Assessing the functions of biodiversity in Chilean forest ecosystems

Juan J. Armesto
Juan J. Armesto
Facultad de Ciencias, Universidad de Chile
E-mail: jarmesto@uchile.cl 

Doctoral degree: 
1984 Ph. D., Rutgers, the State University, New Jersey, USA

Present Positions:

Full Professor, Facultad de Ciencias, Universidad de Chile. Adjunct Scientist, Institute of Ecosystem Studies, Millbrook, NY, USA (ad-honorem)

President, "Senda Darwin" Foundation, http://www.sendadarwin.cl/ (ad-honorem).

Selected Professional Honors:

1980 Fulbright Travel Fellowship
1983-1984 Louis Bevier Fellowship, Rutgers University, New Jersey, USA
1987 Cary Summer Fellowship, Institute of Ecosystem Studies, The New York Botanical Garden, USA
1992 Premio de Ciencia y Tecnología "Manuel Noriega Morales", in the field of Biological Sciences, OAS, Washington, USA.
1996 Co-recipient of the Mercer Award (with Dr. L.O. Hedin), Ecological Society of America, USA. Award to the best article published in ECOLOGY
1997 J. S. Guggenheim Memorial Fellowship, New York, USA.
1997 Presidential Chair in Science, Government of Chile.

Research Interests:

My research is oriented primarily at understanding and predicting how humans will affect biological diversity in rural landscapes in southern Chile. It addresses the following specific questions: 1) how critical are pollination and seed dispersal mutualisms for the sustainability of plant and animal populations in forests? and how are these interactions modified by habitat fragmentation?, 2) what are the links between soil biodiversity and the processes that sustain productivity in old-growth forests? and how are these processes affected by human impact?, and 3) how are ecosystem engineering properties of trees (not related to trophic interactions) relevant for maintaining biodiversity and for enhancing forest recovery from anthropogenic disturbance?

Chilean temperate forests can be characterized as a biogeographic island because they have been historically isolated from other forest ecosystems within South America for at least 2-3 million years. Arid barriers to the north and east, as well as the massive Andean range, separate austral Chilean rain forests from wet tropical forests by more than 2000 km. This situation has accentuated the endemism of temperate forest taxa and resulted in communities dominated by one or a few species per genera. As a consequence of this biogeographic condition, we may predict that Chilean forests should have low redundancy in ecosystem functions at the species level and therefore be especially sensitive to the loss of biodiversity (as well as to species invasion). On the other hand, during the Pleistocene, Chilean forests have survived through repeated cycles of disturbance by glacial events, massive tectonic movements, and volcanism which leads to the prediction that, despite their low redundancy in ecological functions, these forests should be extremely resilient ecosystems.

We propose to conduct laboratory and field studies to identify the critical species (or functional groups) and biotic processes that sustain the biodiversity and productivity in Chilean temperate rainforests. Specifically, we propose to identify functional groups in temperate forest ecosystems that are most sensitive to losses of biodiversity, using two different approaches: the ecosystem engineering approach and the keystone species approach These two approaches may be effective and complementary for testing hypotheses regarding the functions of species in ecosystems thus linking different hierarchical levels: population, community, and ecosystem. In addition, we propose to evaluate the resilience of Chilean forests to particular types of anthropogenic disturbances by examining changes in biodiversity and ecosystem functions across a chronosequence of successional stands in Chiloé Island.

Specifically, in the Center for Advanced Studies in Ecology & Biodiversity we will: (1) Characterize the major plant-pollinator and plant-disperser functional groups in old-growth forests in Chiloé. (2) Examine how these functional groups are changed in terms of biodiversity and connectivity as forests become increasingly fragmented. (3) Document the consequences of disruption of mutualistic systems for plant reproduction. (4) Use this information to advice land managers about alternative strategies to maintain functional groups and biodiversity in anthropogenic landscapes in southern Chile.

Selected Publications:

Willson, M.F., T.L. DeSanto, C. Sabag & J.J. Armesto (1994). Avian communities of fragmented south-temperate rainforests in Chile. Conservation Biology 8:508-520.

Hedin, L., J.J. Armesto & A. Johnson (1995). Patterns of nutrient loss from unpolluted old-growth temperate forests in Chiloé: evaluation of biogeochemical theory. Ecology 76:493-509.

Smith-Ramirez, C., J.J. Armesto & J. Figueroa (1998) Flowering, fruiting, and seed germination of Myrtaceae in Chilean temperate forests: ecological and phylogenetic constraints. Plant Ecology 136: 119-131.

Devall, M., B. R. Parresol & J.J. Armesto (1998) Dendroecological analysis of a Fitzroya cupressoides and a Nothofagus nitida stand in the Cordillera Pelada, Chile. Forest Ecology and Management 108: 135-145.

Armesto, J.J., R. Rozzi, C. Smith-Ramirez & M. K. Arroyo (1998) Conservation targets in South American temperate forests. Science 279: 1271-1272.

Pérez, C., L.O. Hedin & J.J. Armesto (1998) Nitrogen mineralization in two unpolluted, old-growth forests of contrasting structure and biodiversity. Ecosystems 1:361-373.

Allnutt, T.R., A.C. Newton, A. Lara, A. Premoli, J.J. Armesto, R. Vergara & M. Gardner (1999) Genetic variation in Fitzroya cupressoides (alerce), a threatened South American conifer. Molecular Ecology 8: 975-987.

Díaz, I., C. Papic & J. J. Armesto (1999) An assessment of post-dispersal seed predation in temperate rainforest fragments in Chiloé Island, Chile. Oikos 87: 228-238.

Sala, O. E., F. S. Chapin III, J. J. Armesto, E. Barlow, J. Bloomfield, R. Dirzo, E. Huber-Sanwald, L. Huenneke, R. B. Jackson, A. Kinzing, R. Leemans, D. M. Lodge, H. A. Mooney, M. Oesterheld, N. LeRoy Poff, M. T. Sykes, B. H. Walker, M. Walker & D. W. Hall (2000) Global biodiversity scenarios for the year 2100. Science 287: 1770-1774.

Rozzi R., J. Silander Jr., J. J. Armesto, P. Feinsinger & F. Massardo (2000) Three levels of integrating ecology with the conservation of South American temperate forests: the initiative of Institute of Ecological Research Chiloé, Chile. Biodiversity and Conservation 9: 1199-1217.

Armesto, J. J., I. Díaz, C. Papic & M. F. Willson (2001) Seed rain of fleshy and dry propagates to different habitats in temperate rainforests of Chiloé, Chile. Austral Ecology 26:311-320.

Figueroa, J. A. & J. J. Armesto (2001) Community-wide germination strategies in a temperate rainforest of Southern Chile: ecological and evolutionary correlates. Australian Journal of Botany 49:411-425