Interannual Variation and Control Factors of Soil Respiration in Xeric Shrubland and Agricultural Sites from the Chihuahuan Desert, Mexico

Arid and semi-arid ecosystems dominate the RS variability due to the multiple changing factors that control it. Consequently, any variation, in addition to climate change and land use change, impacts the concentration of CO2 in the atmosphere. Here, the effect of the interannual variation and the controlling factors of RS in native xeric shrublands and agricultural systems is investigated. This study was conducted in four sites per condition for two years (2019 to 2020), where RS and the soil properties were measured. The RS presented a higher variation in the xeric shrubland. The agricultural plots showed the highest RS (0.33 g CO2 m−2 hr−1) compared to the xeric shrubland (0.12 g CO2 m−2 hr−1). The soil water content was the main controlling variable for RS in both land uses. However, soil temperature affected RS only in agricultural plots. The variation in the RS under different land uses confirms that changes in the soil and environmental conditions (i.e., season) control the RS. In addition, if current management practices are maintained in agricultural sites and under a temperature increase scenario, a significant increase in the RS rate is expected.