Paul J. Meiman

Perceptions of Success and the Question of Consensus in Natural Resource Collaboration: Lessons from an Inactive Collaborative Group

To better understand the relationship between collaborative process and results, we interviewed participants of an inactive collaborative group and analyzed their perceptions of success and the role of consensus in the groups process and outcomes. The main objective of the Intermountain Public Land Cooperative (IMPLC, a pseudonym) was to craft a consensus community alternative for the local Bureau of Land Management (BLM) resource areas Resource Management Plan. Participants perceived many benefits from collaboration, including improved communication and relationships, and high-quality input to the BLM planning process. However, the group was unable to reach consensus and one-quarter of those interviewed indicated that they were less likely to collaborate in the future due to their IMPLC experience. The IMPLC case highlights both benefits and costs of using consensus in collaboration.

New Rangeland Residents in Wyoming? A Survey of Exurban Landowners

Abstract Rapid conversion of rural land to exurban development and the ensuing impacts on natural resources have been well-documented, but information about exurban landowners is lacking. To address this knowledge gap, we surveyed exurban landowners in six Wyoming counties and documented demographic characteristics, motivations, knowledge, and attitudes about natural resources and land management. The overall response rate was 55.6%. Generally, respondents were of retirement age, had lived in Wyoming for about 13 yr, and were raised in areas with a population < 10 000. Wyoming respondents lived in exurbia for the lifestyle and aesthetic values and did not expect economic gains from their property. Most respondents had knowledge about, and interest in, invasive species, water quality, landscaping, and gardening. More than half of respondents (54%) had never looked for information regarding land management. Information from this study can be used to strengthen the development and delivery of educational programs. Programs that focus on water quality or weed control likely will appeal to more exurban landowners than those that focus solely on grazing management. Our findings provide an accurate characterization of this audience and their motivations and attitudes regarding land management, and suggest that using a multipronged approach for outreach efforts, which includes both cost- and time-efficient ways to conduct important land management practices, might increase participation in educational programs.

Impacts of Imazapyr and Triclopyr Soil Residues on the Growth of Several Restoration Species

ABSTRACT Herbicides are frequently used in natural systems to control invasive plants, but nontarget impacts from persistent soil residues can result in unintended ecosystem effects. Imazapyr and triclopyr are herbicides that are widely used in noncrop areas such as rangelands to manage perennial weeds, especially woody species such as tamarisk (saltcedar). Due to widespread environmental and anthropogenic changes in the American southwest, tamarisk, which is commonly thought to co-occur only with riparian plants, is increasingly being found in communities of upland rangeland species. Using an in vitro study combined with high-performance liquid chromatography (HPLC) analyses, imazapyr and triclopyr degradation rates were determined in six Colorado soils. In addition, the relative sensitivity of desirable species to the two herbicides was determined in a field dose response study. Exponential decay models estimated that triclopyr degradation (half-lives of 5 – 16 days) was 20 times more rapid than imazapyr degradation (half-lives of 82 – 268 days). All species tested were sensitive to imazapyr residues, but the degree of sensitivity was strongly dependent on soil properties. Sensitive species (alkali sacaton and western wheatgrass) were tolerant of imazapyr residues in some soils 20 – 23 months after applications. Relatively insensitive species (slender wheatgrass) were tolerant of imazapyr residues in the same soils 10 months after applications. American licorice was sensitive to triclopyr residues up to 89 days after applications, and several grasses (including sideoats grama) showed minor sensitivity. Our study indicates that there is an interaction between the spatial variability in herbicide degradation driven by edaphic properties and the sensitivity of plants to a herbicide, which could be exploited by management practitioners to aid in site rehabilitation. Specifically, managers could stagger planting of species temporally on the basis of their sensitivity to herbicide residues or could target areas of treated sites for planting that are known to have soil types facilitating relatively rapid herbicide degradation.

