Environmental controls on carbon sequestration, sediment accretion, and elevation change in the Ebro River Delta: Implications for wetland restoration

Delta wetlands are increasingly recognized as important sinks for ‘blue carbon,’ although this and other ecosystem services that deltas provide are threatened by human activities. We investigated factors that affect sediment accretion using short term (3 years using marker horizons) and longer-term measures (∼50 year using 137Cs soil core distribution and ∼100 year using 210Pb distribution), the associated carbon accumulation rates, and resulting changes in surface elevation in the Ebro River Delta, Catalonia, Spain. Fifteen sites were selected, representing the geomorphological settings and range of salinities typical of the delta's wetlands. Sediment accretion rates as measured by 137Cs distribution in soil cores ranged from 0.13 to 0.93 cm yr−1. Surface elevations increased at all sites, from 0.10 to 2.13 cm yr−1 with the greatest increases in natural impoundments with little connection to other surface waters. Carbon accumulation rates were highly spatially variable, ranging from 32 to 435 g C m−1 yr−1 with significantly higher rates at bay sites (p = 0.02) where hydrologic connectivity is high and sediment resuspension more intense. Sites with high connectivity had significantly higher rates of carbon accumulation (averaging 376 ± 50 g C m−1 yr−1) compared to sites with moderate or low connectivity. We also found high rates of carbon accumulation in brackish sites where connectivity was low and biomass production was characteristically higher than in saline sites. A stepwise regression model explained 81% of variability in carbon accumulation rates across all sites. Our data indicate deltaic wetlands can be important sinks for blue carbon, contributing to climate change mitigation.info:eu-repo/semantics/acceptedVersio

The main drivers of methane emissions differ in the growing and flooded fallow seasons in Mediterranean rice fields

Purpose To assess 1) the cumulative greenhouse gas emissions –GHG- and global warming potential (methane – CH4- and nitrous oxide) from rice fields in the growing and fallow seasons, and 2) the environmental and agronomic drivers of CH4 emissions, and their relative capacity to explain CH4 variation. Methods A two-year multisite field experiment covering the agronomic and environmental variability of a rice growing area in NE Iberian Peninsula was conducted with monthly samplings of GHG and monitoring of both environmental and agronomic factors. Information-theoretic framework analysis was used to assess the relative contribution of the environmental and agronomic variables on methane emissions. Results Two thirds of the CH4 is emitted in the fallow season. Edaphic factors exert more influence during the growing season whereas agronomic factors have a higher impact in the fallow. The implications of these findings on the design of improved mitigation options rice are discussed. Conclusions Soils with higher soil sulphate concentration, bulk density and clay content emit less CH4 in growing season. In the fallow season, the rates of both straw input and nitrogen fertilization stimulate CH4 emissions.info:eu-repo/semantics/publishedVersio

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Appendix A. Complete list of plant species present at 20 wetland study sites and their coefficients of conservatism.

Complete list of plant species present at 20 wetland study sites and their coefficients of conservatism

No-net-loss not met for nutrient function in freshwater marshes: recommendations for wetland mitigation policies

Wetlands provide many important services throughout the world, with an estimated economic value that, in comparison to other ecosystems, far exceeds their relatively small global extent. In recognition of their importance, both national and international regulations exist to protect the world\u27s remaining wetlands. Of growing interest is the “no-net-loss” policy which permits unavoidable destruction of wetlands if compensated by restoration of degraded wetlands or creation of new wetlands. The fundamental assumption of no-net-loss is that wetlands can be created which function equivalently to natural wetlands. One integral function that wetlands perform is cycling of carbon, nitrogen and phosphorus. Here we demonstrate that loss of this nutrient-related function is not being mitigated by creation or restoration of wetlands. We compare indicators of plant- and microbial-mediated functions, as well as abiotic (e.g., soil character, hydrology) and biotic (e.g., plant community composition) structure, between 10 created or restored and 5 natural freshwater depressional wetlands in central Ohio, USA. Nutrient stocks were generally smaller and transformations slower in created wetlands than in natural wetlands, with little development over time. Of particular concern were differences in C- and N-related function. Created wetlands stored 90% less C within litter and 80% less C within soil and processed 60% less N through denitrification, on average compared to natural wetlands. Our study suggests that subversion of natural wetlands into restored or created wetlands could have large-scale environmental consequences such as reduced capacity for nitrate removal and C sequestration

