Mammalian Macroecology in Latin America
Pablo A. Marquet
P. Universidad Católica de ChileDepartamento de Ecología
Casilla 114-D, Santiago Chile
EMPHASIS
•Mostly terrestrial, non-volant mammals
• South America, Latin America, Neotropics
GOALS
• Provide an overview of the kind of macroecologicalpatterns so far documented for mammals
Macroecology (a working definition)
• Macroecology is a research program that aims todiscover the general principles or natural laws underlying the complexity of ecological systems. To some extent it proposes a complementary view to the experimentalreductionistic approaches that have dominated ecology, emphasizing, but not restricted to, the analysis of large scale statistical patternsin the distribution and abundance of species at the interface several scientific disciplines, especially physiology, ecology, biogeography, and evolution.
• Patterns in abundance
• Patterns in distribution
• Patterns in body size
• Patterns in abundance
Region habitat slope intercept n Source
SA & CA --- -0.70 4.06 40 (0.64) Damuth (1987)
NA --- -0.75 4.33 84 (0.66) “
NEOTR. fo T -0.60 3.13 38 (0.38) Damuth (1993)
NEOTR. Io T -0.55 2.92 24 (0.40) “
NEOTR. my T -0.81 3.36 6 (0.75) “
NEOTR. T -0.61 3.12 103 (0.45) “
Table.1. Selected analysisi reporting the relationship between abundance and Body size in Norh and South American mammals. T= tropical, fo=frugivore-ommnivores, Io= Insectivore-ommnivore, my =Myrmecophagous.
• Patterns in abundance
•Abundance decreases with body mass
•Species at higher trophic levels tend to occur at lower densities than primary consumers.
• Within the Americas mammalian species in tropical areas tend to occur at lower densities thanextra-tropical species. This pattern have been shown to hold for Africa, Australia and worldwide (Currie &Fritz 1993, Fa & Purvis 1997, Johnson 1998).
• Patterns in distribution
• The number of species is not uniformly distributedacross South America. There is a consistent pattern of an increase in species richness as we go from the poles to tropical latitudes.
• This pattern hold at the species as well as at macrotaxonomiclevels (orders, families, and genera). (Willig and Sandlin 1989,Willig and Selcer 19889, Ruggiero 1994, Kaufman 1995,Willig and Gannon 1997, Kaufman and Willig 1998, Willigand Lyons 1998, Lyons and Willig 1999)
•Patterns in distribution
• The relationship between richness and latitude is nonlinear, with several groups of species such as marsupials, edentates, carnivores, artiodactyls and hystricognath rodents, reaching maximum richness in subtropical areas. (e.g., Ruggiero 1994, Willig and Gannon 1997).
• Latitude, but not area, is the best explanatory variable of the patterns (e.g., Kaufman 1995, Kaufman and Willig1998, Lyons and Willig 1999).
•Patterns in distribution
• The size of species’ geographic ranges vary with latitude.
• Geographic ranges tend to be smaller at tropical latitudes(Rapoport’s rule) (Ropoport 1975, 1982; Anderson andKoopman 1981, Stevens 1989)
• This patterns holds for some taxonomic groups (bats, primatescarnivora) but not for others (edentates, artiodactyls,hystricognath rodents) (Ruggiero 1994)
• Restricted range specie cluster around coastal and Andeanareas (Ruggiero 1994, Ruggiero et al. 1998)
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• Patterns in body size• Body size distributions are highly modal andright skewed
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SAONAO
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• There is a strong historical signal apparent in the shape of the distribution, which is related to the origin oftaxa (Marquet and Cofre 1999, Oikos).
Mexico
Conabio-Arita
Mapping effort currently underway or already implemented inLatin America.
CHILE
-NDVI & Elevation: http://edcaac.usgs.gov-Pp & Tmp : http://ipcc-ddc.cru.uea.ac.uk-Habitat heterog. : Gajardo (1994).
(Samaniego et al.)
Chilean biodiversity mapping
•Abiotic data incorporated
•0.5x0.5 degree grid
Number of species
Latitudinal Patterns
(Villagran &
Hinojosa 1997)
Latitudinal patterns in Chilean tree, shrub, and vines species richness