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Aims We offer a first classification of South Brazilian grasslands (Campos Sulinos) based on quantitative vegetation data and describing grassland types in terms of dominant and indicator species. Location South Brazilian grasslands (Paraná, Santa Catarina, Rio Grande do Sul states). Methods We described vegetation plots in 167 sampling units throughout the region using a stratified nested design, totalizing 1,502 1 m² quadrats. We classified vegetation using cluster analysis based on Bray–Curtis dissimilarities, establishing three vegetation types and ten subtypes. We conducted indicator species analysis within the resulting subtypes, and for all possible combinations of subtypes. Results In the cluster analyses, a clear separation of poorly drained grasslands from the drier sites appeared. Further, a clear distinction between grasslands in the South Brazilian highland region, situated in the Atlantic Forest biome, and the grasslands of the Pampa biome, to the south, emerged, reflecting climatic and management differences. Highland grasslands showed lower species cover dominance, while in the Pampa, Paspalum notatum clearly was the most important species and the abundance of exotic species was higher. Conclusions Our study provides the first classification of South Brazilian grasslands based on quantitative vegetation data recorded in a standardized sampling design. The data support the division of grasslands into the main phytogeographic units of the region (Brazilian biome classification). Grasslands in these two regions also differ in terms of species dominance pattern (higher dominance in Pampa grasslands, likely also due to higher grazing levels) and in terms of conservation state (low presence of exotic species in highland grasslands). Our results are important for conservation policies, which can now consider the presence of different grassland types in different region, but more data will be necessary for a more detailed classification that considers different abiotic features in more detail.

This study evaluated the influence of vegetation structure on bird diversity, guilds, and the richness and composition of species in different successional stages of the subtropical Atlantic rain forest. Much of the land that was formerly agricultural in the Brazilian Atlantic rain forest region is now given over to secondary forests. The habitat structure of these successional forests vary and are influenced by time, historical use and local variables, all of which affect bird assemblies. Sampling of bird species was carried out through audio-visual point counts conducted in forests varying from six years after abandonment to old-growth areas. Forests in which the point counts were conducted were further classified into initial, intermediate and advanced stages according to 11 vegetation structural variables, through cluster analyses. The study found that bird richness and diversity were similar between initial and intermediate stages, but higher in advanced areas. Bird species composition differed between the initial and advanced stages, whereas the guild composition of initial forests differed in both intermediate and advanced stages. Late successional forests had more heterogeneous habitats, and some species and guilds were found only in this stage. However, bird diversity and species and guild composition were similar in intermediate and advanced forests, emphasizing the importance of successional forests for conservation efforts, especially when they are located near old-growth forests and conservation units. The recovery patterns of the successional forests studied indicate a great potential for the natural regeneration of the Atlantic rain forest, at least in areas where slash-and-burn agriculture was the previous landuse.Keywords: avifauna; habitat modification; secondary forests; vegetation structure. RESUMOEste estudo avaliou a influência da estrutura da vegetação sobre a diversidade, riqueza e composição de espécies e guildas de aves em florestas sucessionais na Mata Atlântica subtropical. Grande parte das áreas agrícolas que cobriam as regiões da Mata Atlântica são atualmente florestas secundárias, podendo variar em estrutura de habitat conforme o histórico de uso e variáveis locais, influenciando as assembleias de aves. A amostragem da avifauna foi realizada pelo método áudio-visual em pontos de escuta em florestas com seis anos de regeneração após o abandono a áreas antigas. Florestas em cada ponto de escuta foram posteriormente classificadas em estágios inicial, intermediário e avançado de acordo com 11 variáveis estruturais da vegetação, através da análise de agrupamento. A riqueza e diversidade de aves foram similares entre os estágios inicial e intermediário, mas maiores no estágio avançado. A composição de espécies diferiu somente entre os estágios inicial e avançado, enquanto a composição de guildas do estágio inicial diferiu dos estágios intermediário e avançado. Florestas tardias foram mais heterogêneas em termos de habitat, e algumas espécies de aves e guildas foram registradas so...

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The level of endemism at a site may indicate species richness of the site. Nevertheless, assessing endemism levels in taxonomic groups such as plants may be difficult because the species richness of plants is high relative to species richness of other taxonomic groups (e.g., vertebrates). A major problem in determining whether plant species are endemic is the lack of standardization of the geographic extent of endemism: species are considered endemic to, for example, countries, continents, or states. We compiled a history of the concept of endemism as it applies to plants. The application of the concept to geographic distribution dates from the 19th century, when European explorers discovered many taxa exclusive to regions outside Europe. Two types of endemism, paleoendemism and neoendemism, were then acknowledged, according to evolutionary age, and these categories are still in use. In the 20th century, most of the research on endemism focused on explaining range restriction on the basis of cytological data, edaphic and geological factors, and phylogeny. This research led to a vast number of concepts, of which only edaphic endemism remains relatively well accepted. More recently, researchers suggest that competition may determine endemism in some cases. We suggest that plants be labeled as endemic only if their distribution occurs in a distinct ecological unit, such as a biome. On the basis of a literature review of the factors that cause range restriction, we categorized endemic taxa as paleoendemic, neoendemic, edaphically endemic, or suppressed endemic. For example, Schlechtendalia luzulifolia, is a rare forb that is a paleoendemic species of the granite and sandstone-based grasslands of the Pampa. Levels of endemism in southern Brazilian grasslands are poorly known. We emphasize the importance of recognizing these grasslands as a single transnational biome so that levels of endemism of species therein can be assessed correctly.

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Grassland ecosystems are evolutionarily linked to disturbances such as grazing and fire. These disturbances define grassland plant communities and habitat heterogeneity, which influence animal communities. We evaluated the influence of fire disturbance on plant and bird communities and on habitat structure by sampling grassland fragments with different time elapsed since the last fire event. Habitat structure was sampled using plant life forms and abiotic variables and birds were sampled through point counts. We recorded 862 bird individuals from 70 species. Intermediately-burnt sites harbor higher habitat heterogeneity and plant species richness in comparison with recently or long-burnt sites. Bird abundance and taxonomic diversity decreased linearly as time since fire increased. Finally, time since fire influenced the relative distribution of plant life forms and bird food guilds. Our results indicate that fire management should be included in the framework for conservation and sustainable use of grasslands, because it promotes habitat heterogeneity and diversity. To maintain habitat heterogeneity and the related habitat-specific bird species and functional groups, conservation efforts should maintain grassland patches under different management intensities and frequencies on a landscape level. However, studies focused on determining the periodicity with which fire management should be used are still lacking.

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