Enhanced UV-B and elevated CO(2) impacts sub-arctic shrub berry abundance, quality and seed germination

Linkages between stratospheric ozone, UV radiation and climate change and their implications for terrestrial ecosystems

Linkages between stratospheric ozone, UV radiation and climate change: terrestrial ecosystems.

Solar ultraviolet radiation and ozone depletion-driven climate change: effects on terrestrial ecosystems

We summarise advances in our knowledge of how UV-B radiation (280–315 nm) together with other climate change factors interact in their influence on terrestrial organisms and ecosystems.

Completing the FACE of elevated CO₂ research

We appraise the present geographical extent and inherent knowledge limits, following two decades of research on elevated CO2 responses in plant communities, and ask whether such research has answered the key question in quantifying the limits of compensatory CO2 uptake in the major biomes. Our synthesis of all ecosystem-scale (between 10 m(2) and 3000 m(2) total experimental plot area) elevated CO2 (eCO2) experiments in natural ecosystems conducted worldwide since 1987 (n=151) demonstrates that the locations of these eCO2 experiments have been spatially biased, targeting primarily the temperate ecosystems of northern America and Europe. We consider the consequences, suggesting fundamentally that this limits the capacity of the research to understand how the world's major plant communities will respond to eCO2. Most notably, our synthesis shows that this research lacks understanding of impacts on tropical forests and boreal regions, which are potentially the most significant biomes for C sink and storage activity, respectively. Using a meta-analysis of the available data across all biomes, we show equivocal increases in net primary productivity (NPP) from eCO2 studies, suggesting that global validation is needed, especially in the most important biomes for C processing. Further, our meta-analysis identifies that few research programs have addressed eCO2 effects on below-ground C storage, such that at the global scale, no overall responses are discernable. Given the disparity highlighted in the distribution of eCO2 experiments globally, we suggest opportunities for newly-industrialized or developing nations to become involved in further research, particularly as these countries host some of the most important regions for tropical or sub-tropical forest systems. Modeling approaches that thus far have attempted to understand the biological response to eCO2 are constrained with respect to collective predictions, suggesting that further work is needed, which will link models to in situ eCO2 experiments, in order to understand how the world's most important regions for terrestrial C uptake and storage will respond to a future eCO2 atmosphere.

Ecosystem change and stability over multiple decades in the Swedish subarctic: complex processes and multiple drivers

The subarctic environment of northernmost Sweden has changed over the past century, particularly elements of climate and cryosphere. This paper presents a unique geo-referenced record of environmental and ecosystem observations from the area since 1913. Abiotic changes have been substantial. Vegetation changes include not only increases in growth and range extension but also counterintuitive decreases, and stability: all three possible responses. Changes in species composition within the major plant communities have ranged between almost no changes to almost a 50 per cent increase in the number of species. Changes in plant species abundance also vary with particularly large increases in trees and shrubs (up to 600%). There has been an increase in abundance of aspen and large changes in other plant communities responding to wetland area increases resulting from permafrost thaw. Populations of herbivores have responded to varying management practices and climate regimes, particularly changing snow conditions. While it is difficult to generalize and scale-up the site-specific changes in ecosystems, this very site-specificity, combined with projections of change, is of immediate relevance to local stakeholders who need to adapt to new opportunities and to respond to challenges. Furthermore, the relatively small area and its unique datasets are a microcosm of the complexity of Arctic landscapes in transition that remains to be documented.