Land use is both a major cause of the biodiversity crises and a potential solution to it. Decisions about land use are made in complex social–ecological systems, yet conservation research, policy, and practice often neglect the diverse and dynamic nature of land use. A deeper integration of land system science and conservation science provides major opportunities in this context, through a transfer of concepts, data, and methodologies. Specifically, a closer exchange between land-use data developers and users will enable common terminology and better data use, allowing to move beyond coarse land-cover representations of land use. Similarly, archetyping and regionalization approaches can help to embrace, rather than oversimplify, the diversity of land-use actors and practices. Finally, systematically linking land-use actors to portfolios of pressures on biodiversity, beyond their direct impact on habitat, can better represent and map co-occurring and interacting threats. Together, this will enable conservation policymakers and planners to recognize the often-complex and wicked nature of conservation challenges related to land, allowing for more context-specific conservation policymaking and planning, and more targeted conservation interventions.
Invasive species are a major cause of biodiversity loss and are notoriously expensive and challenging to manage. We developed a decision-analytic framework for evaluating invasive species removal strategies, given objectives of maximizing eradication probability and minimizing costs. The framework uses an existing estimation model for spatially referenced removal data—one of the most accessible types of invasive species data—to obtain estimates of population growth rate, movement probability, and detection probability. We use these estimates in simulations to identify Pareto-efficient strategies—strategies where increases in eradication probability cannot be obtained without increases in cost—from a set of proposed strategies. We applied the framework post hoc to a successful eradication of veiled chameleons (Chamaeleo calyptratus) and identified the potential for substantial improvements in efficiency. Our approach provides managers and policymakers with tools to identify cost-effective strategies for a range of invasive species using only prior knowledge or data from initial physical removals.
The preservation of genetic variation is fundamental in biodiversity conservation, yet its importance for population viability remains contentious. Mixed-source reintroductions, where individuals are translocated into a single vacant habitat from multiple genetically divergent and often depauperate populations, provide an opportunity to evaluate how genetic variation and hybridization influence individual and relative population fitness. Population genetic theory predicts that individuals with higher genetic variation and hybrids among populations should have higher fitness. We tested these two hypotheses by analyzing individual and population-scale data for westslope cutthroat trout (Oncorhynchus clarkii lewisi) in four mixed-source reintroductions. We observed more hybrid and fewer nonhybrid offspring than expected across four independent mixed-source reintroductions. We also found clear evidence that heterozygosity influenced individual reproductive and relative population fitness. Overall, we found a strong, positive relationship between genetic variation, hybridization, and transplant fitness, emphasizing the importance of genetic variation and population mixing in conservation.