25 research outputs found
Long-term carbon loss in fragmented Neotropical forests
Tropical forests play an important role in the global carbon cycle, as they store a large amount of carbon (C). Tropical forest deforestation has been identified as a major source of CO2 emissions, though biomass loss due to fragmentationâthe creation of additional forest edgesâhas been largely overlooked as an additional CO2 source. Here, through the combination of remote sensing and knowledge on ecological processes, we present long-term carbon loss estimates due to fragmentation of Neotropical forests: within 10 years the Brazilian Atlantic Forest has lost 69 (±14) Tg C, and the Amazon 599 (±120) Tg C due to fragmentation alone. For all tropical forests, we estimate emissions up to 0.2âPg Câyâ1 or 9 to 24% of the annual global C loss due to deforestation. In conclusion, tropical forest fragmentation increases carbon loss and should be accounted for when attempting to understand the role of vegetation in the global carbon balance.This study was part of the project âBiodiversity conservation in a fragmented landscape at the Atlantic Plateau of SĂŁo Pauloâ (BIOTA/Caucaia and BioCAPSP) funded by FAPESP (Fundação de Amparo Ă Pesquisa do Estado de SĂŁo Paulo, project no. 99/05123-4, 01/13309-2, 02/02125-0, 02/02126-7), CNPq (Conselho Nacional de Desenvolvimento CientĂfico e TecnolĂłgico, project no. 690144/01-6), Fundação O BoticĂĄrio de Proteção Ă Natureza, and by BMBF (German Federal Ministry of Education and Research, project n. 01LB0202). J.P.M. and M.C.R. thank the Brazilian Science Council (Conselho Nacional de Desenvolvimento CientĂfico) for his research fellowship (process no. 307934/2011-0 and 312045/2013-1, respectively). A.H. and S.P. were supported by the ERC advanced grant 233066. M.M. has been supported by BMBF (project n. 01LB0202), and the Department of Ecological Modelling of the Helmholtz Centre for Environmental Research (UFZ). We thank Birgit Felinks for the support during the Mata AtlĂąntica project. Florian Hartig provided valuable comments on an earlier version of this manuscript. S.P. has been funded by the Helmholtz Association of German Research Centres within the project âBiomass and Bioenergy systemsâ. A.H. was also supported by the Helmholtz-Alliance Remote Sensing and Earth System Dynamics. A.H. thanks C. Wissel and H. Bossel for supporting the FORMIND project over the years
A new species of Passiflora in section Tetrastylis (Passifloraceae) and two overlooked species of Passiflora from Brazil
Passiflora contracta, a new species from coastal forests of Brazil, is described and illustrated. Based on recent collections, Passiflora hypoglauca and P. luetzelburgii, two rare and overlooked species last collected in the 19th century, have had their descriptions emended, are illustrated here for the first time, and have had their distributions expanded.561899
Clonal growth and reproductive strategies of the understory tropical palm Geonoma brevispatha: an ontogenetic approach
We investigated the patterns of growth and reproduction of the understory clonal palm Geonoma brevispatha based on the identification of post-germinative ontogenetic stages, over a 3-year period. Genets were monitored in 100 5 x 5 m plots and 100 2 x 2 m subplots, in a 1-ha area of swamp forest in Sao Paulo state, southeastern Brazil. Ramets pass through four ontogenetic stages (bifid-leafed juveniles, pinnatifid-leafed stemless immatures, stemmed nonreproductive virgins, and reproducers). Leaf size, leaf number, and leaf production rate increased during ontogeny, but diameter growth rate was higher among immatures. Stem length, number of nodes, and leaf rachis length were positively correlated across ontogenetic stages, but crown height was smaller than stem length in adult palms because of frequent leaning. Leaf number and sexual fecundity increased with ramet size, but declined in larger, senescent ramets. Clonal fecundity preceded sexual fecundity, and sexual and clonal fecundity increased continuously with genet size. No relationship was found between sexual and clonal fecundity. Growth and survival strategies of G. brevispatha were consistent with the patterns found in other tropical clonal palm species. Sexual fecundity and cloning seem to be two integrated processes favored by environmental conditions that also support the growth of existing ramets.81210111
Pattern of tree species diversity in riparian forest fragments of different widths (SE Brazil)
Width is an essential element of the spatial configuration of riparian forests and may be fundamental in determining their corridor function. In the present study we tested the effect of forest width on floristic structure (tree species composition and diversity) in 15 fragments of riparian forest in an agricultural fragmented landscape of SE Brazil. All these fragments were chosen in a geomorphological homogeneous river reach under similar soil, topographic and human disturbance conditions in order to minimize the influence of these factors. The forest widths considered ranged from 30 to 650 m. The results showed that total species richness and climax species richness were significantly greater when we consider larger fragments, as has been observed in other studies. Nevertheless, species diversity and evenness were not significantly correlated with forest width. The analysis of species composition showed that the narrowest fragments were characterized by species well adapted to temporary flood conditions, while medium and wide fragments showed a composition typical of drier upland areas. Therefore, the effect of forest width on floristic structure appears to be more strongly linked to the effect of river floods in the case of the fragments studied. The existence in riparian corridors of a drier forest, in general richer and more diversified than the annually flooded forest, seems to favor the maintenance of regional species diversity in fragmented landscapes.133213515