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NATIVE PLANTS

Physiographic Regions &Major Plant Associations

of Maryland

Presented byLouisa Rogoff Thompson

(Louisa Gardener)2005

• Why does this plant grow here?

• . . . and not there?

Prickly Pear (above), Huckleberry

Habitat

• Habitat = home – a place where plants & animals live, where

they can meet all their needs for nutrients, water, shelter, and reproduction.

– It is the physical place,

– including both living and non-living components.

• (An ecosystem is both the place and the activities and relationships within it.)

• What habitats occur in our region?

• Why?

The Physical Place:Geology and Landforms

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Geologic forces create landforms:

• Raise mountains

• Move continents – creating faults and folds

• Raise and lower sea levels

Landforms are also shaped by climate and by animals (e.g. beavers) and humans.

Physiographic regions of Maryland

• Oldest landform in our region is the PIEDMONT– Remains of a

mountain centered near Baltimore

– At Soldiers Delight, the earth’s mantle(usually a mile below the earth’s crust) is exposed

– The Piedmont plateau is made of soil formed as the mountain weathered & eroded

• The older the soil, the finer the texture (clay)

• Tiny soil particles have a high ratio of surface area to interior higher cationinterior – higher cation exchange capacity (CEC) = more mineral nutrients available to plants

– So the Piedmont has very rich soil

Calmes Neck

Northern VA

• 2nd oldest region is the BLUE RIDGE & its VALLEYS

• South Mountain, Catoctin Mountain in MD

• Great Valley: Hagerstown Valley in MD, Shenandoah Valley in VA

• Middletown Valley & Monocacy River Valley

• 500 million years ago, much of the Blue Ridge was submerged under the sea.

Redbud Columbine

g

• Skeletons of marine animals – high in calcium –became limestone & dolomite

• Remains of marine plants became greenstone

• Today we have limestone barrens on the west side of the Blue Ridge, and fertile, neutral soil – the best farmland in the Mid-Atlantic – in the valleys.

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• A huge uplifting of the earth’s surface created the APPALACHIAN MOUNTAINS.

• These have had enough time to erode somewhat, forming the ALLEGHENY PLATEAU - mostly in PA and WV. Western half of Garrett County, MD.

• Steep-sided river valleys are hundreds of feet deep.

Savage River Valley, Garrett County, MD

• To the east of the Appalachians proper (Allegany County, MD – Dan’s Mountain to Sideling Hill) intense folding created the RIDGE & VALLEY Province.

• Here we can see mountains that have not yet created deep soil.

Road cut reveals geology at Sideling Hill

• Shale bedrock is often exposed, creating shale barrens.

• Newest physiographic province in the Mid-Atlantic region is the Coastal Plain –portion of Atlantic coastal shelf above sea level.

• Size and location have changed grepeatedly as sea levels rose and fell.

• Soil is not weathered in place from bedrock, but deposited by rivers and waves.

Beach at Calvert Cliffs, western shore of Chesapeake Bay

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• Because the soil is “young,” its particles are large, i.e., gravelly or sandy.

– Like clay, sandy soil tends to be acidic

– Unlike clay, it drains quickly

– Large particles have much less surface area relative to volume = much lower CEC (fertility).

O A

B

Profile of sandy soil

C1

C2

Soil Profile: O = organic layer (leaf litter); A = topsoil, B = weathered subsoil, C = minimally weathered subsoil

• Between the Piedmont and the Coastal Plain is the Fall Zone

– Edge of piedmont plateau – exposed rock

– Marked by waterfalls –“l di ” h i l i l ti hi ld• “landings” where, in colonial times, ships could go no further

• US 1 was built to connect those landings

Cascade Stream Valley, Patapsco Valley State Park

• On the Coastal Plain, just below the fall line– Old floodplains

have left gravel tterraces

– Also some ancient beaches

This beach is visible from I-95 in Silver Spring. Privately owned, used as a gravel mine and dump, it will be destroyed by the ICC.

