Research with a broad geographic scope reveals that inexorable climate change is increasing fire frequency, extent, and severity.

In the Pacific Northwest an abrupt harbinger of the effects of future climate warming may have been the unprecedented 110+ degree heat wave of June 2021. This multi-day, extreme heat event scorched green foliage on these maple trees trying to recover from the fire nine months before. The brown, scorched leaves evident in summer 2021 fell to the ground and the treetops died.

Sprouts emerging from the base of maple trees supported a lush crop of foliage in early summer 2021, but the heat wave of late June overwhelmed the trees’ capacity to deliver cooling water to many leaves, so the leaf margins turned brown from heat damage. When the heat wave abated, the shoots put out a flush of dense clusters of small, lighter green leaves.

What challenges will continued climate change and the associated heat waves present to future forests?

Frequent clearcut logging and single-species tree plantations have been widespread across the industrial forestlands of this region for decades. Simple plantations of young trees on intensively managed lands burned with notable completeness, and many were quickly salvage-logged to become forest products. Cutting at a frequency driven by financial considerations alone may risk the productive capacity of the land; a longer cutting cycle managed by local, family-run firms may prove more sustainable in the long run. The blaze on this tree marks the edge of the logging area to be cut.

This sequence of three images shows stages of the burned forest following fire. First, in March 2021, the blackened young forest that grew after logging of an old forest, now represented by decomposed logs and stumps, is devoid of vegetation. The second image shows vegetation returning in August 2021, but soon logging of burned trees occurred, shown here in January 2022.

Looking along a cutting unit boundary in September of 2021, we see the contrast between production forestry management on one side of the ownership line and practices of a land trust, the McKenzie River Trust, on the other. The Trust is leaving the burned forest to retain biodiversity, nutrients, and carbon to nurture resilience of future forests as they face the uncertainties ahead.

A pile of rusty cans marks the boundary between the former logging camp and the forest beyond. Here invasive plants are spreading from the gardens and lawns of the old logging camp into the forest, displacing native species.

The vigorous invasive species Scotch broom is particularly dense and persistent. Here it crowds up against a clump of maple sprouts in their fall colors and suppresses seedlings of native Douglas fir, redcedar, and hemlock. A monoculture of Scotch broom also eliminates the wild diversity of native shrubs and herbs, which supports complex foodwebs of invertebrates, birds, and other taxa.

Invasive plants, such as the thistle shown here, can be prolific seed producers.

We can sense the challenge of restoring native forest as the land undergoes a transition from the management objectives of intensive forestry to conservation of native ecosystems. In this case it follows a transition of ownership from a forestry company to a land trust. Here, a hardy crew of all-terrain, all-weather volunteers uses a variety of tools to remove invasive weeds so native plants have a greater chance to persist.