Climatic signals in growth rings of Cedrela fissilis in different types of South Brazil rainforests

Os anéis de crescimento de Cedrela fissilis foram analisados em duas unidades fitogeográficas do estado do Paraná, em áreas de Florestas Ombrófilas Densa e Mista, litoral e planalto, no domínio da Floresta Atlântica, buscando encontrar sinais climáticos nas séries radiais temporais de anéis de crescimento. As áreas não apresentam estação seca bem definida, com precipitações bem distribuídas ao longo do ano. Na área do litoral, as temperaturas são altas e constantes durante todo o ano, enquanto que na área do planalto as temperaturas são mais amenas, ocorrendo considerável variação durante o ano. Nas duas áreas foram coletadas 3-4 amostras radiais dos indivíduos selecionados, sendo 15 no litoral e 21 no planalto. Os anéis de crescimento foram marcados, mensurados, submetidos ao controle de qualidade por meio do programa COFECHA® e as cronologias foram geradas utilizando o programa ARSTAN®. Sinais climáticos nas séries foram identificados utilizando-se Correlações de Pearson. As séries analisadas provenientes da área de planalto apresentaram melhores correlações com as variáveis temperatura e precipitação, sendo identificados sinais climáticos, enquanto que as séries do litoral não puderam ser datadas com total acurácia. É atribuída a hipótese da competição, principalmente por luz, para explicar a dificuldade na datação dos indivíduos do litoral.Palavras-chave: Anéis de crescimento; dendrocronologia; Floresta Atlântica. AbstractClimatic signals in growth rings of Cedrela fissilis in different types of South Brazil rainforests. Cedrela fissilis tree-rings were examined in two distinct phytogeographic units of the State of Paraná, Brazil. The analysis was carried out in areas of tropical rain forest, Atlantic Forest (cost), and Araucaria Forest (plateau) in order to seek for climatic signals in tree rings series. In the coast area, temperatures are high and constant throughout the year, while in the area of the plateau, temperatures are milder and considerable variations occur during the year. In both areas 3-4 radial samples of each selected individual were collected, 15 from the coast and 21 from the plateau. Growth rings were marked, measured, submitted to quality control using the COFECHA® software, and chronologies generated using the ARSTAN® software. Climatic signals in growth rings were identified using Pearson correlations. Tree rings series from plateau revealed better correlations with temperature and rainfall compared to the coast ones; they were accurately dated while the other from coast could not be dated with accuracy. Climatic signals were found in the well-dated chronology. The hypothesis of competition, mainly by light, is raised to explain the difficulty to establish a good chronology for coast area.Keywords: Growth rings; dendrochronology; Atlantic Forest.AbstractCedrela fissilis tree-rings were examined in two distinct phytogeographic units of the State of Paraná, Brazil. The analysis was carried out in areas of tropical rain forest, Atlantic Forest (cost), and Araucaria Forest (plateau) in order to seek for climatic signals in tree rings series. In the coast area, temperatures are high and constant throughout the year, while in the area of the plateau, temperatures are milder and considerable variations occur during the year. In both areas 3-4 radial samples of each selected individual were collected, 15 from the coast and 21 from the plateau. Growth rings were marked, measured, submitted to quality control using the COFECHA® software, and chronologies generated using the ARSTAN® software. Climatic signals in growth rings were identified using Pearson correlations. Tree rings series from plateau revealed better correlations with temperature and rainfall compared to the coast ones; they were accurately dated while the other from coast could not be dated with accuracy. Climatic signals were found in the well-dated chronology. The hypothesis of competition, mainly by light, is raised to explain the difficulty to establish a good chronology for coast area.Keywords: Growth rings; dendrochronology; Atlantic Forest