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Microbial respiration in relation to temperature and moisture in fynbos soils of Swartboskloof, Jonkershoek
Thesis (M. Sc.) -- University of Stellenbosch, 1994.
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| Format: | Thesis |
| Language: | English |
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Stellenbosch : Stellenbosch University
2012
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| _version_ | 1867613821140467712 |
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| access_status_str | Open Access |
| author | De Koker, Theodorus Hermanus |
| author2 | Loos, M. A. |
| author_browse | De Koker, Theodorus Hermanus Loos, M. A. |
| author_facet | Loos, M. A. De Koker, Theodorus Hermanus |
| author_sort | De Koker, Theodorus Hermanus |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (M. Sc.) -- University of Stellenbosch, 1994. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/58457 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:42:14.156Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2012 |
| publishDateRange | 2012 |
| publishDateSort | 2012 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/58457 Microbial respiration in relation to temperature and moisture in fynbos soils of Swartboskloof, Jonkershoek De Koker, Theodorus Hermanus Loos, M. A. Randall, J. H. Stellenbosch University. Faculty of Science. Dept. of Microbiology. Soils -- South Africa -- Stellenbosch Soil moisture -- South Africa -- Stellenbosch Soil temperature -- South Africa -- Stellenbosch Microbial respiration Soil microbiology -- South Africa -- Stellenbosch Fynbos -- South Africa -- Stellenbosch Jonkershoek (South Africa) Dissertations -- Microbiology Thesis (M. Sc.) -- University of Stellenbosch, 1994. The relationship between soil microbial respiration rate (CO2 evolved), soil temperature and soil moisture was determined for a Nomanci and Clovelly soil sampled under Protea nerlifolla plants in Swartboskloof, Jonkershoek. The soils were sampled periodically to ensure different soil moisture contents, and were sieved before determination of the respiration between days 10 and 20 of incubation at 4, 9, 14, 18, 26 and 30°C. The fit of three different models to the respiration data was examined by standard analysis of variance. The models were compared with each other across soils. The first model was a linear relationship between untransformed respiration data, soil moisture and soil temperature (°C). For the other two models the relationships were determined between log transformed respiration data, soil moisture and temperature, either as °C (Q10-type model) or as the inverse of absolute temperature, 1/°K (Arrhenius-type model). These models had different parameters for the two soils. The fits of the Q10-type and Arrhenius-type models were similar, with prediction residual sum of square values of 93.3153 and 93.2250, respectively. These two models had a r2 value of 0.59. The models for untransformed data had r2 values of 0.62 and 0.57 for the Nomanci and Clovelly sols, respectively. The abilities of different models to predict daily mean soil temperature at different depths were investigated. Daily mean air temperature at the main weather station in Swartboskloof, Jonkershoek, approximately 1km from the study sites, provided an adequate estimate of soil temperature. Models to predict soil moisture content from daily rainfall and pan evaporation data were developed. The models took the effect of evapotranspiration, which was different for the two soils, into account. Simulated soil moisture was limited to values equal to or below field capacity. The models were able to predict soil moisture trends for the Nomanci and Clovelly soils accurately when compared to periodically measured soil moisture contents. The soil temperature and moisture models were used as input for the Arrhenius-type models to simulate daily mean CO2 evolution trends. Soil respiration was simulated for the Nomanci and Clovelly soils from 21 February 1984 to 31 December 1988. Simulated respiration was low during winter with an increase through spring to a maximum in summer followed by a decrease during autumn to winter values. These trends were similar to trends of CO2 evolution measured in situ for a French mediterranean soil of a Quercus ilex ecosystem, but differed from soil microbial ATP trends in the Nomanci and Clovelly soils, which tended to show peaks in autumn and spring with declines in winter and summer. However, the simulated respiration for the Clovelly soil during summer regularly showed sharp declines to low levels superimposed on the high main trend of the summer respiration. Masters 2012-08-27T11:38:59Z 2012-08-27T11:38:59Z 1994 Thesis http://hdl.handle.net/10019.1/58457 en Stellenbosch University 115 pages : ill. application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Soils -- South Africa -- Stellenbosch Soil moisture -- South Africa -- Stellenbosch Soil temperature -- South Africa -- Stellenbosch Microbial respiration Soil microbiology -- South Africa -- Stellenbosch Fynbos -- South Africa -- Stellenbosch Jonkershoek (South Africa) Dissertations -- Microbiology De Koker, Theodorus Hermanus Microbial respiration in relation to temperature and moisture in fynbos soils of Swartboskloof, Jonkershoek |
| title | Microbial respiration in relation to temperature and moisture in fynbos soils of Swartboskloof, Jonkershoek |
| title_full | Microbial respiration in relation to temperature and moisture in fynbos soils of Swartboskloof, Jonkershoek |
| title_fullStr | Microbial respiration in relation to temperature and moisture in fynbos soils of Swartboskloof, Jonkershoek |
| title_full_unstemmed | Microbial respiration in relation to temperature and moisture in fynbos soils of Swartboskloof, Jonkershoek |
| title_short | Microbial respiration in relation to temperature and moisture in fynbos soils of Swartboskloof, Jonkershoek |
| title_sort | microbial respiration in relation to temperature and moisture in fynbos soils of swartboskloof jonkershoek |
| topic | Soils -- South Africa -- Stellenbosch Soil moisture -- South Africa -- Stellenbosch Soil temperature -- South Africa -- Stellenbosch Microbial respiration Soil microbiology -- South Africa -- Stellenbosch Fynbos -- South Africa -- Stellenbosch Jonkershoek (South Africa) Dissertations -- Microbiology |
| url | http://hdl.handle.net/10019.1/58457 |
| work_keys_str_mv | AT dekokertheodorushermanus microbialrespirationinrelationtotemperatureandmoistureinfynbossoilsofswartboskloofjonkershoek |