Climate change has major impacts on biodiversity and may alter vital ecosystem services for human wellbeing. Tropical forests play a central role in carbon sequestration; however, human-driven disturbances have led the conversion of natural forest into agricultural lands for most of world's tropical biomes, which has resulted in the increase of secondary forests. Particularly, Upper Andean Tropical Forests (UATF) have been largely transformed for centuries, especially in Colombia where more than 70% of the original forest cover is fragmented or lost. To better understand carbon cycling dynamics, it is necessary to know the fluxes by which organic material is decomposed and reincorporated from soils and debris to plant tissues. In this regard, leaf-litter decomposition is one of the most important functions in the maintenance of productivity and carbon release, being directly involved in plant-soil interactions, but at the same time, is one of the less explored fluxes in UATF. Most of the knowledge about the determinants of leaf-litter decomposition comes from studies conducted in temperate ecosystems and lowland tropical forests, which have pointed out three main drivers of decomposition: environmental conditions, litter quality, and decomposer community. Nevertheless, these factors have been analyzed separately and a holistic framework including these components together with other ecological variables including the influence of plant diversity, above- and belowground productivity, successional stage and a detailed analysis of functional traits may provide key information to a comprehensive view of decomposition in UATF. This is especially true in the montane forests of Colombia where carbon dynamics remain poorly understood along the highly transformed peri urban forests of the Sabana de Bogotá. Therefore, this study aimed to understand the principal biotic and abiotic mechanisms involved in leaf-litter decomposition along a successional gradient of UATF and its linkages with soil carbon storage and forest productivity. To do so, I will (1) determine the relationships between decomposition rates of leaf-litter, leaf functional traits and edaphic conditions along a successional gradient of UATF, (2) establish the relationships between the underlying anatomical leaf traits, that are at the basis of the Leaf Economics Spectrum, and decomposition rates in UATF woody species, (3) analyze the influence of soil fauna community attributes on decomposition rates along a successional gradient in UATF, (4) develop a dynamic model that describe how soil physico-chemical and climatic conditions, soil fauna community attributes and functional traits explain decomposition rates and their linkages with carbon cycling along a successional gradient of UATF. The research will be performed in a network of 14 permanent plots of 400m2 around the Sabana de Bogotá in four localities. To study decomposition rates, I will perform a multiple-species translocation experiment with 15 representative species of the plots by using 2520 litterbags distributed in 42 experimental units (three litterbeds per plot) for 1.5 yearlong with four harvesting times (3,6,12,18 months). Litter communities will be collected through soil samples obtained in each litterbed as well as soil mesofauna found in each litterbag. A second experiment will be conducted testing the effect of soil macrofauna by using a litter mixture (6 spp.) with micro and mesofauna only (control) and micro, meso and macrofauna (treatment). Chemical, physical and anatomical traits will be measured to identify the better predictors of decomposition process. Finally, pre-existing measurements of soil carbon stocks, above- and belowground productivity obtained from the plots will be integrated into a dynamic model altogether with leaf functional traits, soil communities and environmental variables in a structural equation modeling to identify the factors that have a major influence on decomposition and how this is related to soil carbon storage and forest productivity. This analysis will also allow to better understand the carbon cycle along the successional gradient of UATF because integrates simultaneously the above- and belowground compartment in a single model.
Soil carbon storage; Climate gradient; Ecological succession; Soil communities; Trait-based approach; Tropical mountain forest
|Effective start/end date||1/12/23 → 1/12/25|
UN Sustainable Development Goals
In 2015, UN member states agreed to 17 global Sustainable Development Goals (SDGs) to end poverty, protect the planet and ensure prosperity for all. This project contributes towards the following SDG(s):
Main Funding Source
- Competitive Funds