This is a postdoctoral project involving Liting Zheng, Peter Reich and Kai Zhu.

High-frequency climate variability is threatening global forest ecosystems.

Research questions:

1)How do neighborhood interactions (mediated by the diversity of neighbors) influence tree growth?

2)How does climate variability (drier or wetter conditions) influence the strength of the neighborhood interaction effects on tree growth?

Figure 1. Study sites and example of trait-based neighborhood interactions. A, This study used tree growth data form ten tree diversity experimental sites. Within the site (e.g., MyDiv), a focal tree was determined and a fixed radius of 3m around a tree was used to define the area of a focal tree’s neighborhood. B, An example shows that a focal tree (tf) has neighbors (tn1 and tn2) with different functional traits. C, Two main trait-based neighborhood interaction effects on a focal tree’s growth. Hierarchical trait difference hypothesis: neighborhood interactions depend on the hierarchical trait differences between the focal tree and the neighbors. The more acquisitive traits (i.e., higher SLA and LNC and lower LDMC) of the focal tree than the neighbors, the higher competitive ability of the focal tree, which therefore increases the growth of the focal tree. Trait dissimilarity hypothesis: the more dissimilarity between the traits of focal tree and its neighbors, the lower intensity of competition between tree species,which therefore increases the growth of the focal tree.