Floristic heterogeneity of flooding Pampa grasslands: a multi-scale analysis

$61.74 plus tax (Refund Policy)

Buy Article:

Abstract:

The present paper describes vegetation heterogeneity at contrasting spatial scales in order to analyse patterns of floristic diversity and vegetation – environment relations in the Flooding Pampa grasslands of Argentina. The overall grassland flora contains a large proportion of exotic species, which are mostly annual forbs. At a regional scale, there is a latitudinal turnover in relative abundance of major grass tribes, and C 3 grasses become increasingly common in grasslands at higher latitudes. The principal gradients in overall vegetation composition were associated with landscape-level changes in topography and soil chemistry. Both native and exotic species richness increased with topographic elevation, and markedly decreased in flood-prone habitats with acidic or saline soils. In remnants of tussock grassland, the predominant physiognomy of the Pampas in pre-settlement times, the presence of the tall native grass Paspalum quadrifarium is a strong determinant of local community structure, reducing the percentage of exotic species. Heterogeneity analysis at the community scale revealed a fine-grained species packing that was in sharp contrast with spatial mosaics observed in other grasslands under livestock grazing. At this scale, spatial variation in floristic composition correlated with changes in various soil parameters, but not with subtle differences in topographic relief. The studied grasslands possess some unique features that contribute towards a better understanding of how current vegetation heterogeneity is controlled by historical, environmental and management factors.

Keywords: Exotics; grazing; plant community types; spatial scales; species richness

Document Type: Research Article

DOI: http://dx.doi.org/10.1080/11263500500340714

Affiliations: IFEVA-CONICET, Departamento de Recursos Naturales y Ambiente, Facultad de Agronomía, Universidad de Buenos Aires, Argentina

Publication date: November 1, 2005

Related content

Share Content

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
X
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more