Habitat-specific vegetation and seasonal drivers of bird community structure and function in southern Patagonian forests

MARTÍNEZ PASTUR, G; LENCINAS, MV; GALLO, E; DE CRUZ, M; SOLER, R; ANDERSON, CB

COMMUNITY ECOLOGY

AKADEMIAI KIADO RT

Lugar: Budapest; Año: 2015 vol. 16 p. 55 - 65

1585-8553

Biodiversity conservationrequires knowledge about the factors that influence the structure and functionof biotic assemblages. In southern Patagonian Nothofagus forests, birdsare the most abundant and diverse vertebrates and are known to have differentrequirements for nesting, breeding and feeding. Therefore, we chose this groupto analyze key drivers of avian community dynamics; for conservation purposes,this information is requisite to manage Nothofagus forest landscapes andtheir associated biota. We first characterized forest structure and understory floristiccomposition in open and closed canopy broadleaved forests of mixed deciduous(MD) and mixed deciduous-evergreen (MDE) species on the southern coast ofTierra del Fuego National Park, Argentina. For each habitat, bird assemblageswere assessed using point counts, checklists and mist-netting. We used ANOVAsand multivariate methods to analyze changes in bird species richness, density,and biomass as a function of habitat and seasonal characteristics. Foreststructure and understory plant communities influenced avian assemblage anddensity; MDE forests had significantly greater species richness, but lower densitythan MD. Plus, particular species were associated with specific understoryconditions, such as Anairetes parulus and Zonotrichia capensis whosepresence was related to shrubs. Additionally, variations observed betweenseasons apparently were related to differential uses of each habitat typeduring certain times of year. Finally, it was not possible to define a singleforest type with greater conservation value for birds; each had a specific birdspecies assemblage. Consequently, our results suggest the importance of a fullrepresentation of habitats to preserve the region?s bird diversity, which alsohas been described for forest invertebrates and understory plants.