How bird community responds to different ages of reforestation? Implications for restoration of a highly threatened Atlantic Forest phytophysiognomy.

We evaluated the bird composition, forest dependence, trophic guilds and avian representativeness associated with 7, 10 and 15 years old reforestations and mature forest patches in order to verify the successional process and avian contribution to the forest restoration. Analyses revealed a segregation of bird composition with a gradual increasing in forest dependent species from 7 years to mature forest. Detrended Correspondence Analysis ranged from those birds often present in semi-open habitats to forest birds, canopy frugivorous and understory insectivorous as the successional stages progressed from the most recent reforestation to the most mature. Although 7 and 10 years of reforestation had the largest composition range, the more generalist, granivorous and forest independent birds, three years were enough to have different bird diversity between them. Avifauna of 15 years patches resembled most closely that of mature forest but still lacked 18 species. In this way, we addressed: 1) planting of herbaceous/shrub and freshy-fruited species in reforestations and; 2) establish riparian forest corridors along the Paraná river to connect these reforestation patches with mature forest. These measures will allow higher avian beta-diversity to maximize the diaspores dispersed by birds to expand and accelerate the rehabilitation of this threatened for forest.

Light environment influences the flood tolerance in Cordia americana (L.) Gottschling & J.S.Mill.

The subtropical riverine forests present a variation in soil water availability throughout the year, following precipitation seasonality. The objective of this work was to evaluate the responses of Cordia americana to different light intensities combined with soil flooding. Seedlings were acclimated to light treatments, with full sun and shade conditions. Sun and shade plants were subjected to soil flooding during periods of 10 (short) and 30 (longer) days. After 10 days, flooded plants had a higher root dry mass accumulation and soluble sugars content, regardless of the light condition. Shade plants presented higher shoot soluble sugars content in relation to the sun plants. After 30 days, a higher shoot soluble sugar content was observed in sun and shade flooded plants. In addition, a higher root soluble sugar content was also observed in sun plants under flood. Periods of short flooding, characterized in subtropical forests as from 5 to 15 days, favor the growth of shade plants and the roots sugar accumulation, fact that can explain the species distribution. However, long periods of flooding may be associated with light environment plasticity, suggesting that the sun plants present a higher flooding tolerance, directly associated with the ability to maintain the sugar content.