Search

It's sunrise in Cave Creek Canyon on the eastern face of Arizona's Chiricahua Mountains. The melodious, descending whistles of a canyon wren fill the cool air along with the insistent [...]

A complex combination of environmental, biological, chemical, and physical properties and processes determine soil biodiversity and its relationship to biogeochemical functions and ecosystem services. Vegetation, land-use, and land management, in turn, influence diversity and function in the soil ecosystem. The objective of this review was to assess how different land-use systems (crop production, animal production, and planted forest) affect soil biodiversity, and how consequent changes in soil biodiversity influence energy (carbon) and nutrient dynamics. Deficiencies in understanding relationships between soil biodiversity and biogeochemical function in managed ecosystems are highlighted, along with the need to investigate how diversity influences specific processes across different functional groups and trophic levels. The continued development and application of molecular techniques and data informatics with descriptive approaches will contribute to advancing our understanding of soil biodiversity and function in managed agricultural and forest ecosystems. Additional keywords: animal production, crop production, planted forest. Received 21 March 2019, accepted 27 September 2019, published online 31 October 2019, Introduction Soils have a key role in food security by producing 95% of the global food supply (FAO 2015). As the global population rises, there is mounting pressure on land [...]

Biodiversity loss can heavily affect the functioning of ecosystems, and improving our understanding of how ecosystems respond to biodiversity decline is one of the main challenges in ecology.sup.1-4. Several important aspects of the longer-term effects of biodiversity loss on ecosystems remain unresolved, including how these effects depend on environmental context.sup.5-7. Here we analyse data from an across-ecosystem biodiversity manipulation experiment that, to our knowledge, represents the world's longest-running experiment of this type. This experiment has been set up on 30 lake islands in Sweden that vary considerably in productivity and soil fertility owing to differences in fire history.sup.8,9. We tested the effects of environmental context on how plant species loss affected two fundamental community attributes--plant community biomass and temporal variability--over 20 years. In contrast to findings from artificially assembled communities.sup.10-12, we found that the effects of species loss on community biomass decreased over time; this decrease was strongest on the least productive and least fertile islands. Species loss generally also increased temporal variability, and these effects were greatest on the most productive and most fertile islands. Our findings highlight that the ecosystem-level consequences of biodiversity loss are not constant across ecosystems and that understanding and forecasting these consequences necessitates taking into account the overarching role of environmental context.A long-term biodiversity manipulation experiment using plant communities on thirty Swedish lake islands reveals the importance of environmental context for determining the consequences of species loss at the ecosystem level., Author(s): Paul Kardol [sup.1] , Nicolas Fanin [sup.1] [sup.2] , David A. Wardle [sup.1] [sup.3] Author Affiliations:(1) Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden(2) [...]

The lakes surrounding the iron ore mining region of Schefferville, Quebec, Canada, sit within a landscape of historical disturbances, two of which have been relatively well documented over time: metal contamination and nutrient loading. Based on the analysis of sediment cores, we used cladoceran zooplankton subfossil assemblages from two lakes located in Schefferville to track both alpha and beta diversity over the last 100+ years. We showed that high metal concentrations were correlated with decreased cladoceran diversity, and that the site that experienced both direct wastewater input and atmospheric metal loading (Lake Dauriat) had the greatest declines in cladoceran richness. In both lakes, turnover in cladoceran assemblages was highest in the mining period. During the period of mine closures and improvement of wastewater treatment, some decreases in metal enrichment in the sediments and increases in cladoceran richness were observed in Lake Dauriat. Overall, a combined use of species richness and beta diversity metrics showed alpha and beta diversity are not always congruent, and that there are various ways to interpret scenarios of temporal beta diversity in northern freshwater systems. Les lacs entourant la region miniere ferrifere de Schefferville (Quebec, Canada) se trouvent dans un paysage marque par des perturbations passees, dont deux sont relativement bien documentees dans le temps, a savoir la contamination par les metaux et l'apport de nutriments. A la lumiere de l'analyse de carottes de sediments, nous avons utilise des assemblages de cladoceres zooplanctoniques subfossiles provenant de deux lacs situes a Schefferville pour caracteriser les diversites alpha et beta au cours des 100 dernieres annees et plus. Nous demontrons que de fortes concentrations de metaux sont correlees a une diversite de cladoceres reduite et que le site ayant recu des apports directs d'eaux usees et des apports atmospheriques de metaux (lac Dauriat) presente les plus fortes baisses de richesse des cladoceres. Dans les deux lacs, le renouvellement des assemblages de cladoceres etait a son plus fort durant la periode d'exploitation miniere. Durant la periode des fermetures de mines et de l'amelioration du traitement des eaux usees, certaines baisses de l'enrichissement en metaux dans les sediments et augmentations de la richesse des cladoceres ont ete observees dans le lac Dauriat. Dans l'ensemble, l'utilisation combinee de mesures de la richesse specifique et de la diversite beta a permis de demontrer que les diversites alpha et beta ne concordent pas toujours et qu'il y a differentes manieres d'interpreter les scenarios de diversite beta dans le temps dans les systemes d'eau douce nordiques. [Traduit par la Redaction], Introduction Perturbation of freshwater systems is of broad concern because of their importance in providing ecosystem services (Limburg 2009), their role as biodiversity hotspots (Strayer and Dudgeon 2010), and the [...]

Antarctic terrestrial biodiversity occurs almost exclusively in ice-free areas that cover less than 1% of the continent. Climate change will alter the extent and configuration of ice-free areas, yet the distribution and severity of these effects remain unclear. Here we quantify the impact of twenty-first century climate change on ice-free areas under two Intergovernmental Panel on Climate Change (IPCC) climate forcing scenarios using temperature-index melt modelling. Under the strongest forcing scenario, ice-free areas could expand by over 17,000km[sup.2] by the end of the century, close to a 25% increase. Most of this expansion will occur in the Antarctic Peninsula, where a threefold increase in ice-free area could drastically change the availability and connectivity of biodiversity habitat. Isolated ice-free areas will coalesce, and while the effects on biodiversity are uncertain, we hypothesize that they could eventually lead to increasing regional-scale biotic homogenization, the extinction of less-competitive species and the spread of invasive species., Author(s): Jasmine R. Lee (corresponding author) [1, 2]; Ben Raymond [3, 4, 5]; Thomas J. Bracegirdle [6]; Iadine Chads [2, 7]; Richard A. Fuller [1]; Justine D. Shaw [1, 7]; [...]

Author(s): Jun Y. Lim (corresponding author) [1, 2]; Charles R. Marshall (corresponding author) [1, 2] Establishing the relationship between rates of change in species richness and biotic and abiotic environmental [...]