Can mitigation schemes produce detectable long-term temporal trends and spatial patterns in aquatic pesticide pollution?

2021 ◽  
Author(s):  
Clément Fabre ◽  
Reynold Chow ◽  
Ruth Scheidegger ◽  
Tobias Doppler ◽  
Anne Dietzel ◽  
...  
Keyword(s):  
Interannual Variability ◽  
Temporal Trends ◽  
Weather Conditions ◽  
Pesticide Use ◽  
Pesticide Application ◽  
Regional Patterns ◽  
Agricultural Pesticide ◽  
Pesticide Pollution ◽  
Concentration Levels

<p>Agroecological schemes are implemented worldwide in order to reduce water quality impairment from agricultural pesticide use. However, evaluating the success or failure of these schemes is challenging because other influencing factors can confound their effects. For instance, aquatic pesticide pollution has been found to vary greatly due to the interannual variability in weather conditions (e.g., the timing, intensity, and duration of precipitation events) and changes in pesticide application practices (e.g., changing pest pressure, phasing-out and replacement of specific products, development of pesticide resistance).</p><p>Our research investigates the necessary conditions to detect significant trends in pesticide concentrations in the context of the Swiss National Action Plan (NAP), which aims to halve aquatic pesticide pollution risk from agricultural pesticide use within Swiss river networks by 2027.</p><p>We base our analyses for temporal trends on a calibrated model for pesticide transport at the catchment scale, which we use to separate the long-term effects of the NAP from interannual variability due to weather conditions. Our results indicate that the interannual variability due to weather conditions can override the effects of even a 50% reduction in pesticide application for rain-driven input. This implies that the concentration levels themselves may be insufficient to demonstrate the effectiveness of the NAP within a reasonable time horizon of a decade. This is because the lowering of in-stream pesticide concentrations can be due to the timing and intensity of precipitation relative to the application of pesticides and not from the effectiveness of pesticide mitigation measures. Therefore, we have further explored potential methods to account for the weather effects on the pesticide concentration levels. Accounting for the weather conditions by considering the dependence of concentration levels on discharge conditions during the application period improves the statistical power to detect trends.</p><p>Furthermore, we assess the potential to extrapolate the trends observed at 23 monitoring sites from different catchments (varying in size 1 km<sup>2</sup> to > 20,000 km<sup>2</sup>) across Switzerland to the entire Swiss river network. As a first step, we analyzed substances applied to corn because this crop is widespread in the country, is easy to follow as herbicides are applied only once a year, and only a few pesticides are applied. The analysis revealed that for some of these corn herbicides, the seasonal patterns were consistent across many catchments and in agreement with the crop specific expectations. However, for other herbicides we identified regional patterns with unexpected concentration peaks in the fall. This observation requires more detailed inquiries in regional use patterns and highlights the need to account for regionalized pesticide use when extrapolating monitoring data to larger scales.</p>

Counterfactual hydrological pesticide transport modelling: Can we detect long-term in-stream pesticide trends due to mitigation?

2020 ◽  
Author(s):  
Reynold Chow ◽  
Ruth Sceidegger ◽  
Tobias Doppler ◽  
Anne Dietzel ◽  
Fabrizio Fenicia ◽  
...  
Keyword(s):  
Interannual Variability ◽  
Action Plan ◽  
Weather Conditions ◽  
Mitigation Measures ◽  
Pesticide Application ◽  
Catchment Scale ◽  
Pesticide Transport ◽  
Concentration Levels ◽  
Precipitation Events

