Combined impact of moss crust coverage rates and distribution patterns on wind erosion using beryllium-7 measurements

Abstract

Although biological soil crusts (BSCs) provide considerable control over wind erosion in arid and semiarid regions, understanding of BSCs coverage rates and distribution patterns impacts on wind erosion is remain limited, which further causes poor quantification of BSCs factors in wind erosion prediction models. This study estimated wind erosion affected by moss crust coverage rates and distribution patterns using the weighting approach and beryllium-7 measurements through wind tunnel experiments, and screened factors that significantly influence wind erosion based on landscape metrics and multiple linear regression. Results showed that both moss crust coverage and distribution pattern significantly affected wind erosion and deposition. When moss crust coverage increased from 10% to 80%, average erosion rates in bare soil areas of trays almost all decreased logarithmically from 623.0 to 27.4 g m−2 min−1, while the average deposition rates in moss crust covered areas decreased from −21.7 to −16.7 g m−2 min−1. Moss crust located at the middle area of trays (SCS) showed better overall erosion control effects, while moss crust located at downwind of sand (SC) showed better sediment trapping effects compared to other distribution patterns when moss crust coverage was the same. The SCS and SC patterns decreased wind erosion and deposition rates reached up to 81.9% and 38.0%, respectively. Moreover, wind erosion rates when arranged moss crust parallel to the wind direction resulted in significantly higher soil erosion (i.e., by a factor up to 7.3) compared to that of perpendicular to the wind direction. Stepwise regression showed that only wind velocity and moss crust coverage were included in the linear regression equation with a relatively low R2 value (R2 = 0.35), but excluded other landscape metrics. This is indicated the importance of developing composite indices and their associative algorithms should be considered when quantifying spatial distribution impacts of BSCs on wind erosion.