Tree Canopies Drive δ<sup>13</sup>C and δ<sup>15</sup>N Patterns in Mediterranean Wood Pastures of the Iberian Peninsula

Mediterranean wood pastures are the result of traditional silvo-pastoral uses that shaped these ecosystems into a mosaic of trees and open grassland. This ecosystem structure is generally associated with increased soil fertility under tree canopies. However, the response of herbaceous plant function...

Full description

Saved in:
Bibliographic Details
Main Authors: Mercedes Ibañez, Salvador Aljazairi, María José Leiva, Cristina Chocarro, Roland A. Werner, Jaleh Ghashghaie, Maria-Teresa Sebastià
Format: Article
Language:English
Published: MDPI AG 2025-05-01
Series:Land
Subjects:
Online Access:https://www.mdpi.com/2073-445X/14/6/1135
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Mediterranean wood pastures are the result of traditional silvo-pastoral uses that shaped these ecosystems into a mosaic of trees and open grassland. This ecosystem structure is generally associated with increased soil fertility under tree canopies. However, the response of herbaceous plant functional types (PFTs)—grasses, legumes, and non-legume forbs—to these heterogeneous microenvironments (under the canopy vs. open grassland) remains largely unknown, particularly regarding carbon (C) and nitrogen (N) acquisition and use. Even less is known about how different tree species and environmental conditions influence these responses. In this study, we aim to assess how tree canopies influence carbon and nitrogen cycling by comparing the effects of traditional oak stands and pine plantations on herbaceous PFTs and soil dynamics. For that we use C and N content and natural isotopic abundances (δ<sup>13</sup>C and δ<sup>15</sup>N) as proxies for biogeochemical cycling. Our results show that ecosystem C and N patterns depend not only on herbaceous PFTs and the presence or absence of tree canopies but also on tree species identity and environmental conditions, including climate. In particular, pine-dominated plantations exhibited lower nitrogen availability compared to those dominated by oak, suggesting that oak stands may contribute more effectively to enhance soil fertility in Mediterranean wood pastures. Furthermore, the canopy effect was more pronounced under harsher environmental conditions, highlighting the role of trees in buffering environmental stress, particularly in arid regions. This suggests that changes in tree cover and tree species may drive complex changes in ecosystem C and N storage and cycling.
ISSN:2073-445X