<p>In many countries, agroecological schemes are implemented in order to reduce water quality impairment from agricultural pesticide use. However, demonstrating the success or failure of these schemes is challenging because other influencing factors can confound their effects. For instance, in-stream pesticide concentrations have been found to vary greatly due to the interannual variability in weather conditions (e.g., the timing, intensity, and duration of precipitation events) and pesticide application practices (e.g., the variability in timing and spatial application of differing pesticides that have different chemical properties).</p><p>Our current work aims to investigate the necessary conditions to detect significant trends in pesticide concentrations in the context of the Swiss National Action Plan (NAP), which aims to halve the pesticide risk from agricultural activities within Swiss river networks by 2027. We use a modelling approach to explore possibilities and limitations of the existing monitoring scheme for separating long-term effects of the NAP from interannual variability due to weather conditions. For that purpose, we use an existing model for simulating pesticide transport at the catchment scale. After calibration, we simulated 10 years of herbicide concentrations with and without (i.e., the counterfactual) an assumed 50% reduction of the pesticide applied and evaluated the resulting concentration levels.</p><p>Our results indicate that the interannual variability due to weather conditions can exceed even a 50% change in pesticide application. This implies that the concentration levels themselves are insufficient to demonstrate the effectiveness of the NAP within a reasonable time horizon of a decade. This is because the lowering of in-stream pesticide concentrations may be due to the timing and intensity of precipitation relative to the application of pesticides and not from the effectiveness of pesticide mitigation measures. Therefore, we explore ways to account for the weather effects on the pesticide concentration levels. Furthermore, we found that comparing the pesticide concentrations in years that have both above average precipitation during pesticide application periods and contain precipitation events that occur shortly after pesticide application can lead to more robust statements about the effectiveness of the mitigation measures. Preliminary double mass analyses of cumulative rainfall during the application period versus cumulative maximum concentrations suggest that significant trends can be identified with 11 years of data (6 years before NAP implementation and 5 years into it). We are currently exploring how sensitive our results are to pesticide properties, such as sorption and degradation half-lives.</p>

scholarly journals Linking population size structure, heat stress and bleaching responses in a subtropical endemic coral

Coral Reefs ◽  
2021 ◽  
Author(s):  
Liam Lachs ◽  
Brigitte Sommer ◽  
James Cant ◽  
Jessica M. Hodge ◽  
Hamish A. Malcolm ◽  
...  
Keyword(s):  
Heat Stress ◽  
Size Structure ◽  
Temporal Trends ◽  
Early Recovery ◽  
Size Frequency Distribution ◽  
Frequency Distributions ◽  
Community Organisation ◽  
Size Frequency ◽  
Eastern Australia

AbstractAnthropocene coral reefs are faced with increasingly severe marine heatwaves and mass coral bleaching mortality events. The ensuing demographic changes to coral assemblages can have long-term impacts on reef community organisation. Thus, understanding the dynamics of subtropical scleractinian coral populations is essential to predict their recovery or extinction post-disturbance. Here we present a 10-yr demographic assessment of a subtropical endemic coral, Pocillopora aliciae (Schmidt-Roach et al. in Zootaxa 3626:576–582, 2013) from the Solitary Islands Marine Park, eastern Australia, paired with long-term temperature records. These coral populations are regularly affected by storms, undergo seasonal thermal variability, and are increasingly impacted by severe marine heatwaves. We examined the demographic processes governing the persistence of these populations using inference from size-frequency distributions based on log-transformed planar area measurements of 7196 coral colonies. Specifically, the size-frequency distribution mean, coefficient of variation, skewness, kurtosis, and coral density were applied to describe population dynamics. Generalised Linear Mixed Effects Models were used to determine temporal trends and test demographic responses to heat stress. Temporal variation in size-frequency distributions revealed various population processes, from recruitment pulses and cohort growth, to bleaching impacts and temperature dependencies. Sporadic recruitment pulses likely support population persistence, illustrated in 2010 by strong positively skewed size-frequency distributions and the highest density of juvenile corals measured during the study. Increasing mean colony size over the following 6 yr indicates further cohort growth of these recruits. Severe heat stress in 2016 resulted in mass bleaching mortality and a 51% decline in coral density. Moderate heat stress in the following years was associated with suppressed P. aliciae recruitment and a lack of early recovery, marked by an exponential decrease of juvenile density (i.e. recruitment) with increasing heat stress. Here, population reliance on sporadic recruitment and susceptibility to heat stress underpin the vulnerability of subtropical coral assemblages to climate change.

scholarly journals Studies of insect temporal trends must account for the complex sampling histories inherent to many long-term monitoring efforts

2021 ◽  
Author(s):  
Ellen A. R. Welti ◽  
Anthony Joern ◽  
Aaron M. Ellison ◽  
David C. Lightfoot ◽  
Sydne Record ◽  
...  
Keyword(s):  
Temporal Trends ◽  
Complex Sampling ◽  
Long Term Monitoring ◽  
Term Monitoring

scholarly journals Long-Term Temporal Trends of Polychlorinated Biphenyls and Their Controlling Sources in China

