Management prescriptions for contemporary ponderosa pine (Pinus ponderosa Dougl.) forests often incorporate the restoration to a structure that more closely resembles pre-European contact forests. Successful restoration programs should incorporate the herbaceous understory component; however, published research specifically addressing changes in understory species composition is minimal. Ponderosa pine influence on the undercanopy environment may be an important factor in understory vegetation distribution. In this study, we addressed the relationships among ponderosa pine abundance, undercanopy environment, and understory species composition and made inferences with respect to restoration potential. Data representing vegetation, soil, and environmental attributes were measured in 28 plots in an eastern Oregon ponderosa pine forest. Relationships among the parameters measured were evaluated using cluster analysis, indicator species analysis, and ordination. Ponderosa pine occupancy was inversely related to understory perennial bunchgrass abundance and species diversity and appeared to regulate the undercanopy habitat through alterations in light intensity, nitrogen availability, and soil temperature. Light availability was the most important ponderosa pine-influenced undercanopy environmental parameter associated with understory vegetation distribution. These data suggested that degradation in the undercanopy environment associated with higher levels of ponderosa pine abundance may be temporary and that restoration practices that reduce pine occupancy should promote undercanopy conditions favorable to perennial bunchgrass growth. However, understory vegetation recovery in stands with excessive pine ingrowth may be constrained by desired understory species loss or invasion by more competitive understory vegetation.

Perceptions of cattle distribution and resource conflicts are often based upon qualitative observations of cattle by managers or the general public. Such information on cattle presence and inferred habitat preferences may not reflect true habitat correlates of cattle because observations do not include any sampling design. We documented cattle presence and used presence data to model distribution of cattle with respect to landscape features on the Lincoln National Forest (LNF) of south-central New Mexico, an area of conflict with regard to cattle herbivory. We recorded cattle presence both from visual observations of cattle while conducting other research activities and from randomized pellet-group transects during the spring-autumn period when cattle grazed the high-elevation habitats. Distribution of cattle differed for several habitat variables between datasets, although distribution models from both datasets indicated that elevation, slope, distance to water and roads, and vegetation cover type most influenced cattle presence. Cattle presence was associated with a variety of cover types, and cattle were generally within 500 m of water and on slopes of < 15- 20%. Observation-based models showed positive associations with open cover types, including the strongest positive association with montane meadows, the area of conflict in LNF. In contrast, transect-based models showed positive associations with more cover types (11) than did observation-based (6). Observation-based models also showed higher association with areas closer to roads. Inferred habitat preferences based on casual observations of cattle may not accurately reflect true distribution or use, as transect-based models predicted much broader distribution throughout LNF and higher overall probabilities of cattle presence. Because cattle distribution included many other vegetation cover types in addition to montane meadows, management to enhance positive correlates of cattle distribution on LNF may be useful to alter cattle distribution away from areas of perceived conflict./Percepciones sobre la distribución del ganado y el conflicto de recursos se basan frecuentemente en observaciones cualitativas de los manejadores del ganado y el público en general. Esta información, sobre la presencia del ganado y la suposición de la preferencia de hábitat, tal vez no refleja la verdadera correlación entre hábitat y ganado por que las observaciones no incluyen un diseño de muestreo. Documentamos la presencia del ganado y usamos estos datos para modelar la distribución del mismo con respecto a las características del paisaje en Lincoln National Forest (LNF) en la parte Sur-Central de Nuevo México, en un área de conflictos que involucra el ganado. Se registro la presencia del ganado con observaciones visuales mientras se realizaban otras actividades de investigación y de transectos aleatorios grupo-pellet durante el periodo de primavera-otoño cuando, el ganado pastoreaba el hábitat de mayor elevación. La distribución del ganado difiere en diferentes variables del hábitat entre las bases de datos aunque, los modelos de distribución de ambas bases de datos indicaban la elevación, pendiente, distancia a los abrevaderos y caminos y cubierta vegetal que más influencian la presencia del ganado. La presencia del ganado fue asociada con una variedad de tipos de cubiertas y el ganado estuvo generalmente, a 500 metros del abrevadero y pendientes del 15-20%. Modelos basados en observaciones mostraron una asociación positiva con los tipos de cubierta abiertos incluyendo una fuerte asociación positiva con las praderas montane que es el área de conflicto en el LNF. En contraste, los modelos basados en transectos mostraron una asociación positiva con mas tipos de cubiertas (11) que los basados en observaciones (6). Los modelos basados en observaciones mostraron mayor asociación con áreas cerca de los caminos. Preferencias de hábitat basadas en deducciones y observaciones casuales del ganado no pueden reflejar de manera precisa la verdadera distribución o uso de la misma forma que lo hacen los modelos basados en transectos que predicen de manera más amplia la distribución a través del LNF y mayores probabilidades en general de presencia de ganado. Debido a que la distribución del ganado incluye algunos otros tipos de cubierta vegetal en adición a las praderas montane el manejo que promueva una correlación positiva en la distribución del ganado en el LNF podría ser de utilidad el alterar la distribución del ganado fuera de las áreas donde se percibe que hay conflicto.

