Do forest fires encourage the spread of invasive plants?

A number of invasive plants thrive in forested and grassland areas disturbed by fire, floods, erosion, wind, insects, or diseases, so increases in disturbed areas associated with climate variability and altered land-use could assist in the spread of this group of invasive plants. Cheatgrass (Bromus tectorum), one of the most invasive species in the western shrublands and woodlands of the U.S., has been common on severely burned areas. Recent studies suggest that increased wildfire activity in the western …

Invasive Species in Forests

The kudzu vine, pictured here growing on trees in Atlanta, Georgia, is an invasive species brought to the United States from Japan and initially planted in the South to control erosion. Photo: Scott Ehardt, Wikimedia Commons (Public Domain).

A primary goal of a forest owner is to have a healthy forest. To most forest owners, a healthy forest means healthy, living trees. Indeed, inspecting your trees regularly is important. However, to maintain a healthy, thriving forest, you must take other …

Regional Climate Hub Assessment of Climate Change Vulnerability and Adaptation and Mitigation Strategies

General storm damage

USDA’s Regional Climate Hubs were established in February of 2014 to deliver science-based knowledge, practical information, and program support to farmers, ranchers, forest landowners, and resource managers to enable climate-informed decision-making in light of the increased risks and vulnerabilities associated with a changing climate. As part of their function, the Hubs were tasked with providing periodic regional assessments of risk and vulnerability to production sectors and rural economies, building on material provided under the National Climate Assessment conducted through the …

Thinning Forests to Reduce Risks from Wildfires


A burnt section of forest in the Catalina Mountains, Tucson, Arizona. Photo: Melanie Lenart.

If you own wooded land, it is helpful to understand factors that make some parts of your forest susceptible to fire, and what you can do about it. 

The US wildfire season of 2012 burned more than 9 million acres, making it another extraordinary year for big, out-of-control fires. Forest stands with high densities of small trees face a greater risk of bark beetle infestation, according

Managing for Resilient Forests: An Introduction

Lodgepole pine regenerating naturally after the 1988 fire in Yellowstone National Park. Photo: Paul Bolstad, University of Minnesota,

Forests are dynamic, changing ecosystems. Trees grow, eventually die, and are replaced by new trees, often of different species. This natural pattern of succession is punctuated by disturbances, which change the environmental condition of the forest. Disturbances include fires, insect outbreaks, ice and windstorms, and droughts and floods, and they may be small or large in scale.

Disturbances are part of …

A Regional View of Invasive Plants

How does what I do in my yard, on my land and in my garden affect what plants invade our forests and grasslands?  What has happened on the land where you live (its history of use), and what you plant now, can have a long-lasting impact. Land use legacies appear to play a large role in the patterns of invasive plants and the impacts they may have. The progression of time shows how well a plant manages to spread, and …

Plantation Forests and Climate Change

Written by Amy Grotta, University of Oregon


Plantation forests are a type of managed forest in which the trees are planted (as opposed to naturally regenerated), of the same age and generally of the same species, and are intended to maximize the production of wood fiber. Trees in a plantation forest are usually planted uniformly in rows to maximize the site’s growing space and resources, to ensure uniform growth, and to facilitate the use of mechanized harvesting equipment.

Figure 1.

The Hydrologic Cycle

Adapted from: Mary Nichols. 2007. Chapter 3: Hydrologic Processes in Riparian Areas. In: G. Zaimes (ed). Understanding Arizona’s Riparian Areas. University of Arizona Cooperative Extension. AZ 1432. Available at

The hydrologic cycle, or water cycle (Fig. 1), explains how water is moved from the earth to the atmosphere. Water moves to the atmosphere as water vapor through evaporation and transpiration. It condenses and falls to the earth’s surface as precipitation. Water then either travels across land surfaces in watersheds …

Oak Decline

Written by D.J. Moorehead and G.K. Douce for Forest Encyclopedia Network

Causal Agents

Oak decline is the name given to a slow-acting disease complex stemming from interactions between biotic and abiotic stressors of oaks (Quercus spp.). Abiotic factors that contribute to oak decline include tree maturity, low site productivity, drought, and spring frost. Biotic factors include root diseases such as Armillaria root disease (Fig. 1) (Armillaria spp.), canker causing fungi such as Hypoxylon canker (Fig. 2) …

Sudden Oak Death in the Eastern United States

  Adapted from: D.J. Moorhead and G.K. Douce for Forest Encyclopedia Network     


Sudden oak death, caused by the pathogen Phytophthora ramorum, is a potentially devastating disease. P. ramorum has been found in nurseries in California, Oregon, Washington, and British Columbia, and more recently in the eastern United States. Sudden oak death causes leaf and shoot blights in most hosts, and is known as Ramorum shoot and leaf blight in the nursery industry. In the forest the fungus can cause bole