To test whether the flora is organized in discrete or continuous units along a topographic gradient, three physiognomies were assessed on different soil classes in a semi-arid region of northeastern Brazil: caatinga (xeric shrubland) at altitudes from 300 to 500 m, deciduous forest at altitudes from 500 to 700 m and carrasco (deciduous shrubland) at 700 m. In each physiognomy a species inventory was carried out, and plants were classified according to life- and growth-forms. Species richness was higher in the deciduous forest (250) than in the carrasco (136) and caatinga (137). The caatinga shared only a few species with the carrasco (6 species) and the deciduous forest (18 species). The highest species overlap was between the deciduous forest and the carrasco (62 species). One hundred and four species occurred only in the caatinga, 161 only in the deciduous forest and 59 only in the carrasco. Woody species predominated in physiognomies on sedimentary soils with latosol and arenosol: 124 species occurred in the deciduous forest and 68 in the carrasco. In the caatinga on crystalline basement relief with predominance of planosol, herbs showed the highest species richness (69). Comparing the biological spectrum of Brazilian plant life-forms, the caatinga stood out with higher proportion of therophytes and chamaephytes. Considering the flora of the three phytophysiognomies studied here, we can affirm that the caatinga is a discrete floristic unit.

We provide, for the first time, data on phenology and dispersal modes for the Carrasco, a tropical deciduous shrubland in the Brazilian semiarid. The study was conducted in the Serra das Almas Reserve (5°8 0 45 00 S, 40°55 0 43 00 W), northeastern Brazil. We sampled 2,790 individuals from 39 species, 30 genera, and 17 families. Fabaceae, Euphorbiaceae, and Myrtaceae were the most representative. All species lose leaves, fully or partially, during the dry season. Leaf flush was observed to increase at the end of the dry season with a peak during the rainy season. Similarly, the peak of flowering/fruiting occurred at the end of the dry and the beginning of the rainy season. Air humidity and maximum temperature were the only variables correlated with leaf flush. Most species showed annual flowering/fruiting. Flowering lasted 2-5 months, but even longer fruiting periods were observed. Zoochory was the most frequent dispersal mode, followed by autochory. Zoochoric, barochoric, and autochoric species fruited throughout the year, while for anemochorics fruiting occurred at the end of the rainy and/or during dry season. Despite both, the Carrasco and the Caatinga are deciduous, the Carrasco has a greater intensity and duration of phenological events and a higher frequency of zoochory, thus being more similar to less arid ecosystems. We discuss the local implications of these patterns, as well as how our results are in accordance with other regional and global studies with similar approaches.

The objective of this study was to characterize the galls of Clusia nemorosa G. Mey (Clusiaceae). We selected 30 young plants in trails of Refugio Charles Darwin, an Atlantic forest fragment in Pernambuco, Brazil. The height of each plant was measured and the number of leaves, leaves with galls, and galls per leaf were counted. Leaves with galls were collected from ten specimens and brought to laboratory to be described and to have the inductor observed. We observed galls in only ten individuals of the thirty initially selected. The number of galls per plant varied from 3 to 336. Out of 1,399 leaves inspected, 541 galls were counted in 137 leaves. The galls were deep green, elliptical, crossing the abaxial and adaxial leaf surfaces, preferentially located at the center of the leaf (H=23,48; p<0.01; n=137), but with 49% at the leaf margin. The galls had 5.5 mm and 4.7 mm bearing one larval chamber with one larvae, and were induced by an unidentified species of Hymenoptera. Keywords: Cecidomyiidae, trophic interaction, plant-herbivore interaction, herbivory, galls.