-chemical properties in the areas at a DTW index ≤1 did not differ significantly from the ones in other zones. However, the values of the QBS-ar index in areas with a low DTW index were significantly lower than the ones in zones at the DTW index >1. Therefore, the obtained findings reveal that the DTW index is a reliable tool to identify and predict which areas are more prone to impact soil biological properties.