A5019641118- Ecology and Vegetation Dynamics Studies
- Geology and Paleoclimatology Research
- Botany, Ecology, and Taxonomy Studies
- Rangeland and Wildlife Management
- Plant Water Relations and Carbon Dynamics
- Plant and animal studies
- Soil erosion and sediment transport
- Archaeology and Natural History
- Insect and Arachnid Ecology and Behavior
- Aeolian processes and effects
- Wildlife Ecology and Conservation
- Landslides and related hazards
- Tree-ring climate responses
- Avian ecology and behavior
- Plant Ecology and Soil Science
- Botanical Research and Applications
- Fish Ecology and Management Studies
- Freshwater macroinvertebrate diversity and ecology
- Animal Ecology and Behavior Studies
- Turtle Biology and Conservation
- Aquatic Invertebrate Ecology and Behavior
- Geological formations and processes
- Botany and Plant Ecology Studies
- Tree Root and Stability Studies
- Earth Systems and Cosmic Evolution
Desert Botanical Garden
2006-2024
Allegheny College
2024
University of New Mexico
2018
Australian National Botanic Gardens
2011-2013
University of Nevada, Las Vegas
1988-1994
University of Arizona
1984
University of Montana
1983
Interspecific competition for space limits the distribution and abundance of many benthic insects on stones in a western Montana stream. The sessile caddisfly larva Leucotrichia pictipes is territorial aggressively eliminates conspecifics other species from its foraging territories. Territoriality produces an intraspecific pattern regular spacing negative spatial associations between several insects: Parargyractis confusalis, Rhetanytarsus sp. Eukiefferiella Experimental removals resulted...
Three alluvial piedmonts (bajadas or fans) studied in the Sonoran Desert near Tucson, Arizona are complex mosaics of distinct geological landforms. These landscape have been produced through temporally episodic and spatially discontinuous aggradation surfaces destruction other parts by erosion. geomorphic processes produce abrupt juxtapositions soils different ages degrees profile development. Vegetation patterns correspond closely to this mosaic. Larrea tridentata predominates on most...
Many simple plant communities in extremely arid regions of the Sonoran Desert consist essentially two shrub species, Ambrosia dumcsa and Larrea tridentata. These species exhibit completely different recruitment patterns rates population turnover. In these communities, majority space is devoid perennial cover, readily colonize this open space. Recruitment occurs less frequently largely limited to areas beneath canopies large, older individuals. The dynamics systems can be modeled as Markov...
Experiences sur le terrain precisant la competition entre les larves Glossosoma et, d'autre part, Ephemerella doddsi et Baetis sp. dans un cours d'eau du Montana
In the arid southwestern United States, subtle differences in soil horizon development affect seasonal hydrology and consequently influence plant performance community structure. We measured canopy development, population structure, ecophysiology (predawn water potential, ψpd, midday net photosynthetic assimilation, Anet) of two co-dominant warm-desert shrubs, evergreen Larrea tridentata drought-deciduous Ambrosia dumosa, five Mojave Desert soils varying surface sub-surface we used...
Abstract 1. In warm arid and semiarid environments, the accumulation of clay minerals produces increasingly well developed soil horizons with passage time. Differences in strength development two prominent horizons, silt‐ clay‐rich surface vesicular (Av), clay‐enriched subsurface argillic (Bt), may strongly influence amount seasonal continuity plant‐available water physiological activity long‐lived desert shrubs. Three sites were selected on an alluvial piedmont ( bajada ) Mojave Desert that...
Abstract. The Log‐series survey method allows rapid estimates of density and cover is applicable for studies perennial vegetation in arid environments. An optical rangefinder used to determine boundaries large circular plots. Numbers individuals each species within a plot are assessed; this information assign logarithmic classes equivalent the logarithm base 2 actual abundances. Each then assigned canopy class, logarithmbase average per individual. Log total obtained by addition classes....
In what are now the warm deserts of American Southwest, direct effects changing climate on plant distributions typically viewed as principal driver vegetation changes that followed late Pleistocene–Holocene transition (LPH). However, at a semi-arid site in eastern Mojave Desert, to modern, shrub-dominated desert scrub xeric, south-aspect hillslopes occurred only after erosion relatively thick soils toward end mid-Holocene. Soils with well-developed Bt horizons began form Pleistocene both...
In the Sonoran Desert giant columnar cactus, Carnegiea gigantea, often shows a highly clumped distribution because of its frequent establishment beneath tree canopies. An apparent consequence this pattern, where several are associated with single tree, is intraspecific competition for limited water. The relative amount stored water, rate water uptake, apical growth, and reproductive potential individual all lowered as function increased levels crowding. These ecological interactions may...