B R I A N VA N E E R D E N

D I R E C TO R , V I RG I N I A P I N E L A N D S P RO G R A M

The State of Virginia Beach’s

Forests

USING NATURE TO ADDRESS FLOODING

Identifying nature based solutions

• Basic forest hydrology

• Overview of VA Beach’s

forests

• State of the forest

• Forest conservation strategies

Outline

A forest is more than the trees.

Different forests provide different services.

A larger forest can provide more services and benefits

than a smaller forest.

Basic forest concepts

• Flood storage • Shoreline armoring/storm surge protection • Water quality protection • Wildlife habitat • Commercial forest products • Aesthetics • Recreation • Carbon storage • Air quality protection

Services Forests Provide

Soil water storage

Trees are water managers

saturated zone

unsaturated zone

Land surface

1. Rate of surface water infiltration into the unsaturated zone 2. Water storage capacity of the unsaturated zone

infiltration

Surface runoff

Factors influencing amount of surface water runoff

saturated zone

unsaturated zone

Land surface

infiltration

Surface runoff

Sea level rise and loss of soil water storage

Photo courtesy of LEARN NC, www.learnnc.org

Water Budget for Natural Ground Cover

Surface Area

Water Budget for 75% - 100% Impervious

Surface Area

Effect of forest cover on infiltration

The influence of forest cover on water runoff

saturated zone

unsaturated zone

Land surface

infiltration

Surface runoff

The role of trees as groundwater pumps

evapotranspiration

Clear cut event

Years since clear cut harvest of mature forest

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http://msbusiness.com/2018/06/the-bottom-line-on-bottomland-hardwood-forests/

Natural shoreline and floodplain armoring

saturated zone

unsaturated zone

• Soil infiltration • Water pumping – maintaining soil water storage capacity • Storm surge/shoreline protection

Land surface

infiltration

Surface runoff

Summary of forest hydrology concepts

evapotranspiration

Forest hydrology is complex!

Outline Basic forest hydrology

• Overview of VA Beach’s

forests

• State of the forest

• Forest conservation strategies

How much forest cover is there in VA Beach?

Total land area: 155,314 acres

Total tree canopy area:

58,291 acres

False Cape SP

First Landing SP

Sandbridge

N. Landing River

W. Neck Crk.

Cover type percent

Tree canopy 36%

Grass/shrub 30%

Other paved 16%

Buildings 9%

Roads 8%

Bare soil 1%

• Urban area % tree canopy cover: 36%

• Rural area % tree canopy cover: 35%

Forest types: hardwood

Fire-maintained pine woodland

Cypress-gum/tupelo forest Mixed hardwood forest

Cypress shoreline

Forest types: pine and mixed hardwood/pine

Pine pocosin

Fire-maintained pine woodland Maritime forest Mixed hardwood/pine forest

Loblolly pine plantation

2006 NLCD, NWI data

Distribution of forest types

Total Forest Cover • 23,566 acres wetland • 16,799 acres upland

Back Bay

North Landing

River

Waterway and wetland forest cover

Back Bay

North Landing

River

West Neck Creek

Land elevation of forested areas

Conserved forest lands

• Approx. 50% of forest under conservation ownership.

• Approx. 57% of wetland forest conserved.

• Approx. 38% of upland forest conserved.

2006 NLCD

Conservation ownership map

VA DCR

TNC

Summary of forest conservation achievements

• 20,650 acres of forestland conserved in VA Beach • approx. 50% of all forest land • @ $750/acre = $15,450,000 value

• Meeting primary objectives • wildlife protection • recreation, aesthetics, water quality protection, AICUZ

• Contributions to flood storage and storm surge protection?

State of VA Beach Forest

• Considerable forest cover (36% tree canopy cover) • Well positioned for storm surge abatement in

some areas • Over 50% conserved and managed for old-growth

• Challenges:

• Little forest cover in residential areas and smaller waterways

• Difficult to predict future of forest on private lands

• Low-lying forest vulnerable to sea level rise

Forest Conservation Strategies

1. Evaluate flood risk reduction value of forest blocks.

Flood storage value Evapotranspiration potential Shoreline armoring Evaluate contributions under

current and future sea level rise scenarios.

2. Create incentives for private landowners to conserve land. 3. Pursue opportunities to increase forest cover.

Questions?