Catch Up #6 - Living With Global Change
Given that my aim here is to catch you up on happenings and changes that have shaped the forests – and us forest keepers – between 2020 and 2025, there is an important chapter that remains untold. The common thread running through it is “unwelcome arrivals, present and pending”. While it is understandable and appropriate that the possible impacts of human-driven climate change gets much attention, it is far from the only form of stress and disturbance impacting the forests and those of us who care for them. Accordingly, the broader, more inclusive focus to “global change” feels more accurate and appropriate.
Within only a few days of working in our forests, one can see how profoundly the forests have been shaped, over many years, by the arrival and dominating spread of non-native, invasive organisms. The main forest shapers, with which we’ve battled for generations, are Scotch broom (Cytisus scoparius) and Himalayan blackberry (Rubus bifrons). Wherever a biotic vacuum exists, exposing bare soil, one or both will rapidly colonize and dominate, often overwhelming all native species. For us, “just let nature take its course” is not a viable option. Not surprisingly, those who brought these aggressive plants to our region, did so with good, but ill-informed intentions. We’re told that the choice to use broom to stabilize the miles of loose soil between the lanes of the newly built Interstate 5 served as a powerful vector of its spreading far and wide. Of the multiple tales about how the blackberry ended up here, my favorite is that the first cuttings were given to nuns in Oregon City with the hope that wine from the juice might be fund the path to their economic survival and independence. Regardless of how and why these impactful plants arrived, these forests have been changing for as long as they have existed and new arrivals have always brought change, ranging from tiny to major.
Though we feel like our hands are already full with learning how to live with the aggressive blackberry and broom, we have no choice but to summon the energy and resources needed to deal with what’s more recently arrived and on its way. On the afternoon of June 30th, 2022, while picking his child up for school in Forest Grove, our friend Dominic Maze spotted what are thought to be the first population of Emerald ash borers in Oregon. Having tracked and learned from the spread of this tree-killing insect from its native Asia, to the eastern US, through the Lake States and on to Colorado, we know how serious this unwanted news is. Though we assumed that the question of its arrival was “not if, but when?”, we had hoped that it would not jump to our home region, ten miles from Mt. Richmond Forest, so soon. Oregon ash is a lovely tree, both living and as lumber. Thriving in wet, low lying, poorly drained portions of the forest, we look on it as an ecologically vital restoration workhorse. It grows well where few other trees can survive. Based on research from forests that have been impacted by it further east, we know that it is essentially certain that at least 95% of our ash will die in a decade or less. In the two years since Dominc spotted it in Forest Grove, the iridescent green, tiny insects have already covered 75% of the distance to our forest and spread to multiple counties.
In the spirit of “the changing forest changes us, once again”, we’re busy preparing the “unwelcome mat”. Actions include setting up and regularly using a 1.5 mile walking route through the main ash stands helping us to both inventory the trees and begin monitoring, working with state and federal scientists to collect baseline data in anticipation of the die off, and researching and preemptively test planting alternative tree species amongst our ash. This essay digs more deeply into the psychological dimensions of having the destructive borers nearby and heading our way. As we prepare to lose one of the most colorful and valued threads pulled from the forest tapestry, I am reminded of this nugget from our friend, Tom Hampson:
“The string broke in the midst of the concerto,
Isaac played on.
Afterwords, he said, ‘Your task is to make music with what remains.’.”
Once again, the forests teach us the lesson that love and grief are inseparably intertwined.
More detail on Emerald ash borer in Oregon may be found here.
In August of 2023, before we were able to get our heads – and hearts – around the news of the ash borer, word reached us of the discovery of another tree killing insect less than thirty miles away, in Wilsonville. Though less well understood than the oak borer, Mediterranean borer has the potential to kill or weaken another of the most prized and ecologically important species in Mt. Richmond Forest, Oregon white oak (Quercus garryana). Two reasons why the new threat is troubling are that oak plays a much larger role in the forest than ash and oak has already been removed from over 95% of its historic range in our region. At this point, we, again, have much to learn and good reason to be alert, but, fortunately, the immediate threat seems to be lower than with the ash borer. More information may be found here.
In July of 2024, we learned that we were not at the end of hearing troubling discoveries. While walking through the Mt. Richmond Forest working to control invasive blackberry, a knowledgeable and observant, Spanish-speaking contractor spotted another anticipated and damaging biotic addition to the forest’s plant community – False brome (Brachypodium sylvaticum). Knowing of its ecologically degrading presence in nearby forests, for the past twenty years we’ve been on the lookout and taken steps to limit the risks of its coming into the forest. Steps include requiring that all equipment be thoroughly cleaned before coming into the forests and learning to identify the tough to identify grass. Though false brome appears to be innocuous, we know that when it arrives and is not controlled, it is likely to rapidly and aggressively overwhelm the forest’s diverse, native understory plant community. Given our commitment to restoring the forest’s ecological health, and to, at least, take no actions that harm it, it is tough and troubling to have to acknowledge that, in spite of best efforts, we have, in this case, failed. Our actions apparently led to the arrival of an ecologically damaging plant. Immediately after the discovery, we began efforts to eradicate the plant and strategically launched survey efforts. We are most fortunate to be working in close partnership with our knowledgeable and good partners at Tualatin Soil and Water Conservation District. Together we are developing a more comprehensive plan for limiting and, ideally, removing the brome.
The arrival of False brome, the imminent arrival of the ash borer, and the potential impacts of the oak borer have begun to change the forest and have decisively changed our priorities, strategies and duties as forest caretakers. Just five years ago, in 2020, we’d arrived at a workable relationship with the invasive broom and blackberries and had an uneasy awareness of what might be headed our way. Five years later, the situation is very different. We have a wider range of unwanted, damaging organisms to study, monitor and/or prepare for and respond to. No matter how hard and carefully we work, the forest’s ecology is highly likely to experience big ecological change within this decade. Changes in the forest, in turn, change us and our relationships to the forest. The ever evolving dance between people and land continues. And then.......
