Functional complexity and ecosystem stability: an experimental approach

Technical Report · Sun Jan 01 00:00:00 EST 1978

DOI:https://doi.org/10.2172/5228227· OSTI ID:5228227

Van Voris, P.; O'Neill, R. V.; Shugart, H. H.; Emanuel, W. R.

The complexity-stability hypothesis was experimentally tested using intact terrestrial microcosms. Functional complexity was defined as the number and significance of component interactions (i.e., population interactions, physical-chemical reactions, biological turnover rates) influenced by nonlinearities, feedbacks, and time delays. It was postulated that functional complexity could be nondestructively measured through analysis of a signal generated from the system. Power spectral analysis of hourly CO/sub 2/ efflux, from eleven old-field microcosms, was analyzed for the number of low frequency peaks and used to rank the functional complexity of each system. Ranking of ecosystem stability was based on the capacity of the system to retain essential nutrients and was measured by net loss of Ca after the system was stressed. Rank correlation supported the hypothesis that increasing ecosystem functional complexity leads to increasing ecosystem stability. The results indicated that complex functional dynamics can serve to stabilize the system. The results also demonstrated that microcosms are useful tools for system-level investigations.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5228227
• Report Number(s): ORNL/TM-6199; TRN: 78-006168
• Resource Relation: Other Information: Thesis. Submitted by P. Van Voris to Univ. of Tennessee, Knoxville
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
TERRESTRIAL ECOSYSTEMS
POPULATION DYNAMICS
STABILITY
CALCIUM
CARBON DIOXIDE
DATA ANALYSIS
NUTRIENTS
SPECTRA
ALKALINE EARTH METALS
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
ECOSYSTEMS
ELEMENTS
METALS
OXIDES
OXYGEN COMPOUNDS
510100* - Environment
Terrestrial- Basic Studies- (-1989)