Aboveground net primary production (ANPP) is an important ecosystem property that is affected by environmental variability. ANPP in grasslands is typically measured by clipping peak live plant material. However, this method is time intensive (and therefore expensive), making it difficult to capture spatial and temporal variability. Additionally, it is impractical to use a destructive method to estimate ANPP in long-term, permanent plots. Thus, many double-sampling techniques have been developed to reduce costs and increase sample size. The objective of our study was to assess the accuracy and precision of nondestructive techniques to estimate ANPP as supplements to the traditional method of peak biomass harvest at two grassland sites. We harvested biomass and compared estimates from the same plots to 1) canopy interception using a point frame, 2) green cover estimates derived from a digital camera, and 3) reflectance measurements using a handheld radiometer. We calculated the optimum allocation of sampling effort to direct and indirect methods to minimize sampling cost yet achieve a desired precision. We found that the point frame technique explained the highest proportion of the variability in biomass at both sites (R2 = 0.91, 0.90). However, our cost-optimization analysis revealed that the radiometer technique, although less accurate (R2 = 0.38, 0.51), could achieve a desired precision for lower labor costs than the point frame. The radiometer and point frame methods will be a useful tool for grassland ecologists and rangeland managers who desire fast, nondestructive estimates of ANPP./La producción primaria neta PPN es una propiedad importante en el ecosistema que es afectada por la variabilidad medioambiental. La PPN en pastizales se mide normalmente por medio de cortes de la parte viva de la planta. Sin embargo, este método consume mucho tiempo (y es caro) haciendo difícil estimar la variabilidad espacial y temporal. Además, es impráctico usar métodos destructivos para estimar la PPN en el largo plazo en parcelas permanentes. Por esto, técnicas de doble muestreo se han desarrollado para reducir el costo y aumentar el taman ̃ o de muestra. El objetivo de nuestro estudio fue evaluar la eficacia y eficiencia de técnicas no destructivas para estimar la PPN como complementos del método tradicional de cosecha de la biomasa en dos tipos de pastizales. Se cosecho la biomasa y se comparo las estimaciones de las mismas parcelas para 1) intercepción del dosel con el método del punto, 2) estimación de la cubierta verde derivada de una cámara digital, y 3) medidas de reflejo usando un radiómetro manual. Calculamos la ubicación óptima de esfuerzo de muestreo por métodos directos e indirectos para reducir el costo de muestreo y lograr la precisión deseada. Encontramos que la técnica del punto explico la mayor proporción de la variabilidad de biomasa en ambos sitios (R2 = 0.91, 0.90). Sin embargo, el análisis optimización-costo revelo que la técnica del radiómetro aunque menos precisa (R2 = 0.38, 0.51) podría lograr la precisión deseada con menor costo que el punto. Los métodos del radiómetro y el punto serán herramientas útiles para ecólogos y manejadores de pastizales que requieren de estimaciones de PPN rápidas y no destructivas.

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.

