Spatial, temporal, and biological factors influencing plant responses to deicing salt in roadside bioinfiltration basins.

Plants are arguably the most visible components of stormwater bioretention basins and play key roles in stabilizing soils and removing water through transpiration. In regions with cold winters, bioretention basins along roadways can receive considerable quantities of deicing salt, much of which migrates out of the systems prior to the onset of plant growth but the rest remains in the soil. The resulting effects on plants presumably vary with time (due to annual weather patterns), space (because stormwater exposure is location-dependent), and biology (because plant taxa differ in their salt tolerance).

Canopy composition drives variability in urban growing season length more than the heat island effect.

The elevated heat of urban areas compared to their surroundings makes humid temperate cities a useful preview of future climate effects on natural forest phenology. The utility of this proxy rests on the expectation that trees in urban areas alter their phenology in response to warmer site conditions in spring and fall. However, it is possible that apparent lengthening of the growing season is instead governed by human-driven tree species selection and plant functional type (PFT; trees, shrubs, turfgrass) heterogeneity typical of managed landscapes.

Systematic review of quantitative preference studies of treatments for rheumatoid arthritis among patients and at-risk populations.

Treatments used for rheumatoid arthritis (RA) are under investigation for their efficacy to prevent RA in at risk groups. It is therefore important to understand treatment preferences of those at risk. We systematically reviewed quantitative preference studies of drugs to treat, or prevent RA, to inform the design of further studies and trials of RA prevention.

Responses of stomatal features and photosynthesis to porewater N enrichment and elevated atmospheric CO in Phragmites australis, the common reed.

Premise: Biological invasions increasingly threaten native biodiversity and ecosystem services. One notable example is the common reed, Phragmites australis, which aggressively invades North American salt marshes. Elevated atmospheric CO and nitrogen pollution enhance its growth and facilitate invasion because P.

Rapid recovery of carbon cycle processes after the cessation of chronic nutrient enrichment.

Salt marshes provide critical ecosystem services including some of the highest rates of carbon storage on Earth. However, many salt marshes receive very high nutrient loads and there is a growing body of evidence indicating that this nutrient enrichment alters carbon cycle processes. While many restoration plans prioritize nutrient management in their efforts to conserve salt marsh ecosystems, there has been little empirical investigation of the capacity for carbon cycle processes to recover once nutrient loading is reduced.

Fine-root traits are linked to species dynamics in a successional plant community.

Despite the importance of fine roots for the acquisition of soil resources such as nitrogen and water, the study of linkages between traits and both population and community dynamics remains focused on aboveground traits. We address this gap by investigating associations between belowground traits and metrics of species dynamics. Our analysis included 85 species from a long-term data set on the transition from old field to forest in eastern North America (the Buell-Small Succession Study) and the new Fine-Root Ecology Database.

Maintenance of photosynthesis by Betula populifolia in metal contaminated soils.

Improving our understanding of plant responses to elevated trace metal concentrations under field conditions will enhance restoration and urban greening practices in settings with contaminated soils. This study examined the effects of trace metal pollution on the leaf gas exchange rates of mature, field-grown Betula populifolia Marsh. (gray birch) trees, additionally assessing whether elevated temperature and drought compounded the effects of trace metal contamination.

Nitrogen uptake kinetics and saltmarsh plant responses to global change.

Coastal wetlands are important carbon sinks globally, but their ability to store carbon hinges on their nitrogen (N) supply and N uptake dynamics of dominant plant species. In terrestrial ecosystems, uptake of nitrate (NO) and ammonium (NH) through roots can strongly influence N acquisition rates and their responses to environmental factors such as rising atmospheric CO and eutrophication. We examined the N uptake kinetics of three dominant plant species in North American coastal wetlands (Spartina patens, C grass; Phragmites australis, C grass; Schoenoplectus americanus, C sedge) under ambient and elevated CO conditions.