2017 ◽  
Vol 51 (5) ◽  
pp. 2838-2845 ◽  
Author(s):  
Shizhen Zhao ◽  
Knut Breivik ◽  
Guorui Liu ◽  
Minghui Zheng ◽  
Kevin C. Jones ◽  
...  
Keyword(s):  
Polychlorinated Biphenyls ◽  
Temporal Trends

scholarly journals Agricultural Pesticide Use and Hypospadias in Eastern Arkansas

2006 ◽  
Vol 114 (10) ◽  
pp. 1589-1595 ◽  
Author(s):  
Kristy J. Meyer ◽  
John S. Reif ◽  
D.N. Rao Veeramachaneni ◽  
Thomas J. Luben ◽  
Bridget S. Mosley ◽  
...  
Keyword(s):  
Pesticide Use ◽  
Agricultural Pesticide

Temporal trends in pulmonary arterial hypertension: Results from the COMPERA registry

2021 ◽  
pp. 2102024
Author(s):  
Marius M. Hoeper ◽  
Christine Pausch ◽  
Ekkehard Grünig ◽  
Gerd Staehler ◽  
Doerte Huscher ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Pulmonary Arterial Hypertension ◽  
Combination Therapy ◽  
Arterial Hypertension ◽  
Temporal Trends ◽  
Survival Rates ◽  
Term Survival ◽  
Pulmonary Arterial ◽  
Early Combination Therapy

BackgroundSince 2015, the European pulmonary hypertension guidelines recommend the use of combination therapy in most patients with pulmonary arterial hypertension (PAH). However, it is unclear to what extend this treatment strategy is adopted in clinical practice and if it is associated with improved long-term survival.MethodsWe analysed data from COMPERA, a large European pulmonary hypertension registry, to assess temporal trends in the use of combination therapy and survival of patients with newly diagnosed PAH between 2010 and 2019. For survival analyses, we look at annualized data and at cumulated data comparing the periods 2010–2014 and 2015–2019.ResultsA total of 2,531 patients were included. The use of early combination therapy (within 3 months after diagnosis) increased from 10.0% in patients diagnosed with PAH in 2010 to 25.0% in patients diagnosed with PAH in 2019. The proportion of patients receiving combination therapy 1 year after diagnosis increased from 27.7% to 46.3%. When comparing the 2010–2014 and 2015–2019 periods, 1-year survival estimates were similar (89.0% [95% CI, 87.2%, 90.9%] and 90.8% [95% CI, 89.3%, 92.4%]), respectively, whereas there was a slight but non-significant improvement in 3-year survival estimates (67.8% [95% CI, 65.0%, 70.8%] and 70.5% [95% CI, 67.8%, 73.4%]), respectively.ConclusionsThe use of combination therapy increased from 2010 to 2019, but most patients still received monotherapy. Survival rates at 1 year after diagnosis did not change over time. Future studies need to determine if the observed trend suggesting improved 3-year survival rates can be confirmed.

scholarly journals Variability of Cloudiness over Mountain Terrain in the Western United States

2017 ◽  
Vol 18 (5) ◽  
pp. 1227-1245 ◽  
Author(s):  
Edwin Sumargo ◽  
Daniel R. Cayan
Keyword(s):  
United States ◽  
Large Scale ◽  
Spatial Scales ◽  
High Elevation ◽  
Empirical Orthogonal Functions ◽  
Western United States ◽  
Spatial And Temporal Variability ◽  
Regional Patterns ◽  
Cloud Albedo

Abstract This study investigates the spatial and temporal variability of cloudiness across mountain zones in the western United States. Daily average cloud albedo is derived from a 19-yr series (1996–2014) of half-hourly Geostationary Operational Environmental Satellite (GOES) images. During springtime when incident radiation is active in driving snowmelt–runoff processes, the magnitude of daily cloud variations can exceed 50% of long-term averages. Even when aggregated over 3-month periods, cloud albedo varies by ±10% of long-term averages in many locations. Rotated empirical orthogonal functions (REOFs) of daily cloud albedo anomalies over high-elevation regions of the western conterminous United States identify distinct regional patterns, wherein the first five REOFs account for ~67% of the total variance. REOF1 is centered over Northern California and Oregon and is pronounced between November and March. REOF2 is centered over the interior northwest and is accentuated between March and July. Each of the REOF/rotated principal components (RPC) modes associates with anomalous large-scale atmospheric circulation patterns and one or more large-scale teleconnection indices (Arctic Oscillation, Niño-3.4, and Pacific–North American), which helps to explain why anomalous cloudiness patterns take on regional spatial scales and contain substantial variability over seasonal time scales.

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