Ricardo Ribeiro Rodrigues

Bacterial Diversity in Tree Canopies of the Atlantic Forest

We found an extraordinary level of bacterial biodiversity in the tree leaf canopy of a tropical Atlantic forest by using culture-independent molecular methods. Our survey suggests that each tree species selects for a distinct microbial community. Analysis of the bacterial 16S ribosomal RNA gene sequences revealed that about 97% of the bacteria were unknown species and that the phyllosphere of any one tree species carries at least 95 to 671 bacterial species. The tree canopies of tropical forests likely represent a large reservoir of unexplored microbial diversity.

Seed bank and seed rain in a seasonal semi-deciduous forest in south-eastern Brazil

To examine the influence of seasonality on the abundance and com- position of species in the community, we studied the seed rain and the seed bank in a seasonal, semi-deciduous forest in south-eastern Brazil. Soil samples (depth 3 cm, 0.25 m 2 ) were collected within a 1-ha plot in the dry seasons of 1996 and 1997 and the rainy season of 1997 (84 samples per collection). Thirty-five seed traps (0.25 m 2 each) were placed randomly in the forest from March 1997 to February 1998. The greatest density of seeds in the soil occurred in samples collected during the rainy season, the period which coincides with the main fruiting period in this forest. The Sorensen similarity index values for the seed bank composition among the three periods were high (> 0.50). The fallout of propagules was strongly sea- sonal, with more than half of the annual total number of seeds being caught in the two months around the end of the dry season and beginning of the rainy season. The mean density of seeds in the soil bank was nearly 86% lower than the seed rain density. There was no clear evidence of seasonal effects on species den- sity and richness in this forest.

Biodiversity Conservation Research, Training, and Policy in São Paulo

The BIOTA-FAPESP program is linking a decade of research on biodiversity into public policy in the state of São Paulo. Since the Convention on Biological Diversity (CBD) in 1992, biodiversity conservation (the protection of species, ecosystems, and ecological processes) and restoration (recovery of degraded ecosystems) have been high priorities for many countries. Scarce financial resources must be optimized, especially in developing countries considered megadiverse (1), by investing in programs that combine biodiversity research, personnel training, and public-policy impact. We describe an ongoing program in the state of São Paulo, Brazil, that may be a useful example of how conservation initiatives with a solid scientific basis can be achieved.

Creating space for large‐scale restoration in tropical agricultural landscapes

Poorly planned, large-scale ecological restoration projects may displace agricultural activities and potentially lead to the clearance of native vegetation elsewhere, with associated impacts on biodiversity and ecosystem services. Yet few studies have considered these risks and the ways in which restoration can increase competition for land. Here, we address this issue by examining whether large-scale restoration of the Brazilian Atlantic Forest could displace cattle production, as a result of land shortages. Although the risks of displacement are indeed high when reforestation is planned in areas with high cattle productivity, we discuss how these risks can be minimized through a combination of productivity increases, a regional restoration planning framework, and the prioritization of marginal agricultural land for restoration. We also consider how restoration can, in some circumstances, be made more economically sustainable by incorporating income-generating activities such as exploitation of timber an...

Colonization of gaps produced by death of bamboo clumps in a semideciduous mesophytic forest in south-eastern Brazil

The study was carried out in 16 gaps produced by bamboo clump death (Merostachys riedeliana Rupr. ex Doell) in a semideciduous mesophytic forest in the Santa Genebra County Reserve (22°49′45″ S and 47°06′33″ W), Campinas, SP, south-eastern Brazil. All shrub and tree individuals in the gap with height ≥ 0.50 m were sampled. The floristic similarity among the colonizing vegetation in these gaps and in gaps produced by treefall was assessed by the Jaccard similarity index and cluster analysis. The colonization process of these gaps was found to be similar to that in gaps formed by treefall, but this colonization only began after the bamboo clump death. The gap area varied from 35 m2 to 454 m2, but small gaps predominated. In the set of gaps, 3677 individuals were sampled belonging to 40 families, 83 genera and 114 species. The families with the greatest species richness in the gaps were Myrtaceae (10), Euphorbiaceae (9) and Solanaceae and Rubiaceae (8 each). The species with the greatest number of individuals in the gaps were the pioneers Celis tala Gillies ex Planchon and Croton priscus Muell. Arg. and the shade-tolerant shrubs Actinostemon klotschii (Muell. Arg.) Pax, Polygala klotzschii Chod., Psychotria hastisepala Muell. Arg. and Galipea multiflora Engl. Late secondary species predominated because of the greater number of small gaps. The gaps formed by bamboo clump death contributed to the successional and structural organization of the forest, creating suitable environments for colonization by shrub and tree species of the different successional groups.

