Phytosociology and natural subtropical grassland communities on a granitic hill in southern Brazil

Abstract

A phytosociological survey was carried out in a study area located at Serra do Sudeste, southern Brazil, where forests and grasslands are distributed in a mosaic, seeking to unravel diversity patterns in four different grassland communities. Grassland management traditionally adopted by the local population is characterized by burning practices that aim to eliminate woody species, delaying the forest expansion process that is favored by the extant climate. The number of plots distributed per community was as follows: rocky grasslands (17), dry grasslands (33), moist grasslands (15) and marshy grasslands (5). Different numbers of plots were used due to the natural conditions of these communities, with highest cover for dry grasslands, followed by rocky, moist and marshy grasslands. Data analyses consisted of calculating community indexes and parameters and exploratory multivariate analysis. We verified that c. 15% of species among the 177 registered taxa were highly dominant in the constitution of the vegetation matrix in all communities, whereas most of the species showed low frequency and cover values. Rocky and dry grasslands showed higher similarity and diversity indexes than moist and marshy grasslands. We concluded that the large number of rare or intermediate-frequency species is decisive for the high diversity found in these grasslands.

Edaphic filters and the functional structure of plant assemblages in grasslands in southern Brazil

“…The strong convergence in species composition between wet areas and the overlap in species composition between dry and rocky grasslands were previously observed (Dalazoana et al. ; Setubal & Boldrini ). It is possible that this pattern results from an effect of higher monocot richness in wet grasslands (where the soils are deeper) compared to other grassland types.…”

“…The floristic differentiation among the grassland types in all regions, including the core areas of the states of Rio Grande do Sul and Santa Catarina, is relatively well established (Setubal & Boldrini ). In the Campos Gerais region, the presence of rock outcrops creates an additional substrate factor that is rare in other regions.…”

Delimitação biofísica de sistemas ecológicos campestres no Estado do Rio Grande do Sul, sul do Brasil

“…This approach allowed us to discriminate different spatial units of the grassland ecosystems, expanding previous observations and descriptions (IBGE 1986, Boldrini 2009. Recent vegetation studies (in the region) confirm statements of several authors on the influence of relief and soil on the spatial distribution of herbaceous plant communities (Boldrini et al 2009, Ferreira et al 2010, 2020, Freitas et al 2010, Setúbal & Boldrini 2012, Pinto et al 2013, Menezes et al 2015, Andrade et al 2016, 2019, Menezes et al 2022. Andrade et al (2019) refers to 1,502 samples of 1 m² of the SISBIOTA Project (National System Research on Biodiversity -"Sistema Nacional de Pesquisa em Biodiversidade"), Ferreira et al (2020) refers to 262 samples of 1 m² along five years of the PELD Project (Long Term Ecological Research-South Brazilian Campos -"Pesquisas Ecológicas de Longa Duração-Campos Sulinos"), and Menezes et al (2022) refers to 1,080 samples of 1 m² of the PPBIO Project (Research Program on Biodiversity of the South Brazilian Campos -"Programa de Pesquisa em Biodiversidade nos Campos Sulinos").…”

Florística e fitossociologia em três diferentes fitofisionomias campestres no Sul do Brasil

“…Apesar da grande variação na riqueza florística nos campos do Sul do Brasil (Boldrini & Miotto 1987, Kozera et al 2009, Dalazoana & Moro 2011, os trabalhos na região dos Campos Gerais do Paraná têm registrado número de espécies superior (Ferreira & Setubal 2009, Boldrini et al 2008, Setubal & Boldrini 2012. Neste estudo a escolha dos métodos contribuiu para alcançar alta riqueza, já que o levantamento adicional de até 50 m de distância das unidades amostrais representou quase 40% do total de espécies amostradas.…”