Underappreciated plant vulnerabilities to heat waves.

With climate change, heat waves are becoming increasingly frequent, intense and broader in spatial extent. However, while the lethal effects of heat waves on humans are well documented, the impacts on flora are less well understood, perhaps except for crops. We summarize recent findings related to heat wave impacts including: sublethal and lethal effects at leaf and plant scales, secondary ecosystem effects, and more complex impacts such as increased heat wave frequency across all seasons, and interactions with other disturbances. We propose generalizable practical trials to quantify the critical bounding conditions of vulnerability to heat waves. Collectively, plant vulnerabilities to heat waves appear to be underappreciated and understudied, particularly with respect to understanding heat wave driven plant die-off and ecosystem tipping points.

Phytoremediation Reduces Dust Emissions from Metal(loid)-Contaminated Mine Tailings.

Environmental and health risk concerns relating to airborne particles from mining operations have focused primarily on smelting activities. However, there are only three active copper smelters and less than a dozen smelters for other metals compared to an estimated 500000 abandoned and unreclaimed hard rock mine tailings in the US that have the potential to generate dust. The problem can also extend to modern tailings impoundments, which may take decades to build and remain barren for the duration before subsequent reclamation. We examined the impact of vegetation cover and irrigation on dust emissions and metal(loid) transport from mine tailings during a phytoremediation field trial at the Iron King Mine and Humboldt Smelter Superfund (IKMHSS) site. Measurements of horizontal dust flux following phytoremediation reveals that vegetated plots with 16% and 32% canopy cover enabled an average dust deposition of 371.7 and 606.1 g m-2 y-1, respectively, in comparison to the control treatment which emitted dust at an average rate of 2323 g m-2 y-1. Horizontal dust flux and dust emissions from the vegetated field plots are comparable to emission rates in undisturbed grasslands. Further, phytoremediation was effective at reducing the concentration of fine particulates, including PM1, PM2.5, and PM4, which represent the airborne particulates with the greatest health risks and the greatest potential for long-distance transport. This study demonstrates that phytoremediation can substantially decrease dust emissions as well as the transport of windblown contaminants from mine tailings.

Interactive effects of grazing and burning on wind- and water-driven sediment fluxes: rangeland management implications.

Rangelands are globally extensive, provide fundamental ecosystem services, and are tightly coupled human-ecological systems. Rangeland sustainability depends largely on the implementation and utilization of various grazing and burning practices optimized to protect against soil erosion and transport. In many cases, however, land management practices lead to increased soil erosion and sediment fluxes for reasons that are poorly understood. Because few studies have directly measured both wind and water erosion and transport, an assessment of how they may differentially respond to grazing and burning practices is lacking. Here, we report simultaneous, co-located estimates of wind- and water-driven sediment transport in a semiarid grassland in Arizona, USA, over three years for four land management treatments: control, grazed, burned, and burned + grazed. For all treatments and most years, annual rates of wind-driven sediment transport exceeded that of water due to a combination of ongoing small but nontrivial wind events and larger, less frequent, wind events that generally preceded the monsoon season. Sediment fluxes by both wind and water differed consistently by treatment: burned + grazed > burned >> grazed > or = control, with effects immediately apparent after burning but delayed after grazing until the following growing season. Notably, the wind:water sediment transport ratio decreased following burning but increased following grazing. Our results show how rangeland practices disproportionally alter sediment fluxes driven by wind and water, differences that could potentially help explain divergence between rangeland sustainability and degradation.

Identifying prenatal ultrasound predictors and the ideal neonatal management of closing gastroschisis: the key is prevention.

OBJECTIVE: To evaluate the optimal approaches to initial surgical management and the potential for prenatal ultrasound detection of patients with closing gastroschisis. STUDY DESIGN: We performed a retrospective analysis of patients born with gastroschisis to determine clinical and surgical outcomes and the ability to determine prognosis by prenatal imaging. Data collected included operative findings and postoperative outcome, as well as prenatal imaging features from a subset of cases with and without closing gastroschisis. Statistical analyses were performed as appropriate. RESULTS: We included 197 patients with gastroschisis. No statistical significance was seen in outcomes between closing gastroschisis patients undergoing resection versus intracorporeal parking (n = 18). Ultrasound review was performed on 33 of these patients, 11 with closing gastroschisis, and 22 without. Significantly more closing gastroschisis patients had imaging indicative of progressive defect narrowing and defect diameter ≤8 mm after 30 weeks of gestation versus non-closing patients (p = 0.002). CONCLUSION: Parking of extruded bowel offers potential for intestinal remodeling. In addition, prenatal ultrasound may be useful in detection of closing gastroschisis in utero.