Relevance of Geology

• How can we use what we’ve learned so far?

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Ice Ages

• Four Ice Ages during last million years

• Last was Wisconsin, from Great Lakes to New York City– Began about 80,000 years ago

– At its height 18,000 years ago

– Retreated about 13,000-10,000 years ago

• Did not cover Mid-Atlantic, but changed climate, species composition

• Maryland was covered by – boreal forest (spruce, pine, birch)

– also marshes, & wet meadows

Remnants of boreal forest & boreal bogs remain,

at the highest elevations in Garrett CountyGarrett County

• Effects of Glaciation on Land– Glacier alters landforms:

• pushes earth in front of it (moraines)

• carves mountains, mounds hills

• diverts rivers

• compresses land unevenly

• causes drop in sea level (water is locked up in ice)

• Retreating glacier– left deep lakes (none this far south) &

sphagnum bogs (Garrett County)

– left rocks and soil from further north

– allowed sea level to rise (some areas far inland were covered by seas)

• The Susquehanna floodplain became the Chesapeake Bay

– This cobble at Chapman Forest (Charles Co.) was carried by the swollen Potomac, all the way from the Ridge & Valley

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• Effects of Glaciation on Species

– Pushes plants, animals south during ice age• greater diversity in non-glaciated areas --

Appalachian cove forests

– Cooler temp’s favor wetland development• less evaporation

• Permafrost blocks drainage, leading to formation of bogs

– Species return northwards as ice retreats• Spores, very fine seeds, & winged seeds

travel on wind -- travel furthest– mosses, lichens, then ferns, some sedges,

grasses, flowers, trees (maples, etc.)

– maples & elms moved 650-800’ per year

• Seeds dispersed by birds and large animals• Seeds dispersed by birds and large animals move more slowly

– Those dispersed by small animals, even slower

– acorns -- 500’ in 25 years

• Some plants have not yet reached the fullest extent of their potential range

Implications for Permaculture Design?

Major Plant Associations of Maryland

• Allegheny Plateau –Garrett County, MD

Chestnut Oak & Chestnut Oak-Bear Oak Associations in highest, driest portions

Sugar Maple-Basswood Association on lower, moister slopes

Hemlock-Birch Associationin river valleys Rosebay rhododendron, hemlock

Savage River State Forest

• Allegany County - Ridge and Valley Province – In the rain shadow of the Appalachians

• Much less rain, esp. on eastern slopes

• with local exceptions

– Ridges and mountainsides of:• sand and sandstone

• siltstone

• shale -- barrens on steep, south-facing shale slopes (many rare plants)

– Chestnut Oak-Bear Oak Association (scrub)

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• Great Valley –

Washington County– loamy, rich,

calcareous soil –richest in MD (prime farmland)

– many plants uncommon in MD

Sugar Maple-Basswood Association

• Catoctin Mountains (Blue Ridge) --Frederick & Carroll Counties

Chestnut Oak A i tiAssociation

on uplands

Hemlock-Birch Association

in mountain

stream valleys

• Limestone bluffs along Potomac

• Sinkholes, caverns

Plants adapted to high pH

Wild Columbine

• Piedmont (portions of Frederick, Carroll, Montgomery, Howard, Baltimore, Harford Counties)

– 50-250’ elevation at fall line

– Up to 900’ approaching Blue Ridge

– Rolling to steep hills

– Extremely varied geology

– Highly weathered (clay) soil

– Abundance of rivers and streams

Eastern Hardwood Forest Associations:

Chestnut Oak Association – drier, thinner soil on steep slopes; often more acidic

Chestnut Oak-Post Oak-Blackjack Oak Association on serpentinite and other extremely dry, rocky soils

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Tulip Poplar Association on moist uplands -- pioneer trees, young woodlands

Hudgens native plant garden, Harford County

Dogwood, fall foliage

Oak-Hickory Forest (Mature Forest)

