Ecoenzymatic stoichiometry at the extremes: How microbes cope in an ultra-oligotrophic desert soil. (August 2015)

• Record Type: Journal Article
• Authors: Tapia-Torres, Yunuen; Elser, James J.; Souza, Valeria; García-Oliva, Felipe
• Is Part Of: Soil biology and biochemistry. Volume 87(2015)
• Page Start: 34
• Page End: 42
• Publication Date: 2015-08
• Subjects: Chihuahuan desert -- Ecological stoichiometry -- Enzyme -- México -- Microbial community homeostasis -- Threshold elemental ratio; Soil biochemistry -- Periodicals; Soil biology -- Periodicals; Sols -- Biochimie -- Périodiques; Sols -- Biologie -- Périodiques; Sols -- Microbiologie -- Périodiques; Bodembiologie; Biochemie; 631.46
• DOI: 10.1016/j.soilbio.2015.04.007
• Languages: English
• ISSNs: 0038-0717

Abstract

Abstract: Arid ecosystems are characterized by stressful conditions of low energy and nutrient availability for soil microorganisms. It has been observed that the ecoenzymes needed for the transformation of organic compounds into assimilable products show similar scaling relationships in different habitats (logarithmic C:N:P scaling ratios ∼1:1:1). In this study in Cuatro Ciénegas Basin (CCB) in the Chihuahuan desert of México, we report among the lowest ecoenzymatic activities yet quantified in soil. Nevertheless, activities for both organic N and organic P acquisition enzymes scale with C acquisition with a slope of ∼1.0, indicating that the soil microbial communities of this ultra-oligotrophic desert ecosystem follow the global ecoenzymatic stoichiometry patterns. CCB soil microbial communities were co-limited by C and either by N or P but this co-limitation played out differently in different parts of the CCB as indicated by microbial ecoenzymatic shift to allocate more resources to acquire and immobilize the scarcer nutrient. By extending ecoenzymatic analyses to these ultra-oligotrophic soils, our findings support the broad utility of the approach in illuminating how microbes acquire limiting resources in arid ecosystems. Highlights: The slope of ecoenzyme activity stoichiometry for C:N:P is ∼1.0. Soil microbial communities are co-limited by C and either by N or by P. Soil microbial communities allocate more energy for the acquisition of the scarcer nutrient. The soil ecoenzymatic activities found in this ultra-oligotrophic site are among the lowest reported.