Elba Maria Nogueira Ferraz

Caatinga revisited: ecology and conservation of an important seasonal dry forest.

Besides its extreme climate conditions, the Caatinga (a type of tropical seasonal forest) hosts an impressive faunal and floristic biodiversity. In the last 50 years there has been a considerable increase in the number of studies in the area. Here we aimed to present a review of these studies, focusing on four main fields: vertebrate ecology, plant ecology, human ecology, and ethnobiology. Furthermore, we identify directions for future research. We hope that the present paper will help defining actions and strategies for the conservation of the biological diversity of the Caatinga.

Floristic similarities between lowland and montane areas of Atlantic Coastal Forest in Northeastern Brazil

Studies undertaken in the Atlantic Coastal Forest have revealed a notable floristic heterogeneity within this vegetation type in NE Brazil. However, there is still a great need for detailed comparisons of the floristic relationships between the various forest types found there. This work presents an analysis of the floristic similarity (at the species level) of these forest as revealed by floristic surveys, with the aim of better understanding and defining this vegetation. Using a binary matrix, grouping, ordering, and TWINSPAN analysis were performed on 742 tree/shrub species listed in 35 different plant surveys. These tree/shrub species were divided by these analysis into two large floristic groups – ombrophilous and semideciduous. The semideciduous group was formed, in general, by forest areas located at altitudes above 700 m (montane forests), and could itself be divided into two subgroups. The first subgroup was located more inland (Pernambuco), while the second subgroup was located nearer the coast (within the states of Pernambuco and Ceará). The ombrophilous group was quite heterogeneous, but could also be divided into two floristic subgroups: i) lowland forests (below 100 m a.s.l) in the states of Pernambuco, Paraíba, and in two areas of Bahia, as well as some montane forests (in Pernambuco, between 640 and 900 m a.s.l.); ii) lowlands forests in the states of Alagoas and Bahia. This latter subgroup is the largest and best defined, and has the highest degree of internal similarity. Nonetheless, it can be further subdivided into two smaller classes, one in Alagoas and the other in Bahia State. The results of this study demonstrate that the concept of the Atlantic Coastal Forest could also include montane ombrophilous forests in Pernambuco State, as these forests form a single floristic unit together with lowland forests in that state.

Diversidade de herbáceas em microhabitats rochoso, plano e ciliar em uma área de caatinga, Caruaru, PE, Brasil

Objetivou-se avaliar a influencia da heterogeneidade micro-espacial no aumento da fitodiversidade herbacea em uma area de caatinga de Caruaru, Pernambuco, Brasil. Microhabitats rochosos, planos e ciliares foram selecionados, e nesses foi realizado um levantamento quali-quantitativo das herbaceas ocorrentes em 35 parcelas de 1 m2, em cada microhabitat. Todas as ervas nas parcelas foram contadas, marcadas e identificadas, coletando-se tambem outras especies herbaceas ocorrentes entre as parcelas. A riqueza taxonomica total de herbaceas foi mais elevada ao se considerar o conjunto dos microhabitats. A flora total foi de 62 especies, 42 destas ocorrendo no microhabitat rochoso, 32 no plano e 39 no ciliar. O indice de similaridade floristica de Jaccard entre os microhabitats variou de 42% (plano × ciliar) a 57% (rochoso × plano). Isoladamente, as riquezas de especies nos microhabitats plano, rochoso e ciliar foram de 3,09; 3,88 e de 4,18 especies (ln ind.)-1 e as diversidades, pelo indice de Shannon-Wiener, foram de 2,08; 2,09 e de 2,52 nats.ind.-1, respectivamente. Malvaceae, Euphorbiaceae e Poaceae apresentaram maior numero de especies. A densidade total de herbaceas foi de 4.009 ind.105 m-2, sendo 1.749 individuos do microhabitat rochoso, 1.020 do ciliar e 1.240 do plano. Cerca de 19% das especies eram trepadeiras e foram consideradas como um grupo importante para conservacao da biodiversidade local. Evidenciou-se a importância da inclusao das herbaceas dos diferentes microhabitats, para a determinacao da riqueza floristica da caatinga.

