Influence of removal of a non-native tree species Mimosa caesalpiniifolia Benth. on the regenerating plant communities in a tropical semideciduous forest under restoration in Brazil

Exotic species are used to trigger facilitation in restoration plantings, but this positive effect may not be permanent and these species may have negative effects later on. Since such species can provide a marketable product (firewood), their harvest may represent an advantageous strategy to achieve both ecological and economic benefits. In this study, we looked at the effect of removal of a non-native tree species (Mimosa caesalpiniifolia) on the understory of a semideciduous forest undergoing restoration. We assessed two 14-year-old plantation systems (modified taungya agroforestry system; and mixed plantation using commercial timber and firewood tree species) established at two sites with contrasting soil properties in S��o Paulo state, Brazil. The experimental design included randomized blocks with split plots. The natural regeneration of woody species (height ���0.2��m) was compared between managed (all M. caesalpiniifolia trees removed) and unmanaged plots during the first year after the intervention. The removal of M. caesalpiniifolia increased species diversity but decreased stand basal area. Nevertheless, the basal area loss was recovered after 1��year. The management treatment affected tree species regeneration differently between species groups. The results of this study suggest that removal of M. caesalpiniifolia benefited the understory and possibly accelerated the succession process. Further monitoring studies are needed to evaluate the longer term effects on stand structure and composition. The lack of negative effects of tree removal on the natural regeneration indicates that such interventions can be recommended, especially considering the expectations of economic revenues from tree harvesting in restoration plantings.

Cerrado vegetation and global change: the role of functional types, resource availability and disturbance in regulating plant community responses to rising CO2 levels and climate warming

Conselho Nacional de Desenvolvimento Cient��fico e Tecnol��gico (CNPq)

How can an invasive grass affect fire behavior in a tropical savanna? A community and individual plant level approach

Conselho Nacional de Desenvolvimento Cient��fico e Tecnol��gico (CNPq)

Bacterial functional redundancy along a soil reclamation gradient

A strategy to measure bacterial functional redundancy was developed and tested with soils collected along a soil reclamation gradient by determining the richness and diversity of bacterial groups capable of in situ growth on selected carbon substrates. Soil cores were collected from four sites along a transect from the Jamari tin mine site in the Jamari National Forest, Rondonia, RO, Brazil: denuded mine spoil, soil from below the canopy of invading pioneer trees, revegetated soil under new growth on the forest edge, and the forest floor of an adjacent preserved forest. Bacterial population responses were analyzed by amending these soil samples with individual carbon substrates in the presence of bromodeoxyuridine (BrdU), BrdU-labeled DNA was then subjected to a 16S-23S rRNA intergenic analysis to depict the actively growing bacteria from each site, the number and diversity of bacterial groups responding to four carbon substrates (L-serine, L-threonine, sodium citrate, and or-lactose hydrate) increased along the reclamation-vegetation gradient such that the preserved forest soil samples contained the highest functional redundancy for each substrate. These data suggest that bacterial functional redundancy increases in relation to the regrowth of plant communities and may therefore represent an important aspect of the restoration of soil biological functionality to reclaimed mine spoils. They also suggest that bacterial functional redundancy may be a useful indicator of soil quality and ecosystem functioning.

Ocorr��ncia de plantas aqu��ticas nos reservat��rios da Companhia Energ��tica de S��o Paulo

O objetivo do presente trabalho foi caracterizar as comunidades de plantas aqu��ticas presentes nos reservat��rios da Companhia Energ��tica de S��o Paulo. Os levantamentos foram realizados entre janeiro e dezembro de 1999, percorrendo-se com um barco as margens dos reservat��rios de Tr��s Irm��os, Jupi��, Ilha Solteira, Porto Primavera, Paraibuna e Jaguari, visando identificar as ��reas com infesta����es de plantas aqu��ticas. em cada ponto de avalia����o, fez-se a identifica����o das esp��cies e estimou-se visualmente a ��rea total infestada e a participa����o de cada esp��cie (em % da ��rea total). Com as informa����es coletadas em campo, procedeu-se a uma etapa de trabalhos em escrit��rio, incluindo a identifica����o das esp��cies de plantas aqu��ticas nos casos em que n��o era poss��vel identificar as esp��cies no local; a determina����o de classes de plantas aqu��ticas (emersas, emersas com folhas flutuantes, submersas, flutuantes); a identifica����o das esp��cies mais freq��entes; e o estabelecimento de rela����es de domin��ncia e co-domin��ncia. S��o apresentados os resultados obtidos em cada reservat��rio.

