Forest Management and Watershed Values - nswa.ab.ca Winship Weyer... · Cc panel 0503.ppt 1 ... Forest Management and Watershed Values . ... • Timber harvesting under sustainable

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Weyerhaeuser Pembina Timberlands

Forest Management and Watershed Values

Presentation to the NSWA Headwaters Educational Forum Feb 5, 2015

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Green Zone Activities/Events • Fire, mountain pine beetle, storms, forest succession • Timber harvesting

• Sustainable forest management • <1% of forest area under tenure harvested annually • Prompt reforestation to regulated Free-To-Grow standards

• Oil & gas • Well sites, pipelines, roads, facilities

• Gravel • Grazing • Recreation • Community development

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Broad Picture of North Saskatchewan Region Green Zone • Diverse forest region (sub-alpine to foothills to parkland),

coniferous to the west/higher and mixedwoods to the east • Fire has predominantly shaped the forest with natural fire cycles of 45 – 80 years, but current forest is overmature (120+ years) • 50% of landscape is managed forest for timber (balance is

protection, “non-productive”, other land uses) • 50 - 75,000 ha. grazing dispositions • >000’s of well sites and facilities • Average 2-3 km. / km2 (wide range) of lineal developments • Land withdrawals in ‘000’s ha. per year • Increasing recreation use (long weekend = 000s !!)

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Forest Management 101

Sustainable Forest Management Sustained yield of fibre Ecological, biodiversity Conservation, protection Enviro certification

Integrated Resource Management Detailed Forest Management Plans Strategic, long term (200+ year forecasts) Stakeholder engagement

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Land & Forest Inventory

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Yield

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Forest Management Strategies • Sustainable consistent flow of timber

• Land management (energy, ag, recreation) • Ecological / habitat

• Watershed protection • Silviculture regimes • Stakeholder engagement (Aboriginal, resource users)


Harvest Design - Criteria Aesthetics Wildlife

Watershed

Timber

Logistics

Ecological

Reforestation


Forest Watersheds are highly variable


Forest Hydrology • Simplified long term water balance expression Q = P – ET

• Storage capacity, interception, groundwater fluxes minor • Few studies on paired watersheds

• Watershed classification • Topographic divides (vs. phreatic or groundwater) & predictive mapping

tools • Stream order (Strahler class 4 and higher)

• Streamflow - Foothills vs. Boreal Forest • Snow vs. summer rain, annual precipitation, ET potential • Storage capacity (landscape, wet area “sponges”) • Peak flows and recurrence intervals (extrapolation, deduction) • Effective discharge vs. storm events


Annual Hydrographs Nordegg R. 2002 (875 km2) Saultaux R. 2000 (2600 km2)

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Nordegg - 2002 Saulteaux River - 2000


Annual Water Yields Saultaux R and Nordegg River

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Watershed Management – Impacts on Water Yield Timber harvesting & water yield:

• Timber removal = reduced ET, reduced interception, increased run-off / stream flow (peak flow metric)

• Cooler, drier Alberta climate = less effect • Greatest impact is immediately after timber harvesting, hydrologic

recovery follows forest regeneration as measured by leaf area (speculative but aspen 15 – 25 years, Lodgepole pine 25 – 50 years)

• Greatest / significant impact occurs in small watersheds where watershed response depends on % area harvested


Timber harvesting & water yield (cont’d): • Watersheds recover from disturbance providing the disturbance is

within thresholds and the forest grows back • Forest harvesting and reforestation is modeled by watershed over

rotation cycles to determine maximum levels of disturbance / forest harvesting temporally and spatially = Equivalent Cut Area (ECA) • Watershed specific qualitative factors used in step analysis e.g.

slope, soil conditions, critical habitats • Other models can be used as needed e.g. WRENNS • Constrains harvesting levels and patterns

• Generally used threshold for watershed protection is maximum 20 - 25% ECA at any point in time (case study references )







Watershed Management – Impacts on Water Quality • Roads and stream crossings

• Sedimentation • Stream flow • Habitat (water temp, substrate, dissolved oxygen, nutrients, cover),

fishing pressures (access control, regulations) • Non-forested area (grazing, roads, pipelines, leases, etc.) increasing • Difficulty in monitoring non-point sources of sedimentation

• Landscape / cumulative effects • Natural variance as the benchmark • Chronic low level vs. acute events


Watersource Protection • Road construction (temp) & stream crossing design & construction

guidelines / standards (bridges preferred) • Aquatic environment assessments on critical crossings • Stream Crossings erosion control standards, ongoing monitoring &

inspections, maintenance plans • Erosion potential vs. sediment monitoring

• Treed “buffers” on water source areas • Timing restrictions i.e. frozen conditions only • Reclamation and restoration planning • Detailed site planning for water source & sensitive soils (e.g. Wet Areas

Mapping & LiDar)


Route selection


Regulatory Framework Provincial

• Presence of fish & critical habitat (or potential of) trigger • Road & stream crossings guidelines and disposition conditions (below the Reg

line), critical habitat • Wetland Policy

Federal • DFO

• Permitted developments vs. Operating Guidelines • “Deposition of deleterious material”

• Nav Waters • Amendments to ease pressure for triggering CCEA, defining navigable


Watershed Management (cont’d) Future Strategic: • Better methods to map watershed / watersource areas • Challenges to modeling (research):

• Anthropogenic vs. natural variability? • Referencing “pre/undisturbed” watersheds • Stream valuations

• Natural disturbance events (MPB, fire, severe weather) • Climate change and changes to forest cover • Larger scale cooperative (e.g. Ducks Unlimited project, Foothills Stream

Xing Assoc, fish critical habitat inventories) • Integrated Land Management to manage cumulative footprint & footstep


Summary: • Watersheds recover as long as the forest grows back and the

disturbance is within thresholds • Timber harvesting under sustainable forest management has little

impact on higher order (larger) watersheds • Natural disturbances / events / trends important • Roads and crossings!! Integrated Land Management • Keeping the Green Zone green (with trees)


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Forest Management and Watershed Values - nswa.ab.ca Winship Weyer... · Cc panel 0503.ppt 1 ... Forest Management and Watershed Values . ... • Timber harvesting under sustainable