Dryland vegetation productivity is strongly modulated by water availability. As precipitation patterns and variability are altered by climate change, there is a pressing need to better understand vegetation responses to precipitation variability in these ecologically fragile regions. Here we present a global analysis of dryland sensitivity to annual precipitation variations using long‐term records of normalized difference vege...

Hybridization in nature offers unique insights into the process of natural selection in incipient species and their hybrids. In order to evaluate the patterns and targets of selection, we examine a recently discovered baboon hybrid zone in the Kafue River Valley of Zambia, where Kinda baboons ( Papio kindae ) and grey‐footed chacma baboons ( P. ursinus griseipes ) coexist with hybridization. We genotyped baboons at 14,962 vari...

In oligotrophic ocean regions, dissolved organic phosphorus (DOP) plays a prominent role as a source of phosphorus (P) to microorganisms. An important bioavailable component of DOP is phosphonates, organophosphorus compounds with a carbon‐phosphorus (C‐P) bond, which are ubiquitous in high molecular weight dissolved organic matter (HMWDOM). In addition to being a source of P, the degradation of phosphonates by the bacterial C‐...

Summary Porphyromonas species are frequently isolated from the oral cavity and are associated with periodontal disease in both animals and humans. Black, pigmented Porphyromonas spp. isolated from the gingival margins of selected wild and captive Australian marsupials with varying degrees of periodontal disease (brushtail possums, koalas and macropods) were compared phylogenetically to Porphyromonas strains from non‐marsupials...

Summary Carbohydrate‐induced laminitis in horses is characterized by marked changes in the composition of the hindgut microbiota, from a predominantly Gram‐negative population to one dominated by Gram‐positive bacteria. The objective of this study was to monitor changes in the relative abundance of selected hindgut bacteria that have previously been implicated in the pathophysiology of equine laminitis using fluorescence in si...

Summary In the horse, carbohydrate overload is thought to play an integral role in the onset of laminitis by drastically altering the profile of bacterial populations in the hindgut. The objectives of this study were to develop and validate microbial ecology methods to monitor changes in bacterial populations throughout the course of experimentally induced laminitis and to identify the predominant oligofructose‐utilizing organ...

A set of near‐stream flowpaths in pasture, native forest and exotic pine plantations in New Zealand was sampled to describe differences in dissolved organic carbon (DOC). The quantity and bioavailability of DOC varied among flowpaths in different land uses, with higher concentrations of DOC in near‐stream flow paths than the parent groundwater emerging from the hillslope. Tiles incubated in these waters did not consistently yi...

The influences of leaf characteristics on stream invertebrate communities were investigated to improve the basis for selecting plants for riparian management to enhance stream invertebrate abundance and biodiversity. Invertebrate colonisation of leaves of five native and five exotic riparian plants were compared over 4 months in field experiments in a New Zealand pasture stream and adjacent channels, and laboratory experiments...

The factors influencing in‐stream disintegration and uptake of dissolved nutrients by leaves were investigated to improve the basis for selecting plants for riparian management. Leaves from five introduced and five New Zealand native plants were studied in 12 streamside channels and a natural stream. Fallen, air‐dried leaves were tethered in packs attached to tiles in the channels and stream, and measured for mass loss, nitrog...

Although the importance of the subsurface saturated interstitial zone (hyporheic zone) to the ecological functioning and maintenance of water quality of stream ecosystems is well known, there is little information on the impacts of different forms of land use upon this zone. Hyporheic physico‐chemistry and invertebrates were compared among small streams draining hill‐country catchments under pasture, exotic pine forest, and na...

The effects of shade on periphyton and invertebrates were investigated by comparisons in 12 replicate channels beside a pasture stream where shade cloth reduced the photosynthetically available radiation (PAR) by 0, 60, 90, and 98%. Periphytic productivity decreased with increasing shade. Periphyton chlorophyll a was consistently low ( −2 ) under 98 and 90% shade and usually low at 60% shade, whereas blooms were common during...