Temperatura ótima de germinação de sementes de espécies arbóreas brasileiras

The objective of this study was to evaluate the ecological and applied aspects of temperature for seed germination of Brazilian tree species. The information obtained from secondary data for temperature effects on the seed germination of 272 Brazilian tree species was analyzed and the relationships between optimal temperature and the biome where the species occur and the species succession group were developed. Temperatures of 25 °C and 30 °C were the most favorable for seed germination and the optimal germination temperature was related to the biome where the species occur but not to its succession group. Based on these results, a temperature of 25 °C may be recommended for germination tests of Brazilian tree species which grow in the Cerrado and Atlantic forest biomes, and 30 °C for those species from the Amazon biome, except for species which have specific requirements of alternating temperatures for overcoming seed dormancy.

Instrumentos legais podem contribuir para a restauração de florestas tropicais biodiversas

The failure of most efforts undertaken to restore natural high-diversity tropical forests, like the Atlantic Forest, has resulted in a very intense round of discussions on the science and best-practice of ecological restoration in the state of Sao Paulo, southeastern Brazil. This culminated in the participatory elaboration of a state resolution concerning technical and orientation aspects for restoration activities, which has been reviewed and updated periodically in workshops that bring together more than 200 professionals. The aim of this resolution was to maximize the establishment of biologically viable forests, with plant richness consistent with the reference ecosystem, to ensure the persistence of restored forests and protect native biodiversity. The contributions of this resolution for the improvement and stimulation of restoration actions are evident today. Between 2003 and 2008, when the resolution was heavily discussed, seedling production of native shrubs and trees in the state increased from 13,000,000 (55 nurseries) to 33,000,000 (114 nurseries) per year, and average number of plant species produced in nurseries also increased from 30 to over 80, reflecting the increase of restoration actions. In our view, the existing legal instrument has served well as a mechanism to accompany environmental public policy aimed at protection of the collective interests of society. In particular, it guides and orients the bulk of investments in ecological restoration and enhances the prospects for maximizing the societal benefits that can and should be obtained from restoration activities, including the persistence of biodiversity in human-modified tropical landscapes.

Alterations following a fire in a forest community of Alto Rio Xingu

This study records the consequences of fire upon the soil and structure of the Amazonian Forest of Gaucha do Norte, Mato Grosso state, Brazil (13812 0 S and 53820 0 W). For this, the number of individuals sampled in 1 ha of the forest, during a phytosociological survey completed 2 days before the accidental fire, was compared with the survivors recorded afterwards in the reinventory of the area taken 2 days and 10 months after the fire. For the surveys, the area of 1 ha was subdivided into 50 plots of 10 m � 20 m, and all the individuals with circumference at breast height ðCBH Þ� 15 cm were sampled. Chemical analysis of the 30 soil samples collected 2 days before the fire were compared with those obtained 15 days and 1 year after the fire. It was seen that, soon after the fire, there was a significant increase in the nutrient levels in the soil, an increase in the pH and a decrease in the aluminum toxicity. However, after 1 year, losses by lixiviation resulted in a nutrient reserve in the soil of less than that before the fire. The tree mortality was extremely high (23.98%), particularly amongst the younger individuals of the population (93.68% of the total of deaths in the period). There was no significant reduction in the forest richness analyzed: 60% of the species had reduced populations after the fire, but just four species were locally extinct. Results, however, demonstrated a role for fire in the selection of resistant species or those adapted to fires, since some species demonstrated a greater tolerance to the fire than others. # 2003 Elsevier Science B.V. All rights reserved.

Análise temporal da heterogeneidade florística e estrutural em uma floresta ribeirinha

Floristic composition and phytosociological structure were studied in a fragment of riverine semideciduous forest, along Passa Cinco River, Ipeuna, Sao Paulo State, southeastern Brazil. A total of 157 continuous plots (5 x 10 m) totalising 0.785 ha were sampled. All trees ³ 5 cm DBH were measured and mapped in 1989 and 1998. The presence of a vegetacional mosaic was observed and possible factors determining this heterogeneity are discussed. Multivariate analysis of vegetation revealed the presence of three vegetacional groups, indicating a strong relationship with edaphic features in the area. Quantitative analysis of community structure showed differences among these groups, which have not changed over time, reinforcing the correlation with soil cover. Vegetational type above alluvial soil, at river banks, showed strong floristic differences, greater diversity, basal area and density. After nine years, few changes occurred in the phytosociological structure for the most important species in the area, with an increase of 2.01% in the total density and 2.80% in total basal area.

Permeability - impermeability: canopy trees as biodiversity filters

Each tropical and subtropical forest canopy species may create specific microsite conditions below its crown, which works as a filter for those species that attempt to regenerate below it. In function of the permeability or impermeability level, each canopy species could partially determine a plant community structure and composition beneath its crown projection. Therefore, present and future forest plant community biodiversity could be partially determined by the present structure of the canopy tree species community (filter effect). Some theoretical and practical aftermaths are suggested.