Soil microbial activity is resistant to recreational camping disturbance in a Prosopis dominated semiarid savanna

Abstract:

Recreational camping has been shown to suppress plant cover and expand bare ground area in temperate and mesic ecosystems. These shifts have important implications for soil health. We used campsites at the Santa Rita Experimental Range (SRER) in Arizona to test the hypotheses that 1) recreational camping also limits plant cover and soil microbial activity in semiarid savannas, and 2) the presence of Prosopis, which is known to encourage a fertile island effect, increases soil microbial activity within campsites. Camping disturbance did not influence edaphic measures, plant cover, or soil microbial biomass and exoenzyme activities. However, the presence of Prosopis resulted in elevated litter, total dissolved nitrogen (TDN), and dissolved organic carbon (DOC). Multiple linear regression models suggest that observed resistance of soil microbial activities to camping disturbance may be due to both increased availability of organic C and N substrates beneath Prosopis and heightened seasonal water availability.