Jeffrey A. Andresen

East African food security as influenced by future climate change and land use change at local to regional scales

Climate change impacts food production systems, particularly in locations with large, vulnerable populations. Elevated greenhouse gases (GHG), as well as land cover/land use change (LCLUC), can influence regional climate dynamics. Biophysical factors such as topography, soil type, and seasonal rainfall can strongly affect crop yields. We used a regional climate model derived from the Regional Atmospheric Modeling System (RAMS) to compare the effects of projected future GHG and future LCLUC on spatial variability of crop yields in East Africa. Crop yields were estimated with a process-based simulation model. The results suggest that: (1) GHG-influenced and LCLUC-influenced yield changes are highly heterogeneous across this region; (2) LCLUC effects are significant drivers of yield change; and (3) high spatial variability in yield is indicated for several key agricultural sub-regions of East Africa. Food production risk when considered at the household scale is largely dependent on the occurrence of extremes, so mean yield in some cases may be an incomplete predictor of risk. The broad range of projected crop yields reflects enormous variability in key parameters that underlie regional food security; hence, donor institutions’ strategies and investments might benefit from considering the spatial distribution around mean impacts for a given region. Ultimately, global assessments of food security risk would benefit from including regional and local assessments of climate impacts on food production. This may be less of a consideration in other regions. This study supports the concept that LCLUC is a first-order factor in assessing food production risk.

Soils Cool as Climate Warms in the Great Lakes Region: 1951–2000

Abstract We modeled soil temperatures at 50-cm depth, using 1951–2000 air temperature and precipitation data from 194 National Weather Service stations in Wisconsin and Michigan. The accuracy and bias of the physical model used in this study were validated by comparing its output data to 22,401 actual soil temperature readings taken from sandy soils at thirty-nine forested sites throughout northern Michigan; the model was shown to have almost no temperature bias. Although mean annual air temperatures across the region show no strong spatial or temporal trends over the fifty-year period, at many sites, especially in Wisconsin, wintertime air temperatures have been increasing slightly in recent years. Conversely, mean annual soil temperatures have been decreasing at most sites in the region, some by more than 0.5°C. Likewise, wintertime soil temperatures are also decreasing, especially at sites downwind from the Great Lakes—many of which are in snowbelt locations. Increasing wintertime air temperatures over the past fifty years coincide with (and probably have led to) more variable and thinner snowpacks, lessening their insulating impact and contributing to decreasing wintertime soil temperatures that our model show are occurring in the eastern and northern parts of the region. These findings illustrate the complex response of natural systems to slow atmospheric warming, and draw attention to the potential changes that are occurring in growing season characteristics, phenology, and spring runoff characteristics in the Great Lakes region.

Extension′s role in disseminating information about climate change to agricultural stakeholders in the United States

The U.S. Cooperative Extension Service was created 100 years ago to serve as a boundary or interface organization between science generated at the nation′s land grant universities and rural communities. Production agriculture in the US is becoming increasingly complex and challenging in the face of a rapidly changing climate and the need to balance growing crop productivity with environmental protection. Simultaneously, extension budgets are diminishing and extension personnel are stretched thin with numerous, diverse stakeholders and decreasing budgets. Evidence from surveys of farmers suggests that they are more likely to go to private retailers and consultants for information than extension. This paper explores the role that extension can play in facilitating climate change adaptation in agriculture using data from a survey of agricultural advisors in Indiana, Iowa, Michigan and Nebraska and a survey of extension educators in the 12 state North Central Region. Evidence from these surveys shows that a majority of extension educators believe that climate change is happening and that they should help farmers prepare. It also shows that private agricultural advisors trust extension as a source of information about climate change. This suggests that extension needs to continue to foster its relationship with private information providers because working through them will be the best way to ultimately reach farmers with climate change information. However extension educators must be better informed and trained about climate change; university specialists and researchers can play a critical role in this training process.

Effects of winter temperatures on gypsy moth egg masses in the Great Lakes region of the United States

Accurate prediction of winter survival of gypsy moth (Lymantria dispar L.) eggs and phenology of egg hatch in spring are strongly dependent on temperature and are critical aspects of gypsy moth management programs. We monitored internal temperatures of egg masses at three heights aboveground level and at the four cardinal aspects on oak tree stems at two different locations in Michigan during the winter seasons of 1997/1998, 1998/1999 and 1999/2000. Effects of aspect were more strongly associated with observed egg mass temperatures than height above the ground surface. Instantaneous differences between egg mass temperatures on sunny days were as high as 30 ◦ C greater on the southern aspect vs. egg mass temperatures on other aspects, resulting in substantial differences in pre-hatch growing degree accumulations for egg masses on a single tree. Egg masses on southern and western aspects, where solar loading and temperatures were greatest, experienced substantial mortality. Mean survival of eggs averaged across the three seasons was less than 25% on southern and western aspects, compared with averages of 53 and 73% on eastern and northern aspects, respectively. Linear regression of mean monthly egg mass–air temperature differences (between north and south aspects) and mean daily solar flux density resulted in slope coefficient estimates of 0.13 and 0.21 ◦ CM J m −2 , and correlation coefficients of 0.81 and 0.82 at the two field locations, respectively. Using a simple egg mass hatch phenological model, such dissimilarities in temperature and growing degree day accumulation resulted in differences in estimated egg hatch dates of up to 25 days. Snow cover moderated egg mass temperature, with extreme seasonal minimum winter temperatures under snow cover as much as 7.1 ◦ C warmer than those

Climate forecasts for corn producer decision making

AbstractCorn is the most widely grown crop in the Americas, with annual production in the United States of approximately 332 million metric tons. Improved climate forecasts, together with climate-related decision tools for corn producers based on these improved forecasts, could substantially reduce uncertainty and increase profitability for corn producers. The purpose of this paper is to acquaint climate information developers, climate information users, and climate researchers with an overview of weather conditions throughout the year that affect corn production as well as forecast content and timing needed by producers. The authors provide a graphic depicting the climate-informed decision cycle, which they call the climate forecast–decision cycle calendar for corn.

