Germination and initial growth of Campomanesia xanthocarpa O. Berg. (Myrtaceae), in petroleum-contaminated soil and bioremediated soil

In 2000 there was an oil spill at the Getúlio Vargas Refinery (REPAR) in Paraná. Nearly five years after contamination and the use of bioremediation, a study was carried out to identify the effects of the contaminated soil and the bioremediated soil on the germination and initial growth of C. xanthocarpa. The experiment was established with soil from REPAR, with three treatment groups: contaminated soil (C), bioremediated soil (B) and uncontaminated soil (U); with five repetitions of 50 seeds each. There was no significant difference in the percentage of germination and the speed of germination index. The production of total biomass (30 - 60 days) and shoot biomass (60 days) was greater in the bioremediated soil compared to the other treatments. The averages for the root biomass were lower in the contaminated soil than in the bioremediated soil. The shoot length and the total length of the seedling in the contaminated soil and uncontaminated soil were lower than in the bioremediated soil

Dendroecological Studies with Cedrela odorata L., Northeastern Brazil

Northeastern Brazil is home to the Caatinga Forest, characterized as a Tropical Dry Forest (TDF), and the Dense Ombrophilous Forest (the Atlantic Forest) predominates near the coast. In the Caatinga, the climate is semiarid, with <600 mm of mean annual precipitation and a mean annual air temperature of 27 °C ± 6 °C. The precipitation presents a seasonal pattern, with a rainy season concentrated in the first half of the year and at least 6 months of dry season, with volumes <50 mm/month. The climate in the Atlantic Forest has a milder air temperature and a mean rainfall of 1450 mm/year. In both regions the tree species, Cedrela odorata L., widely studied in dendrochronology, presents populations in farms, with several individuals per hectare. In recent decades, 10 chronologies of C. odorata have been produced and compared to precipitation and other environmental factors, and their competition with lianas and support of the herbivorous process has been noted. This chapter presents the potential of C. odorata for dendrochronology in Northeastern Brazil; the anatomy of true rings with marginal parenchyma associated with vessels differed from the false rings by the absence of vessels. Absent rings were also observed. Nine chronologies had correlations above the critical level of 0.51 (0.51?0.79) and sensitivity between 0.547 and 0.771. The correlation between all series (rbt) of all chronologies had values between 0.27 and 0.68 and expressed population signal (EPS) above 0.85 (between 0.88 and 0.98). In both biomes, several populations of C. odorata have resulted in climate-related chronologies that showed the seasonal rainfall from May to July induces metabolism and growth rings formation. We also presented the methodology used for tropical dendroecology studies and the relationship between plant growth and environmental conditions.Fil: Lisi, Claudio Sergio. Universidade Federal de Sergipe; BrasilFil: Alves Pagotto, Mariana. Universidade Federal de Sergipe; BrasilFil: Anholetto, Claudio Roberto. Universidade Federal de Sergipe; BrasilFil: Carvalho Nogueira, Francisco. Universidade Federal de Sergipe; BrasilFil: Lima Santos, Helberson . Universidade Federal de Sergipe; BrasilFil: Costa, Clayane Matos . Universidade Federal de Sergipe; BrasilFil: Romany Nunes Menezes, Ítallo  . Universidade Federal de Sergipe; BrasilFil: Roig Junent, Fidel Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Filho, Mario Tommasiello . Universidade de Sao Paulo; Brasi

Tropical tree growth driven by dry-season climate variability

Interannual variability in the global land carbon sink is strongly related to variations in tropical temperature and rainfall. This association suggests an important role for moisture-driven fluctuations in tropical vegetation productivity, but empirical evidence to quantify the responsible ecological processes is missing. Such evidence can be obtained from tree-ring data that quantify variability in a major vegetation productivity component: woody biomass growth. Here we compile a pantropical tree-ring network to show that annual woody biomass growth increases primarily with dry-season precipitation and decreases with dry-season maximum temperature. The strength of these dry-season climate responses varies among sites, as reflected in four robust and distinct climate response groups of tropical tree growth derived from clustering. Using cluster and regression analyses, we find that dry-season climate responses are amplified in regions that are drier, hotter and more climatically variable. These amplification patterns suggest that projected global warming will probably aggravate drought-induced declines in annual tropical vegetation productivity. Our study reveals a previously underappreciated role of dry-season climate variability in driving the dynamics of tropical vegetation productivity and consequently in influencing the land carbon sink