Neighborhood Diversity Promotes Tree Growth in a Secondary Forest: The Interplay of Intraspecific Competition,...

Area of Science:

• Ecology
• Forest Science
• Biodiversity Research

Background:

• The biodiversity-productivity relationship (BPR) is vital for conservation and ecosystem management.
• Mechanisms driving forest productivity at local neighborhood scales are not fully understood.

Purpose of the Study:

• To investigate how neighborhood diversity, intraspecific competition, and interspecific competition affect tree growth across different spatial scales.
• To elucidate the interplay between biotic interactions and spatial scale in modulating tree growth.

Main Methods:

• Established a 9.6 ha dynamic forest plot.
• Analyzed tree growth using linear mixed-effects models.
• Quantified neighborhood species richness (NSR), conspecific and heterospecific densities, and resource competition.

Main Results:

• A significant positive correlation was found between neighborhood species richness (NSR) and relative growth rate (RGR).
• Intraspecific competition negatively impacted RGR at finer scales, while interspecific competition had negligible effects.
• The influence of diversity and competition on tree growth varied with spatial scale, with NSR's positive effect increasing at larger scales.

Conclusions:

• Intraspecific competition is a dominant negative factor at fine scales, whereas neighborhood diversity promotes growth at broader scales.
• Spatial scale significantly modulates the effects of biotic interactions on tree growth and the BPR.
• Understanding local interactions and spatial variability is crucial for accurate BPR studies and effective forest management.