The use of biodiversity as source of new chemical entities against defined molecular targets for treatment of malaria, tuberculosis, and T-cell mediated diseases: a review

The modern approach to the development of new chemical entities against complex diseases, especially the neglected endemic diseases such as tuberculosis and malaria, is based on the use of defined molecular targets. Among the advantages, this approach allows (i) the search and identification of lead compounds with defined molecular mechanisms against a defined target (e.g. enzymes from defined pathways), (ii) the analysis of a great number of compounds with a favorable cost/benefit ratio, (iii) the development even in the initial stages of compounds with selective toxicity (the fundamental principle of chemotherapy), (iv) the evaluation of plant extracts as well as of pure substances. The current use of such technology, unfortunately, is concentrated in developed countries, especially in the big pharma. This fact contributes in a significant way to hamper the development of innovative new compounds to treat neglected diseases. The large biodiversity within the territory of Brazil puts the country in a strategic position to develop the rational and sustained exploration of new metabolites of therapeutic value. The extension of the country covers a wide range of climates, soil types, and altitudes, providing a unique set of selective pressures for the adaptation of plant life in these scenarios. Chemical diversity is also driven by these forces, in an attempt to best fit the plant communities to the particular abiotic stresses, fauna, and microbes that co-exist with them. Certain areas of vegetation (Amazonian Forest, Atlantic Forest, Araucaria Forest, Cerrado-Brazilian Savanna, and Caatinga) are rich in species and types of environments to be used to search for natural compounds active against tuberculosis, malaria, and chronic-degenerative diseases. The present review describes some strategies to search for natural compounds, whose choice can be based on ethnobotanical and chemotaxonomical studies, and screen for their ability to bind to immobilized drug targets and to inhibit their activities. Molecular cloning, gene knockout, protein expression and purification, N-terminal sequencing, and mass spectrometry are the methods of choice to provide homogeneous drug targets for immobilization by optimized chemical reactions. Plant extract preparations, fractionation of promising plant extracts, propagation protocols and definition of in planta studies to maximize product yield of plant species producing active compounds have to be performed to provide a continuing supply of bioactive materials. Chemical characterization of natural compounds, determination of mode of action by kinetics and other spectroscopic methods (MS, X-ray, NMR), as well as in vitro and in vivo biological assays, chemical derivatization, and structure-activity relationships have to be carried out to provide a thorough knowledge on which to base the search for natural compounds or their derivatives with biological activity.

Flor��stica de uma Floresta Estacional Semidecidual, localizada em ec��tono sav��nico-florestal, no munic��pio de Bauru, SP, Brasil

Informa����es flor��sticas escassas, referentes ao munic��pio de Bauru, e a elabora����o de hip��teses sobre mecanismos de ocupa����o de fitocenoses florestais por esp��cies sav��nicas, representaram as principais quest��es motivadoras do presente estudo, desenvolvido em dois fragmentos de floresta estacional semidecidual (5 ha e 7 ha) mantidos pelo Jardim Bot��nico de Bauru, que abriga tamb��m savana florestada. O material bot��nico foi coletado a partir de caminhadas ao acaso e em parcelas implantadas durante estudo fitossociol��gico. Foram encontradas 264 esp��cies arbustivo-arb��reas, pertencentes a 58 fam��lias. Dessas esp��cies 126 foram coletadas apenas na fitocenose florestal, e 66 esp��cies foram coletadas em ambas as fitocenoses. As duas fam��lias com o maior n��mero de esp��cies foram Rubiaceae (25 esp��cies) e Myrtaceae (21 esp��cies). Foi realizada an��lise de similaridade flor��stica, a partir do ��ndice de Jaccard (SJ), entre a floresta do JBMB e outros 11 remanescentes florestais, alguns dos quais, sob influ��ncia flor��stica sav��nica. A riqueza flor��stica dos fragmentos florestais do JBMB sofreu incremento, pela ocupa����o de esp��cies sav��nicas, oriundas da savana florestada cont��gua. Inc��ndios pret��ritos, al��m da ocorr��ncia de microambientes distintos, representaram prov��veis fatores de facilita����o para a invas��o dessas esp��cies sav��nicas.

