Neighborhood structure, more than soil nutrients, influences net tree interactions among different functional types in a temperate forest

Autor: Tingting Liu, Xuetao Qiao, Minhui Hao, Chunyu Fan, Juan Wang, Xiuhai Zhao, Chunyu Zhang
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Ecological Indicators, Vol 167, Iss , Pp 112666- (2024)
Druh dokumentu: article
ISSN: 1470-160X
DOI: 10.1016/j.ecolind.2024.112666
Popis: Tree-tree interactions are fundamental in shaping forest community dynamics, driven by factors such as nutrient availability and species composition. While recent research underscores the role of functional traits in influencing tree sensitivity to neighborhood interactions, a clear consensus is lacking on how these traits interact with biotic and abiotic factors. Based on a multi-level modeling approach, this study examines how specific leaf area (SLA), potential maximum tree height (Hmax), and wood density (WD) mediate the combined effects of soil nutrients and neighborhood biotic factors on net tree interactions among 4,210 individual stems for 13 species in a 30-ha temperate forest in northeastern China. The findings indicate that while functional traits independently account for a small portion of the variation in net tree interaction intensity (NIntC), they significantly mediate the effects of neighborhood crowding, neighborhood structure, and soil nutrients on NIntC. Specifically, only the response of growth NIntC of species with low-Hmax to available phosphorus (AP) was consistent with the stress gradient hypothesis. Conspecific neighborhood crowding consistently increases competitive NIntC, whereas heterospecific neighborhood crowding significantly facilitates survival NIntC. Moreover, the positive impact of heterospecific crowding on survival NIntC is significantly greater for high-Hmax species compared to low-Hmax species. Neighborhoods with higher tree species diversity, greater size heterogeneity, and more uniform distribution increase the facilitative NIntC of high-SLA or high-WD species but intensify the competitive NIntC of low-SLA or low-WD species. Our results also indicate that the relative importance of neighborhood structure exceeds that of soil nutrients in explaining variation in NIntC. When environmental conditions are difficult to change, adjusting the forest stand structure may be a more efficient way to regulate the intensity of interactions between trees and improve forest productivity.
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