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We have developed a new approach to the measurement of phylogenetic signal in character state matrices called relative apparent synapomorphy analysis (RASA). RASA provides a deterministic, statistical measure of natural cladistic hierarchy (phylogenetic signal) in character state matrices. The method works by determining whether a measure of the rate of(More)
Causes for the widespread abundance of the alien grass Bromus tectorum (cheatgrass) after fire in semiarid areas of western North America may include: (1) utilization of resources freed by the removal of fireintolerant plants; and (2) successful competition between B. tectorum and individual plants that survive fire. On a site in northwestern Nevada (USA),(More)
Throughout the western states, riparian ecosystems have been affected by water diversions or spring and seep developments that decrease the quantity of instream flows and result in lowered water-tables. Water extraction is especially damaging in arid and semi-arid regions where the presence of instream and ground-water flows are crucial to riparian(More)
You may order additional copies of this publication by sending your mailing information in label form through one of the following media. Please specify the publication title and series number. Numerous studies have documented the expansion of woodlands in the Intermountain West; however, few have compared the chronology of expansion for woodlands across(More)
Elasticity in conventionally built walking robots is an undesired side-effect that is oppressed as much as possible because it makes control very hard, and thus complex control algorithms must be used. The human motion apparatus, in contrast, shows a very high degree of flexibility with sufficient stability. In this research we investigate how elasticities(More)
Elasticity in conventionally built walking robots is an undesired sideeffect that is suppressed as much as possible because it makes control very hard and thus complex control algorithms must be used. The human motion apparatus, in contrast, shows a very high degree of flexibility with sufficient stability. In this research we investigate how compliance and(More)
Piñon–juniper is a major vegetation type in western North America. Effective management of these ecosystems has been hindered by inadequate understanding of 1) the variability in ecosystem structure and ecological processes that exists among the diverse combinations of piñons, junipers, and associated shrubs, herbs, and soil organisms; 2) the prehistoric(More)
Stratigraphic, geomorphic, and paleoecological data were collected from upland watersheds in the Great Basin of central Nevada to assess the relationships between late Holocene climate change, hillslope processes and landforms, and modern channel dynamics. These data indicate that a shift to drier, warmer climatic conditions from approximately 2500 to 1300(More)
We determined how ecophysiological characteristics of two juniper species, Juniperus occidentalis Hook. (western juniper) and Juniperus osteosperma (Torr.) Little (Utah juniper), changed along altitudinal and regional environmental gradients in the Great Basin of western North America. We obtained diurnal measurements of leaf gas exchange and xylem water(More)
Piñon (Pinus spp.) and juniper (Juniperus spp.) trees are reduced to restore native vegetation and avoid severe fires where they have expanded into sagebrush (Artemisia tridentata Nutt.) communities. However, what phase of tree infilling should treatments target to retain desirable understory cover and avoid weed dominance? Prescribed fire and tree felling(More)