Turkey Lakes Watershed Study reference list: 2004

04-01 Bourbonniere, R.A., F.D. Beall, and I.F. Creed. Carbon dioxide effluxes at the edge: importance of the ecotone between wetland and upland in forests. Geophysical Letters submitted.

Summary: Two catchments within the TLW were chosen as representative of the complex terrain in the watershed for purposes of measuring soil surface CO2 effluxes in the ecotone, or transition boundary between uplands and wetlands.  This proves to be a zone of maximum soilCO2 efflux and is therefore important in calculating soil carbon budgets in forests with complex terrains.

04-02 Spoelstra, J. Nitrate sources and cycling at the Turkey Lakes Watershed: a stable isotope approach. Ph.D. Thesis, Dep’t. of Earth Sciences, University of Waterloo, Waterloo, Ontario. 180pp, 2004.

Summary: A dual nitrate isotope technique was developed and used at the TLW to trace nitrate sources and cycling in the watershed before and after harvesting. The method was found to be effective expecially when combined with d15N analysis of ammonium, soil organic matter and vegetation.

04-03 Spoelstra, J., S.L. Schiff, D.S. Jeffries, and R.G. Semkin. Effect of storage on the isotopic composition of nitrate in bulk precipitation. Environ. Sci. Technol. 38, 4723-4727, 2004.

Summary: Nitrate isotopic ratios in precipitation samples from the TLW were used to detect changes in nitrate concentrations during storage. No production or assimilation of nitrate occurred, demonstrating that bulk collectors can be used to accumulate large volumes over an extended time period with no change in nitrate concentration.

04-04 Kreutzweiser, D.P., S.S. Capell, and F.D. Beall. Effects of selective forest harvesting on organic matter inputs and accumulation in headwater streams. Northern Journal of Applied Forestry 21, 19-30, 2004.

Summary: Time trend analyses were used to examine headwater stream organic matter inputs and accumulations in the TLW following selective harvesting. It was found that a harvesting intensity of 89% basal area removal resulted in a reduction of organic matter and accumulation in streams,but no significant reductions occurred for a 42% basal area removal. Harvesting impacts are reduced by retention of streamside trees and avoidance of felling into the streams.

04-05 Kreutzweiser, D.P., S.S.Capell, and K.P. Good. Stream invertebrate communities as indicators of logging disturbance in northern hardwood forests of Ontario. In: G.J. Scrimgeour, G. Eisler, B. McCulloch, U. Silins and M. Monita, (eds.) Forest Land-Fish Conference II - Ecosystem Stewardship Through Collaboration, pp165-166, 2004. Proc. Forest-Land-Fish Conf. II, April 26-28, 2004, Edmonton, Alberta.

Summary: The effects on aquatic insect communities of different logging intensities was examined 2 years before and 3 years after harvesting. At 29% basal area removal no changes were observed, at 42% removal small changes occurred, whereas at the high-intensity disturbance sites (89% removal) larger and more distinct changes in insect community structure were observed. This high-intensity logging is above normal harvesting rates. If the riparian code that prohibits tree removal within 3 m of stream edges is observed, harmful effects of harvesting are minimal.

04-06 Laudon, H., P.J. Dillon, M.C. Eimers, R.G. Semkin, and D.S. Jeffries*. Climate-induced episodic acidification of streams in Central Ontario. Environ. Sci. Technol. 38, 6009-6015, 2004. (*Author of correspondence).

Summary: This study analyzed the hydrochemical effect of hydrological episodes preceded by drought in 9 headwater streams in central Ontario and included 3 streams in the TLW: S1, S47 and S50. The lower the runoff preceding each episode the larger the decline in ANC following the episode, for all streams except S47. Sulphate was the driving mechanisam in all cases except S47 where NO3 was the most important factor. Thus SO4 from anthropogenic sources stored in the stream catchments and released during episodes following drought can profoundly affect general recovery of lakes and streams from acidification.

04-07 Lovett*, G.M., and M.J. Mitchell. Sugar maple and nitrogen cycling in the forests of eastern North America. Front. Ecol. Environ. 2, 81-88, 2004. (*Contact D.S. Jeffries for correspondence).

Summary: The TLW is one of a number of sugar maple-dominated watersheds studied to examine nitrogen cycling in forest soils. If the population of sugar maple increases because of anthropogenic stress on competitive tree species, the result will be lower N retention in the soils and increased leaching. Nitrate leaching contributes to the depletion of nutrient cations and causes acidification of streams and lakes and ultimately eutrophication of estuaries and coastal waters.

04-08 Lim, K.S. and P.M. Treitz. Estimation of above ground forest biomass from airborne discrete return laser scanner data using canopy-based quantile estimators. Scand. J. For. Res. 19, 558-570, 2004.

Summary: The forest at the TLW watershed was used to test a model correlating airborne discrete return laser scanner data with above ground biomass and components such as stemwood, stem bark, live branch and foliage. The model, based on laser height metrics was able to estimate these components using canopy-based quantile estimators, although forests of different ages and maturity need further assessment and a single quantile of the distributions of laser canopy heights may not give an accurate estimation of forest parameters.

04-09 Pratt*, T.C. Habitat-specific production rate estimates from 5 Canadian Shield lakes. Canadian Science Advisory Secretariat, Res. Doc.2004/085, 18pp, 2004.(*Contact D.S. Jeffries for correspondence).

Summary: Four lakes from the TLW were used in a study to estimate habitat-specific production rates for the littoral zone fish population. These data assist assessing development proposals and their impact.

04-10 Lindsay, J.B., I.F. Creed and F.B. Beall. Drainage basin morphometrics for depressional landscapes. Water Resources Research 40, W09307, doi:10.1029/2004WR003322, 2004.

Summary: This dissertation considers the practice of removing depressions (artifact and actual) and enforcing uninterrupted flow paths in DEMs for hydrogeomorphic applications. The TLW was used to evaluate several aspects of this practice. Preserving actual depressions in DEMs was found to be important for hydrogeomorphic applications involving simulated overland flow. Simple measures of size, position, and connectivity of depressions were found to explain a significant amount of variance in runoff from 12 headwater catchments at the TLW.  Therefore, use of depressionless DEMs for hydro-geomorphic applications is not prudent.

04-11 Lindsay, J.B. Coping with topographic depressions in digital terrain analysis. PhD. Thesis, Department of Geography, University of Western Ontario, London. 125pp, 2 appendices, 2004.

Summary: A fine-resolution DEM was used to delineate wetlands within 12 catchments at the TLW. Wetland metrics as predictors of runoff variation were superior to catchment area and mean slope, two common basin metrics. During wet periods, catchments containing extensive wetlands were marked by a significant decrease in maximum peak discharge and increase in duration of flow. During mesic and dry periods, catchments containing extensive wetlands were marked by an increase in rise and recession times of peak discharge events and the duration of flows.

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