Review of plant biogeographic studies in Brazil

Abstract

Molecular phylogenetic studies have become a major area of interest in plant systematics, and their impacts on historical biogeographic hypotheses are not to be disregarded. In Brazil, most historical biogeographic studies have relied on animal phylogenies, whereas plant biogeographic studies have largely lacked a phylogenetic component, having a limited utility for historical biogeography. That country, however, is of great importance for most biogeographic studies of lowland tropical South America, and it includes areas from a number of biogeographic regions of the continent. Important biogeographic reports have been published as part of phylogenetic studies, taxonomic monographs, and regional accounts for small areas or phytogeographic domains, but the available information is subsequently scattered and sometimes hard to find. In this paper we review some relevant angiosperm biogeographic studies in Brazil. Initially we briefly discuss the importance of other continents as source areas for the South American flora. Then we present a subdivision of Brazil into phytogeographic domains, and we cite studies that have explored the detection of biogeographic units (areas of endemism) and how they are historically related among those domains. Examples of plant taxa that could be used to test some biogeographic hypotheses are provided throughout, as well as taxa that exemplify several patterns of endemism and disjunction in the Brazilian angiosperm flora. Key words angiosperms, biogeography, Brazil, disjunction, distribution patterns, endemism.Brazil is the fifth largest country in the world, with more than 8.5 million km 2 , and one of the most diverse in vascular plant species, with an estimated 55,000-60,000 species (Prance, 1994;Giulietti et al., 2005). The territory occupied by Brazil encompasses most of the world's remaining areas of tropical rainforests (primarily in the Amazon), as well as considerable areas of tropical savannas (the central Brazilian Cerrado) and seasonally dry tropical forests (SDTFs; mostly in the Caatinga). The country is also one of the few that includes two hotspots for the conservation of biodiversity sensu Myers et al. (2000), the Atlantic Forest and the Cerrado.Despite its unquestionable importance for the study of South American biogeography in general, there is a serious lack of biogeographic synthesis about Brazilian plants. Most studies so far have emphasized the detection of patterns of geographic distribution by mapping occurrence data, relegating the explanations on how these patterns were achieved to a somewhat speculative level. Because the vast majority of the available studies lack a phylogenetic perspective (e.g., Prance, 1979Prance, , 1988Giulietti & Pirani, 1988; Acevedo-Rodríguez, 1990; Alves et al., 2003;Gonçalves, 2004;Cavalcanti, 2007;Fiaschi & Pirani, 2008), the information generated has been regarded as having little relevance for historical biogeography, as the detection of areas of geographic distribution correspond only to the very first step of any h...

Orchidaceae das Serras Negra e do Funil, Rio Preto, Minas Gerais, e similaridade florística entre formações campestres e florestais do Brasil

“…Este tipo de vegetação ocorre ao nível do mar e é constituído por uma grande variedade de comunidades de plantas, em decorrência da topografi a distinta e da combinação de variáveis ambientais de origem continental e oceânica (Flexor et al 1984;Suguio & Tessler 1984). Este resultado reforça a conclusão de que a heterogeneidade de habitats na Mata Atlântica pode ter tido um papel importante na diversifi cação e nos endemismos de sua fl ora (Fiaschi & Pirani 2009).…”

Myrtaceae throughout the Espinhaço Mountain Range of centraleastern Brazil: floristic relationships and geoclimatic controls

“…However, there is also an expressive contingent of species that are widely distributed in the neotropics or in two or more domains (Fiaschi & Pirani 2009). Several studies mention the strong contribution of Myrtaceae to tree component of neotropical forests, particularly Atlantic Forest (Mori et al 1983;Gentry 1995;Oliveira-Filho & Fontes 2000;Kamino et al 2008).…”

“…Biogeographic hypotheses involving plant species composition, for instance, often result from previous surveys (Clarke & Funk 2005;Funk 2006). Nevertheless, most phytogeographic studies conducted in Brazil have been published as sections of phylogenetic studies or floristic descriptions of small areas or of entire domains (Fiaschi & Pirani 2009). …”

Quiinaceae do Nordeste

“…Apesar da maior diversidade taxonômica nas florestas ao norte do país, foram encontradas amostras da floresta atlântica em acervos locais. Para o domínio Atlântico (sensu Fiaschi & Pirani 2009), com exceção da Flora brasiliensis (Engler 1888), os estudos com a família estão restritos às Regiões Sudeste (Souza & Bianchini 2001;2007) e Sul (Reitz 1965;1972), não tendo sido citada para o Nordeste do Brasil por Barbosa et al (2006). No entanto, Grilo et al (2006), Barreto et al (2006) e Ferraz & Rodal (2006 citam a família como parte integrante de suas listas florísticas, apesar de apresentarem imprecisão na identificação das amostras.…”