Research on the impacts of wildfire and invasive plants in rangelands has focused on biophysical rather than human dimensions of these environmental processes. We offer a synthetic perspective on economic and social aspects of wildfire and invasive plants in American deserts, focusing on the Great Basin because greater research attention has been given to the effects of cheatgrass expansion than to other desert wildfire/invasion cycles. We focus first on impacts at the level of the individual decision-maker, then on impacts experienced at the human community or larger socio-political scales. Economic impacts of wildfire differ from those of invasive grasses because although fire typically reduces forage availability and thus ranch profit opportunities, invasive grasses can also be used as a forage source and ranchers have adapted their grazing systems to take advantage of that circumstance. To reduce the threat of increased ranch bankruptcies, strategies are needed that can increase access to alternative early-season forage sources and/or promote diversification of ranch income streams by capturing value from ranch ecosystem services other than forage. The growth of low-density, exurban subdivisions in Western deserts influences not only the pattern and frequency of wildfire and plant invasions but also affects prevailing public opinion toward potential management options, and thereby the capacity of land management agencies to use those options. Outreach efforts can influence public opinion, but must be rooted in new knowledge about multiple impacts of invasion and increased wildfire in American deserts./La investigación se ha centrado en el impacto biofísico del los incendios naturales y las plantas invasoras en los pastizales, en lugar de la dimensión humana en esos procesos medioambientales. Ofrecemos una perspectiva sintética sobre aspectos económicos y sociales de los incendios naturales y las plantas invasoras en los desiertos de América, enfocándonos a la región de la Grean Basin debido a la importancia de las investigaciones sobre el efecto de la expansión del zacate cheatgrass que a otros incendios/ciclos de invasión en los otros desiertos. Nos enfocamos primero, en los impactos a nivel individual de toma de decisiones después, en los impactos experimentados a nivel comunidades humanas o escalas socio-políticas mayores. El impacto económico de los incendios naturales difiere de aquel provocado por la invasión de pastos porque, mientras el fuego reduce la disponibilidad de forraje y la oportunidad de un ingreso en el rancho, pastos invasores también pueden ser usados como fuente de forraje y los rancheros han adaptado sus sistemas de pastoreo para sacar ventaja de esta circunstancia. Para reducir el riesgo de bancarrota en el rancho, se requieren estrategias que incrementen el acceso a fuentes de alternativas de forraje al principio de la temporada y/o promover la diversificación del ingreso del rancho valorando los servicios medioambientales de éste, en lugar de solo el forraje. El crecimiento de subdivisiones ex-urbanas de baja densidad en los desiertos del Oeste, influencian no solo el patrón y frecuencia de incendios naturales e invasión de plantas sino también, afectan la opinión pública actual hacia opciones potencial de manejo y como consecuencia la capacidad de las agencias que manejan las tierras de aplicar esas opiniones. Los esfuerzos para influenciar la opinión pública tienen que estar basados en conocimiento nuevo a cerca del impacto múltiple de las invasiones y aumento de incendios naturales en los desierto de América.

Millions of hectares of rangeland in the western United States have been invaded by annual and woody plants that have increased the role of wildland fire. Altered fire regimes pose significant implications for runoff and erosion. In this paper we synthesize what is known about fire impacts on rangeland hydrology and erosion, and how that knowledge advances understanding of hydrologic risks associated with landscape scale plant community transitions and altered fire regimes. The increased role of wildland fire on western rangeland exposes landscapes to amplified runoff and erosion over short- and long-term windows of time and increases the risk of damage to soil and water resources, property, and human lives during extreme events. Amplified runoff and erosion postfire are a function of storm characteristics and fire-induced changes in site conditions (i.e., ground cover, soil water repellency, aggregate stability, and surface roughness) that define site susceptibility. We suggest that overall postfire hydrologic vulnerability be considered in a probabilistic framework that predicts hydrologic response for a range of potential storms and site susceptibilities and that identifies the hydrologic response magnitudes at which damage to values-at-risk are likely to occur. We identify key knowledge gaps that limit advancement of predictive technologies to address the increased role of wildland fire across rangeland landscapes. Our review of literature suggests quantifying interactions of varying rainfall intensity and key measures of site susceptibility, temporal variability in strength/influence of soil water repellency, and spatial scaling of postfire runoff and erosion remain paramount areas for future research to address hydrologic effects associated with the increased role of wildland fire on western rangelands.