Global patterns and environmental drivers of forest functional composition

Aim To determine the relationships between the functional trait composition of forest communities and environmental gradients across scales and biomes and the role of species relative abundances in these relationships. Location Global. Time period Recent. Major taxa studied Trees. Methods We integrated species abundance records from worldwide forest inventories and associated functional traits (wood density, specific leaf area and seed mass) to obtain a data set of 99,953 to 149,285 plots (depending on the trait) spanning all forested continents. We computed community-weighted and unweighted means of trait values for each plot and related them to three broad environmental gradients and their interactions (energy availability, precipitation and soil properties) at two scales (global and biomes). Results Our models explained up to 60% of the variance in trait distribution. At global scale, the energy gradient had the strongest influence on traits. However, within-biome models revealed different relationships among biomes. Notably, the functional composition of tropical forests was more influenced by precipitation and soil properties than energy availability, whereas temperate forests showed the opposite pattern. Depending on the trait studied, response to gradients was more variable and proportionally weaker in boreal forests. Community unweighted means were better predicted than weighted means for almost all models. Main conclusions Worldwide, trees require a large amount of energy (following latitude) to produce dense wood and seeds, while leaves with large surface to weight ratios are concentrated in temperate forests. However, patterns of functional composition within-biome differ from global patterns due to biome specificities such as the presence of conifers or unique combinations of climatic and soil properties. We recommend assessing the sensitivity of tree functional traits to environmental changes in their geographic context. Furthermore, at a given site, the distribution of tree functional traits appears to be driven more by species presence than species abundance

Impacts of Climate Change on the Distribution of Larix Spp. and Pinus Sylvestris and Their Climatypes in Siberia

climate change, climatic envelope, climate transfer function, climatypes, interspecies competition, Larix sibirica , L. dahurica , L. sukaczewii , permafrost, Siberia, tree species Pinus sylvestris ,

Terrestrial ecosystems and their change

This chapter considers the current state of Siberian terrestrial ecosystems, their spatial distribution, and major biometric characteristics. Ongoing climate change and the dramatic increase of accompanying anthropogenic pressure provide different but mostly negative impacts on Siberian ecosystems. Future climates of the region may lead to substantial drying on large territories, acceleration of disturbance regimes, deterioration of ecosystems, and positive feedback to global warming. The region requires urgent development and implementation of strategies of adaptation to, and mitigation of, negative consequences of climate change

Energy and Mass Exchange and the Productivity of the Main Ecosystems of Siberia (From Eddy Covariance Measurements). 1. Heat Balance Structure in the Vegetation Season

На основе прямых измерений составляющих теплового баланса (турбулентного теплообмена и за трат тепла на испарение) методом турбулентных пульсаций в течение 1998–2000 и 2002–2004 гг. по лучены данные по дневной, сезонной и годичной динамике потоков энерго и массообмена между атмосферой и типичными экосистемами Сибири (среднетаежными сосновым лесом и верховым бо лотом, настоящей четырехзлаковой степью, с привлечением данных по типичной тундре) вдоль Енисейского меридиана (90° в.д.)