Understory

Early seedling death from summer drought stress is a major threat to reforestation success. In bare root seedlings especially, low survival rates can limit potential financial savings compared to container seedlings. Many land managers seek to improve survival by applying superabsorbent polymer root dips to bare root seedlings during planting. In theory, the polymer should absorb and slowly release water, mitigating drought stress, but research on root dipping is limited and has shown mixed results. In response to this research gap, we tested a novel biodegradable superabsorbent polymer on two...

Agroforestry – the intentional integration of agriculture and forestry – has tremendous potential to increase food production, wildfire mitigation, and recreation opportunities on America’s working lands. In Hawaiʻi, 88% of food is imported and nearly 40% of agricultural lands are unmanaged fallow, primarily covered in invasive species. Returning productivity to these lands is an important strategy for increasing rural food security and reducing wildfire risk. The Forest Service, in collaboration with many dedicated partners, is at the forefront of developing solutions to increase the extent, ...

Discussions with resource managers, policy makers, and others prompted our team to investigate the effectiveness of novel semiochemical repellents to protect spruce trees from mortality attributed to spruce beetle in Alaska.

Healthy headwater streams are critical to protecting downstream water quality for many natural ecosystems and societal water uses. Attention to the critical role that headwater watersheds play in providing clean surface water for ecosystems and human consumption has been magnified in recent years as threats to their sustainability continue to intensify through land use change, urbanization, timber harvesting, and climate change induced extreme events and wildfires. Many of the headwater catchments in the United States and across the world are forested, with forests providing several functions ...

Wildfires are increasing in size and severity, as well as in social, economic, and environmental costs. These wildfire events that once affected only rural and Wildland-Urban Interface (WUI) communities are now more frequently affecting cities and highly populated, densely built, and diverse communities throughout the world. These events are now being referred to as “urban fires” since they are no longer solely driven by vegetation fuel types and altered climates and landscape treatments, but also by flammable building structures, extreme wind events, and urban forest structure, composition, a...

Effective beginning 06/04/2025: This website, and all linked websites under the control of the agency is under review and content may change.Blue carbon is carbon stored in coastal ecosystems like mangrove forests, seagrass beds, and salt marshes. Blue carbon ecosystems make up less than 2% of the earth’s coastal area but store ~15% of the carbon found in coastal sediments. Ensuring these ecosystems thrive helps lessen impacts of climate change and protects coastal communities and livelihoods. Mangroves are ecologically and culturally important. Intact mangrove forests store more carbon than a...

Non-native invasive plants cause enormous damage to native Hawaiian ecosystems and agricultural lands. Weeds like strawberry guava, Christmas berry, albizia, Himalayan ginger, miconia and Koster’s curse have spread across vast areas. They outcompete and displace native species, and impede agriculture. These invaders transform Hawaii’s landscapes, compromise access, reduce biodiversity, and degrade watersheds. Controlling these invasive plants by hand or with herbicides at large scales and in remote areas is simply not practical. Since 1984, scientists at the Institute of Pacific Islands Forest...

ʻŌhiʻa lehua (Metrosideros polymorpha) is Hawaii’s most important native tree. It covers nearly one million acres and is deeply intertwined with Native Hawaiian cultural practices. However, Rapid ʻŌhiʻa Death (ROD) caused by the invasive fungal pathogens Ceratocystis lukuohia and Ceratocystis huliohia, has killed over one million ʻōhiʻa trees across 270,000 acres. ROD poses a significant threat to Hawaii's biodiversity and cultural heritage. Safeguarding ʻōhiʻa and halting ROD’s spread requires urgent and coordinated action. Through its ROD research programs, the Forest Service is taking up th...

Since its initial detection in 2012, Rapid ʻŌhiʻa Death (ROD) has killed millions of ʻōhiʻa trees. It is caused by two non-native fungal pathogens, Ceratocystis lukuohia and Ceratocystis huliohia. C. lukuohia is recently introduced to Hawai’i (i.e., within the last 25 years) and is the more virulent fungus, killing trees on Hawaiʻi Island and Kauaʻi. The less virulent and impactful C. huliohia has likely existed in Hawai’i for hundreds of years and has currently been detected on Hawaiʻi Island, Maui, Oʻahu, and Kauaʻi.

The US Department of Agriculture (USDA) Forest Service Research Natural Areas (RNAs) network protects some of the finest examples of natural ecosystems for the purposes of scientific study, education and maintenance of biological diversity. RNAs are managed to maintain the natural features for which they were established and to maintain natural processes. Because of the emphasis on natural conditions, they represent a valuable ecological resource for scientists, managers and educators. The Forest Service encourages scientific and educational use of Research Natural Areas. This application and ...