Environmental drivers of forest structure and stem turnover across Venezuelan tropical forests

Autor: Gerardo Aymard, Lionel Hernández, Geertje M. F. van der Heijden, Luis E. Gámez, Hirma Ramírez-Angulo, Emilio Vilanova, Gregory J. Ettl, Cristabel Durán, Oliver L. Phillips, Armando Torres-Lezama, Rafael Herrera
Jazyk: angličtina
Rok vydání: 2018
Předmět:
0106 biological sciences
010504 meteorology & atmospheric sciences
Rain
Plant Science
Forests
01 natural sciences
Trees
Tropical climate
Biomass
Biomass (ecology)
Principal Component Analysis
Multidisciplinary
Ecology
Plant Anatomy
Temperature
Eukaryota
Plants
Terrestrial Environments
Wood
Alluvial plain
Productivity (ecology)
Regional variation
Research Design
Medicine
Seasons
Research Article
Census
Ecological Metrics
Death Rates
Science
Biomass (Ecology)
Climate change
Context (language use)
Research and Analysis Methods
010603 evolutionary biology
Ecosystems
Population Metrics
Precipitation
0105 earth and related environmental sciences
Tropical Climate
Survey Research
Population Biology
Productivity (Ecology)
Ecology and Environmental Sciences
Organisms
Biology and Life Sciences
15. Life on land
Venezuela
Carbon
Earth Sciences
Environmental science
Zdroj: PLoS ONE
PLoS ONE, Vol 13, Iss 6, p e0198489 (2018)
ISSN: 1932-6203
Popis: Using data from 50 long-term permanent plots from across Venezuelan forests in northern South America, we explored large-scale patterns of stem turnover, aboveground biomass (AGB) and woody productivity (AGWP), and the relationships between them and with potential climatic drivers. We used principal component analysis coupled with generalized least squares models to analyze the relationship between climate, forest structure and stem dynamics. Two major axes associated with orthogonal temperature and moisture gradients effectively described more than 90% of the environmental variability in the dataset. Average turnover was 1.91 ± 0.10% year-1 with mortality and recruitment being almost identical, and close to average rates for other mature tropical forests. Turnover rates were significantly different among regions (p < 0.001), with the lowland forests in Western alluvial plains being the most dynamic, and Guiana Shield forests showing the lowest turnover rates. We found a weak positive relationship between AGB and AGWP, with Guiana Shield forests having the highest values for both variables (204.8 ± 14.3 Mg C ha-1 and 3.27 ± 0.27 Mg C ha-1 year-1 respectively), but AGB was much more strongly and negatively related to stem turnover. Our data suggest that moisture is a key driver of turnover, with longer dry seasons favoring greater rates of tree turnover and thus lower biomass, having important implications in the context of climate change, given the increases in drought frequency in many tropical forests. Regional variation in AGWP among Venezuelan forests strongly reflects the effects of climate, with greatest woody productivity where both precipitation and temperatures are high. Overall, forests in wet, low elevation sites and with slow turnover stored the greatest amounts of biomass. Although faster stand dynamics are closely associated with lower carbon storage, stem-level turnover rates and woody productivity did not show any correlation, indicating that stem dynamics and carbon dynamics are largely decoupled from one another.
Databáze: OpenAIRE
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