Estudo florístico do componente herbáceo e relação com solos em áreas de caatinga do embasamento cristalino e bacia sedimentar, Petrolândia, PE, Brasil

Floristic surveys were carried out in two close caatinga areas, one on the crystalline shield and the other on a sedimentary basin, both at Petrolândia, Pernambuco, Brazil, with the objective of identifying differences between the two areas in composition, habit and life form of the herbaceous flora. One hundred 1×1 m plots were established in each area and all the herbaceous species were identified. Soil samples were collected at 0-20 and 20-40 cm depths. In general, the soil in the crystalline shield area was shallower, had greater clay content, with higher water holding capacity, and was more fertile. The number of families, genera and species in the sedimentary basin and crystalline shield areas were 32, 62 and 78 and 31, 53 and 69, respectively. The floristic similarity between the areas was high (75%). The clustering analysis showed that the floristic arrangements between the sampled plots are more similar within the areas than between areas, suggesting the existence of distinct groups. Soil type seems not to be a factor determining the floristic similarity, habit or life forms of the caatinga vegetation herbs when the areas are near, but it may influence the occurrence and the frequency of some species.

INTERAÇÕES ENTRE OS COMPONENTES HERBACEO E ARBUSTIVO-ARBÓREO EM UMA REGIÃO SEMIÁRIDA NO NORDESTE DO BRASIL: COMPETIÇÃO OU FACILITAÇÃO?

Under conditions of high stress, interactions between species can be positive. Islands of perennial vegetation can improve the conditions of the understory and facilitate the establishment of herbaceous plants. The hypothesis of this study is that islands of perennial vegetation in an area of caatinga harbor, a greater richness, diversity and density of herbaceous plants, and that individuals reach a greater height and diameter than in open spaces. The study was conducted in Petrolândia, Pernambuco, Brazil. Twenty-seven plots were installed in the center of the islands, 38 at the edge of the islands (in a total of 38 islands) and 35 in the open spaces. A total of 51 species were recorded in the center and 55 on the edge of the islands and 48 in the open spaces. The mean richness of the open spaces was lower than on the islands. The diversity was greater in the center of the island and became less on the edge of the island and in the open spaces. The mean density was lower in the open spaces than on the islands. The mean density at the edge of the islands was greater than in the center of the islands. There was no difference in mean diameter of herbaceous plants. The mean height of the individuals was higher in the center of the islands. The herbaceous community growing on the islands exhibited higher richness, diversity, density and height than in open spaces. Thus, islands of perennial vegetation facilitate the establishment of herbaceous species.

Urban or rural areas: which types of surrounding land use induce stronger edge effects on the functional traits of tropical forests plants?

Questions Which types of land use adjacent to Atlantic Tropical Forests induce the strongest edge effects in terms of the functional responses of arboreal and understorey plants? Which functional traits respond to stress imposed by each land-use type in the two forest layers? Location Full-protection conservation areas in the metropolitan region of Recife, Pernambuco State, Brazil. Methods We calculated the proportions of species and individuals of woody plants in terms of their functional traits (seed size, maximum height, dispersal syndrome and regeneration strategy) along the edge and in the interior of tropical Atlantic Forest remnants exposed to different degrees of adjacent urbanization along their borders (urban, suburban and rural) by establishing 120 sampling points (60 plots considering the arboreal components and 60 subplots considering woody understorey plants).The degree of urbanization adjacent to the edges of the remnant forests were determined by mapping the sites based on satellite images. The intensities of the edge effects on functional composition, and the differences in the functional traits were assessed using multivariate analysis. Results Functional composition along the edges and within the forest interiors of remnants with the highest densities of urban areas around them demonstrated the greatest variability of both the arboreal and understorey components. The arboreal component of the forest sites adjacent to rural areas (intense agricultural activities) tended to demonstrate intermediate intensity edge effects. Species showing shade intolerance, with smaller maximum heights, producing small seeds and with abiotic dispersion were present in high proportions in forests bordering heavily urbanized areas. Biotic dispersal predominated in the arboreal component of the rural remnant. Conclusions From a functional point of view, the forest with the most highly urbanized border is more impacted by edge effects than forests bordering on suburban or rural areas. Nonetheless, in an urban–rural gradient, intense agricultural activity was observed to create intermediate pressure in terms of the intensities of its edge effects. These edge effects differentially impact the functional traits of the arboreal and understorey components, influencing different traits, depending on the type of border.