|Assessing the functions of biodiversity in Chilean forest ecosystems
Juan J. Armesto
Facultad de Ciencias, Universidad de Chile
1984 Ph. D., Rutgers, the State University, New Jersey, USA
Full Professor, Facultad
de Ciencias, Universidad de Chile. Adjunct Scientist, Institute
of Ecosystem Studies, Millbrook, NY, USA (ad-honorem)
President, "Senda Darwin"
Selected Professional Honors:
1983-1984 Louis Bevier Fellowship, Rutgers University, New Jersey,
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,
1996 Co-recipient of the Mercer Award (with Dr. L.O. Hedin),
Ecological Society of America, USA. Award to the best article published
1997 J. S. Guggenheim Memorial Fellowship, New York, USA.
1997 Presidential Chair in Science, Government of Chile.
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.
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.
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.
Willson, M.F., T.L. DeSanto,
C. Sabag & J.J. Armesto (1994). Avian communities of fragmented
south-temperate rainforests in Chile. Conservation Biology
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
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
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.
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