Effect Of Winter Precipitation Research Articles

Effects of precipitation, heat, and drought on incidence and expansion of coccidioidomycosis in western USA: a longitudinal surveillance study

Drought is an understudied driver of infectious disease dynamics. Amidst the ongoing southwestern North American megadrought, California (USA) is having the driest multi-decadal period since 800 CE, exacerbated by anthropogenic warming. In this study, we aimed to examine the influence of drought on coccidioidomycosis, an emerging infectious disease in southwestern USA. We analysed California census tract-level surveillance data from 2000 to 2020 using generalised additive models and distributed monthly lags on precipitation and temperature. We then developed an ensemble prediction algorithm of incident cases of coccidioidomycosis per census tract to estimate the counterfactual incidence that would have occurred in the absence of drought. Between April 1, 2000, and March 31, 2020, there were 81 448 reported cases of coccidioidomycosis throughout California. An estimated 1467 excess cases of coccidioidomycosis were observed in California in the 2 years following the drought that occurred between 2007 and 2009, and an excess 2649 drought-attributable cases of coccidioidomycosis were observed in the 2 years following the drought that occurred between 2012 and 2015. These increased numbers of cases more than offset the declines in cases that occurred during drought. An IQR increase in summer temperatures was associated with 2·02 (95% CI 1·84-2·22) times higher incidence in the following autumn (September to November), and an IQR increase in precipitation in the winter was associated with 1·45 (1·36-1·55) times higher incidence in the autumn. The effect of winter precipitation was 36% (25-48) stronger when preceded by two dry, rather than average, winters. Incidence in arid counties was most sensitive to precipitation fluctuations, while incidence in wetter counties was most sensitive to temperature. In California, multi-year cycles of dry conditions followed by a wet winter increases transmission of coccidioidomycosis, especially in historically wetter areas. With anticipated increasing frequency of drought in southwestern USA, continued expansion of coccidioidomycosis, along with more intense seasons, is expected. Our results motivate the need for heightened precautions against coccidioidomycosis in seasons that follow major droughts. National Institutes of Health.

Pollen, δ15N and δ13C guano-derived record of late Holocene vegetation and climate in the southern Carpathians, Romania

Two cores of bat guano were recovered from Topolnița and Gura Ponicovei Caves in the south-west region of Romania and analyzed for δ15N, δ13C and pollen. Deposition of guano began in CE 1537 at Gura Ponicovei and CE 1694 at Topolnița, allowing for the development and interpretation of climate and vegetation records since the Little Ice Age. δ15N values were found to record phases of the North Atlantic Oscillation through the effect of winter precipitation on the local nitrogen cycle. Alternatively, δ13C values are interpreted to correspond with variation in summer precipitation. Both records suggest progressively drier conditions during the termination of the LIA in the region at CE 1870. The transition to landscape openness, with patchy forests of Tilia, Carpinus betulus, and Quercus during this time could be related to the lower water availability at both sites. Wetter conditions inferred from a 3‰ increase in δ15N values between CE 1879 and CE 1970 occurred contemporaneously with a similar trend in European winter precipitation and increased frequency of positive NAO phases during this interval. The δ13C values between CE 1885 and CE 1968 suggest a trend towards a wetter summer climate as well. Although there is at times evidence of forest dynamics being controlled by climate, vegetation appears to be more closely associated with human impact, particularly around Topolnița Cave. The contribution of ruderal pollen indicators from CE 1985 – present is likely related to agricultural practices.

Influence of winter precipitation on spring phenology in boreal forests.

Understanding the variations in spring vegetation phenology associated with preseason climate conditions can significantly improve our knowledge on ecosystem dynamics and biosphere-atmosphere interactions. Recent studies have shown that wet winters can delay the start date of the vegetation growing season (SOS) in the high latitudes. However, associated underlying mechanisms remain unclear due to the lack of observation sites as well as complex interactions between various climate and ecosystem variables. In this study, the impact of winter precipitation on year-to-year variations of the SOS in boreal forests from 1982 to 2005 was investigated. Two experiments were performed using the Community Land Model version 4.5. In the control experiment, observed precipitation was used; in the sensitivity experiment, precipitation in the year 1982 was repeated throughout the period. The SOS in the control experiment shows high temporal correlations with the SOS estimated from the satellite-retrieved leaf area index, indicating that the land model is capable of simulating realistic response of vegetation to interannual climate variability. The effects of winter precipitation on the SOS are examined by comparing the two model experiments for wet- and dry winters. After wet winters, the SOS was delayed by 2.7days over 70.1% of the boreal forests than after dry winters; this accounts for 42.5% of the interannual variation in the SOS. The SOS delay is related to the decrease in the growing degree-days (GDD) based on soil temperatures, suggesting that the effects of heat exposure on vegetation growth is strongly modulated by winter precipitation. The GDD decrease is related to both the increase in snowmelt heat flux and reduced absorption of solar radiation, which are proportional to the amount of winter precipitation and the ratio of short plants to tall trees, respectively. Our results provide a physical basis for the winter precipitation-SOS relationship, suggesting that an increase in winter precipitation can alleviate strong advancing trends in spring vegetation growth in conjunction with global warming even for temperature-limited ecosystems.

