CNPS 2009 Conservation Conference: Strategies and Solutions Abstracts for Oral and Poster Presentations Note: Abstracts listed alphabetically by first or presenting author. ACREE, LISA, National Park Service. Yosemite National Park, P.O. Box 700, El Portal, CA, 95318; [email protected] APPLYING THE ENVIRONMENTAL PROTECTION AGENCY (EPA) ECOSYSTEM FRAMEWORK TO EVALUATE THE COLLECTIVE PERFORMANCE OF MEADOW STUDIES IN YOSEMITE Yosemite National Park is home to over 8,000 montane and subalpine meadows, many of high interest to park visitors, resource managers, and scientists. This appreciation and interest has generated a number of broad to small-scale meadow studies on a variety of topics that range from changes in vegetation on a landscape-scale to (fortunately unsuccessful) hunts for Argentine ants. While all of these studies contribute to an understanding of the biotic integrity of Yosemite meadows, this poster evaluates their collective performance, using a systematic tool developed by the EPA known as A Framework For Assessing and Reporting on Ecological Condition: An SAB Report (EPA Framework). The EPA Framework describes six Essential Ecological Attributes: landscape condition; biotic condition; chemical and physical characteristics; ecological processes; hydrology and geomorphology; and natural disturbance regimes. This poster presents the current meadow studies in Yosemite meadows as organized under the EPA Framework, which is used as a guide to aggregate information. The EPA Framework proved to be a valuable tool to illuminate information gaps at a variety of scales, and facilitate the sharing of data, models, and insights. The Framework (and its subcategories such as indicators and measures) also lends itself for creative applications such as determining a defensible range of biotic indicators for user capacity determinations. The EPA Framework is also a useful tool for outreach and reporting efforts, as it aids in organizing this complex set of studies for reporting to a variety of audiences, depending on the level of interest and expertise of the audience. Session 13: Contributed Posters, Sun., Jan. 18, 11:40 to 1:40 p.m. and 6:00 to 7:00 p.m. CNPS 2009 Conservation Conference: Strategies and Solutions Page 1 of 197 ADAMS, SHERRY and Daniel Gluesenkamp, The Bouverie Preserve of Audubon Canyon Ranch, PO Box 1195, Glen Ellen, CA 95442; [email protected] DISTURBANCE AND VERNAL POOL GRASSLANDS Many California habitats experience disturbance regimes which differ from historic conditions. In particular, inland grasslands which once experienced regular burning and grazing now often have both processes excluded and suffer impacts from adjacent roadsides. Given the high conservation priority of these communities, it is important to understand how altered disturbance regimes affect community structure and abiotic factors. We must overcome political hurdles to restoring historic processes such as fire and grazing, as well as address the complexity of management issues, in a milieu of invasive species and human pressures such as roads. We present results of recent work at Bouverie Preserve in Sonoma Valley, site of a vernal pool grassland with a history of grazing which now abuts a busy highway. Our goals for the site include sustaining a diverse assemblage of native forbs and grasses, restoring degraded vernal pools, and reintroducing rare plants such as Blennosperma bakeri and Downingia pusilla. However, we also focus our management on the broader goals of restoring processes and structure. Our data show that the nearby roadside may impact plants via elevated nitrogen deposition; that maintaining a grazing program in an area with fragmented grasslands is a challenge; and that fire can be used to meet some management goals, such as reducing presence of annual grasses and exposing bare ground, but not others, such as reducing presence of non- native perennials. Session 13: Contributed Posters, Sun., Jan. 18, 11:40 to 1:40 p.m. and 6:00 to 7:00 p.m. AICHER, REBECCA and Katharine N. Suding; Department of Ecology and Evolutionary Biology, University of CA-Irvine, 5205 McGaugh Hall, Irvine, CA 92697; [email protected] COMMUNITY ASSEMBLY IN CA GRASSLANDS DIFFERS WITH SOIL NITROGEN Only one percent of native California grasslands remain intact. Human development pressures, global change and the spread of invasive species continue to threaten grassland diversity. We examined how biotic processes interact with soil nitrogen (N) conditions to determine the assembly trajectory in southern California grassland communities. We hypothesized: 1) negative frequency dependence (when a species performance decreases as it becomes more common) causes community-level convergence and 2) soil N availability affects the intensity of