Determining nature’s contributions to achieve the sustainable development goals

Academics and policy-makers recognize that humans and nature should be studied and managed as integrated social?eco-logical systems. Recently, the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) approved the Summary for Policy-makers of the Regional and Subregional Assessment of Biodiversity and Ecosystem Services for the Americas, concluding the environment should be mainstreamed across development sectors. Beyond its mandate to generate understanding of nature and human well-being from diverse knowledge sources, IPBES is also tasked with advancing science-policy tools to aide information uptake into decisions. Based on the Americas Assessment?s 3-year, continental-scale experience, we developed three strategies to guide decisions regarding nature?s contributions to people (NCP) for achieving the sustainable development goals (SDGs). Specifically, we prioritized contributions, recognized nature?s plural values, and grouped diverse human?nature relationships to orient attention towards important NCP?SDG linkages, expand the suite of environment?development criteria considered, and create bundles to facilitate the incorporation of complexity into decisions.Fil: Anderson, Christopher Brian. Universidad Nacional de Tierra del Fuego; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Seixas, Cristiana S.. Universidade Estadual de Campinas; BrasilFil: Barbosa, Olga. Universidad Austral de Chile; Chile. Instituto de Ecología and Biodiversidad; ChileFil: Fennessy, M. Siobhan. Kenyon College; Estados UnidosFil: Díaz José, Julio. Universidad Veracruzana; México. Tecnologico Nacional de Mexico; MéxicoFil: Bernal Herrera, F.. Fundación para el Desarrollo de la Cordillera Volcánica Central; Costa Rica. Universidad Nacional de Costa Rica; Costa Ric

Determining nature’s contributions to achieve the sustainable development goals

Academics and policy-makers recognize that humans and nature should be studied and managed as integrated social–ecological systems. Recently, the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) approved the Summary for Policy-makers of the Regional and Subregional Assessment of Biodiversity and Ecosystem Services for the Americas, concluding the environment should be mainstreamed across development sectors. Beyond its mandate to generate understanding of nature and human well-being from diverse knowledge sources, IPBES is also tasked with advancing science-policy tools to aide information uptake into decisions. Based on the Americas Assessment’s 3-year, continental-scale experience, we developed three strategies to guide decisions regarding nature’s contributions to people (NCP) for achieving the sustainable development goals (SDGs). Specifically, we prioritized contributions, recognized nature’s plural values, and grouped diverse human–nature relationships to orient attention towards important NCP–SDG linkages, expand the suite of environment–development criteria considered, and create bundles to facilitate the incorporation of complexity into decisions14254354

Section 2: Status and trends. In: Gardner, R.C and Finlayson, C.M. (eds), Global Wetland Outlook: State of the World’s Wetlands and their Services to People. Gland, Switzerland: Ramsar Convention Secretariat

Conservation and wise use of wetlands are vital for human livelihoods. The wide range of ecosystem services wetlands provide means that they lie at the heart of sustainable development. Yet policy and decision-makers often underestimate the value of their benefits to nature and humankind.Understanding these values and what is happening to wetlands is critical to ensuring their conservation and wise use. The Global Wetland Outlook summarizes wetland extent, trends, drivers of change and the steps needed to maintain or restore their ecological character

Advocating for Science: Amici Curiae Brief of Wetland and Water Scientists in Support of the Clean Water Rule

The Trump administration has proposed replacing the Clean Water Rule, a 2015 regulation that defined the statutory term waters of the United States to clarify the geographic jurisdiction of the Clean Water Act. Since its promulgation, the Clean Water Rule has been subjected to numerous judicial challenges. We submitted an amici curiae brief to the United States Court of Appeals for the Sixth Circuit, explaining why the Clean Water Rule, and its definition of waters of the United States, is scientifically sound. The definition of waters of the United States is a legal determination informed by science. The best available science supports the Clean Water Rule's categorical treatment of tributaries because compelling scientific evidence demonstrates that tributaries significantly affect the chemical, physical, and biological integrity of traditional navigable waters (primary waters). Similarly, the best available science supports the Clean Water Rule's categorical treatment of adjacent waters based on geographic proximity. Compelling scientific evidence demonstrates that waters within 100ft of an ordinary high water mark (OHWM) significantly affect the chemical, physical, and biological integrity of primary waters, as do waters within 100-year floodplains and waters within 1500ft of high tide lines of tidally influenced primary waters or OHWMs of the Great Lakes. This review article is adapted from that amici brief

Practical Guide to Measuring Wetland Carbon Pools and Fluxes

Wetlands cover a small portion of the world, but have disproportionate influence on global carbon (C) sequestration, carbon dioxide and methane emissions, and aquatic C fluxes. However, the underlying biogeochemical processes that affect wetland C pools and fluxes are complex and dynamic, making measurements of wetland C challenging. Over decades of research, many observational, experimental, and analytical approaches have been developed to understand and quantify pools and fluxes of wetland C. Sampling approaches range in their representation of wetland C from short to long timeframes and local to landscape spatial scales. This review summarizes common and cutting-edge methodological approaches for quantifying wetland C pools and fluxes. We first define each of the major C pools and fluxes and provide rationale for their importance to wetland C dynamics. For each approach, we clarify what component of wetland C is measured and its spatial and temporal representativeness and constraints. We describe practical considerations for each approach, such as where and when an approach is typically used, who can conduct the measurements (expertise, training requirements), and how approaches are conducted, including considerations on equipment complexity and costs. Finally, we review key covariates and ancillary measurements that enhance the interpretation of findings and facilitate model development. The protocols that we describe to measure soil, water, vegetation, and gases are also relevant for related disciplines such as ecology. Improved quality and consistency of data collection and reporting across studies will help reduce global uncertainties and develop management strategies to use wetlands as nature-based climate solutions