In late June 2021, multiple days of record-breaking heat caused an unprecedented amount of foliage death in the forests of the Pacific Northwest. Portions of tree canopies with healthy green foliage…
Forest succession theory predicts long-term dynamics of tree species and ecosystem biomass through time, with shifts from early- to late seral species and cessation of live biomass accumulation being…
The 200-year log decomposition study, now entering year 40, is already yielding unexpected insights. Read the full story in the September 2025 issue of Scientific American magazine.
“People say, ‘Oh the forest was lost.’ It’s not lost. It’s changed,” said Mark Harmon, a forest decomposition expert and professor emeritus at Oregon State University. Half of his research plots at…
Researchers studied the impact of experimentally reduced streamflow and increased temperature on fish and salamander. Results suggest that future shifts in community dynamics may favor trout under…
Watersheds and streams, such as this one at the H.J. Andrews Experimental Forest, are impacted by disturbances such as fire and reduced snowpack. Photo by Ben Nash.
Wildfires are increasingly affecting the wet forests of the Pacific Northwest, a trend expected to intensify with climate change. These fires disrupt water quality and streamflow, threatening aquatic…
Andrews Forest graduate students and their work are featured in the Winter 2025 issue of the National Widlife Magazine, in an article written by Marina Richie, titled, “ Undaunted, Grad Students…
In September 2020, the Holiday Farm Fire, driven by fierce east winds, burned 173,000 acres along the forested McKenzie River valley in Oregon. The "Following Fire" project weaves a complex story of…
Researchers detailed how wind, vegetation structure (e.g., canopy height, the age of trees, etc.), and site topography played a significant role in burn severity patterns of five megafires that burned…
Pre-fire conditions and burn severity are strong predictors of vegetation response to fire, and distinct differences in the species composition of young and old stands can lead to very different post…
Dick Iverson, USGS scientist, ran experiments on the HJA flume for three decades. His findings have been pivotal in modeling debris flow runout, which is critical in hazard assessments/predictions…
The Holiday Farm fire ignited the night of September 7, 2020, south of the H.J. Andrews Experimental Forest (HJA). Fire entered the HJA on September 12, at the south boundary of Watershed 9, and…
Dwarf mistletoe’s quaint name belies its severity. The native parasitic plant commonly infects western hemlock trees in western Oregon and Washington via projectile seeds that land on branches and…
Dwarf mistletoe infections cause changes in tree growth and water use. To understand the effect of mistletoe in the canopy of a tree, and in the broader area of a forest, researchers are climbing into…
A recent publication out of the HJ Andrews Experimental Forest LTER site illustrates the role that summer research experiences can play in contributing to LTER science and in engaging and mentoring…
Clearcuts often create stark boundaries between forest habitats. Researchers used remote sensing to assess how harvest edges influence tree basal area and how those effects varied with harvest size…
Analysis of 60‐year records of daily streamflow from eight paired‐basin experiments in the H.J. Andrews Experimental Forest revealed that the conversion of old‐growth forest to Douglas‐fir plantations…