The 63-year changes in annual streamflow volumes across Europe with a focus on the Mediterranean basin

Determining the spatiotemporal variability in the annual streamflow volume plays a relevant role in hydrology with regard to improving and implementing sustainable and resilient policies and practices of water resource management. This study investigates annual streamflow volume trends in a newly assembled, consolidated, and validated data set of daily mean river flow records from more than 3000 stations which cover near-natural basins in more than 40 countries across Europe. Although the data set contains streamflow time series from 1900 to 2013 in some stations, the statistical analyses were carried out by including observations from 1950 to 2013 in order to have a consistent and reliable data set over the continent. Trends were detected by calculating the slope of the Theil–Sen line over the annual anomalies of streamflow volume. The results show that annual streamflow volume trends have emerged at European scale, with a marked negative tendency in Mediterranean regions, with about -1×103 m3/(km2 yr−2), and a generally positive trend in northern ones, with about 0.5×103 m3/(km−2 yr−2). The annual streamflow volume trend patterns appear to be in agreement with the continental-scale meteorological observations in response to climate change drivers. In the Mediterranean area, the decline of annual streamflow volumes started in 1965, and since the early 1980s, volumes have consistently been lower than the 1950–2013 average. The spatiotemporal annual streamflow volume patterns observed in this work can help to contextualize short-term trends and regional studies already available in the scientific literature, as well as to provide a valid benchmark for further accurate quantitative analysis of annual streamflow volumes.

African Soil Protection Law

The protection of soil and the sustainable management of soils is a precondition for sustainable development, food security and the survival of humankind. Africa is the continent with the least land degradation. Yet, the pressure on soils is already enormous and continuously increasing due to a range of factors, including poverty, over-exploitation, population growth and climate change. Drivers of unsustainable soil management include overstocking, overgrazing, water erosion, landslides, and over-application of agro-chemicals. In light of this, the underlying legal, societal and political conditions have been comparatively analysed in “African Soil Protection Law”. Distinct country studies from Kenya, Cameroon and Zambia serve to comparatively expose the serious impediments of soil in Africa. While mapping out options for model legislation for improved sustainable soil management in Africa, the publication addresses intertwined, interdisciplinary and complex questions pertaining to soils, which may also be of comparative interest to other continents and jurisdictions.

Microbial growth and carbon use efficiency show seasonal responses in a multifactorial climate change experiment

Microbial growth and carbon use efficiency (CUE) are central to the global carbon cycle, as microbial remains form soil organic matter. We investigated how future global changes may affect soil microbial growth, respiration, and CUE. We aimed to elucidate the soil microbial response to multiple climate change drivers across the growing season and whether effects of multiple global change drivers on soil microbial physiology are additive or interactive. We measured soil microbial growth, CUE, and respiration at three time points in a field experiment combining three levels of temperature and atmospheric CO2, and a summer drought. Here we show that climate change-driven effects on soil microbial physiology are interactive and season-specific, while the coupled response of growth and respiration lead to stable microbial CUE (average CUE = 0.39). These results suggest that future research should focus on microbial growth across different seasons to understand and predict effects of global changes on soil carbon dynamics.

Micro-Fragmentation as an Effective and Applied Tool to Restore Remote Reefs in the Eastern Tropical Pacific

Coral reef ecosystems are continuously degraded by anthropogenic and climate change drivers, causing a widespread decline in reef biodiversity and associated goods and services. In response, active restoration methodologies and practices have been developed globally to compensate for losses due to reef degradation. Yet, most activities employ the gardening concept that uses coral nurseries, and are centered in easily-accessible reefs, with existing infrastructure, and impractical for coral reefs in remote locations. Here we evaluate the effectiveness of direct outplanting of coral micro-fragments (Pavona clavus and Pocillopora spp.) as a novel approach to restore remote reefs in the Islas Marías archipelago in the Eastern Tropical Pacific. Coral growth (height-width-tissue cover), survival percentage, extension rates (cm year−1), skeletal density (g cm−3) and calcification rates (g cm−2 year−1) were assessed over 13 months of restoration. In spite of detrimental effects of Hurricane Willa, transplants showed a greater-than-twofold increase in all growth metrics, with ~58–61% survival rate and fast self-attachment (within ~3.9 months) for studied species, with Pocilloporids exhibiting higher extension, skeletal density, and calcification rates than Pavona. While comprehensive long-term studies are required, direct transplantation methodologies of coral micro-fragments are emerging as time-effective and affordable restoration tools to mitigate anthropogenic and climate change impacts in remote and marginal reefs.

Forging the path to achieving land degradation neutrality: Global patterns and drivers of land degradation at global scales

<p>Land degradation – the reduction or loss of the productive potential of land – is a global challenge. More than 20% of the Earth’s vegetated surface is estimated to be degraded, affecting over 1.3 billion people, with an economic impact of up to US$10.6 trillion. Land degradation reduces agricultural productivity and increases the vulnerability of those areas already at risk of impacts from climate variability and change. Addressing land degradation, Sustainable Development Goal (SDG) target 15.3, is essential to improve the livelihoods of those most affected, and to build resilience to safeguard against the most extreme effects of climate change. Drivers of land degradation include natural processes and human activities, and understanding such drivers is key for deploying effective interventions for addressing it. The parties to the United Nations Convention to Combat Desertification (UNCCD) have adopted a framework for assessing and monitoring land degradation at national scale, by measuring three sub-indicators: Changes in land cover, changes in soil organic carbon, and changes in primary productivity. In this study, we use the framework developed by the UNCCD and Trends.Earth, the most widely tool used for producing such indicators, to assess land condition globally for the period 2001-2015, the SDG 15.3.1 baseline period. Using a Bayesian hierarchical model, we then assessed the contribution of 12 drivers of land degradation, including key biophysical and anthropogenic variables, to the observed patterns to provide insight into the main drivers of land degradation at global, regional, and national scales. These results are critical for designing locally relevant plans for assessing land degradation contributing to the global goal of achieving a land degradation neutral world by 2030. The results of this analysis allow identification of not only the significant drivers in a given region, but also of those areas where unexpected trends (either improvement or degradation) are indicative of potential policy successes or failures.</p>