Possible Impacts of Projected Temperature Change on Commercial Fruit Production in the Great Lakes Region

Abstract Commercial fruit production is a primary revenue source for many locations within the Great Lakes region. Projected climate change may have a profound impact on this highly climate sensitive activity, which owes its existence to the moderating influence of the Great Lakes. Downscaled daily maximum and minimum temperature series provided by the U.S. National Assessment were utilized to evaluate 1) possible changes in the frequency and timing of several agronomically-relevant temperature threshold events and 2) potential interactions between crop phenology and a commercially-important insect pest ( Cydia pomonella (L.)). The analyses are for the two future decades of 2025 to 2034 and 2090 to 2099. The assessments for 2025 to 2034 suggest that fruit-growing areas in the Great Lakes region will experience a moderate increase in growing season length and seasonal heat accumulation and a decrease in the frequency of freezing temperatures. In addition, important growth stages will occur earlier in the calendar year than at present. Very large changes in the temperature threshold parameters are projected for 2090 to 2099. However, it is unclear for both assessment decades whether fruit production will be more or less susceptible to damage from cold temperatures after critical growth stages are reached. Projected warming may also result in increases in the number of generations per season of a primary insect pest and the number of necessary pesticide applications.

Assessing the climatic potential for epizootics of the gypsy moth fungal pathogen Entomophaga maimaiga in the North Central United States.

The fungal pathogen Entomophaga maimaiga Humber, Shimazu et Soper has become an important biocontrol for gypsy moth (Lymantria dispar (L.)) in the northeastern United States and is commonly introduced into new areas with established gypsy moth populations. Germination of the fungus is dependent on spring temperature and moisture, but specific conditions associated with epizootics have not been determined. Whether E. maimaiga will be as effective in other regions that experience different weather conditions is not yet known. We examined similarity of weather conditions associated with 16 documented E. maimaiga epizootics with conditions at 1351 North American locations using the climate-matching software CLIMEX. Based on CLIMEX’s overall index of climatic similarity, long-term annual climatic patterns across much of the eastern United States were 60%–80% similar to the conditions associated with epizootics. Monthly weather records from 1971 to 2000 in nine North Central states were examined to compare prec...

Calibration and Validation of the Hybrid-Maize Crop Model for Regional Analysis and Application over the U.S. Corn Belt

AbstractDetailed parameter sensitivity, model validation, and regional calibration of the Hybrid-Maize crop model were undertaken for the purpose of regional agroclimatic assessments. The model was run at both field scale and county scale. The county-scale study was based on 30-yr daily weather data and corn yield data from the National Agricultural Statistics Service survey for 24 locations across the Corn Belt of the United States. The field-scale study was based on AmeriFlux sites at Bondville, Illinois, and Mead, Nebraska. By using the one-at-a-time and interaction-explicit factorial design approaches for sensitivity analysis, the study found that the five most sensitive parameters of the model were potential number of kernels per ear, potential kernel filling rate, initial light use efficiency, upper temperature cutoff for growing degree-days’ accumulation, and the grain growth respiration coefficient. Model validation results show that the Hybrid-Maize model performed satisfactorily for field-scale ...

Spatial and Temporal Study of Climatic Variability on Grape Production in Southwestern Michigan

Daily climatic data were obtained from several sources to calculate growing degree days (GDD) for multiple sites in southwest Michigan, which contains the Lake Michigan Shore American Viticultural Area. The data were examined for spatial and temporal (1950 to 2011) patterns and trends over the region in order to better quantify the role of Michigan climate on juice grape production. The occurrence and severity of frost and freezing temperatures were also considered in this study, as subfreezing temperatures in late spring and early fall can have severe impacts on the region’s juice grape production and fruit quality at harvest. Michigan’s cool-cold climate has warmed in recent decades, particularly since 1980, with an average increase over the region of more than 3.7 GDD (base 10°C) per year. Southwestern Michigan was also found to have higher seasonal temperature variability when compared with Napa Valley (California). Since 1980, the season-to-season variability in Michigan has increased at a more rapid pace. The impacts of the increasing GDD have been positive for fruit quality, with a strong positive correlation between seasonal GDD and fruit maturation, indexed as total soluble solids (Brix). The growing season has also increased by 28 days in length since 1971. However, despite warmer temperatures, the number of days of potential frost and their seasonal variability in southwestern Michigan have remain unchanged, which continues to pose a risk for grapegrowers in the region. While it has become warmer in Michigan, and the spring warm-up is typically arriving earlier in the year, the number of days with damaging frost still has a profound impact on overall climate-related risk for grape production.

Crop models capture the impacts of climate variability on corn yield

We investigate the ability of three different crop models of varying complexity for capturing El Nino–Southern Oscillation-based climate variability impacts on the U.S. Corn Belt (1981–2010). Results indicate that crop models, irrespective of their complexity, are able to capture the impacts of climate variability on yield. Multiple-model ensemble analysis provides best results. There was no significant difference between using on-site and gridded meteorological data sets to drive the models. These results highlight the ability of using simpler crop models and gridded regional data sets for crop-climate assessments.