Evaluating the effects of nitrogen urea fertilization on western redcedar growth, soil carbon stocks, and greenhouse gas emissions on Haida Gwaii, B.C. ...

• Main Author: Boyer, Christophe Richard
• Format: Text
• Language: English
• Published: University of British Columbia 2023
• Subjects: haida
• Online Access: https://dx.doi.org/10.14288/1.0429368; https://doi.library.ubc.ca/10.14288/1.0429368

Western redcedar (Thuja plicata) is a major component of native forests on Haida Gwaii, British Columbia, Canada, and a culturally indispensable species to the Haida people. However, its natural regeneration is unachievable due to intensive grazing by the island’s overabundant population of Sitka black-tailed deer. Forest fertilization with nitrogen (N)-urea has been shown to increase the growth rate of western redcedar in the Pacific Northwest, thus increasing aboveground carbon (C) sequestration. N-urea fertilization can also increase soil C storage by increasing litter inputs and decreasing the rate of soil organic matter decomposition. Using a paired-tree design, we tested the effects of N-urea fertilization (200 kg N/ha⁻¹) on western redcedar growth, soil C, N, and microbial biomass C in the forest floor and mineral soil one year following fertilization at six replicate plots in 14–19-year-old stands on Graham Island, Haida Gwaii. We also measured soil greenhouse gas fluxes (CO₂, CH₄, N₂O) for a period ...