Comment on egusphere-2025-2660

Abstract

<strong class="journal-contentHeaderColor">Abstract.</strong> Agroforestry systems &mdash; combining trees with crops and/or livestock &mdash; are increasingly promoted as sustainable and climate-resilient land-use strategies. Despite their widespread presence in the Sahel, experimental data on their potential as carbon sinks are scarce. This study presents a full-year, high-frequency dataset of CO₂ fluxes in a Sahelian agro-silvo-pastoral parkland dominated by <em>F. albida</em>, located in Senegal&rsquo;s groundnut basin. CO₂ fluxes were continuously measured using automated static chambers, allowing the quantification of soil and crop respiration (Rch), gross primary production (GPPch), and net carbon exchange (FCO₂ch) under both full sun and shaded (under tree canopies) environments. Seasonal patterns of CO₂ fluxes were similar in both environments, with peaks during the rainy season. Rch and GPPch were significantly higher under tree canopies, indicating a &lsquo;fertile island&rsquo; effect. CO₂ flux variability was primarily driven by soil moisture and leaf area index. Chamber-based GPP estimates closely matched those from Eddy Covariance measurements. On an annual scale, <em>F. albida</em> trees contributed approximately 50 % of total ecosystem GPP, with a carbon use efficiency of 0.48. Net annual CO₂ exchange was estimated at &minus;1.4 &plusmn; 0.02 and &minus;1.8 &plusmn; 0.01 Mg C-CO₂ ha⁻&sup1; using chamber and Eddy Covariance methods, respectively. These findings underscore the role of <em>F. albida</em>-based agroforestry systems as effective carbon sinks in Sahelian landscapes, supporting their potential contribution to climate change mitigation.