Optimal Placement of Off-Stream Water Sources for Ephemeral Stream Recovery

Uneven and/or inefficient livestock distribution is often a product of an inadequate number and distribution of watering points.Placement of off-stream water practices (OSWP) in pastures is a key consideration in rangeland management plans and is criticalto achieving riparian recovery by improving grazing evenness, while improving livestock performance. Effective OSWPplacement also minimizes the impacts of livestock use radiating from OSWP, known as the ‘‘piosphere.’’ The objective of thisstudy was to provide land managers with recommendations for the optimum placement of OSWP. Specifically, we aimed toprovide minimum offset distances of OSWP to streams and assess the effective range of OSWP using Normalized DifferenceVegetation Index (NDVI) values, an indicator of live standing crop. NDVI values were determined from a time-series of SatellitePour l’Observation de la Terre (SPOT) 20-m images of western South Dakota mixed-grass prairie. The NDVI values inephemeral stream channels (in-channel) and uplands were extracted from pre- and post-OSWP images taken in 1989 and 2010,respectively. NDVI values were normalized to a reference imagine and subsequently by ecological site to produce nNDVI. Ourresults demonstrate a significant (P,0.05) increase in the nNDVI values of in-channel vegetation within 1 250 m of OSWPfollowing their implementation. The area of piospheres (n¼9) increased with pasture size (R2¼0.49,P¼0.05) and increasedwith average distance to OSWP in a pasture (R2¼0.43,P¼0.07). Piospheric reduction in nNDVI was observed within 200 m ofOSWP, occasionally overlapping in-channel areas. The findings of this study suggest placement of OSWP 200 to 1 250 m fromstreams to achieve optimal results. These results can be used to increase grazing efficiency by effectively placing OSWP andinsure that piospheres do not overlap ecologically important in-channel areas

Influence of management and precipitation on carbon fluxes in Great Plains grasslands

Suitable management and sufficient precipitation on grasslands can provide carbon sinks. The net carbon accumulation of a site from the atmosphere, modeled as the Net Ecosystem Productivity (NEP), is a useful means to gauge carbon balance. Previous research has developed methods to integrate flux tower data with satellite biophysical datasets to estimate NEP across large regions. A related method uses the Ecosystem Performance Anomaly (EPA) as a satellite-derived indicator of disturbance intensity (e.g., livestock stocking rate, fire, and insect damage). To better understand the interactions among management, climate, and carbon dynamics, we evaluated the relationship between EPA and NEP data at the 250 m scale for grasslands in the Central Great Plains, USA (ranging from semi-arid to mesic). We also used weekly estimates of NEP to evaluate the phenology of carbon dynamics, classified by EPA (i.e., by level of disturbance impact). Results show that the cumulative carbon balance over these grasslands from 2000 to 2008 was a weak net sink of 13.7 g C m−2 yr−1. Overall, NEP increased with precipitation (R2 = 0.39, P \u3c 0.05) from west to east. Disturbance influenced NEP phenology; however, climate and biophysical conditions were usually more important. The NEP response to disturbance varies by ecoregion, and more generally by grassland type, where the shortgrass prairie NEP is most sensitive to disturbance, the mixed-grass prairie displays a moderate response, and tallgrass prairie is the least impacted by disturbance (as measured by EPA). Sustainable management practices in the tallgrass and mixed-grass prairie may potentially induce a period of average net carbon sink until a new equilibrium soil organic carbon is achieved. In the shortgrass prairie, management should be considered sustainable if carbon stocks are simply maintained. The consideration of site carbon balance adds to the already difficult task of managing grasslands appropriately to site conditions. Results clarify the seasonal and interannual dynamics of NEP, specifically the influence of disturbance and moisture availability

