Forests as water management tools
Paul Egginton
Community Stewardship Council of Lanark County
Why should we reforest areas ?
Timber Pulp and paper Firewood Other forest products
mushrooms maple syrup
Erosion and flood control Shade Carbon sequestration Bio-fuels Biodiversity Water ?
The Hydrological Cycle
and Climate Change
Mean Daily Stream Flow Comparison
Mississippi River @ Appleton (WSC
02KF006)
Discharge Mississippi Watershed - 30 year averages for different periods
Lehman (2010)
Egginton and Lavender 2008
If all else is constant then the hydrological consequences of afforestation or forest restoration are:
• increased interception and water loss
• reduced delivery of water to the soil surface
• increased transpiration from a larger leaf area
• reduced soil water contents, and groundwater recharge
• all of the above changes initially leading to reductions in streamflow (annual, peak & low flows)
Forests and water
There are ways to manipulate forests/plantations forincreased water yield, including:
Selecting species of different water-use efficiencies and interception efficiencies and form (e.g. coniferous versus deciduous)
Consider reducing planting density or adopt specific planting patterns
Limit the percent of the catchment planted Change the rotation time
Forests, and water
Interception
Interception
Accumulation under Pine Forest in 2010 was only 50 % of open areas
Open up the spacing !
Open Field 20 11
Closed Canopy 10 5
Edge of clearing 23 9
Mid clearing 38 16
Edge of stand 43 23
LocationSnow depth (cm)
March January
Spring Melt
Spring Melt
Transpiration and soil moisture deficits
Hu et al 2010
Transpiration in a Colorado – sub-alpine forest
Hu et al 2010
Carbon uptake is related to transpiration
Relative Transpiration rates
Lanark County
Note – data demonstrate relative values only
Transpired mm/100 days
Burr Oak 43
Red Oak 17
Sugar Maple 14
Poplar 128
Willow 99
Changes in forest cover can/will change river flows, lake levels
In Mississippi Watershed evapotranspiration = 62% of all precip
Moving the discussion forward
CMOS- CGU session, Ottawa, June 3, 2010Forest Hydrology and Water Management
NRCan Panel Discussion, Ottawa June 4, 2010Forests: a tool for water management in the face of climate change
Changes in river flow – related to forest age
Jackson 2010
Changes in river flow – related to forest age
There may well be untended consequences from our planting and forest management strategies such as degradation of water quality or quantity and trade-offs and choices may be required in terms of what we manage for (e.g. timber, water, or carbon).
Water managers need to consider the implications of planting programs on basin or sub-basin flow conditions.
There are benefits to managing forests/plantations from a watershed perspective instead of from a stand perspective
Forests, water and climate change
Forests, water and climate change
Climate change will affect forests and water resources profoundly.
In the next 10 to 20 years, climate policy (promotion of bio-fuel uses, carbon offsets etc.) will likely affect forests and water resources in some catchments more than climate change itself.
Our shared vision begins with restoration. Restoration means managingforest lands first and foremost to protect our water resources, whilemaking our forests more resilient to climate change. Forest restorationled by the dedicated people at the Forest Service opens non-traditionalmarkets for climate mitigation and biomass energy while appropriatelyrecognizing the need for more traditional uses of forest resources."Emerging markets for carbon and sustainable bio-energy will providelandowners with expanded economic incentives to maintain andrestore forests. The Forest Service must play a significant role in thedevelopment of new markets and ensuring their integrity. Carbon andbio-energy aren't the only new opportunity for landowners. Markets forwater can also provide landowners with incentives to restorewatersheds and manage forests for clean and abundant water supplies.
US Forest Service
Jackson 2010, Forests Water and Climate Change Workshop
The New “Forest Product” – Water
Jim Vose and Ann BartuskaUSDA Forest Service
Research and Development
CMOS - CGU 2010
Transpired over yearmm/a
Oak-Pine-Hickory 278
Upland Oak 313
Mixed Pine Hardwood 450
Eucalyptus Plantation 882
Vose and Bartuska 2010
Transpiration in an Eastern US Watershed
There are ways to manipulate forests/plantations forincreased water yield, including:
Selecting species of different water-use efficiencies and interception efficiencies and form (e.g. coniferous versus deciduous)
Consider reducing planting density or adopt specific planting patterns
Limit the percent of the catchment planted Change the rotation time
Forests water and climate change