trees, soil, and water · green infrastructure toolbox planting trees Œ it™s the soil! plant...

Trees, Soil, and Water:Trees, Soil, and Water:Green Infrastructure Green Infrastructure for a Changing Climatefor a Changing Climate

presentation to the APWASymposium on Climate ChangeTempe AZ, April 9-10 2008

David McDonaldSeattle Public Utilities

[email protected]

Source for climate graphics: UNEP, www.vitalgraphics.net

Climate change causes Climate change causes and effects are complexand effects are complex

What we know:What we know:Climate (& related) challenges, next 20Climate (& related) challenges, next 20--50 years50 years

↑↑ Intense storm events Intense storm events = stormwater loading, flooding, = stormwater loading, flooding,

wind damagewind damage

↔↔ Precipitation variability Precipitation variability = = ↓↓ snowpacksnowpack, , ↔↔ water supply, water supply,

↑↑ multimulti--year variations (e.g. drought) year variations (e.g. drought)

↑↑ Energy costs & demands: transport, cooling/heatingEnergy costs & demands: transport, cooling/heating= changing transportation demands, building requirements = changing transportation demands, building requirements

↓↓ Agricultural productivity Agricultural productivity (due to soil loss, fertilizer costs, (due to soil loss, fertilizer costs, weather, climate & political disruptions, etc.)weather, climate & political disruptions, etc.)= local/global food disruptions, = local/global food disruptions, ↑↑ transport coststransport costs

Lessons from the carbon cycle Lessons from the carbon cycle �� soil and vegetation matter!soil and vegetation matter!

Source: UNEP www.vitalgraphics.net

What to do What to do nownow,,in the face of future climate uncertainty?in the face of future climate uncertainty?

�� Build Build resilientresilient infrastructure: flexible, adaptableinfrastructure: flexible, adaptable�� Integrate Integrate ��ecosystem servicesecosystem services�� as infrastructure:as infrastructure:

Green InfrastructureGreen Infrastructure = using natural systems (e.g. = using natural systems (e.g. soils and vegetation) to supplement built systems for:soils and vegetation) to supplement built systems for:�� Waste recycling Waste recycling �� Stormwater management Stormwater management �� Water supply (& conservation) Water supply (& conservation) �� Food security Food security �� Energy conservationEnergy conservation

Climate solutions: green infrastructureClimate solutions: green infrastructure��s roles roleMitigationMitigation (reducing greenhouse gases)(reducing greenhouse gases)�� Soil building Soil building �� to to ��sequestersequester�� carbon from atmospherecarbon from atmosphere

�� Local/regional economies Local/regional economies �� to reduce transport fossil fuel useto reduce transport fossil fuel use

�� Green building Green building �� reduce lifecycle energy & fossil fuel use reduce lifecycle energy & fossil fuel use

�� Organic waste to compost/soil (Organic waste to compost/soil (notnot landfills or incineration) landfills or incineration) �� to reduce methane and COto reduce methane and CO22

AdaptationAdaptation ((��climateclimate--proofingproofing�� our cities) our cities)

�� Soil building Soil building �� for stormwater mgmt., etc. for stormwater mgmt., etc.

�� WaterWater--conserving landscapes conserving landscapes

�� City trees City trees �� reduce energy, improve air, water, environment reduce energy, improve air, water, environment

�� Local food security planningLocal food security planning

Green infrastructure toolboxGreen infrastructure toolbox

SoilSoilBenefits of healthier soil:Benefits of healthier soil:

�� Stormwater infiltrationStormwater infiltration�� Water conservation Water conservation

(cut irrigation 50%) (cut irrigation 50%) �� BiofiltrationBiofiltration of urban air of urban air

& water pollutants & water pollutants �� Reduced need for Reduced need for

fertilizers, pesticides fertilizers, pesticides �� Healthier, drought & Healthier, drought &

diseasedisease--resistant plants resistant plants

UW trials, turf on glacial till soil

Compost-amended till soil – up to 50% reduction in storm water runoff

Compost Compost kickstartskickstarts soil biology, soil biology, repairs damaged soilsrepairs damaged soils


Building healthy soilBuilding healthy soil�� Require soil BMPs for all new and reRequire soil BMPs for all new and re--development:development:

�� Protect native soils and vegetation where possibleProtect native soils and vegetation where possible�� RestoreRestore disturbed soils, by correcting compaction and disturbed soils, by correcting compaction and

amending with compostamending with compost

�� Recycle landscape wastes back into the soil:Recycle landscape wastes back into the soil:�� Shredding leaves and Shredding leaves and pruningsprunings to mulchto mulch�� GrasscyclingGrasscycling�� (mulch mow lawns)(mulch mow lawns)

�� Specify compost & mulch for Specify compost & mulch for construction erosion controlconstruction erosion control

!! www.BuildingSoil.orgwww.BuildingSoil.org!! Stormwater: combine with other Stormwater: combine with other

��Low Impact DevelopmentLow Impact Development�� tools, tools, www.seattle.gov/util/NaturalSystemswww.seattle.gov/util/NaturalSystems

Blanket

Berm Wetland

Washington DOT specifies compost blankets, for cost-effective erosion control and excellent long-term plant establishment.


