Paramount Open Space is small, but this small place contains a variety of habitats from dry upland forests with pacific madrone to a small creek that meanders through wetlands that were once a peat bog.

A small creek runs through a young alder forests before emptying into a restored wetland.

Natural plant communities in Paramount include upland evergreen forest, lowland alder forest, and forested wetlands. Like many urban forests in our region invasive species have degraded the ecological value of this area by diminishing plant diversity and inhibiting tree regeneration.

English ivy will smother and kill native wild flowers over time. In this photo Pacific bleeding heart is being overtaken by English ivy.

Over time invasive species can produce a number of undesirable outcomes including:

  1. Elimination of animal habitat. Fewer plant species means a smaller number of food sources and shelter.
  2. Conversion of forest to shrublands. Invasive species form a dense monoculture in the understory that prevents seedlings from becoming established. Most trees at Paramount are short-lived alder. As they begin to die invasive plants will thrive on the increased sunlight and replace trees.
  3. Negative effects on salmon habitat. Streams that originate in Paramount Open Space flow into Thornton Creek which has been the focus of major stream restoration efforts. Decreases in forest cover due to invasive species encroachment can lead to higher water temperatures and reduced dissolved oxygen concentration. Both are detrimental to salmon.
Western redcedar seedlings emerge from the leaf litter in 2019. This area was covered in Himalayan blackberry until restoration efforts over the past year. Removal if blackberry in this area initiated the first natural tree regeneration in Paramount is 10-20 years. Hundreds of seedlings including cedar, Douglas-fir, grand fir, western hemlock, and red alder have sprouted in the restored area.

Upland Forest

Upland sites are dominated by a mix of conifers, primarily DOUGLAS-FIR (Pseudotsuga menziesii) and to a lesser extent WESTERN HEMLOCK (Tsuga heterophylla), WESTERN REDCEDAR (Thuja plicata), and WESTERN WHITE PINE (Pinus monticola). Deciduous trees include BIGLEAF MAPLE (Acer macrophyllum). The shrub layer includes a mix of native and invasive species while the ground cover is dominated by the invasive ENGLISH IVY (Helix hedera), which has for the most part eliminated native understory grasses and wildflowers.

Lowland Forest

Lowland sites are dominated by RED ALDER (Alnus rubra) with other trees including WESTERN HEMLOCK, WESTERN REDCEDAR, and BLACK COTTONWOOD (Populus trichocarpa) occurring infrequently. The shrub layer is dominated by native SALMONBERRY (Rubus spectabilis), although invasive HIMILAYAN BLACKBERRY (Rubus discolor) is encroaching along forest edges and JAPANESE KNOTWEED (Fallopia japonica) is becoming established in wetter areas, especially along streambanks. As with upland forests ENGLISH IVY is well established in the understory and has mostly eliminated growing space for native herbs.

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