Linking Phenology and Biomass Productivity in South Dakota Mixed-Grass Prairie

Assessing the health of rangeland ecosystems based solely on annual biomass production does not fully describe the condition of the plant community; the phenology of production can provide inferences about species composition, successional stage, and grazing impacts. We evaluated the productivity and phenology of western South Dakota mixed-grass prairie in the period from 2000 to 2008 using the normalized difference vegetation index (NDVI). The NDVI is based on 250-m spatial resolution Moderate Resolution Imaging Spectroradiometer (MODIS) satellite imagery. Growing-season NDVI images were integrated weekly to produce time-integrated NDVI (TIN), a proxy of total annual biomass production, and integrated seasonally to represent annual production by cool- and warm-season species (C3 and C4, respectively). Additionally, a variety of phenological indicators including cool-season percentage of TIN were derived from the seasonal profiles of NDVI. Cool-season percentage and TIN were combined to generate vegetation classes, which served as proxies of the conditions of plant communities. TIN decreased with precipitation from east to west across the study area. However, the cool-season percentage increased from east to west, following patterns related to the reliability (interannual coefficient of variation [CV]) and quantity of midsummer precipitation. Cool-season TIN averaged 76.8% of the total TIN. Seasonal accumulation of TIN corresponded closely (R2 . 0.90) to that of gross photosynthesis data from a carbon flux tower. Field-collected biomass and community composition data were strongly related to TIN and cool-season percentage. The patterns of vegetation classes were responsive to topographic, edaphic, and land management influences on plant communities. Accurate maps of biomass production, cool- and warm-season composition, and vegetation classes can improve the efficiency of land management by facilitating the adjustment of stocking rates and season of use to maximize rangeland productivity and achieve conservation objectives. Further, our results clarify the spatial and temporal dynamics of phenology and TIN in mixed-grass prairie

Detecting the Influence of Best Management Practices on Vegetation Near Ephemeral Streams With Landsat Data

Various best management practices (BMPs) have been implemented on rangelands with the goals of controlling nonpoint sourcepollution, reducing the impact of livestock in ecologically important riparian areas, and improving grazing distribution.Providing off-stream water sources to livestock in pastures, cross-fencing, and rotational grazing are common rangeland BMPsthat have demonstrated success in drawing livestock grazing pressure away from streams. We evaluated the effects of rangelandBMP implementation with six commercial-scale pastures in the northern mixed-grass prairie. Four pastures received a BMPsuite consisting of off-stream water, cross-fencing, and deferred-rotation grazing, and two pastures did not receive BMPs. Wehypothesized that the BMPs increased the quantity of riparian vegetation cover relative to the conditions in these pasturesduring the pre-BMP period and to the two pastures that did not receive BMPs. We used a series of 30-m Landsat normalizeddifference vegetation index (NDVI) images to track the spatial and temporal changes (1984–2010,n¼24) in vegetation cover, towhich NDVI has been well correlated. Validation indicated that the remotely sensed signal from in-channel vegetation wasrepresentative of ground conditions. The BMP suite was associated with a 15% increase in the in-channel NDVI (0–30 m fromstream centerline) and 18% increase in the riparian NDVI (30–180 m from stream center line). Conversely, the in-channel andriparian NDVI of non-BMP pastures declined 30% and 18% over the study period. The majority of change occurred within 2 yrof BMP implementation. The patterns of in-channel NDVI among pastures suggested that BMP implementation likely alteredgrazing distribution by decreasing the preferential use of riparian and in-channel areas. We demonstrated that satellite imagerytime series are useful in retrospectively evaluating the efficacy of conservation practices, providing critical information to guideadaptive management and decision makers

Detecting Channel Riparian Vegetation Response to BMP Implementation in Western South Dakota Ephemeral Streams Using Spot Imagery

Heavily grazed riparian areas are commonly subject to channel incision, a lower water table, and reduced vegetation. Riparian vegetation dissipates flow energy which is critical to maintaining stable channel geometry. Occurrences of prairie cord grass (Spartina pectinata) stands were used as evidence of improved riparian health during post best management practice (BMP) assessment within a watershed frequented by ephemeral gullies. Presence/absence of S. pectinata was recorded during 2010 assessments of ephemeral channels with drainage areas ranging from .54 to 692 hectares. Reach locations (n = 115) were delineated using 2010 National Agriculture Imagery Program (NAIP) imagery resulting in 8-39 sample points per reach subsequently used to extract Normalized Difference Vegetation Index (NDVI) values from a series of Satellite Pour l\u27Observation de la Terre (SPOT) satellite imagery. Normalized NDVI values from 1,981 sample points were determined from pre (1987, 1994, and 1997) and post-BMP (2010) imagery. Mean normalized NDVI values calculated for each reach ranged from -1.33 to 3.16. ANOVA revealed no mean difference in normalized NDVI among S. pectinata classes for pre-BMP years (P = 0.85, 0.74, 0.82), respectively. However, in 2010 (post-BMP), S. pectinata sites had significantly higher normalized NDVI (1.23) compared to non-S. pectinata sites (0.89) (P = 0.01). Reappearance of S. pectinata due to changes in grazing regimes along with construction of off-stream watering sources was successfully detected remotely. Establishment of S. pectinata provides habitat heterogeneity and functions in reducing flow energy which is responsible for the current state of severely incised channels

