Potential aboveground biomass increase in Brazilian Atlantic Forest fragments with climate change.

Fragmented tropical forest landscapes preserve much of the remaining biodiversity and carbon stocks. Climate change is expected to intensify droughts and increase fire hazard and fire intensities, thereby causing habitat deterioration, and losses of biodiversity and carbon stock losses. Understanding the trajectories that these landscapes may follow under increased climate pressure is imperative for establishing strategies for conservation of biodiversity and ecosystem services. Here, we used a quantitative predictive modelling approach to project the spatial distribution of the aboveground biomass density (AGB) by the end of the 21st century across the Brazilian Atlantic Forest (AF) domain. To develop the models, we used the maximum entropy method with projected climate data to 2100, based on the Intergovernmental Panel on Climate Change Representative Concentration Pathway (RCP) 4.5 from the fifth Assessment Report. Our AGB models had a satisfactory performance (area under the curve > 0.75 and p value < .05). The models projected a significant increase of 8.5% in the total carbon stock. Overall, the projections indicated that 76.9% of the AF domain would have suitable climatic conditions for increasing biomass by 2100 considering the RCP 4.5 scenario, in the absence of deforestation. Of the existing forest fragments, 34.7% are projected to increase their AGB, while 2.6% are projected to have their AGB reduced by 2100. The regions likely to lose most AGB-up to 40% compared to the baseline-are found between latitudes 13° and 20° south. Overall, although climate change effects on AGB vary latitudinally for the 2071-2100 period under the RCP 4.5 scenario, our model indicates that AGB stocks can potentially increase across a large fraction of the AF. The patterns found here are recommended to be taken into consideration during the planning of restoration efforts, as part of climate change mitigation strategies in the AF and elsewhere in Brazil.

Recovery of Forest and Phylogenetic Structure in Abandoned Cocoa Agroforestry in the Atlantic Forest of Brazil.

Cocoa agroforests like the cabrucas of Brazil's Atlantic forest are among the agro-ecosystems with greatest potential for biodiversity conservation. Despite a global trend for their intensification, cocoa agroforests are also being abandoned for socioeconomic reasons especially on marginal sites, because they are incorporated in public or private protected areas, or are part of mandatory set-asides under Brazilian environmental legislation. However, little is known about phylogenetic structure, the processes of forest regeneration after abandonment and the conservation value of former cabruca sites. Here we compare the vegetation structure and composition of a former cabruca 30-40 years after abandonment with a managed cabruca and mature forest in the Atlantic forest region of Espirito Santo, Brazil. The forest in the abandoned cabruca had recovered a substantial part of its original structure. Abandoned cabruca have a higher density (mean ± CI95 %: 525.0 ± 40.3 stems per ha), basal area (34.0 ± 6.5 m2 per ha) and species richness (148 ± 11.5 species) than managed cabruca (96.0 ± 17.7; 24.15 ± 3.9 and 114.5 ± 16.0, respectively) but no significant differences to mature forest in density (581.0 ± 42.2), basal area (29.9.0 ± 3.3) and species richness (162.6 ± 15.5 species). Thinning (understory removal) changes phylogenetic structure from evenness in mature forest to clustering in managed cabruca, but after 30-40 years abandoned cabruca had a random phylogenetic structure, probably due to a balance between biotic and abiotic filters at this age. We conclude that abandoned cocoa agroforests present highly favorable conditions for the regeneration of Atlantic forest and could contribute to the formation of an interconnected network of forest habitat in this biodiversity hotspot.

Composition and conservation of Orchidaceae on an inselberg in the Brazilian Atlantic Forest and floristic relationships with areas of Eastern Brazil.

The Brazilian Atlantic Forest presents high levels of richness and endemism of several taxonomic groups. Within this forest, the Orchidaceae may be highlighted as the richest family of Angiosperms found there, and is highly threatened due to collection and habitat destruction. The inselbergs of the Brazilian Atlantic Forest are mostly unknown regarding their floristic composition, but the available information points to occurrence of endemic species, with adaptations to survive to this dry environment. The objectives of this study were to conduct a floristic survey of the Orchidaceae species on the Maciço do Itaoca, an inselberg located in the Northern region of the State of Rio de Janeiro, make a comparative analysis with other sites in Eastern Brazil, and discuss the geographic distribution, floristic relationships and conservation status of the orchid species present on the inselbergs. The floristic composition of the study area was compared with 24 other locations in Eastern Brazil (of which 13 are inselbergs) and the influence of the types of surrounding vegetation on the composition of the Orchidaceae flora on the inselbergs. On Maciço do Itaoca we recorded 18 species from 17 genera: Brasiliorchis picta, Brassavola tuberculata, Campylocentrum robustum; C sellowii, Catasetum luridum, Cattleya guttata, Cyclopogon congestus, Cyrtopodium glutiniferum, Leptotes bicolor, Lophiaris pumila, Miltonia moreliana, Oeceoclades maculata, Phymatochilum brasiliense, Prescottia plantaginifolia, Pseudolaelia vellozicola, Sarcoglottis fasciculata, Sophronitis cernua. and Vanilla chamissonis. The highest floristic similarity was with the Pedra da Botelha (0.43), an inselberg located in the North of Espírito Santo. This result is probably due to the similarity in altitude and distance from the coast in both areas despite the geographical distance between them. Apparently, little influence is exerted by the types of surrounding vegetation on the composition of the flora of inselbergs, due to their unique environmental characteristics which exert a strong selection pressure on plants that are adapted to survive on these inselbergs. The threats observed to the species on this inselberg are the same as for other inselbergs and include the collection of ornamental species, fire and quarrying. Specifically for the Maciço do Itaoca, a possibility for conservation may be the annexation of this area to the Desengano State Park, an important conservation area in the Northern of the State of Rio de Janeiro.

