This story appears in the Spring 2015 edition of Our Big Backyard, a quarterly magazine about parks and nature. Read more stories, plan an outing with a field guide, and find out more about fun nature events and classes.
Winter is planting season in Metro natural areas. On a typical planting day, it’s cool and wet, and I’m in the field before sunrise.
Whatever the weather, a planting day is a day of new beginnings. On a recent morning, we start the reforestation of the headwaters of North Abbey Creek in the North Tualatin Mountains northwest of Portland near Forest Park. The headwaters start in an upland bowl that includes Metro’s newest acquisition in the Rock Creek watershed.
This 15-acre field used to be a forest – and will be again someday. By the end of our work, 20,000 native trees and shrubs will be settling into the soil waiting for the longer days and warmer weather that trigger the surge of green growth.
Headwaters are the small drainages at the uppermost end of a river system. Fed by springs and rainfall, headwaters may carry water only during winter storms and rapid snow melt. Some are so diminutive that their presence is subtle, but they are ecologically significant. Headwater streams make up most of the stream miles in a watershed, so restoring and taking care of these streams is fundamental to protecting water quality.
Even these tiniest streams attract terrestrial insects. Insects provide food for bats and birds, such as long-eared myotis bats and Swainson’s thrush, and are more abundant than in the adjacent upland habitat.
The North Abbey headwater forests were cleared decades ago to create grazing land. The loss of the native trees and shrubs allowed rainwater to move like a flowing sheet over the field, delivering more water faster to the main creek. Without the forest to filter the power of the rain, our frequent winter storms resulted in incised channels and slumped stream banks that sent soil coursing down to Rock Creek and on to the Tualatin River.
Reforesting the headwaters will slow the rush of water to the channel, reduce erosion and improve water quality.
All of that depends on getting native plants and shrubs into the ground.
When the planting crew shows up, I pull on tough rubber pants, field boots, jacket and gloves. The planting crew sorts 24 different species into groups according to where the plants will go. The species that tolerate saturated soil will be planted in the swales that are temporarily inundated with water. All the other plants get lumped as upland species destined for higher ground.
Each planter packs hundreds of plants into hip bags, throws a shovel over his shoulder and heads down to the first line of the day. Moving along the contour of the slope, the planter drives his shovel into the ground, breaks the soil open, bends, tucks a plant into the hole, closes it and moves on.
Each planter will slip a baldhip rose, red elderberry or Sitka willow into the earth and then repeat until hundreds and then thousands of plants are in place. Tomorrow, the process repeats.
The complexity of a forest takes decades to develop, but in a few years, we will begin to see a change in the hydrology and wildlife of the North Abbey headwaters. The seasonal eruption of native plants with their flowers, berries and nuts will attract pollinators. The canopy of needles and leaves will buffer the land from the pounding rain. Intertwining roots will hold the soil and store and slowly release thousands of gallons of water.
Long after I’ve moved on, the trees planted today will grow old and die. The future forest will already have young trees growing in the understory, ready to fill the sunny gap left where the old giants fell.
By the end of planting season, I will have inspected hundreds of trees and shrubs and planted a few myself. We inspect our planters’ work to ensure the native trees and shrubs get a strong start to their wild life. The simple motion of planting one tree will be repeated more than 500,000 times this planting season across Metro natural areas.
Planting is the work of patient optimists. Fortunately, there are many of us.