Storage in cerrado soil and germination of Psychotria vellosiana (Rubiaceae) seeds

The regeneration of plant communities from seed depends, to a large extent, on the capacity of the seed remaining viable in the soil. The viability and germination of artificially buried Psychotria vellosiana seeds in cerrado soil were studied, with the purpose of discovering some physio-ecological aspects of dispersed seeds and evaluating their potential to constitute a soil seed bank. Seed samples were placed in nylon envelopes and buried in the soil of a Cerrado reserve at two different depths and sites. Buried seeds were retrieved periodically and tested for germination along with dry-stored seeds. In general, there was a reduction in seed germination with storage time, both in soil and dry stored conditions, and in some assays exhumed seeds germinated faster than dry stored ones. In general the soil storage favoured seed viability of ungerminated seeds as compared to dry stored ones, with the seeds remaining partially viable after 10 months of storage. The lack of germination of viable seeds suggests that seeds showed true dormancy and/or required an extended time to germinate. It was observed that some seeds had germinated while buried and such in situ germination tended to increase with rainfall. The water availability in the soil might be a limiting factor for successful germination of P. vellosiana in the field, and the seeds may constitute a persistent soil seed bank in the cerrado as dispersed seeds remain viable in the soil until the following period of seed dispersal.

No changes in seedling recruitment when terrestrial mammals are excluded in a partially defaunated Atlantic rainforest

One of the most intriguing questions in ecology is how to identify which and how many species will be able to inhabit human-modified landscapes. Large-bodied mammals structure plant communities by trampling, herbivory, seed dispersal and predation, and their local extinction may have pervasive consequences in plant communities due to the breakdown of key interactions. Although much attention has been given to understanding the effects of defaunation on plant communities, information on the potential impacts on plant functional groups (seed dispersal, seed size and seedling leaves defense) inhabiting continuous forests after defaunation is scarce. We conducted mammal surveys (line transects and camera trapping) to determine the defaunation status of a continuous Atlantic forest in Brazil. Then, we evaluated the effects of defaunation on seedling diversity, richness and abundance of functional groups using 15 plot-pairs (each pair with one open and one exclusion plot) monitored over 36. months. We found that the studied area is partially defaunated because it exhibits high abundance of primates, while terrestrial mammals, such as large rodents and ungulates, are rare. We found no significant changes in either seedling richness and diversity or in the seedling composition of plant functional groups in response to mammal exclosure. Seedling mortality and recruitment were similar between plot types. Our findings suggest that at semi-defaunated areas, where arboreal species are still present, terrestrial mammals have low impacts on the plant community reassembly. �� 2013 Elsevier Ltd.

Engenheiros dos ecossistemas em plantas: modifica����es arquiteturais de folhas por largatas de Lepidoptera influenciam a estrutura de comunidades de artr��podes

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

��caros associados a plantas da regi��o Core do Cerrado e sua influ��ncia na acarofauna em cultivos de soja (Glycine max (L.) Merril) (Fabaceae)

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

An��lise morfom��trica e biodiversidade da vegeta����o na microbacia hidrogr��fica da Fazenda Experimental Edg��rdia

Conselho Nacional de Desenvolvimento Cient��fico e Tecnol��gico (CNPq)

Estrutura da vegeta����o arb��rea em gradiente altitudinal de um morro testemunho em uma floresta estacional semidecidual na regi��o centro-sul do estado de S��o Paulo, sudeste do Brasil

P��s-gradua����o em Ci��ncias Biol��gicas (Bot��nica) - IBB

Extin����o ecol��gica de grandes herb��voros e diversidade de plantas em um gradiente de defauna����o na Mata Atl��ntica

P��s-gradua����o em Ci��ncias Biol��gicas (Zoologia) - IBRC

Efeitos da defauna����o na herbivoria, pisoteio de pl��ntulas, remo����o e preda����o de sementes na Floresta Atl��ntica

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)