Ecosystem restoration, habitat types, and ecosystem geography

ESRM 473

Habitat types

•Coniferous forest

•Eastern deciduous

•Western deciduous

•Woodlands

•Desert

•Shrub-lands

•Meadowlands

•Glades

•Grasslands

•Prairies

•Sand dunes

•Floodplain forest

•Bogs and fens

•Swamp forest

•Riparian forest, woodlands

•Shrub swamps

•Non-estuarine marsh

•Wet prairie, grassland

•Vernal pools

•Mangroves

•Estuarine marsh

Eco-region mapping

•Küchler map of potential natural vegetation of North America

•Bailey’s eco-regions of the United States

Obstacles and Advantages to Restoration in Different Ecosystems

Grasslands and Prairies

•Obstacles

–Grazing

–Fragmentation

–Water supply only seasonally adequate

–Fire-adapted invasives

–Modification of fire regimes

–Encroachment by woody species

•Advantages

–Hardy, adapted natives; many of them grasses

–Native graminoids fire adapted, invasive woody species not.

Oak Woodlands and Savannas

•Obstacles

–Encroachment by conifers

–Encroachment by shrubby understory species

–Poor recruitment

–Grazing

–Modification of fire regimes

–Juniper advance in southwest and midwest

•Advantages

–Fire adaptation

–Very stress-tolerant dominants

–Landscape structure creates refugia

–Rocky landscapes create refugia

Freshwater Wetlands

•Obstacles

–Adequate moisture and light make habitat invasion-prone

–Nasty suite of invasives: reed canarygrass, knotweeds, Phragmites.

–Seeding is not generally effective as the primary mode of installing plant materials.

–Herbivores

•Advantages

–Adequate moisture

–Plantings installed during the wet season do not need additional water

–Abundant sunlight in many systems

–Terrestrial invasives excluded

Coastal Wetlands

•Obstacles

–Salt-affected system; fewer species

–Salt marshes are patchy systems with patches that are very restrictive to plant growth.

–High-salt areas

–Long-inundation areas

–Tides: access is time-limited

–High marsh can become hypersaline

–Geese

•Advantages

–Native species are well-adapted to the unique stresses in this environment.

–Salt-affected systems have limited set of invasives

–Tides moderate salinity and provide water.

–Dominant species are clonal, perennial graminoids that grow and spread rapidly.

Marine Systems

•Obstacles

–Populations of marine plants tend to appear and disappear.

–Water clarity is critical; sediment and nutrients can decrease sunlight penetration.

–Installation often requires diving.

–Algal culturing requires technical competence.

–Grazers and epiphytes inhibit growth

•Advantages

–Eelgrass is easy to salvage and transplant.

–Minus tides in summer allow transplanting without diving.

–Environmental conditions tend to be very stable.

–Growth is fast; algal growth is very fast

Arctic

•Obstacles

–Short growing season, cold, wind, little sun

–Stressful conditions (flooded sites, xeric sites)

–Non-Arctic species will not endure

–Growth is very slow, ecosystem recovery slow

–Melting of ice-rich soils precludes any restoration

–Surface modification may result in melting of soils

–Nitrogen-poor environments

•Advantages

–Well-adapted native species

–Native graminoids will spread

–Patchy environments have some oases.

–Some wet sites may be more amendable to restoration

–Money available from oil company settlements

Alpine

•Obstacles

–Cold, wind, scouring by windborne ice and sand particles

–Big diurnal temperature swings, cryoturbation

–Patchy environment

–Few adapted species

–Slow growth

–Slow ecosystem rebound from disturbance

–Genetic fidelity important

•Advantages

–Snow cover

–Few adapted invasives

–Well-adapted natives

–Growing season conditions nice

–Alpine and subalpine plants can be grown in greenhouses at lower elevation

Aridlands

•Obstacles

–Lack of moisture

–Annual moisture not predictable in warm deserts

–Alien grasses introduced for grazing

–Increased fire frequency

–Cheatgrass

–Grazing

–Vastness, isolation

•Advantages

–Seeding works

–Annual moisture predictable in cool deserts

–Natives well-adapted to low moisture, and some to high salinity

–Plants stress-tolerators

Thornscrub

•Obstacles

–Very fragmented; limited seedbank

–Some thornscrub species grow slowly

–Planting must occur at end of wet season in February; gives only a short window.

–Acreage large; land valuable for other purposes

–Over 150 woody species and 100 grasses; plant material hard to get.

•Advantages

–Some species grow fast

–Some species may be seeded

–Most are woody and very stress-tolerant

–System is shrubby and does not normally burn.

–Since much restoration is re-converting farmland, agricultural techniques may be used

Tropical Moist Forest

•Obstacles

–Conversion of parcels to sunny pasture

–Large forest seeds with short dispersal potential

–Aggressive introduced grasses

–Fire

–Fragmentation resulting in less regional moisture and more fire

–Harsh sunny conditions for shade adapted seedlings

•Advantages

–Fast-growing trees, some wind-borne seeds

–Many species

–Adequate moisture

–Animal dispersers

–Perch trees

Tropical Dry Forest

•Obstacles

–Lack of shade

–Introduction of fire into non-fire-adapted systems

–Introduced invasives (in Hawai’i, Pennisetum setaceum, candelabra grass)

–Grazing

–Pigs

•Advantages

–Well-adapted native species

–Isolated areas protected from fire

–Well-established natives at higher elevations

–Long growing season, seasonal rain.

Old Growth Forest

•Obstacles

–Commercial value of plantation forests

–Historical fire management

–Heavy understory growth

–Some of best old growth is in most inaccessible areas.

•Advantages

–Requires little other than selective harvest

–Some harvested materials can be extracted to finance the restoration

River Restoration

•Obstacles

–Requires a coordinated effort, from watershed to instream scales.

–Permitting is required

–Heavy equipment and transport of materials required for instream work

•Advantages

–Work at watershed or riparian scale may result in restoration at lower scales because of modified sediment and water flows.

–Riparian restoration is done in a system in which establishment and growth is facilitated

–Lots of salmon recovery funding available

Freshwater Tidal Systems

•Obstacles

–Very fragmented

–Less of this system remains than most others

–River systems now dammed and diked; no more floods like historical ones.

–Heavily logged and converted to agriculture

–Diking, tide-gates, culverts, roads, drains

–Land subsidence

•Advantages

–Some of system remains in family farms, wildlife areas, outside of dikes

–Legacy wood exists in some areas now used as pasture.

–Land conservancies have purchased some better sites

–Salmon recovery money has enabled purchase and protection

–Fragmentation may make sites less profitable for logging.