Organic waste Organic waste →→ soil lifesoil lifeYard waste, paper, food waste are too precious to Yard waste, paper, food waste are too precious to burn or landfill burn or landfill �� we need to return them to the soil!we need to return them to the soil!

�� Burning creates COBurning creates CO22, pollution, little energy , pollution, little energy �� LandfillingLandfilling creates methane (23creates methane (23--60 times more potent a 60 times more potent a

greenhouse gas than COgreenhouse gas than CO22 -- only 50only 50--75% of methane is 75% of methane is captured by landfill recovery systems)captured by landfill recovery systems)

�� CompostCompost municipal organic collection: food, yard waste municipal organic collection: food, yard waste (recycle clean paper; compost food(recycle clean paper; compost food--contaminated paper)contaminated paper)

�� Reuse fall leaves, Reuse fall leaves, pruningsprunings (shredded) as mulch (shredded) as mulch �� Promote onPromote on--farm composting of manures, or closed farm composting of manures, or closed

anaerobic digestion with methane capture/use, and anaerobic digestion with methane capture/use, and composting/reuse of residuals composting/reuse of residuals

�� BiofuelsBiofuels production: never at expense of food or soil healthproduction: never at expense of food or soil health


TreesTreesBenefits:Benefits:

�� 1010--3030°°F moderation of temperature (cold or hot) F moderation of temperature (cold or hot) for adjacent buildings and street environments for adjacent buildings and street environments �� a big savings a big savings in cooling and heating costs, material stressesin cooling and heating costs, material stresses

�� EvapoEvapo--transpiration of stormwater transpiration of stormwater �� up to 50% of up to 50% of precipprecip..�� No irrigation req. (after establishment) if right species & soilNo irrigation req. (after establishment) if right species & soil�� Enhance slope and channel stability, reduce erosion Enhance slope and channel stability, reduce erosion �� Enhance quality of life, public health, Enhance quality of life, public health,

habitat, property valueshabitat, property values


TreesTreesWhat to plant? What to plant? �� Select a Select a diversitydiversity of hardy natives or of hardy natives or

locally adapted to the locally adapted to the hotter and dryerhotter and dryerend of current local climate (look south)end of current local climate (look south)

�� Work with local foresters Work with local foresters �� diversity of species gives more diversity of species gives more chance of success, more resiliency as climate changeschance of success, more resiliency as climate changes

Where to plant?Where to plant?�� Conifers/denser species to north of buildings Conifers/denser species to north of buildings �� winter winter

protectionprotection�� Deciduous to south of buildings Deciduous to south of buildings �� winter sun, summer shadewinter sun, summer shade�� Every street needs trees; even more in a hotter worldEvery street needs trees; even more in a hotter world


Tree preservationTree preservationOnly save the tree if you can save Only save the tree if you can save

almost the whole root zone!almost the whole root zone!�� Fence out vehicles & storageFence out vehicles & storage�� Protect roots with 4Protect roots with 4--66�� of coarse of coarse

wood chip (wood chip (��hog fuelhog fuel��) or gravel ) or gravel �� Bore utilities rather than trenching Bore utilities rather than trenching

through roots through roots �� If the soil gets compacted, or grade If the soil gets compacted, or grade

is changed, the tree is (soon) deadis changed, the tree is (soon) dead�� Remove and replant where the Remove and replant where the

root zone canroot zone can��t be savedt be saved

!! www.seattle.gov/transportation/forestry.htmwww.seattle.gov/transportation/forestry.htm


Planting trees Planting trees �� itit��s the soil!s the soil!Plant trees that can grow to Plant trees that can grow to mature sizemature size in available soil in available soil ��to get a 100to get a 100--year lifespan instead of 15 yearsyear lifespan instead of 15 years

�� Trees need 2 cu. ft. of soil access for each Trees need 2 cu. ft. of soil access for each 1 sq. ft. of mature canopy area1 sq. ft. of mature canopy area

�� Soil: max 85Soil: max 85--90% compaction, 90% compaction, min 2min 2--4% organic matter 4% organic matter (= 10(= 10--15% compost volume in soil blend)15% compost volume in soil blend)Use native soil where possible.Use native soil where possible.

