Regional Differences in Stream Water Nitrogen, Phosphorus, and Sediment Responses to Forest Harvesting in the Conterminous USA. Issue 3 (1st May 2019)

• Record Type: Journal Article
• Authors: Muwamba, Augustine; Rau, Benjamin; Trettin, Carl. C.; Amatya, Devendra. M.; Tollner, Ernest W.; Panda, Sudhanshu
• Is Part Of: Journal of Environmental Quality. Volume 48:Issue 3(2019)
• Page Start: 634
• Page End: 644
• Publication Date: 2019-05-01
• Subjects: Agricultural ecology -- Periodicals; Environmental engineering -- Periodicals; Pollution -- Periodicals; 630
• DOI: 10.2134/jeq2018.04.0145
• Languages: English
• ISSNs: 0047-2425

Abstract

Abstract : Forest harvesting and management techniques were hypothesized to result in significant differences in stream water N (NO3 –N), P (total P [TP]), and total suspended sediment (TSS) responses among regions of United States. The objectives were (i) to determine the mean response periods after harvesting for each water quality variable, (ii) to compare the regional response yields, and (iii) to determine relationships among water quality, rainfall, and flow. Watershed‐scale studies where best management practices were implemented provided a basis for water quality analyses. A mixed model was used to estimate the time from harvest to time when the harvested site yielded similar export as the reference site (response period). Normalized water quality yields were calculated as response yields (kg ha −1 yr −1 ) times estimated response periods. Significant differences among yields were identified using ANOVA and Tukey test (α = 0.05), and relationships between water quality and hydrologic variables were identified using multivariate analysis (α = 0.05). The ratio of estimated mean response period for TSS to NO3 –N and TP, each individually, was approximately two. The mean normalized NO3 –N response yield was greater for the northern than the southern and/or western regions. Normalized NO3 –N and TSS response yields were greater for plantations than for other harvest types. The TSS export significantly increased with discharge from plantations. The literature‐based response periods used in this study were not fully monitored, and soil surface manipulations after harvesting pose a significant influence on sediment export in the United States. Core Ideas: Publications on water quality responses to US forest harvesting were explored. The mean response period after harvesting for total suspended sediments (TSS) was 8.8 yr. The mean response period for NO3 –N and total P were 4.3 and 3.9 yr, respectively. The greatest NO3 –N response was 265.2 kg ha −1 for plantations in the northern region. The greatest TSS response was 17, 756.6 kg ha −1 for plantations in the southern region.