Forest Investment Account (FIA) - Forest Science Program
FIA Project Y091045

    Measurement and Modelling of Disturbance Impacts on Site Hydrology and Productivity in British Columbia's Southern Interior
 
Project lead: Carlyle-Moses, Darryl (Thompson Rivers University)
Subject: Forest Investment Account (FIA), British Columbia
Series: Forest Investment Account (FIA) - Forest Science Program
Description:
As of 2006, Provincial Aerial Overview of Forest Health surveys indicated that approximately 42 % of all merchantable pine in British Columbia had been killed as a consequence of the current mountain pine beetle (MPB) epidemic (Walton et al., 2007). Large-scale stand mortality is expected to continue due not only to the MPB infestation, with 77 % of all merchantable pine projected to be lost to this infestation by 2014 (Walton et al., 2007), but also commercial harvesting activities, and wildfires - which are predicted to increase in frequency in the region as a result of global climatic change (BC Ministry of Water, Land and Air Protection, 2004). The magnitude and geographic extent of forest disturbance in the province has raised important socio-economic and natural resources management concerns, including the impact of disturbance regimes on site hydrology and productivity.
Water and energy partitioning by forested landscapes is influenced in no small part by the biophysical characteristics exhibited by that cover, including, for example, canopy cover fraction, canopy volume and stand height (Oke, 1987). Removal of forest canopy generally leads to increased soil moisture and soil temperatures and extends growing season lengths (Bhatti et al., 2000). However, the magnitude and duration of impacts on soil moisture and temperature are dependent on the type and degree of soil disturbance, residual ground cover, and the time required for vegetation to become established and the characteristics of that re-growth (Mahendrappa and Kingston, 1994; Spittlehouse, 2007). Intuitively, these post-disturbance site characteristics are, in large part, not only a function of the magnitude of disturbance, but also on the type of disturbance itself. For example, although the casual observer may view stands affected by wildfire and by MPB similarly, in that both disturbances kill trees that comprise the overstorey, the post-disturbance understorey plant composition and the biophysical character of the forest floor and soil matrix will differ appreciably between the two stands. The dissimilarities in site characteristics under different disturbance scenarios may result in important contrasts in the manner water and energy are partitioned and thus on the productivity and future growing conditions of tree species. Currently, any predictions about how hydrologic and ecosystem processes will differ under different disturbance regimes is largely speculative. The ability to predict such impacts is, however, not only of academic interest. Research is needed to provide forest and watershed managers, policy makers, First Nations groups and research scientists with the quantitative information necessary to evaluate the impact different disturbance regimes have on site water availability and temperature regimes and thus the establishment, growth and health of regenerating stands. In addition, little is known about the hydrological effects of partial versus complete stand mortality or of the time to reach hydrologic recovery in these areas once regeneration begins.
A comprehensive field campaign is proposed near Mayson Lake on the Thompson Plateau in south-central British Columbia in order to address key gaps in our understanding of disturbance impacts on site hydrology and productivity. Specific research questions to be addressed include: i) how do canopy, forest floor and soil rooting zone hydrologic and heat balances differ under different disturbance regimes and stages of re-growth; ii) how do these differences impact soil moisture, soil temperature and related site productivity; and iii) how well can these ecohydrological processes be simulated using forest hydrology models and how can the results of such simulation exercises be extrapolated in both space and time? Growing-season water and heat balances will be derived within grey-attack MPB stands, stands affected by the 2003 McClure wildfire, and stands at various stages of regeneration after harvesting. Mayson Lake is also the site of a long-term snow hydrology research program and a study examining the impact of MPB on the annual forest water balance (see Redding et al., 2007). The approach to be used in order to determine disturbance related changes in site hydrology and productivity includes field measurements of growing-season water and heat fluxes over a two-year period and the use and evaluation of water and heat balance models in simulating soil moisture contents and temperature in the rooting zone. Future forest deterioration and re-growth of the study stands will be simulated and, coupled with the results of the proposed study, will be used to determine the time for stands to recover hydrologically. It is anticipated that the results of the project will be used to guide future policy and practice regarding the planning of forest operations so that optimum timber harvests coupled with minimal environmental impacts can be realized on areas once affected by disturbance. Project-derived results will also help researchers interested in addressing the impacts of disturbance and subsequent re-growth on nitrification (e.g., Powers, 1990), soil biota (e.g., Berch et al., 2007) and ground water and streamflow chemistry (e.g., McEachern et al., 2005). The proposed research also addresses three of the research priorities outlined by Hélie et al. (2005): i) MPB impacts on soil moisture storage; ii) the impacts on interception loss; and iii) the impacts on evapotranspiration. The project will involve the participation of graduate and senior undergraduate students.

