Knowledge coproduction on the impact of decisions for waterbird habitat in a changing climate.

Scientists, resource managers, and decision makers increasingly use knowledge coproduction to guide the stewardship of future landscapes under climate change. This process was applied in the California Central Valley (USA) to solve complex conservation problems, where managed wetlands and croplands are flooded between fall and spring to support some of the largest concentrations of shorebirds and waterfowl in the world. We coproduced scenario narratives, spatially explicit flooded waterbird habitat models, data products, and new knowledge about climate adaptation potential. We documented our coproduction process, and using the coproduced models, we determined when and where management actions make a difference and when climate overrides these actions. The outcomes of this process provide lessons learned on how to cocreate usable information and how to increase climate adaptive capacity in a highly managed landscape. Actions to restore wetlands and prioritize their water supply created habitat outcomes resilient to climate change impacts particularly in March, when habitat was most limited; land protection combined with management can increase the ecosystem's resilience to climate change; and uptake and use of this information was influenced by the roles of different stakeholders, rapidly changing water policies, discrepancies in decision-making time frames, and immediate crises of extreme drought. Although a broad stakeholder group contributed knowledge to scenario narratives and model development, to coproduce usable information, data products were tailored to a small set of decision contexts, leading to fewer stakeholder participants over time. A boundary organization convened stakeholders across a large landscape, and early adopters helped build legitimacy. Yet, broadscale use of climate adaptation knowledge depends on state and local policies, engagement with decision makers that have legislative and budgetary authority, and the capacity to fit data products to specific decision needs.

Coproducción de información sobre el impacto de las decisiones para el hábitat de las aves acuáticas en un clima cambiante Resumen Hay un incremento del uso que dan los científicos, gestores de recursos y los órganos decisorios a la coproducción de información para guiar la administración de los futuros paisajes bajo el cambio climático. Se aplicó este proceso para resolver problemas complejos de conservación en el Valle Central de California (EE. UU.), en donde los humedales y campos de cultivos manejados se inundan entre el otoño y la primavera para mantener una de las mayores concentraciones de aves playeras y acuáticas del mundo. Coproducimos narrativas de escenarios, modelos espacialmente explícitos de hábitats inundados de las aves acuáticas, productos de datos y conocimiento nuevo sobre el potencial de adaptación climática. Documentamos nuestro proceso de coproducción y usamos los modelos resultantes para determinar cuándo y en dónde marcan una diferencia las acciones de manejo y cuándo el clima anula estas acciones. Los resultados de este proceso proporcionan aprendizaje sobre cómo cocrear información útil y cómo incrementar la capacidad adaptativa al clima en un paisaje con mucha gestión. Las acciones de restauración de los humedales y la priorización del suministro de agua originaron un hábitat resiliente al impacto del cambio climático, particularmente en marzo, cuando el hábitat estaba más limitado; la protección del suelo combinado con el manejo puede incrementar la resiliencia del ecosistema al cambio climático; y la captación y uso de esta información estuvo influenciada por el papel de los diferentes actores, el cambio rápido de las políticas del agua, discrepancias en los marcos temporales de la toma de decisiones y las crisis inmediatas de la sequía extrema. Mientras que un grupo amplio de accionistas contribuyó conocimiento para las narrativas de escenarios y el desarrollo del modelo, para coproducir información útil, los productos de datos fueron adaptados para un conjunto pequeño de contextos decisivos, lo que con el tiempo llevó a una reducción en la participación de los actores. Una organización fronteriza convocó a los actores de todo un paisaje y los primeros adoptantes ayudaron a construir la legitimidad. A pesar de esto, el uso a gran escala de la información sobre la adaptación climática depende de las políticas locales y estatales, la participación de los órganos decisorios que tienen autoridad legislativa y presupuestaria y de la capacidad para ajustar los productos de datos a las necesidades específicas de las decisiones.

Effects of 21st-century climate, land use, and disturbances on ecosystem carbon balance in California.

