INVESTIGADORES
CUETO Victor Rodolfo
artículos
Título:
Determinants of bird species richness: role of climate and vegetation structure at a regional scale
Autor/es:
CUETO, V.R.; J. LOPEZ DE CASENAVE
Revista:
Journal of Biogeography
Editorial:
Blackwell Science Ltd.
Referencias:
Año: 1999 vol. 26 p. 487 - 492
Resumen:
We examined the respective roles of climate and vegetation structure on geographical
variation in bird species richness. The Province of Buenos Aires (central-eastern Argentina)
was divided into 146 squares of 50 km on a side. For each square we evaluated the number
of bird species, the value of thirteen climatic variables, and the value of a vegetation strata
index. The climatic matrix was analyzed by Principal Component Analysis (PCA), and the
first factors resulting from PCA were considered as multifactorial climatic gradients. Simple
and Partial Correlation Analysis among bird species richness, vegetation strata, and the
first two factors derived from PCA (65% of total variation) indicated that bird richness
distribution was determined by the availability of vegetation strata, associated with different
vegetation types that, at the same time, were influenced by the climatic conditions summarized
in the first climatic factor (a gradient of precipitation, relative humidity, annual termical
amplitude, and frost occurrence). This relationships reflect the complexity of factors that
can act directly as well as indirectly on the geographical patterns in species richness. Also,
we evaluated the importance of study scale comparing our results with previous studies at
macrogeographic and local scales, found out that the vegetation structure was the principal
determinant of bird species richness at this three geographical scales.