Cosmopolitan Species As Models for Ecophysiological Responses to Global Change: The Common Reed .

is a cosmopolitan grass and often the dominant species in the ecosystems it inhabits. Due to high intraspecific diversity and phenotypic plasticity, has an extensive ecological amplitude and a great capacity to acclimate to adverse environmental conditions; it can therefore offer valuable insights into plant responses to global change. Here we review the ecology and ecophysiology of prominent lineages and their responses to multiple forms of global change.

Nutrient foraging strategies are associated with productivity and population growth in forest shrubs.

Background And Aims: Temperate deciduous forest understoreys are experiencing widespread changes in community composition, concurrent with increases in rates of nitrogen supply. These shifts in plant abundance may be driven by interspecific differences in nutrient foraging (i.e.

Nitrogen-mediated effects of elevated CO on intra-aggregate soil pore structure.

Soil pore structure has a strong influence on water retention, and is itself influenced by plant and microbial dynamics such as root proliferation and microbial exudation. Although increased nitrogen (N) availability and elevated atmospheric CO concentrations (eCO ) often have interacting effects on root and microbial dynamics, it is unclear whether these biotic effects can translate into altered soil pore structure and water retention. This study was based on a long-term experiment (7 yr at the time of sampling) in which a C pasture grass (Paspalum notatum) was grown on a sandy loam soil while provided factorial additions of N and CO .

Box-Counting Dimension Revisited: Presenting an Efficient Method of Minimizing Quantization Error and an Assessment of the Self-Similarity of Structural Root Systems.

Fractal dimension (FD), estimated by box-counting, is a metric used to characterize plant anatomical complexity or space-filling characteristic for a variety of purposes. The vast majority of published studies fail to evaluate the assumption of statistical self-similarity, which underpins the validity of the procedure. The box-counting procedure is also subject to error arising from arbitrary grid placement, known as quantization error (QE), which is strictly positive and varies as a function of scale, making it problematic for the procedure's slope estimation step.

Descendant root volume varies as a function of root type: estimation of root biomass lost during uprooting in Pinus pinaster.

Root systems of woody plants generally display a strong relationship between the cross-sectional area or cross-sectional diameter (CSD) of a root and the dry weight of biomass (DWd) or root volume (Vd) that has grown (i.e., is descendent) from a point.

Jatropha curcas L. root structure and growth in diverse soils.

Unlike most biofuel species, Jatropha curcas has promise for use in marginal lands, but it may serve an additional role by stabilizing soils. We evaluated the growth and structural responsiveness of young J. curcas plants to diverse soil conditions.

Functional morphology underlies performance differences among invasive and non-invasive ruderal Rubus species.

The ability of some introduced plant species to outperform native species under altered resource conditions makes them highly productive in ecosystems with surplus resources. However, ruderal native species are also productive when resources are available. The differences in abundance among invasive and non-invasive ruderal plants may be related to differences in ability to maintain access to or store resources for continual use.

Climate change and microbiological water quality at California beaches.

Daily microbiological water quality and precipitation data spanning 6 years were collected from monitoring stations at southern California beaches. Daily precipitation projected for the twenty-first century was derived from downscaled CNRM CM3 global climate model. A time series model of Enterococcus concentrations that was driven by precipitation, matched the general trend of empirical water quality data; there was a positive association between precipitation and microbiological water contamination (P < 0.

Influence of variable precipitation on coastal water quality in southern California.

Objectives: To examine the consequences of changing precipitation levels on southern California's recreational coastal water quality, and compare the responses of watersheds with differing levels of urban development.

Methods: The geo-temporal relationship for six years (2000-2005) of precipitation levels, discharge rates for the ten primary waterways, and coastal water bacteria concentrations at seventy-eight southern California beaches were examined.

Results: Precipitation levels, river-creek discharge rates, and coastal water bacteria concentrations were significantly correlated (p < 0.

Health risk of bathing in Southern California coastal waters.

Urbanized areas often discharge large volumes of contaminated waste into coastal waters, which may pose a health risk to bathers at nearby beach areas. In this investigation the authors estimated the number of gastrointestinal and respiratory illness episodes associated with the microbial contamination of coastal waters among bathers at Southern California beaches from 2000 through 2004. Bathers at the 67 beaches along the 350-km coastline of Southern California were the study population in this investigation.