Climate change disrupts the seasonal coupling of plant and soil microbial nutrient cycling in an alpine ecosystem.

The seasonal coupling of plant and soil microbial nutrient demands is crucial for efficient ecosystem nutrient cycling and plant production, especially in strongly seasonal alpine ecosystems. Yet, how these seasonal nutrient cycling processes are modified by climate change and what the consequences are for nutrient loss and retention in alpine ecosystems remain unclear. Here, we explored how two pervasive climate change factors, reduced snow cover and shrub expansion, interactively modify the seasonal coupling of plant and soil microbial nitrogen (N) cycling in alpine grasslands, which are warming at double the rate of the global average. We found that the combination of reduced snow cover and shrub expansion disrupted the seasonal coupling of plant and soil N-cycling, with pronounced effects in spring (shortly after snow melt) and autumn (at the onset of plant senescence). In combination, both climate change factors decreased plant organic N-uptake by 70% and 82%, soil microbial biomass N by 19% and 38% and increased soil denitrifier abundances by 253% and 136% in spring and autumn, respectively. Shrub expansion also individually modified the seasonality of soil microbial community composition and stoichiometry towards more N-limited conditions and slower nutrient cycling in spring and autumn. In winter, snow removal markedly reduced the fungal:bacterial biomass ratio, soil N pools and shifted bacterial community composition. Taken together, our findings suggest that interactions between climate change factors can disrupt the temporal coupling of plant and soil microbial N-cycling processes in alpine grasslands. This could diminish the capacity of these globally widespread alpine ecosystems to retain N and support plant productivity under future climate change.

An Evaluation of Barriers and Facilitators for a Pressure Injury Prevention Link Nurse Role: A Mixed-Methods Study in New Zealand.

PURPOSE: The purpose of this study was to identify barriers and facilitators for nurses in a pressure injury prevention (PIP) link nurse role. DESIGN: Mixed-methods study that used nominal group technique with focus groups, followed by online surveys. SAMPLE AND SETTING: The PIP link nurse project recruited 52 RNs; 32 completed the PIP educational program and participated in data collection. The sample was drawn from PIP link nurses, who were invited to participate in focus groups at the end of the project to identify perceived facilitators and barriers to their role. Focus groups were specific to work areas: aged care and community visiting, and hospital. Two were in an urban setting and one in a rural environment. Twenty-two PIP link nurses participated across 3 groups. To ensure comprehensive data from all involved in the project, online surveys were created using focus group priorities as the basis for questions to send to all PIP link nurses, their managers, and workplace colleagues. METHODS: Participants were invited to participate in focus groups to identify perceived facilitators and barriers to their role. These focus groups were organized around care settings: aged care, community visiting, and hospital. Using a nominal group technique focus group process, participants were asked to identify barriers and facilitators to their role. These were shared with the group until all answers were declared and understood. Voting on order of priority then took place, with majority voting leading to a prioritized list of facilitators and barriers for each group. Considering the similarities and differences across group priorities, researchers developed online surveys representing the main facilitators and barriers from the focus groups. Surveys were then distributed to all PIP link nurses, their managers, and colleagues. Survey data were collected and analyzed in REDCap and reported as percentages of agreement to the questions for each group of respondents. RESULTS: Focus group data indicated facilitating priorities included PIP link nurses' commitment to the role, the support they received from their managers and colleagues, and time release to complete the role. Barriers included lack of time-when other work pressures took priority, and PIP link nurses felt the focus on applying quality improvement theory was more challenging than they had anticipated. Surveys from all groups reiterated the importance of the support of the workplace team in facilitating the role, and the time pressures for the PIP link nurse were a barrier to the role. CONCLUSION: While the funding of such projects is advantageous, it should be carefully and generously considered how much time is required if the project is to succeed so that lack of time to complete the role does not become a barrier to successful completion.

A survey of nurses prescribing in diabetes care: Practices, barriers and facilitators in New Zealand and the United Kingdom.

AIMS AND OBJECTIVES: To compare diabetes-related prescribing practices, barriers and facilitators amongst nurse prescribers in New Zealand and the United Kingdom. BACKGROUND: Nurses have been prescribing in the United Kingdom for many years but nurse prescribing in New Zealand is relatively recent. It is unknown whether similar system factors act to facilitate or limit prescribing. DESIGN: A survey of 250 nurses prescribing in diabetes care in New Zealand (n = 111) and the United Kingdom (n = 139). METHODS: A SurveyMonkey questionnaire was used to survey nurses about the extent of their prescribing practices, and barriers and facilitators experienced. Quantitative data were explored descriptively, and qualitative responses were grouped according to content, with quotes provided to exemplify thematic content. This study is reported following STROBE guidelines. RESULTS: Insulin, metformin and sulphonylureas are the drugs most frequently prescribed in both countries. Considerably more New Zealand than United Kingdom nurses reported prescribing for cardiovascular and renal disease. In both countries, direct prescribing to the patient was most common, followed by remote prescribing in New Zealand and via recommendation to other prescribers in the United Kingdom. Most common barriers were lack of time and inadequate mentoring. Most common facilitators were as follows: good supervision; collegial relationships with specialists, pharmacists and peers; and ongoing education. CONCLUSIONS: These New Zealand and United Kingdom nurses are prescribing a broad range of diabetes-related medications. Similar barriers and facilitators were identified in both countries. Adequate supervision, support from multidisciplinary team colleagues and prescribing education and guidelines are paramount. RELEVANCE TO CLINICAL PRACTICE: Important insights on barriers and facilitators to implementation of nurse prescribing in two countries are highlighted and, despite a considerable difference in the longevity of prescribing practice, similar issues were identified.

