Spatial variation of wetland woods in the latitudinal transition to arid regions: a multiscale approach

In order to investigate the occurrence of wetland woods in the latitudinal transition to arid regions in south-western Europe, we studied species patterns (richness and abundance), examined floristic differences between woods along the latitudinal gradient, and determined the relative influence of the underlying environmental drivers of plant variation at various scales

The impact and significance of tephra deposition on a Holocene forest environment in the North Cascades, Washington, USA.

© 2016 Elsevier Ltd. High-resolution palaeoecological analyses (stratigraphy, tephra geochemistry, radiocarbon dating, pollen and ordination) were used to reconstruct a Holocene vegetation history of a watershed in the Pacific Northwest of America to evaluate the effects and duration of tephra deposition on a forest environment and the significance of these effects compared to long-term trends. Three tephra deposits were detected and evaluated: MLF-T158 and MLC-T324 from the climactic eruption of Mount Mazama, MLC-T480 from a Late Pleistocene eruption of Mount Mazama and MLC-T485 from a Glacier Peak eruption. Records were examined from both the centre and fringe of the basin to elucidate regional and local effects. The significance of tephra impacts independent of underlying long-term trends was confirmed using partial redundancy analysis. Tephra deposition from the climactic eruption of Mount Mazama approximately 7600 cal. years BP caused a significant local impact, reflected in the fringe location by changes to open habitat vegetation (Cyperaceae and Poaceae) and changes in aquatic macrophytes (Myriophyllum spicatum, Potamogeton, Equisetum and the alga Pediastrum). There was no significant impact of the climactic Mazama tephra or other tephras detected on the pollen record of the central core. Changes in this core are potentially climate driven. Overall, significant tephra fall was demonstrated through high resolution analyses indicating a local effect on the terrestrial and aquatic environment, but there was no significant impact on the regional forest dependent of underlying environmental changes

Real communities of virtual plants explain biodiversity on just three assumptions

To illuminate mechanisms supporting diversity in plant communities, we construct 2D cellular automata and 'grow' virtual plants in real experiments. The plants are 19 different, fully validated functional types drawn from universal adaptive strategy theory. The scale of approach is far beyond that of even the most ambitious investigations in the physical world. By simulating 496 billion plant-environment interactions, we succeed in creating conditions that sustain high diversity realistically and indefinitely. Our simulations manipulate the levels of, and degree of heterogeneity in the supply of, resources, external disturbances and invading propagules. We fail to reproduce this outcome when we adopt the assumptions of unified neutral theory. The 19 functional types in our experiments respond in complete accordance with universal adaptive strategy theory. We find that spatial heterogeneity is a strong contributor to long-term diversity, but temporal heterogeneity is less so. The strongest support of all comes when an incursion of propagules is simulated. We enter caveats and suggest further directions for working with cellular automata in plant science. We conclude that although (i) the differentiation of plant life into distinct functional types, (ii) the presence of environmental heterogeneity and (iii) the opportunity for invasion by propagules can all individually promote plant biodiversity, all three appear to be necessary simultaneously for its long-term maintenance. Though further, and possibly more complex, sets of processes could additionally be involved, we consider it unlikely that any set of conditions more minimal than those described here would be sufficient to deliver the same outcome

Transferring biodiversity-ecosystem function research to the management of ‘real-world’ ecosystems

Biodiversity-ecosystem functioning (BEF) research grew rapidly following concerns that biodiversity loss would negatively affect ecosystem functions and the ecosystem services they underpin. However, despite evidence that biodiversity strongly affects ecosystem functioning, the influence of BEF research upon policy and the management of ‘real-world’ ecosystems, i.e., semi-natural habitats and agroecosystems, has been limited. Here, we address this issue by classifying BEF research into three clusters based on the degree of human control over species composition and the spatial scale, in terms of grain, of the study, and discussing how the research of each cluster is best suited to inform particular fields of ecosystem management. Research in the first cluster, small-grain highly controlled studies, is best able to provide general insights into mechanisms and to inform the management of species-poor and highly managed systems such as croplands, plantations, and the restoration of heavily degraded ecosystems. Research from the second cluster, small-grain observational studies, and species removal and addition studies, may allow for direct predictions of the impacts of species loss in specific semi-natural ecosystems. Research in the third cluster, large-grain uncontrolled studies, may best inform landscape-scale management and national-scale policy. We discuss barriers to transfer within each cluster and suggest how new research and knowledge exchange mechanisms may overcome these challenges. To meet the potential for BEF research to address global challenges, we recommend transdisciplinary research that goes beyond these current clusters and considers the social-ecological context of the ecosystems in which BEF knowledge is generated. This requires recognizing the social and economic value of biodiversity for ecosystem services at scales, and in units, that matter to land managers and policy makers.</p