frequency dependence leading to differing assembly trajectories. We tested our hypotheses in 135 1m2 experimental annual grassland communities by varying the initial relative abundance of species CNPS 2009 Conservation Conference: Strategies and Solutions Page 2 of 197 through seed addition in 3 soil N levels. We measured species abundances through time. We found species growth rates were more likely to be negatively associated with initial seed frequency (negative frequency dependent) in high N environments. In high N, communities became more similar in composition than communities in ambient and low N environments. Based on our results, negative frequency dependence is important in determining the degree of convergence in community composition in N-enriched environments. Determining the frequency dependence in plant species and understanding soil N levels may aid in restoring native communities. For instance, native species that exhibit positive frequency dependence may be important for conservation strategies. Session 13: Contributed Posters, Sun., Jan. 18, 11:40 to 1:40 p.m. and 6:00 to 7:00 p.m. ALFORD, JIM and Jamie M. Kneitel, Department of Biological Sciences, CA State University, Sacramento, 6000 J Street, Sacramento, CA 95819-6077; [email protected] DIRECT AND INDIRECT EFFECTS OF A SPECIALIST HERBIVORE ON CORN LILY (VERATRUM CALIFORNICUM) IN A SUBALPINE MEADOW COMMUNITY Sub-alpine meadows are important ecosystems of the Sierra Nevada because of their high productivity, diversity, and endemism. Many studies indicate that soil moisture influences plant community dynamics and composition, but few studies have investigated the importance of “top down” factors, such as herbivore effects. Corn lily (Veratrum californicum) dominates many meadows and previous research indicated that it may compete strongly with other meadow plant species. However, Corn lilies are also suppressed by a specialist herbivore, larvae of the sawfly Rhadinoceraea aldrichi, which may then indirectly affect meadow biodiversity in a positive way. We conducted a fully factorial experiment which manipulated both soil moisture and herbivore presence in meadows located in the Van Vleck Meadow Restoration Site in the Eldorado National Forest. Reduction of Corn lilies increased light availability and water addition increased soil moisture. In turn, species responded variably to these treatments, but most species responded positively. Overall, meadow biodiversity increased with soil moisture and Corn lily reduction. Further, these treatments interacted to affect species diversity and cover. These results suggest that in addition to soil moisture, “top down” effects can also control meadow biodiversity. There has been considerable effort to restore meadow habitat; conservation strategies should also take into consideration these important factors to maintain the biodiversity of these important factors. Session 9: Assessing and Mitigating Impacts - Sensitive Plants and Communities, Sun. Jan. 18, 10 a.m. to 5:50 p.m. CNPS 2009 Conservation Conference: Strategies and Solutions Page 3 of 197 ALLEN, EDITH B., Leela E. Rao, Robert J. Steers, Mark E. Fenn, and Andrzej Bytnerowicz; Department of Botany and Plant Sciences (EA, RS), Department of Environmental Sciences (LR), and Center for Conservation Biology (EA), University of CA, Riverside, CA 92521-0124; [email protected], US Forest Service Fire Lab, 4955 Canyon Crest Dr., Riverside, CA 92507 (MF, AB) IMPACTS OF ANTHROPOGENIC NITROGEN DEPOSITION ON INVASIVE AND NATIVE SPECIES AT JOSHUA TREE NATIONAL PARK Joshua Tree National Park is downwind of anthropogenic nitrogen emissions from coastal and inland urban sources, especially automobiles, with higher rates of N deposition in the western than the eastern portions of the Park. Extractable soil N was also generally higher in sites that had higher atmospheric reactive N. Invasive grasses and forbs, such as Schismus barbatus, Bromus madritensis, and Erodium cicutarium have become more productive and widespread in the last few decades. To test the hypothesis that elevated N may be related to invasive species abundance, N fertilizer experiments were done at four sites in the Park at levels of 0, 5 and 30 kg N/ha. Sites with higher and lower N deposition were selected, including creosote bush scrub and pinyon-juniper woodland. Exotic grass biomass increased significantly with 30 kg N/ha at three of the four sites during a year with moderate precipitation, and under 5 kg N/ha during a year with high precipitation. The response of native forbs to fertilizer was related to the amount of exotic grass present initially. The richness of native forbs declined with fertilization at a site with high initial exotic grass cover, but native richness and cover increased