U.S. Geological Survey, Southwest Biological Science Center
Background/Question/Methods Restoring native plant species to federal lands in the western US is challenged by a multitude of biotic, abiotic, economic, social, and legal dimensions. Here, successful restoration in some dryland systems appears particularly thwarted by site-specific factors including the type and level of degradation. Regional challenges include prolonged droughts, heat waves, community shifts, and species invasions, among others. Larger and less clearly defined challenges may exist in the economic and social dimensions of restoration efforts. We present case studies of failed restoration experiments that demonstrate site-level challenges and their interactions with regional climate changes. We use multi-year, multi-site, multi-species seeding trials to demonstrate that restoration may seem nearly improbable at times. In documenting the outcomes of these experiments, we link our results and issues to challenges in meeting management and recovery goals while simultaneously synthesizing suggestions that aim to strengthen connections between restoration science and policy.
Results/Conclusions Our first seeding trial tested 8 sources of Sphaeralcea parvifolia seed collected from across the Colorado Plateau. Of the 15,360 seeds sown, 36 germinated at our site near Flagstaff, Arizona and 0 germinated at our site near Moab, Utah. Of the 36 that germinated, all seed sources were represented by at least one individual and there was no detectable effect of the amount or frequency of precipitation. Our second seeding trial tested 8 sources of Machaeranthera canescens seed. Of the 23,040 seeds seed sown, 381 germinated at our site near Flagstaff and 134 germinated at our site near Moab. Again, all seed sources were represented by at least one individual and there was no detectable effect of the amount or frequency of precipitation. We discuss these outcomes in the context of site-specific conditions, uncontrollable climate conditions, and seed collection methods. Experiments such as ours can and have been modified in response to previous outcomes. Solutions to social challenges may exist as well, including knowledge sharing and transdisciplinary collaboration. We move forward following the incredible rate of innovation in ecological restoration and by pursuing goals set by global restoration targets and initiatives.