Nitrogen availability as a control mechanism of secondary succession within a semiarid shrubland ecosystem

Technical Report · Fri Sep 25 00:00:00 EDT 1992

DOI:https://doi.org/10.2172/7008350· OSTI ID:7008350

Redente, E F; McLendon, T

Three experiments were conducted within a semiarid shrubland to test the role of nitrogen availability as a control mechanism in secondary succession. Secondary succession patterns were documented for seven years and effects of increased and decreased N availability levels, fumigation, and competition by early-seral species were tested. Differential responses by seral species were determined and related to successional patterns. Nitrogen availability was found to be a primary mechanism controlling the rate of succession. Relative growth rate was an important factor determining which species initially dominated and N availability became the primary control factor by the third year. As N availability increased, the rate of succession decreased. Conversely, as N availability was decreased, the rate of succession increased. The abundance of annuals was increased and abundance of perennials decreased by increased N availability. Tissue N concentration was related to lifeform and seral position, and these relationships were important in the transition from early- to mid-seral stages. Decomposer subsystem dynamics were correlated with seral community dynamics. The effect of fumigation was minimized by initially planting with late-seral species. A conceptual model of secondary succession is presented based on N availability, relative growth rate, lifeform, and decomposition dynamics.

• Research Organization: Colorado State Univ., Fort Collins, CO (United States). Dept. of Range Science
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: FG02-87ER60612
• OSTI ID: 7008350
• Report Number(s): DOE/ER/60612-4; ON: DE93000384
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
GRAMINEAE
PLANT GROWTH
LEGUMINOSAE
RANGELANDS
ECOLOGICAL SUCCESSION
SHRUBS
CANOPIES
FERTILIZERS
LAND RECLAMATION
NITROGEN CYCLE
PHOSPHORUS
PROGRESS REPORT
SOIL CHEMISTRY
CHEMISTRY
DOCUMENT TYPES
ECOSYSTEMS
ELEMENTS
GROWTH
LILIOPSIDA
MAGNOLIOPHYTA
MAGNOLIOPSIDA
NONMETALS
PLANTS
TERRESTRIAL ECOSYSTEMS
540210* - Environment
Terrestrial- Basic Studies- (1990-)