Shrub expansion modulates belowground impacts of changing snow conditions in alpine grasslands.

Climate change is disproportionately impacting mountain ecosystems, leading to large reductions in winter snow cover, earlier spring snowmelt and widespread shrub expansion into alpine grasslands. Yet, the combined effects of shrub expansion and changing snow conditions on abiotic and biotic soil properties remains poorly understood. We used complementary field experiments to show that reduced snow cover and earlier snowmelt have effects on soil microbial communities and functioning that persist into summer. However, ericaceous shrub expansion modulates a number of these impacts and has stronger belowground effects than changing snow conditions. Ericaceous shrub expansion did not alter snow depth or snowmelt timing but did increase the abundance of ericoid mycorrhizal fungi and oligotrophic bacteria, which was linked to decreased soil respiration and nitrogen availability. Our findings suggest that changing winter snow conditions have cross-seasonal impacts on soil properties, but shifts in vegetation can modulate belowground effects of future alpine climate change.

Climate change alters temporal dynamics of alpine soil microbial functioning and biogeochemical cycling via earlier snowmelt.

Soil microbial communities regulate global biogeochemical cycles and respond rapidly to changing environmental conditions. However, understanding how soil microbial communities respond to climate change, and how this influences biogeochemical cycles, remains a major challenge. This is especially pertinent in alpine regions where climate change is taking place at double the rate of the global average, with large reductions in snow cover and earlier spring snowmelt expected as a consequence. Here, we show that spring snowmelt triggers an abrupt transition in the composition of soil microbial communities of alpine grassland that is closely linked to shifts in soil microbial functioning and biogeochemical pools and fluxes. Further, by experimentally manipulating snow cover we show that this abrupt seasonal transition in wide-ranging microbial and biogeochemical soil properties is advanced by earlier snowmelt. Preceding winter conditions did not change the processes that take place during snowmelt. Our findings emphasise the importance of seasonal dynamics for soil microbial communities and the biogeochemical cycles that they regulate. Moreover, our findings suggest that earlier spring snowmelt due to climate change will have far reaching consequences for microbial communities and nutrient cycling in these globally widespread alpine ecosystems.

High throughput method for measuring urease activity in soil.

Extracellular enzymes break down soil organic matter into smaller compounds and their measurement has proved to be a powerful tool to evaluate the functionality of soils. Urease is the enzyme that degrades urea and is widely considered to be a good proxy of nitrogen (N) mineralisation. But the methods available to measure this enzyme are time consuming; as such, urease is not commonly included in standard enzyme profiling of soils. We developed a fast, high throughput and reproducible colorimetric microplate technique to evaluate urease activity in soil. The method involves the incubation of soil slurries in 96-deepwell blocks with urea solutions and the measurement, by colorimetric reaction, of ammonium produced. We compared the new method with existing methods, yielding comparable results, and evaluated optimal conditions for urease analysis (soil slurry concentration, substrate concentration, incubation times and extractant salt concentration) in different grassland soils. The method proved to be a faster, higher throughput, and more precise alternative to existing methods for evaluating this important N-related enzyme.

Minimising methodological biases to improve the accuracy of partitioning soil respiration using natural abundance 13C.

RATIONALE: Microbial degradation of soil organic matter (heterotrophic respiration) is a key determinant of net ecosystem exchange of carbon, but it is difficult to measure because the CO2 efflux from the soil surface is derived not only from heterotrophic respiration, but also from plant root and rhizosphere respiration (autotrophic). Partitioning total CO2 efflux can be achieved using the different natural abundance stable isotope ratios (δ(13)C) of root and soil CO2. Successful partitioning requires very accurate measurements of total soil efflux δ(13)CO2 and the δ(13)CO2 of the autotrophic and heterotrophic sources, which typically differ by just 2-8‰. METHODS: In Scottish moorland and grass mesocosm studies we systematically tested some of the most commonly used techniques in order to identify and minimise methodological errors. Typical partitioning methods are to sample the total soil-surface CO2 efflux using a chamber, then to sample CO2 from incubated soil-free roots and root-free soil. We investigated the effect of collar depth on chamber measurements of surface efflux δ(13)CO2 and the effect of incubation time on estimates of end-member δ(13)CO2. RESULTS: (1) a 5 cm increase in collar depth affects the measurement of surface efflux δ(13)CO2 by -1.5‰ and there are fundamental inconsistencies between modelled and measured biases; (2) the heterotrophic δ(13)CO2 changes by up to -4‰ within minutes of sampling; we recommend using regression to estimate the in situ δ(13)CO2 values; (3) autotrophic δ(13)CO2 measurements are reliable if root CO2 is sampled within an hour of excavation; (4) correction factors should be used to account for instrument drift of up to 3‰ and concentration-dependent non-linearity of CRDS (cavity ringdown spectroscopy) analysis. CONCLUSIONS: Methodological biases can lead to large inaccuracies in partitioning estimates. The utility of stable isotope partitioning of soil CO2 efflux will be enhanced by consensus on the optimum measurement protocols and by minimising disturbance, particularly during chamber measurements.