Variance in annual biomass change of Amazonian experimental logged forests and relationships to atmospheric fluctuations
Abstract
Tropical forests account for about 8 % of earth's land surface and are responsible for capturing over 25 percent of the world's carbon, with the Amazon basin alone absorbing 2 billion tons of carbon dioxide a year. However, increased deforestation and forest degradation arising from natural disturbances as well as from human activities such as logging and farming interests, in addition to tree stress and death caused by rising temperatures and increasing drought, have escalated carbon emissions from tropical forests thereby threatening its capacity to remain as a carbon sink. On the other hand, several studies have shown that biomass accumulation of amazon forests has been spiraling upward over the years as a result of spurred tree growth from increased CO 2 fertilization levels. As a consequence, understanding and quantifying forest structural dynamics and year-to-year aboveground biomass fluctuations as a function of climatic variations is vital for efficient carbon cycle modeling. The primary objective of this study is to evaluate the interrelationship between climate fluctuations - measured in terms of anomalies in precipitation, temperature, vapor pressure deficit (VPD), dry season/drought indices (SPEI), number of consecutive dry days, etc. - and annual variance in biomass increment of selectively logged forest. We hypothesize that the variation of year-to-year CO 2 accumulation in aggrading stand patches is significantly more sensitive to environmental variations as compared to undisturbed forest areas. We present our work based on a one-of-its-kind, over 30-year [1986-2019] record of annual forest inventories data of terra firme old-growth forest plots (12 ha) in Central Amazonia, which was collected as part of a controlled logging experiment under the BIONTE (Biomass and Nutrient Experiment) initiative.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMB116.0027M
- Keywords:
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- 3305 Climate change and variability;
- ATMOSPHERIC PROCESSES;
- 3337 Global climate models;
- ATMOSPHERIC PROCESSES;
- 0414 Biogeochemical cycles;
- processes;
- and modeling;
- BIOGEOSCIENCES;
- 0426 Biosphere/atmosphere interactions;
- BIOGEOSCIENCES