Tiller recruitment, survival, growth and reproductive effort were monitored in a highly competitive bunchgrass to contrast the demographic effects of nonuse and dormant season burning with and without subsequent defoliation. The number of tillers recruited were largest during the fall, decreased through the winter and spring, and were smallest during the summer. Tiller mortality was highest during the summer, tillers surviving until fall usually completed senescence the following spring. Biomass accumulation and reproductive effort predominantly occurred during the summer rainfall season. Summer growth and reproduction began earlier and were enhanced by dormant season burning. Defoliation increased summer tiller recruitment and advanced by one month fall tiller recruitment. The wide range of tiller weight-density relationships which occurred among treatments followed the -3/2 Power Law. This species' competitiveness and ability to tolerate grazing is attributable to its ability to respond with plasticity along the -3/2 self-thinning line.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/276507 |
| Date | January 1987 |
| Creators | Obermiller, Craig William, 1958- |
| Publisher | The University of Arizona. |
| Source Sets | University of Arizona |
| Language | en_US |
| Detected Language | English |
| Type | text, Thesis-Reproduction (electronic) |
| Rights | Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. |
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