References:
Berch, S.M., Battigelli, J.P. and G.D. Hope. 2007. Responses of soil mesofauna communities and oribatid mite species to site preparation treatments in high-elevation cutblocks in southern British Columbia. Pedobiologia 51, 23-32.
Bhatti, J.S., Fleming, R.L., Foster, N.W., Meng, F-R, Bourque, C.P.A. and P. A. Arp. 2000. Simulations of pre- and post-harvest soil temperature, soil moisture, and snowpack for jack pine: comparison with field observations. Forest Ecology and Management 138, 413-426.
British Columbia Ministry of Water, Land and Air Protection. 2004. Weather, Climate and the Future: B.C.’s Plan. 42 p.
Hélie, J.F., Peters, D.L., Tattrie, K.R., and J.J. Gibson. 2005. Review and synthesis of potential hydrologic impacts of mountain pine beetle and related harvesting activities in British Columbia. Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre, Victoria, BC. Mountain Pine Beetle Initiative Working Paper 2005-23. 26 p.
Mahendrappa, M.K. and D.G.O. Kingston. 1994. Intensive harvesting impacts on soil temperature and solution chemistry in the Maritimes region of Canada. New Zealand Journal of Forest Science 24, 402-414.
McEachern, P., Prepas, E.E. and D.S. Chanasyk. 2005. Landscape control of water chemistry in northern boreal streams of Alberta. Journal of Hydrology, 323, 303-324.
Oke, T.R. 1987. Boundary Layer Climates (2nd Ed.), Metheun, London, UK. 435 p.
Powers, R.F. 1990. Nitrogen mineralization along an altitudinal gradient: interactions of soil temperature, moisture and substrate quality. Forest Ecology and Management 30, 19-29.
Redding, T., Winkler, R.D, Carlyle-Moses, D. E. and D.L. Spittlehouse. 2007. Mayson
Lake study examines hydrological processes. LINK 9, 10-11
Spittlehouse, D.L. 2007. Modelling the influence of Mountain Pine Beetle infestation in lodgepole pine forests on the site water balance. In: Proceedings of the CMOS, CGU, AMS Congress. May 28 - June 1, 2007. St. John's Congress Centre, Newfoundland and Labrador, Canada. H03-2C4 .4
Walton, A., Hughes, J., Eng, M., Fall, A., Shore, T., Riel, B, and P. Hall. 2007. Provincial-level projection of the current mountain pine beetle outbreak: Update of the infestation projection based on the 2006 Provincial Aerial Overview of Forest Health and revisions to the “model” (BCMPB.v4). British Columbia Ministry of Forests and Range Research Branch, 10
p
Related projects:  FSP_Y102045

    Deliverables:

Executive summary (0.3Mb)
AGU poster abstract - Comparing Three Methods of Sampling Throughfall in a Declining Coniferous Forest at a low Rainfall Site (10Kb)
CGU poster abstract - Results from the Mayson Lake Hydrological Processes Study 2008 Summer Field Season (10Kb)
Social policy report (97Kb)
WDCAG abstract - Mayson Lake: Hydrological Processes Research in British Columbia's Southern Interior (13Kb)
WDCAG abstract - Mayson Lake: The Effects of Tree Growth and Mortality on Snow Accumulation and Ablation (13Kb)
WDCAG abstract - Mayson Lake: Preliminary Study of the Relationship between Tree Size and Stemflow Funnelling Ratios (14Kb)
WDCAG abstract - Mayson Lake: Throughfall, Stemflow and Interception Loss from a Mature Declining Pine - Spruce - Fir Stand (35Kb)
WDCAG abstract - Mayson Lake: Growing-Season Near-Surface Soil Moisture Dynamics within Conifer Forests under Different Stand Conditions (13Kb)
WDCAG presentations (6.8Mb)

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Updated August 16, 2010 

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