Environmental and ecological factors influencing soil functionality of biologically crusted soils by different lichen species in drylands

Biocrusts are an essential soil surface cover at drylands where ecosystems especially fragile to degradation processes due climatic peculiarities. In the present work, (micro)biological and physicochemical properties indicative of functionality were studied in two different biocrust types dominated by Dipolschistes diacapsis Lepraria isidiata underlying depths (SL1, layer right below biocrusts, SL2, SL1) Tabernas desert (southeast Spain). The influence factors (rainfall temperature) general on also analyzed environmental (climatic) conditions over a period years. PERMANOVA analyses showed significant statistical differences (Pseudo-F = 63.9; P (perm) 0.001) among layers. Throughout study period, enzyme activities involved C, N, cycles; microbial biomass-C; basal respiration; several directly related ecosystem productivity (total organic carbon, total nitrogen, concentration ammonium nitrate) higher both than layers, showing that biocrusts improved functions nutrient cycling. These progressively diminished successive layers under (biocrusts > SL1 SL2). greater similarity each other SL2 properties. A distance-based linear model analysis rainfall, pH, mineralized N-NH4+, nitrogen most important variables for predicting biocrusts. Different biochemical behavior between has been found wet periods. After rainfall periods, peaks respiration C cycles. Nevertheless, hardly any peak did not change despite moisture being Correlation corroborated existence relationships enzymatic activities. number positive correlations with enzymes such as ?-glucosidase, invertase, phosphomonoesterase others, whereas it was only correlated cellulase dehydrogenase. regime, predicted models based climate arid semiarid zones, could affect activity thus aggravating these dryland ecosystems.