Tree species diversity of coastal lowland semideciduous forest fragments in northern Rio de Janeiro State, Brazil / Diversidade de espécies arbóreas em fragmentos de floresta semidecidual de terras baixas costeiras no norte do Estado do Rio de Janeiro, Brasil

Habitat destruction has caused Brazilian coastal lowland semideciduous forests to suffer severe fragmentation. In the state of Rio de Janeiro, especially in the northern region, these fragments are under severe threat of destruction, while data on their floristic diversity and community structure are still lacking. In this study, six secondary forest fragments (henceforth called sites) of coastal lowland semideciduous forests with areas ranging from 13 to 1200 ha were studied. The objective was to evaluate the structure and diversity of trees of these sites and relate them to the conservation status of this region. Five plots of 20 x 20 m were established in each site, totalling a sample area of 1.4 ha and all trees with DBH 5cm were sampled. The families with the highest species richness were Fabaceae, Sapotaceae, Myrtaceae and Meliaceae. The most abundant species were: Metrodorea nigra, Pseudopiptadenia contorta and Senefeldera verticillata. The richness, evenness and Shannon diversity values ranged from 59 to 89 species, 0.75 to 0.87 and from 2.59 to 3.79 nats.ind-1, respectively. Sites showed high floristic similarity. The tree density values varied from 1410 to 1840 ind.ha-1 and were within the levels expected for semideciduous forest; however, the basal area values (19.8 to 28.0 m2.ha-1) are those usually observed in disturbed forests. Despite being secondary forests, the sites had high species diversity with occurrence of tree species of recognized conservation value. Urgent action must be taken to manage and conserve these forests, such as: (i) forest corridors establish connecting fragments especially using zoochorous tree species, and (ii) use forest enrichment techniques using species that are absent or presently at low density as a result of intensive exploitation in the past.

A destruição de habitat levou as florestas estacionais semideciduais de tabuleiro brasileiras a sofrerem intensa fragmentação. No estado do Rio de Janeiro, especialmente na região norte, esses fragmentos estão sob grave ameaça de destruição e os dados sobre a florística, diversidade e estrutura da comunidade ainda são insuficientes. Neste estudo, seis fragmentos secundários de florestas semidecíduas costeiras de baixa altitude, com áreas variando de 13 a 1200 ha foram estudados. O objetivo do presente trabalho foi avaliar a estrutura e a diversidade arbórea nesses locais e relacionar esses dados com o estado de conservação da região. Cinco parcelas de 20 x 20 m, foram alocadas em cada local, totalizando uma área amostral de 1,4ha e todas as árvores com DAP 5cm foram amostradas. As famílias com maior riqueza de espécies nas áreas foram Fabaceae, Sapotaceae, Myrtaceae e Meliaceae. As espécies mais abundantes nas áreas foram: Metrodorea nigra, Pseudopiptadenia contorta e Senefeldera verticillata. Os valores de riqueza, diversidade de Shannon e eqüitabilidade, variaram de 59 a 89 espécies, 0,75 a 0,87 e 2,59 a 3,79 nats.ind-1, respectivamente. Foi encontrada alta similaridade florística entre as áreas. Os valores de densidade de árvores variou de 1410 a 1840 ind.ha-1, estando dentro do esperado para uma floresta estacional semidecidual, no entanto, os valores de área basal (19,8-28,0 m2.ha-1) são normalmente observados em florestas perturbadas. Apesar dos fragmentos estudados serem florestas secundárias, os mesmos apresentaram alta diversidade, com ocorrência de espécies de valor conservacionista reconhecido. Medidas urgentes devem ser tomadas para o manejo e conservação dos remanescentes de florestas de tabuleiro, tais como: (1) corredores florestais devem ser definidos conectando fragmentos, especialmente utilizando espécies de árvores zoocóricas e (2) técnicas de enriquecimento florestal, utilizando espécies que estão ausentes ou ocorrem com baixa densidade como resultado da exploração intensiva no passado.