Meta-analysis of soil pore size distribution and its relationship with various soil properties and land management

The size distribution of soil pores is an important key characteristic of soil systems influencing soil functions such as the cycling of water as well as organic matter storage and dynamics. There is a lack of information about the pore size distribution considering a wide variety of soils and whether various soil characteristics pre-dominantly influence specific pore size ranges. Especially, pores with a diameter < 100 µm serve as a key driver of soil water holding capacity and as a habitat for soil microorganisms involved in the decomposition of organic matter. Here, we aim to contribute to the identification of size patterns in the soil pore size distribution and its relationships with soil biogeochemical matter cycles. In our contribution, we will present insights into our literature-based meta-analysis approach enabling relative comparisons by the integration of pore size distributions across different soils using a water retention curve model. To disentangle the effects of soil texture, soil type, organic matter content, and land management on soil pore size distribution, we used multivariate regression, path analysis, and random forest feature importance. By building a quantitative framework of interrelated controls on soil pore size distribution, we aim to discuss the current understanding of the soil pore network and its ecological functions.