RESUMO

Tropical forests hold 30% of Earth's terrestrial carbon and at least 60% of its terrestrial biodiversity, but forest loss and degradation are jeopardizing these ecosystems. Although the regrowth of secondary forests has the potential to offset some of the losses of carbon and biodiversity, it remains unclear if secondary regeneration will be affected by climate changes such as higher temperatures and more frequent extreme droughts. We used a data set of 10 repeated forest inventories spanning two decades (1999-2017) to investigate carbon and tree species recovery and how climate and landscape context influence carbon dynamics in an older secondary forest located in one of the oldest post-Columbian agricultural frontiers in the Brazilian Amazon. Carbon accumulation averaged 1.08 Mg·ha-1 ·yr-1 , and species richness was effectively constant over the studied period. Moreover, we provide evidence that secondary forests are vulnerable to drought stress: Carbon balance and growth rates were lower in drier periods. This contrasts with drought responses in primary forests, where changes in carbon dynamics are driven by increased stem mortality. These results highlight an important climate change-vegetation feedback, whereby the increasing dry-season lengths being observed across parts of Amazonia may reduce the effectiveness of secondary forests in sequestering carbon and mitigating climate change. In addition, the current rate of forest regrowth in this region was low compared with previous pan-tropical and Amazonian assessments-our secondary forests reached just 41.1% of the average carbon and 56% of the tree diversity in the nearest primary forests-suggesting that these areas are unlikely to return to their original levels on politically meaningful time scales.

Assuntos

Ecossistema , Florestas , Biodiversidade , Brasil , Mudança Climática , Secas , Árvores , Clima Tropical

RESUMO

The inelastic bandage is an adaptation of the manual lymphatic drainage, which substitutes the circular movements of the fingers. A patient with lymphoedema underwent 20 sessions using the modified lymphatic drainage technique. Perimetric measurements were taken before and after each session, and volumetric measurements at the first, 10th, and 20th sessions. Limb circumference was significantly reduced at three points on the perimeter (10, 15 and 25 cm): 2.5 cm (7.3%), 2.5 cm (6.5%) and 1.5 cm (5%), respectively. Volumetry decrease of 26.4% from initial limb volume was observed. The use of the inelastic bandage proved to be an effective adaptation when compared with the results using other techniques described.