Grassland or Open

Healthy grasslands grow a diverse community of native bunchgrasses and forbs. Natural grassland habitats seldom occur in the Swan Valley because enough rain and snow fall annually to grow thick forests that shade out grasses. At MPG North, healthy grasslands are absent from the landscape at present. Commercial timber and real estate development created numerous open habitats that attract some grassland-associated wildlife, like elk (Cervus canadensis), American kestrels (Falco sparverius), eastern kingbirds (Tyrannus tyrannus), tree swallows (Tachycineta bicolor) and western meadowlarks (Sturnella neglecta). We plan to manage these open areas for establishment of native grassland plant species. Unhealthy grasslands exist in the Swan Valley where established by human disturbances. Some cleared areas, now used for livestock grazing, will remain free of trees as long as grazing persists. Roads, log decks, and clearcuts with compacted soils and applications of exotic sod grass seeds also inhibit tree growth. At MPG North, previous real estate managers dredged wetland areas to create open ponds. They spread the dredged soils over clearcut areas and seeded them with exotic grasses like meadow timothy (Phleum pratense) and meadow grass (Poa spp.). These grasses thrive on the wetland soil and prevent tree establishment, but exotic invasive forbs like Canada thistle (Cirsium arvense), oxeye daisy (Leucanthemum vulgare), and spotted knapweed (Centaurea stoebe) gain footholds in wetter areas of the fields. Seeds from the grasses and exotic forbs persist in the seedbank and guarantee future generations of this unusual habitat type.

Some wildlife species favor open spaces in the Swan Valley, but few appear to benefit from the mix of exotic grasses and forbs that grow in fields at MPG North. We define "fields" as unhealthy open areas with exotic grasses and forbs that suppress tree growth. The desired future condition is habitat dominated by bunchgrasses and forbs that provide greater nutritional benefit to wildlife than the unhealthy fields did. Natural succession to trees and shrubs should occur in parts of the grassland, but managed disturbance events like fire will maintain open areas at MPG North for wildlife benefit.


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