Secondary succession in disturbed and reclaimed sagebrush communities of northwestern Colorado

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1984

OSTI ID:6136749

Biondini, M E

The objective of this dissertation was the study of natural and induced secondary succession and soil biological activity in disturbed lands and reclaimed areas of a big sagebrush community (Artemisia tridentata) in northwestern Colorado. Four types of treatments were utilized to study soil disturbance effects in secondary succession: 1) vegetation was scraped off with as much topsoil left as possible, 2) vegetation was scraped off and topsoil was ripped to a depth of 30 cm, 3) 1 m of topsoil and subsoil was removed, mixed, and replaced, and 4) 1 m of topsoil and 1 m of subsoil were removed and replaced in reverse order. Treatment 4 drastically altered the successional pattern. In six years, Treatments 1, 2, and 3 became a grass-forb dominated community (Agropyron riparium, A. smithii, Koeleria cristata, and Sphaeralcea coccinea as predominant species) while Treatment 4 became a shrub dominated community (Artemisia tridentata, Chrysothamnus spp., Gutierrezia sarothrae). The rate of succession was not decreased by the increased disturbance levels. Native and introduced seeded communities were utilized to study secondary succession in reclaimed areas. The treatments consisted of 30 cm and 60 cm of topsoil over retorted shale with and without fertilization. The variables studied were plant species composition (expressed as relative cover), soil dehydrogenase and phosphatase enzymatic activities, acetylene reduction, and soil organic matter. Medicago sativa became the dominant species on the introduced seed mixture in the 30-cm topsoil without fertilization. Grasses (Agropyron desertorum, A. intermedium, and A. trichophorum) were dominant in the other treatments. The species composition of the native seed mixture was not affected by fertilization but showed a long-term topsoil effect. The 30-cm plots became dominated by Poa ampla while the 60-cm plots were dominated by Agropyron inermis.

• OSTI ID: 6136749
• Country of Publication: United States
• Language: English

Related Subjects

04 OIL SHALES AND TAR SANDS
041000* -- Oil Shales & Tar Sands-- Environmental Aspects
510500 -- Environment
Terrestrial-- Site Resource & Use Studies-- (-1989)
54 ENVIRONMENTAL SCIENCES
ARID LANDS
CHEMISTRY
COMPARATIVE EVALUATIONS
DESERTS
ECOLOGICAL SUCCESSION
ECOSYSTEMS
GRASS
GROWTH
LAND RECLAMATION
METABOLISM
PLANT GROWTH
PLANTS
SHRUBS
SOIL CHEMISTRY
SPECIES DIVERSITY
SPENT SHALES
TERRESTRIAL ECOSYSTEMS