Search Results (2)

Pinus halepensis dominates coastal to mountain areas throughout the Mediterranean Basin. Its growth plasticity, based on polycyclic shoot formation and dynamic cambial activity, and tolerance to extreme drought and exceptional frosts, allows it to colonize a vast array of environments. We used tree-rings from codominant pines to compare lifespan, growth rates, age and size distribution in a typical coastal (i.e., prolonged drought, occasional low-intensity fires) vs. inland hilly (i.e., moister conditions, recurrent frosts) population. BAI trends, growth-limiting climate factors and tree-ring anatomical anomalies were analyzed considering the differences in climate and phenology obtained from multispectral satellite images. The species maximum lifespan was 100–125 years. Mortality was mainly due to fire on the coast, or heart-rot in the inland site. Populations differed in productivity, which was maintained over time despite recent warming. Site conditions affected the growing season dynamics, the control over ring formation by summer drought vs. winter cold and the frequency of anatomical anomalies. Recurrent frost rings, associated with temperatures below −10 °C, occurred only at the inland site. Pinus halepensis confirmed its remarkable growth plasticity to diverse and variable environmental conditions. Its ability to survive extreme events and sustain productivity confirmed its adaptability to climate change in coastal areas as well as on Mediterranean mountains. Full article

Research Highlights: Tree size and wood characteristics influenced the susceptibility of five Amazonian timber tree species to heartwood decay and colonization by termites. Termites occurred in the heartwoods of 43% of the trees, with Coptotermes testaceus the most abundant species. Background and Objectives: Hollows and rotten cores in the stems of living trees have ecological and economic impacts in forests managed for timber. The decision on whether to cut or maintain hollow trees in such forests must account for the susceptibility of different tree species to decay. We investigated tree and wood characteristics of living trees of five commercial timber species in the eastern Amazon that influenced the likelihood of heartwood decay and the occurrence of termite nests inside the rotten cores. Materials and Methods: We used Pearson’s correlations and one-way analysis of variance (ANOVA) to explore relationships among tree basal area and hollow area. We used principal components analysis (PCA) to analyze the variation of wood anatomical traits, followed by a linear regression to explore the relationships between PCA scores, and heartwood hollow area. We used a logistic model to investigate if the probability the occurrence of colonies of C. testaceus inside tree cores varied with tree and species characteristics. Results: Heartwood hollow areas increased with stem basal area. Larger hollows were more likely to occur in species with higher vessel and ray densities, and smaller diameter vessels. Termites occurred in the hollows of 43% of the trees sampled, with C. testaceus the most common (76%). The probability of encountering termite nests of C. testaceus varied among tree species and was positively related to wood density. Conclusions: This study shows that given the increased likelihood of stem hollows and rotten cores in large trees, tree selection criteria in managed tropical forests should include maximum cutting sizes that vary with the susceptibility of different tree species to stem decay. Full article