Seasonality, risk-factors and burden of community-acquired pneumonia in COPD patients: A population database study using linked healthcare records

Community acquired pneumonia (CAP) is more common in patients with chronic obstructive pulmonary disease (COPD) than in the adult general population, with studies of hospitalised CAP consistently reporting COPD as a frequent comorbidity. However, despite an increasing recognition of its importance, large studies evaluating the incidence patterns over time, risk-factors and burden of CAP in COPD are currently lacking.A retrospective observational study using a large UK-based database of linked primary and secondary care records was conducted. Patients with a diagnosis of COPD aged ?40 years were followed for 5 years from the 1st January 2010. CAP and exacerbation episodes were identified from hospital discharge data and primary care coding records, and rates were calculated per month, adjusting for mortality, and displayed over time. In addition, baseline factors predicting future risk of CAP and hospital admission at CAP, were identified. 14513 COPD patients were identified: 13.4% (n=1938) had ?1 CAP episode, of whom 18.8% suffered from recurrent (?2) CAP. Highest rates of both CAP and exacerbations were seen in winter. A greater proportion of frequent, compared to infrequent exacerbators experienced recurrent CAP (5.1% versus 2.0% respectively, p&lt;0.001) 75.6% of CAP episodes were associated with hospital admission compared to 22.1% of exacerbations. Older age and increasing grade of airflow limitation were independently associated with increased odds of CAP and hospital admission at CAP. Other independent predictors of future CAP included lower body mass index, inhaled-corticosteroid use, prior frequent exacerbations and comorbidities including ischaemic heart disease and diabetes. CAP in COPD demonstrates clear seasonal patterns, with patient characteristics predictive of the odds of future CAP and hospital admission at CAP. Highlighting this burden of COPD-associated CAP during the winter period, informs us of the likely triggers and the need for more effective preventive strategies.<br/

Phenologic Assessment of Western South Dakota Rangelands

Assessing the health of rangeland ecosystems based solely on the annual biomass production does not fully describe plant community condition, as biodiversity and species composition are also critical components in sustaining rangeland systems. The phenology of production is of particular concern in assessing rangeland health due to inferences that can be made on species composition. In this study a variety of phenological indicators were derived from examination of the phenological profiles of sample sites using 2000 to 2008 Moderate Resolution Imaging Spectrometer (MODIS) imagery at 250 m resolution in the Bad River watershed of western South Dakota. Analysis revealed that biomass production decreased with precipitation from east to west across the study area. Alternatively, cool season percentage of total production increased from east to west. Cool season biomass production averaged 76.8% of total which compared favorably to previously reported values for the study area (Tieszen et al. 1997; Foody and Dash 2007). This study, however, provided a much higher spatial resolution than previous work. Additionally, this study reports the spatial, temporal, and spatial-temporal phenologic patterns, each of which offers a unique perspective. Accurate maps of biomass production and dominant photosynthetic pathways are useful to land managers. These maps increase the efficiency of management by denoting areas were degrading practices were occurring. Validation of remotely sensed observations with field data is critically important to any remote sensing study. Remotely sensed phenology and biomass data for western South Dakota rangelands was determined using MODIS normalized difference vegetation index (NDVI) imagery. Validation of remotely sensed data was conducted through a variety of field data sets 1) pasture scale long term plant community and biomass data, 2) gross photosynthesis data from a carbon flux tower, 3) visual obstruction (Robel pole) measurements, 4) Daubenmire vegetation cover data, 5) Soil Survey Geographic (SSURGO) range production values, and 6) State Soil Geographic (STATSGO) C3 percentage. Varying degrees of success were achieved in the six validation methods. Vegetation cover by Daubenmire frame provided a poor relationship with remotely sensed data. Robel pole and pasture-scale validation proved to be moderately related to remotely sensed data. Remotely sensed and flux tower metrics yielded similar results. Remotely sensed time-integrated NDVI (TIN) was strongly related (R2 = 0.87) to SSURGO range production data. Finally, cool season percentage had a moderately robust relationship (R2 = 0.45) with STATSGO C3 percent reference data. These comparisons demonstrated the proficiency of medium resolution remotely sensed data to accurately reflect in situ and reference data