Burning Both Ends

Hello Interactors,

As Canadian and Alaskan wildfire smoke drifts across North American borders, it’s easy to resort to feelings and language of crisis in the demand for urgent, immediate control. But fires are not new to these landscapes, and this “crisis” sits alongside others that are also on fire. Climate crises events bring into focus which histories we forget, whose knowledge we ignore, and which relationships we disrupt. Turns out it’s happening at a cellular level too. The real danger is a world and ecology changing so quickly, and understood so narrowly, that it erases the very temporal patterns, memories, and ecological relationships that make adaptation possible.

FIRE’S FRACTURED FREQUENCY

The climate crisis is often communicated through rising averages. We read of climbing global temperatures, sea levels, atmospheric carbon dioxide concentrations, and acres burned. These measurements are indispensable, but averages can make crisis feel distant and abstract. In a forest, climate change is also experienced as an altered interval — as too little time between one disturbance and the next.

A forest is not a passive surface. It actively shapes its own microclimate, stores carbon, and retains moisture until fire temporarily disrupts these relationships…and in doing so creates new ones.

To understand what shorter fire intervals are doing to Alaska’s boreal forests, ecologist Xanthe Walker and an interdisciplinary team of researchers examined carbon storage and forest recovery across 555 plots associated with thirty-one fires. They compared stands with different fire histories, including sites that had burned repeatedly before black spruce forests could fully recover. The absolute amount of carbon released by individual fires was broadly similar across fire-return intervals, but recently burned landscapes began with smaller remaining carbon pools and therefore lost a greater proportion of what remained. Repeated burning also consumed more legacy carbon — the carbon inherited from earlier vegetation and accumulated soils — and reduced the likelihood that some sites would regenerate as black spruce forest. Fire was doing more than releasing carbon in the present. By interrupting regeneration, it was weakening the landscape’s capacity to store carbon in the future (Walker et al., 2025).

Black spruce forests are not merely tolerant of fire but have evolved with stand-replacing fire as a recurring part of their life cycle. Their cones evolved to be little seed bombs that stay in the trees and release their seeds when they burn. This helps new trees grow on the ground where they’re not protected by the canopy. That strategy works when fires recur at intervals long enough for stands to mature, rebuild their seed stocks, and accumulate biomass. Historically, boreal fire-return intervals commonly ranged from about seventy to 130 years. Black spruce may require roughly fifty years to produce enough seed for self-replacement. Yet intervals of less than thirty years are becoming more common in some areas, allowing another fire to arrive before recovery is complete (Walker et al., 2025).

Under those conditions, fire can push regeneration away from black spruce toward deciduous vegetation or more open landscapes. Such places may remain biologically productive, but they are no longer the same forests. They store carbon, retain moisture, shelter organisms, but also carry subsequent fires differently. The landscape may not simply return to its former state after disturbance; it may cross into another ecological regime, organized by different species, intervals, and feedback loops.

MEMORY, MEANING, AND MALLEABILITY

It is tempting to call such transformations unprecedented. In some measurable respects, they are. We know Industrial greenhouse-gas emissions are rapidly altering atmospheric and ecological systems on a planetary scale, and the effects are not confined to normal oscillations around once-familiar conditions. The rate, direction, and