Trait interactions effects on tropical tree demography depend on the environmental context

Although functional traits are defined based on their impact on demographic parameters, trait-demography relationships are often reported as weak. These weak relationships might be due to disregarding trait interactions and environmental contexts, which should modulate species trait-demography relationships. We applied different models, including boosted regression tree (BRT) models, to investigate changes in the relationship between traits and demographic rates of tropical tree species in plots along an elevational gradient and among time intervals between censuses, analyzing the effect of a strong drought event. Based on a large dataset of 18,000 tree individuals from 133 common species, distributed among twelve 1-ha plots (habitats) in the Atlantic Forest (Brazil), we evaluated how trait interactions and the environmental context influence the demographic rates (growth, mortality, and recruitment). Functional traits, trait-trait, and trait-habitat interactions predicted demography wi..., Data from forest inventories conducted in twelve 1-ha plots distributed in undisturbed areas of “Restinga” (one plot), Lowland forest (four plots), Submontane forest (four plots), and Montane forest (three plots) of the Serra do Mar. All woody stems (trees, palms, and tree ferns) with a diameter at breast height (DBH) equal to or larger than 4.8 cm were tagged, taxonomically identified, and measured for diameter and re-censused four times over 12 years (2005 – 2016). The forest inventories database represents 22,770 stems from 21,509 tree individuals belonging to 685 species from 70 botanical families. For each species, we collected data on six functional traits representing the leaf, seed, and wood economics spectra. We measured leaf area (LA, cm2), leaf dry matter content (LDMC, mg g- 1), and specific leaf area (SLA, cm2 g- 1) from ten leaves of ten individuals per species.  As a measure of the species’ potential size, hereafter referred to as ‘DBH’, we calculated the 0.95 percentile ...,