Characteristics of hummocked and non-hummocked Colorado riparian areas and wetlands

Several hummock formation theories exist in the scientific literature, but are rarely mentioned in management publications where only one or two other theories are stressed. Our objectives were to identify and describe the edaphic, climatic, topographic and vegetation characteristics of riparian areas and wetlands in Colorado that do and do not support hummocks, and to classify hummocked sites according to hummock characteristics. 25 natural resource professionals throughout Colorado identified ten sites each that were a mix of hummocked and non-hummocked in proportion to their local abundance, from which 40 hummocked and 40 non-hummocked sites were randomly selected for sampling. Plant functional group canopy cover was determined using Daubenmire cover classes. Soil samples were collected and numerous site characteristics were recorded. Hummock size, shape and density were measured at hummocked sites. Forward model selection and multiple logistic regression were used to determine relationships between site characteristics and odds of hummock occurrence. Mean winter precipitation, mean annual temperature and forb cover were negatively related to odds of hummock occurrence while soil silt content and plant species richness were positively related to odds of hummock occurrence. Cluster analysis resulted in three groups of hummocked sites with differing hummock morphology, vegetation and climatic characteristics. Differential frost heave and plant biomass accumulation were likely involved in hummock formation at sites examined for this study, but conditions expected to occur following cryoexpulsion of clasts were not observed.

Litter Reduction by Prescribed Burning Can Extend Downy Brome Control

ABSTRACT Downy brome (Bromus tectorum L.) is a highly successful invasive species primarily because it fills an open niche in native plant communities. It also produces large amounts of litter over time. We hypothesized that removing accumulated litter with a prescribed burn before applying herbicides would improve herbicide efficacy, extending the duration of control. In January 2012, two downy brome-infested sites were burned. In March 2012, postemergent applications of glyphosate, imazapic, and tebuthiuron were made in a split-plot design. Above-ground biomass was collected at 6, 18, and 27 months after treatment (MAT) to evaluate treatment effects. In nonburned areas, all herbicide treatments were similar to the control 27 MAT; however, burning combined with imazapic or tebuthiuron reduced downy brome biomass 27 MAT by 81% ± 4.6 SE and 84% ± 19.3 SE, respectively. Remnant species responded positively to burning and herbicide treatments. Native cool-season grass biomass increased after burning whereas native warm-season grass biomass increased following tebuthiuron treatments. The impact of litter on imazapic and tebuthiuron availability was also evaluated. Herbicide interception increased in a linear relationship with increasing litter. For every 50 g · m-2 increase in litter there was a 7% increase in the amount of herbicide intercepted, meaning that 75% of the applied herbicide was intercepted by 360 g · m-2 of litter. A simulated rainfall event of 5 mm, 7 days after application, removed a significant amount of herbicide. This indicates that in sites with surface litter, timely precipitation could be critical for herbicide efficacy; however, when burning was used to remove litter and was followed by herbicides with residual soil activity, downy brome control was extended. Due to downy bromes relatively short seed viability in the soil, extending herbicide efficacy to several years could help to reduce the soil seed bank.

Rangeland dynamics: investigating vegetation composition and structure of urban and exurban prairie dog habitat.

Rapid human population growth and habitat modification in the western United States has led to the formation of urban and exurban rangelands. Many of these rangelands are also home to populations of black-tailed prairie dogs (Cynomys ludovicianus). Our study aimed to compare the vegetation composition of an urban and exurban rangeland, and explore the role that prairie dogs play in these systems. The percent absolute canopy cover of graminoids (grasses and grass-likes), forbs, shrubs, litter, and bare ground were estimated at sampling areas located on and off prairie dog colonies at an urban and an exurban site. Herbaceous forage quality and quantity were determined on plant material collected from exclosure cages located on the colony during the entire growing season, while a relative estimate of prairie dog density was calculated using maximum counts. The exurban site had more litter and plant cover and less bare ground than the urban site. Graminoids were the dominant vegetation at the exurban plots. In contrast, mostly introduced forbs were found on the urban prairie dog colony. However, the forage quality and quantity tests demonstrated no difference between the two colonies. The relative prairie dog density was greater at the urban colony, which has the potential to drive greater vegetation utilization and reduced cover. Exurban rangeland showed lower levels of impact and retained all of the plant functional groups both on- and off-colony. These results suggest that activities of prairie dogs might further exacerbate the impacts of humans in fragmented urban rangeland habitats. Greater understanding of the drivers of these impacts and the spatial scales at which they occur are likely to prove valuable in the management and conservation of rangelands in and around urban areas.

