The need to understand the carbon sequestration ability of trees under current and future climatic scenarios is fundamental to predict the role of forest in counterbalancing the global warming. In this study, we investigated the carbon sequestration ability of Pinus sylvestris L. in a setting of pure and mixed forests with Quercus petraea (Matt.) Liebl. in Central Poland. Beside the traditional growth measures, i.e., Ring Width, Basal Area Increment, and wood density, we utilized also a new Index called BAIden, which combines Basal Area Increment and mean ring wood density to depict the carbon sequestration ability of trees. Pinus sylvestris showed different sensitivity to climatic variability depending on tree admixture, while the Basal Area Increment and wood density presented few differences between pure and mixed forests. According to the BAIden index, carbon accumulation in P. sylvestris showed similar sensitivity to climatic variability in pure and mixed forests. The new index was also informative on the main climatic drivers of carbon sequestration. Considering future climatic scenarios, the carbon sequestration ability of P. sylvestris will be facilitated by rising temperatures in late winter-early spring and reduced by decreasing precipitation and rising temperatures during summer. Finally, we discussed the perspective and applicability of BAIden for further studies on carbon sequestration ability under climate change.

East African riparian corridors are biodiversity hot spots that occur in catchments degrading under deforestation and overgrazing. Quadrats and belt transects were employed to investigate plant succession along the River Gilgil, in the Kenyan Rift Valley. The study found that most species (total 365) were broadly distributed across the tropics, but Rift Valley endemics were 12.5%, and 4%–18% were exotic. Plant composition varied with altitude, lithology, soils and rainfall. Agglomerative (Jaccard) hierarchical clustering and Non-metric Dimensional Scaling identified two and three vegetation groups, for quadrats and transects, respectively, correlated with lithology and soils. Indicator species analysis highlighted that the upstream portion of the catchment was characterised by forest taxa with few exotics. The downstream included woodland species adapted to mesic/xeric conditions and to overgrazing. Longitudinal change in species composition (β diversity) between sites was assessed by taking into consideration the contribution of ‘spatial species turnover’ and ‘nestedness’, resulting from species replacement and species loss, respectively. The β diversity of the riparian corridor vegetation was 0.40 and spatial turnover accounted for 80%–85% of this, while the rest was attributed to the nestedness component. Riverine and native trees increased downstream but with low regeneration. Afromontane vegetation extended its distribution towards lower altitudes.