ISSN:
1752-1688
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Architecture, Civil Engineering, Surveying
,
Geography
Notes:
: The herbicide glyphosate was applied to portions of two watersheds in southwestern British Columbia to kill vegetation that was competing with Pseudotsuga menziesii (Douglas-fir) plantations. This application had little significant effect on streamwater chemistry (K+, Na2+, Mg2+, Ca2+, Cl-, NOs3-, NH4+, PO43-, SO4=, and SiO2 concentrations, electrical conductivity, and pH) when vegetation cover in a watershed was reduced by 4%, but had significant (P〉0.05) effects, which lasted for at least five years, when cover was reduced by 43%. In this case, most parameters increased in value following the application, with K+ and Mg2+ concentrations and pH values exhibiting the most prolonged increases and NO3- concentrations exhibiting the greatest percentage increases. Sulphate and dissolved SiO2 concentrations decreased following the application. Streamwater chemical fluxes showed similar trends to concentrations except that changes in fluxes were less significant and no decreases were observed. Forest management induced losses of NO3-N in streamwater during the first five post-treatment years in the study area decreased in the order: herbicide application (approximately 40 kg/ha) 〈 clearcutting and slashburning (approximately 20 kg/ha) 〈 clearcutting (approximately 10 kg/ha). In watersheds similar to those of the study area, herbicide application is likely to have a greater impact on streamwater chemistry, in general, than would clearcutting or clearcutting followed by slashburning.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1752-1688.1989.tb03098.x
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