Research Highlights

During the 20th century, a mining company dumped billions of pounds of waste material in Michigan’s Keweenaw Bay, just miles from Tribal lands. Today, Northern Research Station scientists are leading efforts to identify promising tree species capable of stabilizing and remediating heavy metal contamination from stamp sands (historical copper ore processing waste materials) at Sand Point, a culturally significant site of the Keweenaw Bay Indian Community in the L’Anse Indian Reservation.

Climate change, invasive species, wildfire risk, changing markets, and evolving societal expectations are leading to a re-evaluation of the approaches used to manage forests. A first of its kind synthesis of an ecological management paradigm is now being used to train the next generation of foresters to better adapt the nation’s forest to these changes.

Beech leaf disease (BLD), a newly emerging disease decimating both native and ornamental beech trees, has spread rapidly and discontinuously across the northeastern United States since it first appeared in Ohio in 2012. But how is it proliferating so fast? Could the answer lie hidden in bird droppings?

Scientists have been working to develop improved lab- and field-based diagnostic assays for phytoplasmas, understudied pathogens impacting American elms and other trees. Ongoing efforts seek to identify the pathogenicity and spread of these organisms and aid in regional detection to monitor disease dynamics.

Woodpeckers are iconic and interesting birds. Many woodpeckers excavate cavities in trees, providing habitat for themselves and many other forest animals. Associations between woodpeckers and decay fungi have long been hypothesized but the details of these relationships have remained almost completely unknown. This study is the first to use high-throughput sequencing of environmental DNA to characterize the fungal communities associated with woodpeckers and their excavations.

What would it be like to see life-sized statues of 125 women scientists on the Washington Mall? Wonder no longer. As part of the If/Then STEM Ambassador program, the Mall in Washington, D.C., now displays the If/Then Statue Exhibit through the end of the year as an inspiration to all girls.

American chestnut, once a majestic and dominant tree of eastern United States forests, was a source of rot-resistant wood and food for wildlife and humans until the arrival of chestnut blight, a disease caused by an invasive fungal pathogen. Current efforts to breed a blight-resistant chestnut and restore it to the landscape face new challenges as the climate changes. Understanding how genetics and the environment influence chestnut growth are important considerations for breeding and restoration programs.

When we build our homes, direction matters. For instance, if you live in a hot climate, would you want your big living room window to face the setting sun? Scientists have recently discovered that when it comes to homes, and in this case tree cavities, direction matters for endangered woodpeckers too.

New priorities can breathe life into long-term field studies. We investigated whether different reforestation techniques can help stands recover fire resistance or complex wildlife habitat. Our results indicate that young stands can develop fire resistance more quickly if managed with shrub control — and that it is better to wait to introduce structural complexity until later.

In 2022, Pacific Southwest Research Station scientists published a ten year study of wildfires on Babeldaob Island, Palau. The first of its kind in the region, the study summarized socio-political, geospatial, and ecological trends of wildfires on Palau’s largest — and Micronesia’s second largest —island.

Current conditions in the Lake Tahoe Basin demand management action to reduce the risk of high severity fire. However, such actions can impact biodiversity, both in the short and long term. To identify and better understand tradeoffs likely to emerge during forest restoration, we built a spatially explicit model of the Lake Tahoe Basin to predict changes in the amount and configuration of wildlife habitat for 100+ species over the next century.

We used various devices to find male hoary bat roosts in redwood forests of northern California. Although most bats select roosts based on thermal properties, we found that hoary bats selected sites in proximity to open flyways. These flyways are the site of intense social interactions related to autumn mating.

Mangrove carbon stocks collected from circular and square subplots may be integrated together to increase the accuracy of national reports, but only when combining all forest classes: closed, open, and degraded.

This research used the choice experiment method to ascertain California homeowners' willingness to pay to reduce the risk of wildfires in and around their residences and communities. In order to better understand homeowner investments in individual and community risk mitigation, the risk mitigation programs chosen varied in how much they reduced wildfire risk, how much financial loss they may result in, and how much their vegetation management program costs. Survey results showed that lower income homeowners and those with lower levels of educational attainment are less likely to invest in wildfire risk mitigation.

Pacific Southwest Research Station scientists evaluated a treatment to reduce the effects of a deadly fungal pathogen killing native amphibians worldwide — and specifically in the mountains of California. Experimental results and population simulations revealed that treating recently metamorphosed Cascades frogs with itraconazole can help maintain amphibian populations threatened by chytrid fungal pathogens. In situ treatment of diseased animals may aid management strategies that reduce the risk of pathogen-mediated population declines and extirpations.

After less than 30 years of secondary succession in a devastated clearcut area of lowland wet forest on Hawaii Island, Ohia-dominated native forests recovered nearly half the aboveground carbon mass exhibited by adjacent, intact, and mature Ohia-dominated forests. Carbon mass values of intact mature Ohia forests rivaled those of mature forests in the continental tropics. Similarly, recovering Ohia-dominated second growth forests acculumulated carbon as a rate comparable to those of highly productive second growth forests in continental tropical forests. However, reestablishing Ohia forest stands likely requires an absence of invasive, non-native plant species.

Spatial literacy, or people's ability to find landscapes and places on maps, can affect their ability to effectively — and equitably — contribute to public particpation processes and how they value ecosystem services.

Meadows in the Sierra Nevada have been transitioning to forests for over 150 years. New research suggests we are down to a third of the historical meadow baseline. Losing meadows means we lose water storage, biodiversity hotspots, fire resilience, and beautiful recreation scenery. Rediscovering the historical baseline allows us to reconsider what is possible: tripling our meadows' potential to store carbon and sediment, improving our water quality, and using meadows as fire breaks.

Pacific Northwest Research Station scientists partnered with academics and tribal members to evaluate how burning enhances access to, and improves quantity and quality of, California hazelnuts shrubs suitable for basketry material. Hazelnut shrubs one season post-burn produced a 13-fold increase in basketry stems compared to shrubs growing at least 3 seasons post-burn. Basketry stem production and stem length decreased as overstory tree basal area increased. Burn areas on lands actively stewarded by indigenous people — compared to federal lands with less frequent prescribed burning — demonstrate how tribal stewardship fosters the abundance and quality of hazelnut shrubs.

Charcoal and pollen in lake sediment, fire scars in tree rings, ethnographic historical records, and local Indigenous knowledge were gathered to better understand forest structure and the potential influence of fire over time. Pollen composition was indicative of more open forests, potentially overriding climatic influences. Tree ring records, ethnographic historical records, and local Indigenous knowledge suggest fire, including Indigenous ignitions, likely maintained this structure and kept forest biomass at lower levels than they are today.