From landscape to ecosystem: across-scales functioning in changing environments (CRN 2005)
1) On the high slopes of the Venezuelan Andes, a winding treeline seems to be advancing upwards over the paramo vegetation due to the twentieth century climate warming.
2) Recurrent fires are crucial drivers controlling the distribution of montane forest and grasslands in the Sierras de Córdoba, Argentina. LEAF aims to understand the specific mechanisms involved in the maintenance of forest-grassland mosaics.
3) In the high and moist tablelands of Rio Grande do Sul, Brazil, mosaics of Araucaria forests, shrublands, natural grasslands and croplands seem to be under the control of climate, land forms, fire and grazing, overlying an extended history of climate fluctuations and ecosystem displacements.
Project information
Universidad de los Andes – Instituto de Ciencias Ambientales y Ecológicas (ICAE),Venezuela
This research continued in SGP-CRA 005, with the same title
Executive summary
How are ecosystem boundaries defined? How do they relate to water availability and climate; how do they shift under global change? Can we predict ecosystem displacements? This study compares the transition zones (ecotones) between forest and non-forest sites under different climate and land use pressures in one Canadian and four South American sites.
Goals
Analyze interactions between vegetation and environment in time and space
Identify current ecotones, and map past changes
Examine the processes of species colonization at ecosystem boundaries
Predict future advances of ecosystems over others under climate change
Indicate risks to ecosystem services when ecosystems are displaced
First results
Ecotones are explained by functional traits of plants that determine the plant’s vulnerability to climate change and human intervention. In the Andes, the boundary between páramo and forest is defined by the effect of temperature and its extremes on trees and on seedling success.Trees, once established, modify the environment to their own advantage, stabilizing the boundary. In contrast, human disturbance favors páramo species, moving the ecotone downward even against climate trends. In Southern Brazil, sediment cores show that forest-grassland boundaries have moved back and forth under variable climate over centuries.
The extensive (80%) deforestation of the Gran Chaco dry forest is due largely to land use, responding to remote markets -e.g., soybean- and facilitated by increasing rainfall.
In Canada and Brazil, increased atmospheric CO2 has increased tree productivity, but that effect is counter-balanced by decreasing water availability, now leading to declining tree growth.This challenges the assumption that increasing CO2 levels invariably boost plant growth.
The project has shown explicable interactions between anthropogenic and natural factors that define ecotones – this can now be explored for conservation and adaptation decisions.
Project investigators
Guillermo Sarmiento – sguille@ula.ve
Universidad de los Andes – Instituto de Ciencias Ambientales y Ecológicas (ICAE),Venezuela
Co-investigators
Fermin Rada, Lina Sarmiento, Dimas Acevedo Luis Daniel Llambi, Eulogio Chacon,Teresa Schwartzkopf, Liccia Romero, Julia Smith, and Carlos García (ICAE,Venezuela); Marcelo Cabido, Daniel Renison, and Ana María Cingolani (IMBIV, Argentina);Valerio Pillar and Lúcia Dillenburg (UFRGS, Brazil); Herman Behling (University of Göttingen, Germany); Fidel A. Roig and Eduardo Martinez Carretero (IANIGLA, Argentina); Lazlo Orloci (University of Western Ontario, Canada); Madhur Anand (Laurentian University, Canada); Magdiel Ablan (School of Systems Engineering, USA))
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Students
Adriana Schüler da Silva, Master, Universidade Federal do Rio Grande, Brazil.
Alberto Arzac, Undergraduate, International Commission on Atmospheric Electricity, Venezuela.
Ana Ines Pais Bosch, PHD, IMBIV-CONICET, Argentina.
Axel von Muller, PHD, IMBIV-CONICET, Argentina.
Bethânia Azamuja, Master, Universidade Federal do Rio Grande, Brazil.
Bruno Gay da Fonseca, Undergraduate, Pontifícia Universidade Católica do Rio Grande do Sul, Brazil.
Camila Schinestsck, Master, Universidade Federal do Rio Grande, Brazil.
Carla Körndorfer, PHD, Universidade Federal do Rio Grande, Brazil.
Carolina Blanco, PHD, Universidade Federal do Rio Grande, Brazil.
Darcy Suarez, Master, International Commission on Atmospheric Electricity, Venezuela.
Eduardo Velez Martin, PHD, Universidade Federal do Rio Grande, Brazil.
Eloy Torres, Undergraduate, International Commission on Atmospheric Electricity, Venezuela.
Felicia Fischer, Undergraduate, Universidade Federal do Rio Grande, Brazil.
Francisca Ely, Master, International Commission on Atmospheric Electricity, Venezuela.
Gabriel Specht, Undergraduate, Universidade Federal do Rio Grande, Brazil.
Ignacio Mundo, PHD, IMBIV-CONICET, Argentina.
Johana Puentes, Master, International Commission on Atmospheric Electricity, Colombia.
Juliano Oliveira, PHD, Universidade Federal do Rio Grande, Brazil.
Julieta Alinari, PHD, IMBIV-CONICET, Argentina.
Laura Hoyos, PHD, IMBIV-CONICET, Argentina.
Leandro Duarte, PHD, Universidade Federal do Rio Grande, Brazil.
Leonardo Ruiz, Master, International Commission on Atmospheric Electricity, Venezuela.
Leticia Dadalt, Master, Universidade Federal do Rio Grande, Brazil
Lianey Sosa, Undergraduate, International Commission on Atmospheric Electricity, Venezuela.
Lirey Ramirez, Undergraduate, International Commission on Atmospheric Electricity, Venezuela.
Lucas Silva, PHD, University of Guelph, Brazil.
Marcela Pinillos, Post PHD, International Commission on Atmospheric Electricity, Colombia.
Marcos Carlucci, Undergraduate, Universidade Federal do Rio Grande, Brazil.
Mariana Vieira, Undergraduate, Pontifícia Universidade Católica do Rio Grande do Sul, Brazil.
Mark Leithead, PHD, University of Guelph, Canada.
Maximiliano de Oliveira, Undergraduate, Pontifícia Universidade Católica do Rio Grande do Sul, Brazil.
Melina M.G. dos Santos, PHD, Universidade Federal do Rio Grande, Brazil.
Melisa Georgis, PHD, IMBIV-CONICET, Argentina.
Patricia Suarez, Undergraduate, International Commission on Atmospheric Electricity, Venezuela.
Paula Marcora, PHD, Universidad Nacional de Córdoba, Argentina.
Paula Tecco, Post PHD, IMBIV-CONICET, Argentina.
Raphael Dulhoste, PHD, International Commission on Atmospheric Electricity, Francia.
Rita Rauber, Master, Universidade Federal do Rio Grande, Brazil.
Victoria Vaieretti, PHD, IMBIV-CONICET, Argentina.
Vivian Jeske Pieruschka, PHD, Georg-August-Universität Göttingen, Brazil.
Wilmer Gonzales, Master, International Commission on Atmospheric Electricity, Colombia.
Wiston Santaella, Undergraduate, International Commission on Atmospheric Electricity, Venezuela.
Yolanda CáceresUndergraduate, International Commission on Atmospheric Electricity, Venezuela.