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apidly changing wildfire regimes across the Western United States have driven more frequent and severe wildfires, resulting in wide-ranging societal threats from wildfires and wildfire-generated smoke. However, common measures of fire severity focus on what is burned, disregarding the societal impacts of smoke generated from each fire. We combine satellite-derived fire scars, air parcel trajectories from individual fires, and predicted smoke PM2.5 to link source fires to resulting smoke PM2.5 and health impacts experienced by populations in the contiguous United States from April 2006 to 2020. We quantify fire-specific accumulated smoke exposure based on the cumulative population exposed to smoke PM2.5 over the duration of a fire and estimate excess asthma-related emergency department (ED) visits as a result of this exposure. We find that excess asthma visits attributable to each fire are only moderately correlated with common measures of wildfire severity, including burned area, structures destroyed, and suppression cost. Additionally, while recent California fires contributed nearly half of the country’s smoke-related excess asthma ED visits during our study period, the most severe individual fire was the 2007 Bugaboo fire in the Southeast. We estimate that a majority of smoke PM2.5 comes from sources outside the local jurisdictions where the smoke is experienced, with 87% coming from fires in other counties and 60% from fires in other states. Our approach could enable broad-scale assessment of whether specific fire characteristics affect smoke toxicity or impact, inform cost-effectiveness assessments for allocation of suppression resources, and help clarify the growing transboundary nature of local air quality. [ABSTRACT FROM AUTHOR]

To purchase or authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1523-1739.2007.00751.x Byline: G. ARTURO SANCHEZ-AZOFEIFA (*), ALEXANDER PFAFF ([dagger]), JUAN ANDRES ROBALINO ([dagger]), JUDSON P. BOOMHOWER ([double dagger]) Keywords: Costa Rica; deforestation trends; ecosystems services; payment for environmental services; PSA Abstract: Abstract: We evaluated the intention, implementation, and impact of Costa Rica's program of payments for environmental services (PSA), which was established in the late 1990s. Payments are given to private landowners who own land in forest areas in recognition of the ecosystem services their land provides. To characterize the distribution of PSA in Costa Rica, we combined remote sensing with geographic information system databases and then used econometrics to explore the impacts of payments on deforestation. Payments were distributed broadly across ecological and socioeconomic gradients, but the 1997-2000 deforestation rate was not significantly lower in areas that received payments. Other successful Costa Rican conservation policies, including those prior to the PSA program, may explain the current reduction in deforestation rates. The PSA program is a major advance in the global institutionalization of ecosystem investments because few, if any, other countries have such a conservation history and because much can be learned from Costa Rica's experiences. Abstract (Spanish): El Programa de Pago de Servicios Ambientales de Costa Rica: Intencion, Implementacion e Impacto Resumen: Evaluamos la intencion, implementacion e impacto del programa de pago de servicios ambientales (PSA) de Costa Rica, que fue establecido al final de la decada de 1990. Los pagos son otorgados a propietarios privados en areas boscosas como reconocimiento a los servicios ecosistemicos que proporcionan sus tierras. Para caracterizar la distribucion de PSA en Costa Rica, combinamos bases de datos de percepcion remota y de sistemas de informacion geografica y posteriormente utilizamos econometria para explorar los impactos de los pagos sobre la deforestacion. Los pagos fueron ampliamente distribuidos a lo largo de gradientes ecologicos y socioeconomicos, pero la tasa de deforestacion 1997-2000 no fue significativamente menor en las areas que recibieron pagos. Otras politicas costarricenses de conservacion exitosas, incluyendo algunas previas al programa PSA, pueden explicar la reduccion actual de tasas de deforestacion. El programa PSA es un avance importante en la institucionalizacion global de las inversiones en ecosistemas porque pocos, si alguno, paises tienen tal historia de conservacion y porque se puede aprender mucho de las experiencias de Costa Rica. Author Affiliation: (*)Earth Observation Systems Laboratory, Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta T6G 2E3, Canada, emailarturo.sanchez@ualberta.ca ([dagger])The Earth Institute, 2910 Broadway, Hogan Hall 104, Columbia University, New York, NY 10025, U.S.A. ([double dagger])Center for Conservation Biology, Department of Biological Sciences, 371 Serra Mall, Stanford University, Stanford, CA 94305-5020, U.S.A. Article History: Paper submitted March 21, 2006; revised manuscript accepted March 21, 2007.

Summary: The physiological strategies that enable organisms to thrive in habitats where environmental factors vary dramatically on a daily basis are poorly understood. One of the most variable and unpredictable habitats on earth is the marine rocky intertidal zone located at the boundary between the terrestrial and marine environments. Mussels dominate rocky intertidal habitats throughout the world and, being sessile, endure wide variations in temperature, salinity, oxygen, and food availability due to diurnal, tidal, and climatic cycles. Analysis of gene-expression changes in the California ribbed mussel (Mytilus californianus) at different phases in the tidal cycle reveals that intertidal mussels exist in at least four distinct physiological states, corresponding to a metabolism and respiration phase, a cell-division phase, and two stress-response signatures linked to moderate and severe heat-stress events. The metabolism and cell-division phases appear to be functionally linked and are anticorrelated in time. The magnitudes and timings of these states varied by vertical position on the shore and appear to be driven by microhabitat conditions. The results provide new insights into the strategies that allow life to flourish in fluctuating environments and demonstrate the importance of time course data collected from field animals in situ in understanding organism-environment interactions. [Copyright &y& Elsevier]