Reallocating budgets among ongoing and emerging conservation projects.

Conserving biodiversity and combating ecological hazards require cost-effective allocation of limited resources among potential management projects. Project priorities, however, can change over time as underlying social-ecological systems progress, novel priorities emerge, and management capabilities evolve. Thus, reallocation of ongoing investments in response to shifting priorities could improve management outcomes and address urgent demands, especially when additional funding is not available immediately. Resource reallocation, however, could incur transaction costs, require additional monitoring and reassessment, and be constrained by ongoing project commitments. Such complexities may prevent managers from considering potentially beneficial reallocation strategies, reducing long-term effectiveness. We propose an iterative project prioritization approach, based on marginal return-on-investment estimation and portfolio optimization, that guides resource reallocation among ongoing and new projects. Using simulation experiments in 2 case studies, we explored how this approach can improve efficacy under varying reallocation constraints, frequencies, costs, and rates of project portfolio change. Periodic budget reallocation could enhance the management of stochastically emerging invasive weeds in Australia and thus reduce the overall risk by up to 50% compared with a static budget. Reallocation frequency and the rate of new weed incursion synergistically increased the conservation gains achieved by allowing unconstrained reallocation. Conversely, budget reallocation would not improve the International Union for Conservation of Nature conservation status of threatened Australian birds due to slow rates of transition among conservation states; extinction risk could increase if portfolio reassessment is costly. Although other project prioritization studies may recommend periodic reassessment and reallocation, our findings revealed conditions when reallocation is valuable and demonstrated a structured approach that can help conservation agencies schedule and implement iterative budget-allocation decisions cost-effectively.

Reasignación de Presupuestos entre los Proyectos de Conservación Emergentes y En Curso Resumen La conservación de la biodiversidad y el combate a los riesgos ecológicos requieren de una asignación rentable de los recursos limitados entre los proyectos potenciales de manejo. Sin embargo, las prioridades de los proyectos pueden cambiar con el tiempo conforme avanzan los sistemas socio-ecológicos subyacentes, emergen prioridades nuevas y evolucionan las capacidades de manejo. Por lo tanto, la reasignación de las inversiones en curso como respuesta a las prioridades cambiantes podría mejorar los resultados de manejo y resolver demandas urgentes, especialmente cuando el financiamiento adicional no está disponible de manera inmediata. Sin embargo, la reasignación de recursos podría incurrir en costos de transacción, requerir de monitoreo y reevaluación adicionales y estar restringida por los compromisos hechos por los proyectos en curso. Dichas complejidades pueden evitar que los administradores consideren estrategias de reasignación potencialmente benéficas, reduciendo así la efectividad a largo plazo. Proponemos un enfoque iterativo de priorización de proyectos basado en una estimación marginal de rentabilidad y en la optimización del portafolio, el cual guíe la reasignación de recursos entre los proyectos nuevos y en curso. Mediante experimentos de simulación en dos estudios de caso, exploramos cómo este enfoque puede mejorar la eficacia bajo cambiantes restricciones de reasignación, frecuencias, costos y tasas de cambio en el portafolio del proyecto. La reasignación periódica de presupuestos podría mejorar el manejo de las hierbas invasoras con surgimiento estocástico en Australia y así reducir el riesgo general hasta en un 50% en comparación con un presupuesto estático. La frecuencia de reasignación y la tasa de incursión de hierbas nuevas incrementaron de manera sinérgica las ganancias de conservación obtenidas al permitir una reasignación sin restricciones. En cambio, la reasignación de presupuestos no mejoraría el estado de conservación según la Unión Internacional para la Conservación de la Naturaleza de las aves australianas amenazadas debido a las tasas lentas de transición entre los estados de conservación; el riesgo de extinción podría incrementar si la reevaluación del portafolio es costosa. Aunque otros estudios de priorización de proyectos pueden recomendar una reevaluación y una reasignación periódicas, nuestros resultados revelaron condiciones cuando la reasignación es valiosa y demostraron una estrategia estructurada que puede ayudar a las agencias de conservación a programar e implementar decisiones iterativas de asignación de presupuestos de manera rentable.

Reduced body sizes in climate-impacted Borneo moth assemblages are primarily explained by range shifts.

Both community composition changes due to species redistribution and within-species size shifts may alter body-size structures under climate warming. Here we assess the relative contribution of these processes in community-level body-size changes in tropical moth assemblages that moved uphill during a period of warming. Based on resurvey data for seven assemblages of geometrid moths (>8000 individuals) on Mt. Kinabalu, Borneo, in 1965 and 2007, we show significant wing-length reduction (mean shrinkage of 1.3% per species). Range shifts explain most size restructuring, due to uphill shifts of relatively small species, especially at high elevations. Overall, mean forewing length shrank by ca. 5%, much of which is accounted for by species range boundary shifts (3.9%), followed by within-boundary distribution changes (0.5%), and within-species size shrinkage (0.6%). We conclude that the effects of range shifting predominate, but considering species physiological responses is also important for understanding community size reorganization under climate warming.

Warming neutralizes host-specific competitive advantages between a native and invasive herbivore.

Although native-invasive species interactions have become a common mechanism shaping ecosystems, whether these interactions shift under warming remains unclear. To investigate how warming may affect native and invasive species separately and together (intraspecific and interspecific competition, respectively) and whether any warming impact is resource dependent, we examined the performance of two competing herbivores (native Pieris canidia and invasive P. rapae) on two common host plants under three temperature settings (control, 3 °C, and 6 °C warming using environmental chambers). The results revealed that warming benefited the development and growth of both Pieris under intraspecific competition, but the benefits were host-plant dependent. Notably, the native or invasive Pieris gained an advantage from interspecific competition (host-plant dependent), but warming neutralized the competitive advantages of either Pieris species. These findings raise the possibility that warming-induced shifts in competitive status may become a crucial mechanism shaping ecosystems worldwide, because most ecosystems are challenged by species invasion and warming. Moreover, this study revealed a discrepancy in species thermal performance between intra- and interspecific competition. Therefore, to predict native-invasive species competition under warming, current thermal performance applications should use species performance curves derived from interspecific rather than intraspecific competition studies (although the latter is more readily available).