This study aims to understand the influence of external forcing (i.e. climate, human influences) changes on the inputs of terrigenous materials from the Kaoping River as well as the biogeochemical responses of carbon and nutrients to riverine fluxes in the Kaoping coastal zone.
The Kaoping River exhibits contrasting patterns in water discharge and material fluxes between wet and dry seasons. In general, river discharge is about 12 times higher in the wet season than in the dry season. Riverine fluxes of terrigenous materials (DOC¡BPOC¡BDSi¡BDIN¡BDIP¡BTDN and TDP) are about 3 to 10 times higher in the wet season than in the dry season. Consequently, distribution patterns of carbon, nutrients and hydrochemical parameters are significant difference among four seasons in the Kaoping coastal zone. Distributions of DOM (dissolved organic matter), POM (particulate organic matter) and nutrients in the Kaoping coastal zone show that the highest concentration is generally found in the area close to the Kaoping estuary, and the concentration decreases with the distance away from the land. The riverine fluxes also affect the ratios of DOC/TOC and £GPOC/£GPN in the coastal zone. The characteristics of DIN and DIP distributions and their ratios imply that the primary productivity may be largely limited by nitrogen (DIN < 1£gM¡AN/P < 10) rather than phosphorus (DIP < 0.2£gM¡AN/P < 30) in the Kaoping coastal zone. The occurring probability of nitrogen limitation varies from season to season during the study period, roughly ranging from 4% to 42% (winter, summer > spring, autumn).
The GP (gross production) ranges from 708-19819 mg C m-2 d-1 in spring, from 2451-16230 mg C m-2 d-1 in summer, and from 844-5549 mg C m-2 d-1 in winter. The DCR (dark community respiration) ranges from 970-6284 mg C m-2 d-1 in spring, from 861-12418 mg C m-2 d-1 in summer, and from 997-5781 mg C m-2 d-1 in winter. Both GP and DCR display the highest value in summer, indicating the significant influence of terrigenous fluxes on biological production and respiration during summer. Meanwhile, correlations are significantly positive between GP (DCR) and temperature and nutrients, but significantly negative between GP (DCR) and salinity, also indicating the impacts of terrigenous inputs on GP and DCR. In the Kaoping coastal zone, the BCD (bacterial carbon demand) is about 15% GP and 64% GP, respectively, in winter and summer, inplying that the contribution of GP to BCD is more important in winter than in summer. Judging from the ratio of GP/DCR in different seasons and sampling stations, we conclude that the study area near the Kaoping estuary is likely to be autotrophic throughout the study period, the other stations are also likely to be autotrophic during summer. Nevertheless, the offshore stations appear to be heterotrophic during the winter season.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0729104-165917 |
| Date | 29 July 2004 |
| Creators | Ho, Cheng-Ming |
| Contributors | none, none, Jia-Jang Hung, James T.Liu |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0729104-165917 |
| Rights | unrestricted, Copyright information available at source archive |
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