Increased belowground tree carbon allocation in a mature mixed forest in a dry versus a wet year.
Glob Chang Biol
; 30(2): e17172, 2024 Feb.
Article
en En
| MEDLINE
| ID: mdl-38343030
ABSTRACT
Tree species differ in their carbon (C) allocation strategies during environmental change. Disentangling species-specific strategies and contribution to the C balance of mixed forests requires observations at the individual tree level. We measured a complete set of C pools and fluxes at the tree level in five tree species, conifers and broadleaves, co-existing in a mature evergreen mixed Mediterranean forest. Our study period included a drought year followed by an above-average wet year, offering an opportunity to test the effect of water availability on tree C allocation. We found that in comparison to the wet year, C uptake was lower in the dry year, C use was the same, and allocation to belowground sinks was higher. Among the five major C sinks, respiration was the largest (ca. 60%), while root exudation (ca. 10%) and reproduction (ca. 2%) were those that increased the most in the dry year. Most trees relied on stored starch for maintaining a stable soluble sugars balance, but no significant differences were detected in aboveground storage between dry and wet years. The detailed tree-level analysis of nonstructural carbohydrates and δ13 C dynamics suggest interspecific differences in C allocation among fluxes and tissues, specifically in response to the varying water availability. Overall, our findings shed light on mixed forest physiological responses to drought, an increasing phenomenon under the ongoing climate change.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Árboles
/
Carbono
Idioma:
En
Revista:
Glob Chang Biol
Año:
2024
Tipo del documento:
Article
País de afiliación:
Israel
Pais de publicación:
Reino Unido