a b s t r a c tThe aim of this work was to characterize the spatial and temporal dynamics of the transformation of the natural cover in the Dry Chaco ecoregion from 1976 to 2012. Dry forests in this region have one of the highest deforestation rates in the world. We analyzed 44 Landsat scenes, including part of Argentina, Paraguay and Bolivia. The analysis was based on tracking individual transformed plots of the entire Dry Chaco region for over more than three decades using the same protocol. Until the end of 2012 15.8 million ha of the original habitats of the Chaco were transformed into croplands or pastures. Our study showed that the greater annual rates of transformation were observed in Paraguay, where deforestation increased dramatically in the last decade, reaching values higher than 4.0% in 2010, the highest historical value in the entire region. The size of the transformed plots increased significantly through the studied period both in Argentina and Paraguay, while in Bolivia decreased. At the landscape level, the use of several fragmentation indices showed the disruption of the continuity and connectivity of the original vegetation. The spatially explicit description of the dynamics of transformed areas is an indispensable tool for natural resources management, territorial planning and deforestation impacts assessment. The developed geo-database is available online at http://monitoreodesmonte.com.ar/ for further analyses and use.
Marine hard-bottom communities are undergoing severe change under the influence of multiple drivers, notably climate change, extraction of natural resources, pollution and eutrophication, habitat degradation, and invasive species. Monitoring marine biodiversity in such habitats is, however, challenging as it typically involves expensive, non-standardized, and often destructive sampling methods that limit its scalability. Differences in monitoring approaches furthermore hinders inter-comparison among monitoring programs. Here, we announce a Marine Biodiversity Observation Network (MBON) consisting of Autonomous Reef Monitoring Structures (ARMS) with the aim to assess the status and changes in benthic fauna with genomic-based methods, notably DNA metabarcoding, in combination with image-based identifications. This article presents the results of a 30-month pilot phase in which we established an operational and geographically expansive ARMS-MBON. The network currently consists of 20 observatories distributed across European coastal waters and the polar regions, in which 134 ARMS have been deployed to date. Sampling takes place annually, either as short-term deployments during the summer or as long-term deployments starting in spring. The pilot phase was used to establish a common set of standards for field sampling, genetic analysis, data management, and legal compliance, which are presented here. We also tested the potential of ARMS for combining genetic and image-based identification methods in comparative studies of benthic diversity, as well as for detecting non-indigenous species. Results show that ARMS are suitable for monitoring hard-bottom environments as they provide genetic data that can be continuously enriched, re-analyzed, and integrated with conventional data to document benthic community composition and detect non-indigenous species. Finally, we provide guidelines to expand the network and present a sustainability plan as part of the European Marine Biological Resource Centre (www.embrc.eu).
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