Preemergence Control of Nine Invasive Weeds with Aminocyclopyrachlor, Aminopyralid, and Indaziflam

There are an estimated 400 million hectares of non-cropland in the United States primarily designated as rangeland and pastureland, and there are more than 300 invasive weeds found on these sites, causing an estimated annual loss of

Scales of snow depth variability in high elevation rangeland sagebrush

5 billion. Among the most invasive and problematic weeds are Dalmatian toadflax, diffuse knapweed, downy brome, and musk thistle. Currently, herbicides are the most common management strategy for broadleaf weeds and invasive winter annual grasses. Indaziflam, a new herbicide for invasive plant management in non-crop areas, is a cellulose-biosynthesis inhibitor capable of providing residual invasive winter annual grass control up to 3 yr after treatment (YAT). A field experiment was conducted to determine whether residual Dalmatian toadflax and downy brome control by aminocyclopyrachlor, imazapic, and picloram could be extended by tank mixing these herbicides with indaziflam. Indaziflam tank mixed with aminocyclopyrachlor, imazapic, and picloram provided increased Dalmatian toadflax (84% to 91%) and downy brome (89% to 94%) control 4 YAT, compared with treatments excluding indaziflam. Treatments without indaziflam controlled 50% to 68% of Dalmatian toadflax and <25% downy brome 4 YAT. Based on these results, a greenhouse dose-response experiment was conducted with aminocyclopyrachlor, aminopyralid, and indaziflam to compare preemergence control of nine common non-crop weeds. Averaged across species, aminocyclopyrachlor and aminopyralid GR50 values (herbicide concentration resulting in 50% reduction in plant biomass) were 29 and 52 times higher compared with indaziflam, respectively. These data suggest that indaziflam could be used for residual control of non-crop weeds as a tank-mix partner with other foliar-applied broadleaf herbicides. Nomenclature: Aminocyclopyrachlor; aminopyralid; imazapic; indaziflam; picloram; Dalmatian toadflax, Linaria dalmatica (L.) P. Mill.; diffuse knapweed, Centaurea diffusa Lam.; downy brome, Bromus tectorum L.; musk thistle, Carduus nutans L.

An agent-based model of cattle grazing toxic Geyer's larkspur

In high elevation semi-arid rangelands, sagebrush and other shrubs can affect transport and deposition of wind-blown snow, enabling the formation of snowdrifts. Datasets from three field experiments were used to investigate the scales of spatial variability of snow depth around big mountain sagebrush (Artemisia tridentata Nutt.) at a high elevation plateau rangeland in North Park, Colorado, during the winters of 2002, 2003, and 2008. Data were collected at multiple resolutions (0.05 to 25 m) and extents (2 to 1000 m). Finer scale data were collected specifically for this study to examine the correlation between snow depth, sagebrush microtopography, the ground surface, and the snow surface, as well as the temporal consistency of snow depth patterns. Variograms were used to identify the spatial structure and the Moran’s I statistic was used to determine the spatial correlation. Results show some temporal consistency in snow depth at several scales. Plot scale snow depth variability is partly a function of the nature of individual shrubs, as there is some correlation between the spatial structure of snow depth and sagebrush, as well as between the ground and snow depth. The optimal sampling resolution appears to be 25-cm, but over a large area, this would require a multitude of samples, and thus a random stratified approach is recommended with a fine measurement resolution of 5-cm.

Usable Science for Managing Animals and Rangeland Sustainability

By killing cattle and otherwise complicating management, the many species of larkspur (Delphinium spp.) present a serious, intractable, and complex challenge to livestock grazing management in the western United States. Among the many obstacles to improving our understanding of cattle-larkspur dynamics has been the difficulty of testing different grazing management strategies in the field, as the risk of dead animals is too great. Agent-based models (ABMs) provide an effective method of testing alternate management strategies without risk to livestock. ABMs are especially useful for modeling complex systems such as livestock grazing management, and allow for realistic bottom-up encoding of cattle behavior. Here, we introduce a spatially-explicit, behavior-based ABM of cattle grazing in a pasture with a dangerous amount of Geyer’s larkspur (D. geyeri). This model tests the role of herd cohesion and stocking density in larkspur intake, finds that both are key drivers of larkspur-induced toxicosis, and indicates that alteration of these factors within realistic bounds can mitigate risk. Crucially, the model points to herd cohesion, which has received little attention in the discipline, as playing an important role in lethal acute toxicosis. As the first ABM to model grazing behavior at realistic scales, this study also demonstrates the tremendous potential of ABMs to illuminate grazing management dynamics, including fundamental aspects of livestock behavior amidst ecological heterogeneity.