| Abstract: | A large area of Pacific Coast forests is characterized by shallow soil, with negligible rainfall in the growing season. This study explores water-seeking strategy on such a site. We studied availability of bedrock water and its effects on growth and ecophysiology of 11-yr-old planted Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) and sprouting Pacific madrone (Arbutus menziesii Pursh). The study was carried out at three regulated densities of madrone sprouts on shallow (<50 cm) residual soils in southwest Oregon. Total bedrock water depleted from March to September, as observed in drill holes by neutron probe, did not differ significantly (P > 0.05) among three densities of madrone. However, cover in plots with the highest density of madrone (1322 sprout clumps/ha) depleted 50 mm of water from the 1.5 m layer by June, whereas vegetation on lower density treatments withdrew 15-28 mm by June, with later withdrawal distributed more uniformly through the growing season. Madrone density significantly affected basal diameter (P a?? 0.0001) and height growth (P a?? 0.002) of Douglas-fir. Madrone was consistently taller than Douglas-fir in all plots. The height of 11-yr-old madrone sprout clumps (424-465 cm) did not differ significantly among densities. Madrone leaf area index and biomass were higher at the high density of madrone than at medium density (P a?? 0.045, LAI; P a?? 0.001, biomass). Physiological advantages and rooting habits of madrone give it a competitive advantage over Douglas-fir in this area that it might not have if bedrock did not provide the principal water reservoir for summer growth. |
| Genre: | Article |
| ProdID: | 1015868 |
| Citation Author: | Wang, Zheng Q.; Newton, M.; Tappeiner, J. C., II |
| Citation Contributing Office: | Forest and Rangeland Ecosystem Science Center |
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| Citation End Page: | 757 |
| Citation Issue: | 4 |
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| Citation Language: | English |
| Citation Larger Work Title: | Forest Science |
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| Citation Month: | NOV |
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| Citation Number Of Pages: | 14 |
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| Citation Phsyical Description: | p. 744-757 |
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| Citation Search Results Text: | Competitive relations between Douglas-fir and Pacific madrone on shallow soils in a Mediterranean climate; 1995; Article; Journal; Forest Science; Wang, Zheng Q.; Newton, M.; Tappeiner, J. C., II |
| Citation Start Page: | 744 |
| Citation Volume: | 41 |
| Citation Year: | 1995 |
| Type: | citation/reference |
| Text: | Competitive relations between Douglas-fir and Pacific madrone on shallow soils in a Mediterranean climate; 1995; Article; Journal; Forest Science; Wang, Zheng Q.; Newton, M.; Tappeiner, J. C., II |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Sun, 1 Jan 1995 00:00 -0600 |
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