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