Floristic and vegetation structure of a grassland plant community on shallow basalt in southern Brazil

Abstract

Few studies have adequately described the fl oristic and structural features of natural grasslands associated with shallow basalt soils in southern Brazil. Th is study was carried out on natural grazing land used for livestock production in the municipality of Santana do Livramento, in the Campanha region of the state of Rio Grande do Sul, Brazil. Th e aim of the study was to describe the fl oristic and structural diversity of the area. Th e fl oristic list obtained comprises 229 plant taxa from 40 botanical families, with a predominance of the families Poaceae (62), Asteraceae (28), Fabaceae (16) and Cyperaceae (12). Th e estimated diversity and evenness in the community were 3.00 and 0.874, respectively. Bare soil and rock outcrops accounted for 19.3% of the area, resulting in limited forage availability. Multivariate analysis revealed two well-defi ned groups among the sampling units. One group showed a high degree of internal aggregation, associated with deep soils, and was characterized by the presence of tussocks, whereas the other was less aggregate and was characterized by prostrate species growing on shallow soil. Ordination analysis indicated a gradient of moisture and of soil depth in the study area, resulting in diff erent vegetation patterns. Th ese patterns were analogous to the vegetation physiognomies described for Uruguayan grasslands. Overall, the grassland community studied is similar to others found throughout southern Brazil, although it harbors more winter forage species. In addition, the rare grass Paspalum indecorum Mez is locally dominant in some patches, behaving similarly to P. notatum Fl., a widespread grass that dominates extensive grassland areas in southern Brazil.

Biophysical delineation of grassland ecological systems in theState of Rio Grande do Sul, Southern Brazil

“…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").…”

Classification of South Brazilian grasslands: Implications for conservation

“…In recent years, there have been advances in the floristic knowledge of grassland ecosystems in the region, but studies usually considered single sites or, at best, smaller regions, and have been conducted using different sampling designs and methods (e.g., for Pampa: Caporal & Boldrini, ; Ferreira & Setubal, ; Freitas, Boldrini, Müller, & Verdum, ; Setubal & Boldrini, ; Pinto et al., ; Menezes, Müller, & Overbeck, ; Silva Filho, Macedo, Souza Vieira, & Neves, ; for highland grasslands: Zanin, Longhi‐Wagner, Souza, & Rieper, ; Moro & Carmo, ; Kozera, Kuniyoshi, Galvão, & Curcio, ; Andrade et al., ; Moraes et al., ; Silva, Andrade, Velazco, Galvao, & Carmo, ). These studies are important for describing local floristic patterns and grassland vegetation structure and can be used to describe regional vegetation patterns.…”

Effect of Grazing on the Plant Community of a Southern Brazilian Swamp

“…Considering the entire swamp, the families with the highest abundance were Poaceae, with 11 species; Cyperaceae, with seven species; and Asteraceae, with five species. These families are also among the main families recorded in papers related to grassland vegetation (Freitas et al, 2009;Pinto et al, 2013;Menezes et al, 2013). Asteraceae presented a higher abundance in the portions without cattle influence, while Poaceae and Cyperaceae showed almost the same number of species in both areas.…”