Rock removal associated with agricultural intensification will exacerbate the loss of reptile diversity

Rocky environments host rich levels of biodiversity and provide vital habitat for specialised organisms, range-restricted species and a broad range of ectotherms adapted to saxicoline environments. In Australia, rock habitat is being destroyed during soil amelioration practices associated with agricultural intensification. Advances in rock crushing technology, developed to expand or increase crop yields and efficiency, pose an undocumented threat to global biodiversity, especially reptiles dependent on non-renewable rock habitat in agricultural landscapes. Rock removal is a legislated key threatening process in parts of Australia and will accelerate biodiversity loss if not mitigated. We estimated reptile species’ range overlap with dryland cropping and modified pastoral regions within the Australian wheat-sheep zone to assess the potential impacts of rock crushing practices. We examined species- and family-richness within the impact zone and across bioregions within the impact zone, to identify areas where rock removal has the greatest potential to impact terrestrial and fossorial squamates. Our analysis revealed that 159 potentially impacted reptile species occur within the study area, representing 16% of Australian terrestrial squamates. Fourteen of these species, including six threatened species, have more than 50% range overlap with areas of intensive agriculture, and include several endangered pygopodids, scincids and agamids. Bioregions rich in rock and burrow-dwelling reptiles include the Brigalow Belt South, Murray Darling Depression, Darling Riverine Plains, Eyre Yorke Block, Avon Wheatbelt, Nandewar, Flinders Lofty Block and New South Wales South Western Slopes. Synthesis and applications. The conservation of reptiles in agricultural landscapes requires appropriate management and retention of surface rocks. Potential yield increases from destroying rock habitat to intensify or expand cropland will not compensate for the net loss of reptile populations dependent on non-renewable resources. Financial incentives to prevent the expansion and transformation of non-arable landscapes to cropland are required to prevent the ongoing loss of biodiversity

Crop, Tillage, and Landscape Effects on Near-Surface Soil Quality Indices in Indiana

Soil quality is a critical link between land management and water quality. We aimed to assess soil quality within the Cedar Creek Watershed, a pothole- dominated subwatershed within the St. Joseph River watershed that drains into the Western Lake Erie Basin in northeastern Indiana. The Soil Management Assessment Framework (SMAF) with 10 soil quality indicators was used to assess inherent and dynamic soil and environmental characteristics across crop rotations, tillage practices, and landscape positions. Surface physical, chemical, and nutrient component indices were high, averaging 90, 93, and 98% of the optimum, respectively. Surface biology had the lowest component score, averaging 69% of the optimum. Crop rotation, tillage, and landscape position effects were assessed using ANOVA. Crop selection had a greater impact on soil quality than tillage, with perennial grass systems having higher values than corn (Zea mays L.) or soybean [Glycine max (L.) Merr.]. Furthermore, soybean rotations often scored higher than corn rotations. Uncultivated perennial grass systems had higher overall soil quality index (SQI) values and physical, chemical, and biological component values than no-till or chisel–disk systems. Chisel–disk effects on overall and component SQI values were generally not significantly different from no-till management except for a few physical indicators. Toe-slopes had higher physical, biological, and overall SQI values than summit positions but toe-slope values were not significantly different from those of mid-slope positions. This work highlights the positive effects of perennial grass systems, the negative effects of corn-based systems, and the neutral effects of tillage on soil quality

Laboratory-based surveillance of Clostridium difficile Infection in Australian health care and community settings, 2013 to 2018

In the early 2000s, a binary toxin (CDT)-producing strain of Clostridium difficile, ribotype 027 (RT027), caused extensive outbreaks of diarrheal disease in North America and Europe. This strain has not become established in Australia, and there is a markedly different repertoire of circulating strains there compared to other regions of the world. The C. difficile Antimicrobial Resistance Surveillance (CDARS) study is a nationwide longitudinal surveillance study of C. difficile infection (CDI) in Australia. Here, we describe the molecular epidemiology of CDI in Australian health care and community settings over the first 5 years of the study, 2013 to 2018. Between 2013 and 2018, 10 diagnostic microbiology laboratories from five states in Australia participated in the CDARS study. From each of five states, one private (representing community) and one public (representing hospitals) laboratory submitted isolates of C. difficile or PCR-positive stool samples during two collection periods per year, February-March (summer/autumn) and August-September (winter/spring). C. difficile was characterized by toxin gene profiling and ribotyping. A total of 1,523 isolates of C. difficile were studied. PCR ribotyping yielded 203 different RTs, the most prevalent being RT014/020 (n = 449; 29.5%). The epidemic CDT+ RT027 (n = 2) and RT078 (n = 6), and the recently described RT251 (n = 10) and RT244 (n = 6) were not common, while RT126 (n = 17) was the most prevalent CDT+ type. A heterogeneous C. difficile population was identified. C. difficile RT014/020 was the most prevalent type found in humans with CDI. Continued surveillance of CDI in Australia remains critical for the detection of emerging strain lineages