Differences in Soil Respiration across a Successional Gradient in a Tropical Dry Forest from Northwestern Mexico
Abstract
Soil respiration (Rs) is an important component of the carbon (C) cycle due to the significant CO2 efflux to the atmosphere as a result of the metabolism and respiration from plants (i.e., roots) and microorganisms (i.e decomposers). Tropical dry forests (TDF) from northwestern Mexico are seasonally dry; thus, the peak of Rs rates occur during the wet season, usually influenced by the North American Monsoon System. However, the relative importance of the controlling biophysical mechanisms and flux magnitudes along successional gradients are still poorly understood. In this study, we present the analysis of three years (2015 to 2017) of systematic quasi-monthly measurements of Rs with static chambers in TDF sites with different land uses: an old-growth (OG), a mid-succession (MS), and an early succession (ES). During the study period, Rs magnitudes from the dry season were similar among sites (between 0.96-1.31 μmol CO2 m-2 s-1). In contrast, during the wet season, Rs rates in OG were consistently higher than in MS and ES, reaching rates of 10.19 μmol CO2 m-2 s-1. We identified by the end of wet season that Rs rates in OG were sustained by a longer time period, while in MS and ES, Rs decreased according to the moisture availability in the system. A preliminary statement about why Rs among study sites is highly variable (particularly in OG) are biophysical factors and biological processes related to features in the microbiota, substrate availability (i.e. litterfall) and decomposition rates, as well as, the influence of the antecedent moisture, instead of temperature.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMB046.0010V
- Keywords:
-
- 0414 Biogeochemical cycles;
- processes;
- and modeling;
- BIOGEOSCIENCES;
- 0428 Carbon cycling;
- BIOGEOSCIENCES;
- 0495 Water/energy interactions;
- BIOGEOSCIENCES