Effects of winter precipitation on automobile collisions, injuries, and fatalities in the United States

To better understand the links between winter precipitation (snow, sleet, and freezing rain) and travel risk, data on weather conditions and vehicle crashes, injuries and fatalities are gathered for 13 U.S. cities. A matched pair analysis is used to construct event-control pairs to determine the relative risk of crash, injury, and fatality. Winter precipitation is associated with a 19% increase in traffic crashes and a 13% increase in injuries compared to dry conditions. The type of winter precipitation (snowfall vs. freezing rain, ice pellets, or sleet) had no significant impact on the relative risk of crash. The relative risk of crash was significantly higher during the evening (1800–2359 local time) than during other times of the day. More intense precipitation led to increased relative risk of crash and injury compared to less intense precipitation. Relative risk of crash, injury, or fatality was not significantly higher during the first three winter precipitation events of the year as compared to subsequent events. The relative risk of both winter precipitation crash and injury showed no significant trend during the 1998–2008 period. Sensitivity of U.S. cities to winter precipitation varies from city to city in a manner that is not easily explained. Future research will be required to determine which safety interventions are most effective in each city and revise or expand safety programs appropriately.

Effect of fertilization system and NO3-N distribution on corn yield

The objectives of the study have been to determine the effects of winter precipitation, NO3-N distribution in the soil profile and their interaction on corn yield in different fertilization systems. Corn yield varied across fertilization systems and winter rainfall in the investigated years (2001–2004). Significantly higher yields were found in variants with manure application in diculture (DC-M-NPK — 12.11 t ha−1) and in monoculture (MC-M-NPK — 9.25 t ha−1). Path coefficients showed that the highest direct positive effects on corn yields were exhibited by NO3-N amounts at soil depths 30–60 cm and 60–90 cm (p = 0.4336** and p = 0.2346**, respectively). Winter precipitation had a direct negative effect on the yield performance (p = −0.1159), however, the downward movement of NO3-N from topsoil (0–30 cm) to deeper soil layers (30–60 and 60–90 cm), whose N levels were directly positively correlated with yield, made the indirect effect of winter precipitation on yield positive.

What are the main climate drivers for shrub growth in Northeastern Siberian tundra?

Abstract. Deciduous shrubs are expected to rapidly expand in the Arctic during the coming decades due to climate warming. A transition towards more shrub-dominated tundra may have large implications for the regional surface energy balance, permafrost stability and carbon storage capacity, with consequences for the global climate system. However, little information is available on the natural long-term shrub growth response to climatic variability. Our aim was to determine the climate factor and time period that are most important to annual shrub growth in our research site in NE-Siberia. Therefore, we determined annual radial growth rates in Salix pulchra and Betula nana shrubs by measuring ring widths. We constructed shrub ring width chronologies and compared growth rates to regional climate and remotely sensed greenness data. Early summer temperature was the most important factor influencing ring width of S. pulchra (Pearson's r = 0.73, p < 0.001) and B. nana (Pearson's r = 0.46, p < 0.001). No effect of winter precipitation on shrub growth was observed. In contrast, summer precipitation of the previous year correlated positively with B. nana ring width (Pearson's r = 0.42, p < 0.01), suggesting that wet summers facilitate shrub growth in the following growing season. S. pulchra ring width correlated positively with peak summer NDVI, despite the small coverage of S. pulchra shrubs (< 5 % surface cover) in our research area. We provide the first climate-growth study on shrubs for Northeast Siberia, the largest tundra region in the world. We show that two deciduous shrub species with markedly different growth forms have a similar growth response to changes in climate. The obtained shrub growth response to climate variability in the past increases our understanding of the mechanisms underlying current shrub expansion, which is required to predict future climate-driven tundra vegetation shifts.

Changing precipitation patterns alter plant community dynamics and succession in an ex‐arable grassland

Summary Changes in the frequency of extreme events, such as droughts, may be one of the most significant impacts of climate change for ecosystems. Models predict more frequent summer droughts in much of England: this paper investigates the impact on different types of plants in an ex‐arable grassland community. A long‐term experiment simulated increased and decreased summer precipitation. Substantial interannual variation allowed the effects of summer drought to be tested in combination with wet and dry weather in other seasons. This is important, as climate models predict increased winter precipitation. Total cover abundance in early summer increased with increasing water supply in the previous summer; there was no effect of winter precipitation. Productivity is therefore likely to decrease with more frequent summer droughts, with no mitigating effect of wetter winters. The percentage cover of perennial grasses declined during a natural drought in 1995–97; this was exacerbated by the experimental drought treatment and reduced by supplemented rainfall. Simultaneously, short‐lived ruderal species increased; this was greatest in drought treatments and least with supplemented rainfall. These trends were subsequently reversed during several years of unusually wet weather, with perennial grasses increasing and short‐lived forbs decreasing. This occurred even in experimentally droughted plots, and we propose that it resulted from rapid coverage of gaps during wet autumns and winters. Deep‐rooted species generally proved to be more drought resistant, but there were exceptions. We conclude that increased frequency of summer droughts could have serious implications for the establishment and successional development of ex‐arable grasslands. Increased winter precipitation would moderate the impact on species composition, but not on productivity.

Effect of Winter Precipitation and Temperature on Overwintering Eggs of Northern an Western Corn Rootworms12

The effect of winter precipitation and temperature on the overwintering eggs of the northern and western corn rootworm, Diabrotica longicornis (Say) and D. virgifera LeConte, respectively, was evaluated in the field by using spring and fall plowing to adjust the depth at which the eggs were buried in the soil. Lack of winter precipitation caused high mortality of eggs near the soil surface. Because South Dakota winters are so variable, neither fall nor spring plowing can be recommended as a reliable method of controlling corn rootworms.