Reconciling Social and Biological Needs in an Endangered Ecosystem: the Palouse as a Model for Bioregional Planning

The Palouse region of southeastern Washington State and an adjacent portion of northern Idaho is a working landscape dominated by agricultural production, with less than 1% of the original bunchgrass prairie remaining. Government agencies and conservation groups have begun efforts to conserve Palouse prairie remnants, but they lack critical information about attitudes and perceptions among local landowners toward biological conservation. Knowledge about the location and condition of native biological communities also remains sparse. Using a bioregional approach, we integrated data collected through biological surveys and social interviews to investigate relationships between biologically and socially meaningful aspects of the landscape. We combined GIS layers of participant-identified meaningful places with maps of native biological communities to identify the overlap between these data sets. We used these maps and interview narratives to interpret how stakeholder perceptions of the landscape corresponded with patterns of native biodiversity. We found several prominent landscape features on the Palouse that supported diverse biological communities and were important to stakeholders for multiple reasons. These places may be expedient focal points for conservation efforts. However, the many small prairie remnants on the Palouse, although ecologically important, were mostly unidentified by participants in this study and thus warrant a different conservation approach. These findings will assist government agencies and conservation groups in crafting conservation strategies that consider stakeholder perceptions and their connection with the Palouse landscape. This study also demonstrates how GIS tools can link biological and social data sets to aid conservation efforts on private land

Endogeic earthworm densities increase in response to higher fine-root production in a forest exposed to elevated CO2

Net primary productivity (NPP) influences soil food webs and ultimately the amount of carbon (C) inputs in ecosystems. Earthworms can physically protect organic matter from rapid mineralization through the formation of soil aggregates. Previous studies at the Oak Ridge National Laboratory (ORNL) Free Air CO2 Enrichment (FACE) experiment showed that elevated [CO2] (e[CO2]) increased fine-root production and increased soil C through soil aggregation compared to ambient [CO2] (a[CO2]) conditions. Our first objective was to study the response of earthworms to increased leaf and root-litter inputs caused by increased atmospheric [CO2] exposure. We also took advantage of the CO2 shutdown at the ORNL FACE site to track the shift of the δ13C signal in leaf-litter, fine roots, earthworms, earthworm casts, and bulk soil. Densities of the most abundant endogeic earthworm, Diplocardia spp., were positively correlated with the previous-year production of leaf litter (r = 0.66, P = 0.02) and fine roots (r = 0.62, P = 0.03); and with the leaf-litter production (r = 0.63, P = 0.03) and fine-root production (r = 0.59, P = 0.05) two years before earthworms were sampled. Within two years after the CO2 fumigation ceased, the 13C/12C ratio increased in leaf litter (P = 0.01) and in fine roots (P = 0.05), showing an ecosystem legacy effect on soil C inputs. However, the C isotopic composition of soil, endogeic earthworms and casts had not changed the two years after the CO2 fumigation ended. The positive response of earthworms to increased root NPP, caused by elevated [CO2], is consistent with the increased soil aggregate formation and increased soil C at the ORNL FACE in the e[CO2] treatment