Our nation's natural and managed ecosystems are essential to public livelihood and its sustainable future. Extreme climate and weather events impose a substantial risk to ecosystem productivity, as such events are the most damaging and costly. Further increases in the frequency, strength, and/or duration of extreme events under altered environmental conditions may also result in irrecoverable damages to ecosystems. Therefore, it is of critical importance to comprehensively observe, understand, document, and predict ecosystems' response and resiliency to extreme environmental conditions and the extent to which irreversible thresholds may be crossed as a result of changes in the Earth's natural and human systems. Improved performance in predictive models is achieved only through observational evidence of ecosystem behavior under the full range of environmental conditions. The current suite of ecologic, meteorological, and hydrologic observations combined with the nation's next-generation National Ecologic Observation Network (NEON) allow an exciting opportunity to enable new analyses that comprehensively span the diverse types of ecosystems across our nation. This study undertakes coordinated calibration, evaluation, enhancement, and experimentation with a hierarchy of predictive tools that includes: models representing the field-scale mechanisms of ecosystems; a high-resolution regional ecosystem-climate model; as well as a global integrated assessment model of the linked earth-human systems. Through these, region-specific thresholds in the productivity, response, and resiliency of ecosystems governed by human-altered shifts in weather and climate extremes as well as land use, which pose severe implications for ecosystem services, will be identified.
The testing and evaluation of ecosystem models against the NEON observations will identify the critical model capabilities required to faithfully predict ecosystem response to extreme conditions. Under the auspice of potential climate and environmental change through the end of this century, projections with regional and global human-earth systems models will also allow for a risk-based assessment of ecologic change and resiliency. This is possible through the ability to run these models across the range of plausible human emissions and the climate/ecologic response. The atmospheric outputs of these regional ecosystem-climate projections could then also be used as boundary conditions for other detailed studies of regional climate impacts - such as air quality and water resources (quantity and quality). Overall, the scientific assessments and predictions from this study will enable local stakeholders as well as national and international policymakers to make more informed decisions regarding mitigation and adaptation strategies - particularly those that are relevant to the protection of natural and managed ecosystems threatened by extreme environments.
