Masters Theses

Date of Award

3-1981

Degree Type

Thesis

Degree Name

Master of Science

Major

Ecology and Evolutionary Biology

Major Professor

Robert E. Farmer

Committee Members

H. A. Fribourg, C. C. Amundsen, H. R. DeSelm

Abstract

The objectives of this study were to examine viable seed banks of forest soils in East Tennessee and to evaluate the potential of the forest topsoil as a source of propagules for use in the revegetation of surface mine sites. Four high elevation sites (800-1000 m), typical of areas being surface mined, were located in Campbell County in the Cumberland Mountains. Four low elevation sites (300-400 m) were located in Anderson County in the Tennessee Valley. At each of these sites, soil samples were collected in the spring and summer of 1978. The samples were incubated in a greenhouse and emergent germinants were identified. The standing vegetation was sampled at each site, and its composition was compared to that of the seed bank. The results showed that there were large quantities of buried viable propagules in the soils, with germinants ranging from 300 to over 2,000 seedlings/m2. A grand total of 199 species germinated from all soil collections, including 170 species from the spring samples and 113 species from the summer samples. Over twice as many germinants emerged from the spring soil collections as from the summer sets. Significantly greater numbers germinated from the high elevation soils than from the low elevation soils with the spring collection. Sites differed greatly from one another in terms of the numbers and species composition of the germinants. Significantly fewer numbers emerged from the litter than from the 0-5 cm and the 5-10 cm depths. At all sites, the species composition of the seed bank was very different from that of the vegetation. The species which were among the most abundant germinants are typically found in early successional environments. On the other hand, most of the species composing the vegetation were apparently absent from the seed bank and tended to germinate from the litter layer. The fact that many of the early successional species germinated in the largest numbers from the 5-10 cm soil depth is evidence in support of the long-term storage of their seeds in the soil. Possible roles of such dormant seeds in the succession of plant communities were considered. The implications of the buried seed populations in terms of the revegetation of disturbed areas were discussed. Although there is great potential within the topsoil to initiate revegetation, further studies are needed to assess its usefulness in surface mine reclamation and post-logging regeneration.

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