The objective of this study was to examine initial effects of the 2003 Lost Creek wildfire (southwestern Rocky Mountains of Alberta) on concentrations and production (yield and total export) of several nitrogen (N) forms, and to explore initial recovery of these effects within the first 3 years after the fire. During the first postfire year, nitrate (NO₃^–), dissolved organic nitrogen (DON), and total nitrogen (TN) concentrations in severely burned watershed streams were 6.5, 4.1, and 5.3 times greater, respectively, than those in reference streams. Weaker effects were evident for concentrations of ammonium (NH₄⁺; 1.5 times) and total particulate nitrogen (TPN; 3.0 times). A rapid decline in mean watershed concentrations and production of NO₃^–, DON, total dissolved nitrogen (TDN), and TN was observed from burned watersheds over the three seasons after the fire. However, elevated NO₃^–, TDN, and TN concentrations and production were still evident during the snowmelt freshet and following precipitation events after 3 years. Effects of the burn were strongly influenced by the regional flow regime, with the most elevated N concentrations and production occurring during higher discharge periods (snowmelt freshet and storm flows).

The potential permeability enhancement of a substrate that has been burrowed by a suite of fauna that inhabit geological firmgrounds (i.e. the Glossifungites ichnofacies) is investigated by using computer simulations, laboratory and field measurements to assess the effective permeability of a Pleistocene Glossifungites surface. All the testing methods indicate that the effective permeability of a substrate is markedly enhanced by the presence of sand-filled Glossifungites burrows in the low-permeability substrate. Furthermore, the permeability of these burrowed horizons can be well approximated by using a modified arithmetic mean that accounts for the degree of interconnectivity between burrows. These formulae are robust and, conceptually at least, can be applied to a variety of geological media and burrow configurations.