Terrestrial ecosystems are an important sink for atmospheric carbon dioxide (CO2 ), sequestering ~30% of annual anthropogenic emissions and slowing the rise of atmospheric CO2 . However, the future direction and magnitude of the land sink is highly uncertain. We examined how historical and projected changes in climate, land use, and ecosystem disturbances affect the carbon balance of terrestrial ecosystems in California over the period 2001-2100. We modeled 32 unique scenarios, spanning 4 land use and 2 radiative forcing scenarios as simulated by four global climate models. Between 2001 and 2015, carbon storage in California's terrestrial ecosystems declined by -188.4 Tg C, with a mean annual flux ranging from a source of -89.8 Tg C/year to a sink of 60.1 Tg C/year. The large variability in the magnitude of the state's carbon source/sink was primarily attributable to interannual variability in weather and climate, which affected the rate of carbon uptake in vegetation and the rate of ecosystem respiration. Under nearly all future scenarios, carbon storage in terrestrial ecosystems was projected to decline, with an average loss of -9.4% (-432.3 Tg C) by the year 2100 from current stocks. However, uncertainty in the magnitude of carbon loss was high, with individual scenario projections ranging from -916.2 to 121.2 Tg C and was largely driven by differences in future climate conditions projected by climate models. Moving from a high to a low radiative forcing scenario reduced net ecosystem carbon loss by 21% and when combined with reductions in land-use change (i.e., moving from a high to a low land-use scenario), net carbon losses were reduced by 55% on average. However, reconciling large uncertainties associated with the effect of increasing atmospheric CO2 is needed to better constrain models used to establish baseline conditions from which ecosystem-based climate mitigation strategies can be evaluated.

Estimation of late twentieth century land-cover change in California.

We present the first comprehensive multi-temporal analysis of land-cover change for California across its major ecological regions and primary land-cover types. Recently completed satellite-based estimates of land-cover and land-use change information for large portions of the United States allow for consistent measurement and comparison across heterogeneous landscapes. Landsat data were employed within a pure-panel stratified one-stage cluster sample to estimate and characterize land-cover change for 1973-2000. Results indicate anthropogenic and natural disturbances, such as forest cutting and fire, were the dominant changes, followed by large fluctuations between agriculture and rangelands. Contrary to common perception, agriculture remained relatively stable over the 27-year period with an estimated loss of 1.0% of agricultural land. The largest net declines occurred in the grasslands/shrubs class at 5,131 km2 and forest class at 4,722 km2. Developed lands increased by 37.6%, composing an estimated 4.2% of the state's land cover by 2000.

Mediterranean California's water use future under multiple scenarios of developed and agricultural land use change.

With growing demand and highly variable inter-annual water supplies, California's water use future is fraught with uncertainty. Climate change projections, anticipated population growth, and continued agricultural intensification, will likely stress existing water supplies in coming decades. Using a state-and-transition simulation modeling approach, we examine a broad suite of spatially explicit future land use scenarios and their associated county-level water use demand out to 2062. We examined a range of potential water demand futures sampled from a 20-year record of historical (1992-2012) data to develop a suite of potential future land change scenarios, including low/high change scenarios for urbanization and agriculture as well as "lowest of the low" and "highest of the high" anthropogenic use. Future water demand decreased 8.3 billion cubic meters (Bm3) in the lowest of the low scenario and decreased 0.8 Bm3 in the low agriculture scenario. The greatest increased water demand was projected for the highest of the high land use scenario (+9.4 Bm3), high agricultural expansion (+4.6 Bm3), and high urbanization (+2.1 Bm3) scenarios. Overall, these scenarios show agricultural land use decisions will likely drive future demand more than increasing municipal and industrial uses, yet improved efficiencies across all sectors could lead to potential water use savings. Results provide water managers with information on diverging land use and water use futures, based on historical, observed land change trends and water use histories.

Estimating carbon sequestration in the piedmont ecoregion of the United States from 1971 to 2010.

BACKGROUND: Human activities have diverse and profound impacts on ecosystem carbon cycles. The Piedmont ecoregion in the eastern United States has undergone significant land use and land cover change in the past few decades. The purpose of this study was to use newly available land use and land cover change data to quantify carbon changes within the ecoregion. Land use and land cover change data (60-m spatial resolution) derived from sequential remotely sensed Landsat imagery were used to generate 960-m resolution land cover change maps for the Piedmont ecoregion. These maps were used in the Integrated Biosphere Simulator (IBIS) to simulate ecosystem carbon stock and flux changes from 1971 to 2010. RESULTS: Results show that land use change, especially urbanization and forest harvest had significant impacts on carbon sources and sinks. From 1971 to 2010, forest ecosystems sequestered 0.25 Mg C ha-1 yr-1, while agricultural ecosystems sequestered 0.03 Mg C ha-1 yr-1. The total ecosystem C stock increased from 2271 Tg C in 1971 to 2402 Tg C in 2010, with an annual average increase of 3.3 Tg C yr-1. CONCLUSIONS: Terrestrial lands in the Piedmont ecoregion were estimated to be weak net carbon sink during the study period. The major factors contributing to the carbon sink were forest growth and afforestation; the major factors contributing to terrestrial emissions were human induced land cover change, especially urbanization and forest harvest. An additional amount of carbon continues to be stored in harvested wood products. If this pool were included the carbon sink would be stronger.