Palynological analysis of a core from the Atlantic rain forest region in Brazil provides unprecedented insight into late Quaternary vegetational and climate dynamics within this southern tropical lowland. The 576-cm-long sediment core is from a former beach-ridge “valley,” located 3 km inland from the Atlantic Ocean. Radio-carbon dates suggest that sediment deposition began prior to 35,000 ¹⁴C yr B.P. Between ca. 37,500 and ca. 27,500 ¹⁴C yr B.P. and during the last glacial maximum (LGM; ca. 27,500 to ca. 14,500 ¹⁴C yr B.P.), the coastal rain forest was replaced by grassland and patches of cold-adapted forest. Tropical trees, such as Alchornea, Moraceae/Urticaceae, and Arecaceae, were almost completely absent during the LGM. Furthermore, their distributions were shifted at least 750 km further north, suggesting a cooling between 3°C and 7°C and a strengthening of Antarctic cold fronts during full-glacial times. A depauperate tropical rain forest developed as part of a successional sequence after ca. 12,300 ¹⁴C yr B.P. There is no evidence that Araucaria trees occurred in the Atlantic lowland during glacial times. The rain forest was disturbed by marine incursions during the early Holocene period until ca. 6100 ¹⁴C yr B.P., as indicated by the presence of microforaminifera. A closed Atlantic rain forest then developed at the study site.

Caívas are traditional silvopastoral systems that occur in the Araucaria Forest biome, Southern Brazil, in which animal production and erva-mate extraction are integrated. Participatory research was conducted in caívas in the Northern Plateau, Santa Catarina State, to identify strategies to intensify pasture use and increase animal productivity. To better understand the outcomes of these strategies, a sustainability assessment was conducted in properties that participated in the research (improved caívas; IC) and those that did not (traditional caívas; TC). The Sustainability Assessment of Food and Agriculture Systems (SAFA) tool 2.0.0 for smallholders was chosen as it evaluates the productive unit as a whole using environmental, social, economic, and governance indicators and is tailored for small-scale production. All evaluated indicators showed higher scores for IC properties in relation to TC. In general, the SAFA analysis showed that when evaluated as productive systems, TCs are a strategic option for rural development, as 65% of their indicators were evaluated as good. With the support of rural outreach and research and the adoption of appropriate technologies, this percentage increased to 86% in ICs. These results confirm that with adequate support caívas can significantly contribute to the development of more sustainable livestock farming in Southern Brazil.

We examined the leaf morphology and anatomy of 89 tree species growing in an area of coastal Atlantic Forest in South Brazil. The majority of the species (> 75%) had small (notophyll and microphyll) elliptical simple leaves with entire margins. These leaves presented a typical anatomical structure consisting of a single epidermal cell layer, single palisade parenchyma cell layer, and spongy parenchyma with 5 to 8 cell layers. The sclerenchyma was limited to the vascular bundles. The majority of the tree species (91%) had leaves with mesomorphic characteristics. Few species depicted leaves with xeromorphic features as would be expected in such oligotrophic sandy soil. These mesomorphic features appeared to be associated to high efficiency mechanisms for nutrient cycling that compensated for the low nutrient content of the mineral soil. Este estudo examinou a morfologia e anatomia foliar de 89 espécies arbóreas de uma área de Floresta Atlântica Litorânea no Sul do Brasil. A maioria das espécies (>75%) possuem folhas pequenas (notófilas e micrófilas) elípticas e simples com margens inteiras. Essas folhas apresentam uma estrutura anatômica formada por epiderme uniseriada, parênquima paliçádico composto por um único estrato de células e o parênquima esponjoso composto por 5 to 8 estratos celulares. O tecido esclerenquimático é limitado aos feixes vasculares. A maioria das espécies arbóreas (91%) possui folhas com características mesomórficas Poucas espécies (9%) são xerófilas como era esperado em florestas que crescem sob solo arenoso oligotrófico. As características mesomórficas parecem estar associadas a eficientes mecanismos de ciclagem de nutrientes que compensam o baixo conteúdo de nutrientes do solo mineral

Bromeliad ornamental species: conservation issues and challenges related to commercialization - doi: 10.4025/actascibiolsci.v34i1.7314