Filters: Tags: blackbrush (X)5 results (240ms)
Soil compaction from human trampling, biking, and off-road motor vehicle activity in a blackbrush (Coleogyne ramosissima) shrubland
Soil compaction from human trampling, biking, and off-road motor vehicle traffic was quantitatively investigated in a blackbrush (Coleogyne ramosissima) shrubland in Kyle Canyon of the Spring Mountains in southern Nevada. A significant difference was detected in soil compaction, bulk density, and percent pore space at a particular frequency of visits in each of 4 disturbance types. On average a single vehicle pass was equivalent to 10 human footprints. Ten and 100 footprints were equivalent to 1 motorcycle pass and 10 vehicle passes, respectively. Soil compaction is a product of increased bulk density and decreased pore space. The degree of soil compaction is a function of disturbance type and visit frequency when...
Differences in anatomical characteristics of blackbrush (Coleogyne ramosissima Torr.) leaves were quantitatively investigated along an elevational gradient in Lee Canyon of the Spring Mountains in southern Nevada. Three elevational sites were selected: a lower blackbrush ecotone, a nearly monospecific stand in the middle of the gradient, and an upper blackbrush ecotone. Stomatal density was significantly greater and palisade parenchyma was significantly shorter in the lower ecotone compared to the upper ecotone. Vessel diameters and areas were significantly smaller, while vessel density was higher with increasing aridity. Blackbrush shrubs exhibited upper and lower elevational ecotypes at the anatomical level in...
Soil responses to human recreational activities in a blackbrush (Coleogyne ramosissima Torr.) shrubland
Soil responses to human trampling, biking, and off-road motor vehicle traffic were quantitatively investigated in a blackbrush (Coleogyne ramosissima Torr.) shrubland in Kyle Canyon of the Spring Mountains in southern Nevada. Soil compaction, bulk density, and temperature increased significantly, while soil moisture, organic matter, and percent pore space (macropore) decreased in disturbed (compacted) areas compared to adjacent undisturbed areas. Among disturbed soils, motor vehicle trails and parking lots had a significantly greater compaction, higher bulk density, and a lower percent pore space compared to human hiking/biking trails. Water infiltration and area of water spread (surface water runoff) were an interactive...
Factors affecting seed germination and seedling establishment of a long-lived desert shrub (Coleogyne ramosissima: Rosaceae)
Long-lived desert shrubs exhibit infrequent, episodic recruitment from seed. In spite of this long time scale, selection on life history attributes that affect seedling recruitment should be strong. We studied factors affecting germination phenology and seedling establishment for Coleogyne ramosissima, a dominant shrub species in the ecotone between warm and cold deserts in western North America. We also examined ecotypic differentiation in establishment strategy in response to selection regimes in two contrasting habitats. We followed patterns of dormancy loss, germination, emergence, and survival in reciprocal field experiments at warm winter Mojave Desert and cold winter Colorado Plateau study sites. Seed germination...
Colorado Plateau REA Conservation Elements - Terrestrial Ecosystems: Colorado Plateau Blackbrush-Mormon-tea Shrubland
This map shows the current and historic distribution of this ecosystem, in the context of change agents and disturbance types, as well as current and near-term status and long term potential for change. This map includes current distribution from LANDFIRE EVT and NatureServe Landcover, and historic distribution from LANDFIRE BpS.