Two strategies for soil volume in urban environments:Two strategies for soil volume in urban environments:!! Structural soilsStructural soils www.hort.cornell.edu/uhiwww.hort.cornell.edu/uhi

go to Outreach>Structural Soilgo to Outreach>Structural Soil

!! ��Silva CellSilva Cell�� www.deeproot.comwww.deeproot.com or other or other structures supporting pavement, while structures supporting pavement, while maintaining large areas of uncompacted maintaining large areas of uncompacted compostcompost--amended soil underneathamended soil underneath


Building a city of treesBuilding a city of trees

Combine good regulation, public works Combine good regulation, public works leadership, and community involvement leadership, and community involvement for a durable, adaptive urban forest.for a durable, adaptive urban forest.

!! American Forests American Forests �� urban forestry planning resources urban forestry planning resources www.americanforests.orgwww.americanforests.org//

!! Tree People Tree People �� successful community projects, creating urban successful community projects, creating urban forests as stormwater infrastructure forests as stormwater infrastructure www.treepeople.orgwww.treepeople.org//

!! Seattle Green Factor Seattle Green Factor �� urban tree, vegetation, & green roof urban tree, vegetation, & green roof guidelines guidelines www.seattle.gov/dpd/greenfactorwww.seattle.gov/dpd/greenfactorand and www.seattle.gov/transportation/forestry.htmwww.seattle.gov/transportation/forestry.htm


WaterWater--conserving landscapesconserving landscapes�� Choose plants that fit the site & local conditions: native or loChoose plants that fit the site & local conditions: native or locallycally--

adapted, pest & drought resistant adapted, pest & drought resistant �� Minimize lawn area Minimize lawn area �� only where needed, put under light tree only where needed, put under light tree

shade. Build playfields on deep, healthy, wellshade. Build playfields on deep, healthy, well--drained soil. drained soil. �� Build healthy soil with compost and mulch Build healthy soil with compost and mulch �� Irrigate just through establishment (2Irrigate just through establishment (2--3 years) 3 years) �� if a landscape if a landscape

cancan��t make it on local rainfall, replant one that cant make it on local rainfall, replant one that can�� Where irrigation is necessary, Where irrigation is necessary,

use smart controllers: ET or use smart controllers: ET or soil moisture basedsoil moisture based

�� Tree canopy cover cuts Tree canopy cover cuts water needs of plants below. water needs of plants below. Plant like the forest: ground Plant like the forest: ground cover, cover, understoryunderstory, canopy, canopy

!! www.buildingsoil.org/tools/Landscaping_Guide.pdfwww.buildingsoil.org/tools/Landscaping_Guide.pdf

100

120

140

160

180

200

220

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Wat

er U

se (m

il ga

l/day

)

0

1

2

3

4

5

6

Rai

nfal

l (in

ches

)

Water UseRainfall

"Summer

landscape irrigation


Local food securityLocal food security�� Regional farmland preservation (including water supplies)Regional farmland preservation (including water supplies)�� Farmers markets and other tools to promote local marketingFarmers markets and other tools to promote local marketing�� Near and inNear and in--city market gardeningcity market gardening�� Community gardens Community gardens �� strategic use of public landstrategic use of public land�� Lean pathLean path�� minimizing waste in food distribution & prepminimizing waste in food distribution & prep�� Reuse of otherwiseReuse of otherwise--wasted institutional & commercial food wasted institutional & commercial food

(support collection & redistribution systems) (support collection & redistribution systems) �� Recycling food waste to compost in backyards, institutions, Recycling food waste to compost in backyards, institutions,

and city collection systemsand city collection systems!! American Planning Assoc. guides American Planning Assoc. guides --

http://www.planning.org/divisions/initiatives/foodsystem.htmhttp://www.planning.org/divisions/initiatives/foodsystem.htm!! Seattle Seattle -- http://www.seattle.gov/council/conlin/http://www.seattle.gov/council/conlin/!! Portland Portland -- http://www.portlandonline.com/shared/cfm/image.cfm?id=171174http://www.portlandonline.com/shared/cfm/image.cfm?id=171174!! google google ��Food SecurityFood Security�� and and ��Community Food SystemsCommunity Food Systems��

To sequester carbon, support sustainable agriculture & forestry

to rebuild Earth�s soils

When the going gets hotWhen the going gets hot��Natural systemsNatural systems ((��green infrastructuregreen infrastructure��) have:) have:�� Lower energy demands Lower energy demands �� Lower maintenance (working Lower maintenance (working withwith nature is always easier)nature is always easier)�� Higher resiliency = more dependableHigher resiliency = more dependable�� Are locally empowering and adaptable over timeAre locally empowering and adaptable over time

trees, soil, and water · green infrastructure toolbox planting trees Œ it™s the soil! plant...

Documents