Climate shifts the interaction web of a marine plankton community

Climatic effects in the ocean at the community level are poorly described, yet accurate predictions about ecosystem responses to changing environmental conditions rely on understanding biotic responses in a food-web context to support knowledge about direct biotic responses to the physical environment. Here we conduct time-series analyses with multivariate autoregressive (MAR) models of marine zooplankton abundance in the Northern California Current from 1996 to 2009 to determine the influence of climate variables on zooplankton community interactions. Autoregressive models showed different community interactions during warm vs. cool ocean climate conditions. Negative ecological interactions among zooplankton groups characterized the major warm phase during the time series, whereas during the major cool phase, ocean transport largely structured zooplankton communities. Local environmental conditions (sea temperature) and large-scale climate indices (El Niño/Southern Oscillation) were associated with changes in zooplankton abundance across the full time series. Secondary environmental correlates of zooplankton abundance varied with ocean climate phase, with most support during the warm phase for upwelling as a covariate, and most support during the cool phase for salinity. Through simultaneous quantitation of community interactions and environmental covariates, we show that marine zooplankton community structure varies with climate, suggesting that predictions about ecosystem responses to future climate scenarios in the Northern California Current should include potential changes to the base of the pelagic food.Keywords: community interactions, California Current, marine zooplankton, time series analysis, MAR models, climate chang

Using Grizzly Bears to Assess Harvest-Ecosystem Tradeoffs in Salmon Fisheries

Using grizzly bears as surrogates for “salmon ecosystem” function, the authors develop a generalizable ecosystem-based management framework that enables decision-makers to quantify ecosystem-harvest tradeoffs between wild and human recipients of natural resources like fish

Comparison of Various Dilutions and Solid-Phase Extraction Cleanup on the Determination of Ephedrine-Type Alkaloids and Internal Standard Recovery in Ephedra Botanical Raw Material and Powdered Extract

Abstract A study was conducted to determine the effect of 3 dilution levels on the precision of the ephedra alkaloid method when used in conjunction with a solid-phase extraction (SPE) column. For the dilutions studied, SPE column cleanup is necessary because it promotes a greater recovery of the internal standard. However, overall, target precision values were not obtained on the test materials. It was determined that the SPE column is not the cause of the lower recovery in the more concentrated solutions. Significant signal suppression of the internal standard occurs in more concentrated solutions within the mass spectrometer. It is hypothesized that this lack of performance on the part of the SPE column may be linked to its inability to fully clean contaminants from the higher concentration solutions and/or a mass spectrometer overload, which resulted in the internal standard not fully correcting for signal suppression in more concentrated solutions. An internal standard is necessary, especially for accuracy, for the determination of all alkaloids, and only dilute solutions can be accurately analyzed. Due to the sensitivity of the mass spectrometer, it is recommended that the determination of ephedrine alkaloids in dietary supplements and botanicals should be studied using a standard graph at a level 10× less than the current method. It is also recommended that the SPE column used should be evaluated on its need for the sample dilutions made to fit the newly recommended standard graph.</jats:p

tower_longterm_surfacewater

File contains 7 years of surface water chemistry from the Timberlake Observatory for Wetland Restoration (TOWeR) site

Data from: Fertilizer legacies meet saltwater incursion: challenges and constraints for coastal plain wetland restoration

Coastal wetland restoration is an important tool for climate change adaptation and excess nutrient runoff mitigation. However, the capacity of restored coastal wetlands to provide multiple ecosystem services is limited by stressors, such as excess nutrients from upstream agricultural fields, high nutrient legacies on-site, and rising salinities downstream. The effects of these stressors are exacerbated by an accelerating hydrologic cycle, expected to cause longer droughts punctuated by more severe storms. We used seven years of surface water and six years of soil solution water chemistry from a large (440 ha) restored wetland to examine how fertilizer legacy, changes in hydrology, and drought-induced salinization affect dissolved nutrient and carbon concentrations. To better understand the recovery trajectory of the restored wetland, we also sampled an active agricultural field and two mature forested wetlands. Our results show that nitrogen (N) and phosphorus (P) concentrations in soil solution were 2–10 times higher in the restored wetland compared to two mature forested wetlands, presumably due to legacy fertilizer mobilized by reflooding. Despite elevated nutrient concentrations relative to reference wetlands, the restored wetland consistently attenuated N and P pulses delivered from an upstream farm. Even with continued loading, N and P concentrations in surface water throughout the restored wetland have decreased since the initial flooding. Our results suggest that high nutrient concentrations and export from wetlands restored on agricultural lands may be a severe but temporary problem. If field to wetland conversion is to become a more widespread method for ameliorating nutrient runoff and adapting coastal plain ecosystems to climate change, we should adopt new methods for minimizing the initial export phase of wetland restoration efforts

Evolutionary responses by native species to major anthropogenic changes to their ecosystems: Pacific salmon in the Columbia River hydropower system

84-9