White oak, Caves Valley, Baltimore County

– Shrub layer • heath family in acidic soil

• maple-leaf viburnum in dry neutral soil

• spicebush in moist, rich soil

Spicebush Maple-Leaf ViburnumSpicebush Maple Leaf Viburnum

– Herbaceous layer of spring wildflowers, ferns, sedges

• Inner Coastal Plain (northern and western parts of P.G., A. A., and Cecil Counties)

– elevations to 50’, rolling hills, some steep ravines and river banks (Potomac)

Fall Zone – Coastal Plain Chapman Forest

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– mostly sandy soil (well-drained, acidic, less rich than piedmont)

– abundant rivers and streams

– 3+ centuries of European-American farming

Oak-Hickory ForestOak Hickory ForestTulip Poplar Association on richer soils

sweet gum; southern red oak tends to replace northern

Chestnut Oak-Post Oak-Blackjack Oak Association on poorer soils

Sweet Gum

River Birch-Sycamore Association on river and stream banks

Chestnut Oak-Post Oak-Blackjack Oak Association on the richest of the sandy soils in southern Maryland

Basket Oak, Loblolly Pine, & Willow Oak AssociationsAssociations– poorly drained bottomlands, very sandy,

acidic soils

– Loblolly Pine on tidal marshes in southern portions

– Basket Oak can grow farther north

– Willow Oak on better drained soil

Some Rare Plant Associations of Maryland

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Tamarack Association

– Boreal Forest: Spruce, Fir, Hemlock

– Boreal Bogs and Swamps: Tamarack, Sphagnum Moss, CranberrySphagnum Moss, Cranberry

• glacial depressions, no natural drainage– extremely acidic water

– very slow decomposition – formation of peat

Triassic Basin --near Darnestown in western Montgomery Co. & south into VA

(Piedmont)• Shingle Oak

Walking fern at Calmes Neck, VA

gAssociation, including Redbud, Nannyberry, Dwarf Juniper, Dwarf Hackberry, many rare plants

• Serpentine Outcrops (Piedmont)• unusual rock formation, earth’s mantle

• dry, rocky soils high in Mg, heavy metals

Serpentine barrens -- sandplain gerardia, fameflower, other desert-like plants

Almost pure gravel – mostly sandstone, some serpentinite (greenish)

Lyre-leaved rock-cress

serpentinite (greenish)

Serpentine wetlands -- fringed gentian, New York ironweed (note paucity of flowers)

Serpentine woodland --post oak, blackjack oak, blueberries Now invaded by

Virginia pine – one of those slowly migrating trees movingtrees, moving north since the Ice Age

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Serpentine grassland –

little and big bluestem, Indian grass, prairie wildflowers

Butterfly Weed Big bluestem

Coastal Plain Bogs (Magnolia Bogs)• once common (more than 30) in Anne Arundel

and Prince George’s Counties

• most have been drained or filled

• Suitland Bog can be visited

• slow-draining (not true bogs) due to impermeable soil, perched water tables

• acidic, low rate of decomposition, insectivorous plants (pitcher plant, etc.)

• also sweet bay magnolia, swamp azalea, poison sumac, rose pogonia

Magnolia bogs typically include blueberry, mountain laurel, swamp azalea, large ferns, insectivorous plants

Bald Cypress Swamps –Coastal Plain– a few small swamps in

southern MD, both Eastern and Western Shore

– Bald Cypress Association includes black gum, sweetbay magnolia, wax myrtle, Virginia sweetspire, sweet pepperbush, other plants uncommon in MD

Dunes - Atlantic Coast & Barrier Islands– shaped by wind and

water– desert-like conditions due

to fast drainage, exposure to sun, wind, salt

– succession starts with– succession starts with dune grass, whose rhizomes hold soil and build humus

– plants conserve moisture through succulent stems; waxy, gray, hairy, narrow or folded leaves; deep or extensive roots

So . . . What does it mean to say a plant is y p“native to Maryland?”