Grassland ecosystem type drives AM fungal diversity and functional guild distribution in North American grasslands.

Nutrient exchange forms the basis of the ancient symbiotic relationship that occurs between most land plants and arbuscular mycorrhizal (AM) fungi. Plants provide carbon (C) to AM fungi and fungi provide the plant with nutrients such as nitrogen (N) and phosphorous (P). Nutrient addition can alter this symbiotic coupling in key ways, such as reducing AM fungal root colonization and changing the AM fungal community composition.

Stronger fertilization effects on aboveground versus belowground plant properties across nine U.S. grasslands.

Increased nutrient inputs due to anthropogenic activity are expected to increase primary productivity across terrestrial ecosystems, but changes in allocation aboveground versus belowground with nutrient addition have different implications for soil carbon (C) storage. Thus, given that roots are major contributors to soil C storage, understanding belowground net primary productivity (BNPP) and biomass responses to changes in nutrient availability is essential to predicting carbon-climate feedbacks in the context of interacting global environmental changes. To address this knowledge gap, we tested whether a decade of nitrogen (N) and phosphorus (P) fertilization consistently influenced aboveground and belowground biomass and productivity at nine grassland sites spanning a wide range of climatic and edaphic conditions in the continental United States.

Synthesis of Benzo[]thiophenes via Electrophilic Sulfur Mediated Cyclization of Alkynylthioanisoles.

A stable dimethyl(thiodimethyl)sulfonium tetrafluoroborate salt was employed for the electrophilic cyclization reaction of -alkynyl thioanisoles for the synthesis of 2,3-disubstituted benzo[]thiophenes. The reaction described herein works well with various substituted alkynes in excellent yields, and a valuable thiomethyl group was introduced with ease. The reaction utilizes moderate reaction conditions and ambient temperature while tolerating various functionalities.

Soil carbon stocks in temperate grasslands differ strongly across sites but are insensitive to decade-long fertilization.

Enhancing soil carbon (C) storage has the potential to offset human-caused increases in atmospheric CO . Rising CO has occurred concurrently with increasing supply rates of biologically limiting nutrients such as nitrogen (N) and phosphorus (P). However, it is unclear how increased supplies of N and P will alter soil C sequestration, particularly in grasslands, which make up nearly a third of non-agricultural land worldwide.

Non-random species loss in a forest herbaceous layer following nitrogen addition.

Nitrogen (N) additions have decreased species richness (S) in hardwood forest herbaceous layers, yet the functional mechanisms for these decreases have not been explicitly evaluated. We tested two hypothesized mechanisms, random species loss (RSL) and non-random species loss (NRSL), in the hardwood forest herbaceous layer of a long-term, plot-scale, fertilization experiment in the central Appalachian Mountains, USA. Using a random thinning algorithm, we simulated changes in species densities under RSL and compared the simulated densities to the observed densities among N-fertilized (+N), N-fertilized and limed (+N+L), and reference (REF) plots in regenerating forest stands.

A reference-based approach for estimating leaf area and cover in the forest herbaceous layer.

Cover data are used to assess vegetative response to a variety of ecological factors. Estimating cover in the herbaceous layer of forests presents a problem because the communities are structurally complex and rich in species. The currently employed techniques for estimating cover are less than optimal for measuring such rich understories because they are inaccurate, slow, or impracticable.

Is recovery faster for mobile-bearing unicompartmental than total knee arthroplasty?

Unlabelled: How does unicompartmental compare with total knee arthroplasty in durability, incidence of complications and manipulations, recovery, postoperative function, and return to sport and work? We matched 103 patients (115 knees) treated with a mobile-bearing unicompartmental device through July 2005 to a selected group of 103 patients (115 knees) treated with cruciate retaining total knee arthroplasty for bilaterality, age, gender and body mass index. Patients who underwent a unicompartmental surgery had better range of motion at discharge and shorter hospital stay than those who had a total knee arthroplasty (77 degrees versus 67 degrees and 1.4 versus 2.