Kacy Hollenback.

A small archaeological settlement in ponderosa pine forest.

Although human-induced climate change is making wildfires more frequent and intense, natural cycles have sparked wildfires in the Southwest for centuries.

New research in the journal Science Advances examines how Native American cultural practices softened their impacts.

Researchers NAU, UA and elsewhere — including four tribal members — studied evidence from more than 4,800 fire-scarred trees in Arizona and New Mexico during the years 1500 to 1900.

That area experienced cycles of above-average rainfall followed by drought — the classic one-two punch of plant-growth and drying that fuels many wildfires.

Although fire practices differed among the Apache, Navajo and Jemez tribes who lived in the study areas, the authors found they reduced wildfire impacts in their surroundings — even across entire mountain ranges.

Nevertheless, climate effects still dominated over larger areas.

The paper raises the question of whether emulating some of those traditional practices at broader scales would translate to more widespread wildfire benefits.

T.J. Ferguson.

Fire-scarred dead ponderosa pine with cross-sectional "cookie" sample removed.

Tom Swetnam.

Grove of ponderosa pine with historical stand structure.