Fire management, managed relocation, and land conservation options for long-lived obligate seeding plants under global changes in climate, urbanization and fire regime.

Abstract: Most species and ecosystems face multiple anthropogenic disruptions. Few studies have quantified the cumulative influence of multiple threats on species of conservation concern, and far fewer have quantified the potential relative value of multiple conservation interventions for population persistence in light of these threats. We linked spatial distribution and population viability models to explore conservation interventions under projected climate change, urbanization and changes in fire regime on a long-lived obligate seeding plant species sensitive to high fire frequencies; a dominant plant functional type in many fire-prone ecosystems, including the biodiversity hotspots of the Mediterranean-type ecosystems. First, we investigated the relative risk of population decline for plant populations in landscapes with and without land protection under an existing multiple species habitat conservation plan. Second, we modeled the effectiveness of relocating both seedlings and seeds from a large patch with predicted declining suitable habitat to two unoccupied recipient patches with increasing suitable habitat under two projected climate change scenarios. Finally, we modeled eight fire return intervals approximating the outcomes of different management strategies that effectively control fire frequency. Our results show that, invariably, fire return intervals must be maintained at or above a minimum level for long-lived obligate seeding populations to remain viable. Land conservation and seedling relocation efforts may lessen the impact of climate change and land-use change on obligate seeding populations to differing degrees depending on the climate change scenario, but neither of these are as generally effective as frequent translocation of seeds. While none of the modeled strategies fully compensated for the effects of land-use and climate change, an integrative conservation approach managing multiple threats can diminish population declines for species in complex landscapes. Conservation plans designed to mitigate the impacts of a single threat are likely to fail if additional threats are ignored.