Treesearch

Eastern oak (Quercus spp.) forests in the United States have experienced significant ecological changes over the past century due to fire exclusion and land-use changes. Historically, anthropogenic (human-ignited) fire regimes maintained oak dominance by reducing mesophytic (shade-tolerant, fire-intolerant) competitors, such as red maple (Acer rubrum) and American beech (Fagus grandifolia). With the loss of fire across the landscape, these species have become more abundant, suppressed oak regeneration, and altered forest structure in a process known as mesophication. Natural resource...

A checklist of 488 fall webworm Hyphantria cunea (Drury) natural enemies was compiled based on documentation in previous research across its world distribution, including 289 predators and 199 parasitoids. Predators in the checklist include 67 species from 17 families of Insecta, 1 species of Chilopoda, 183 species from 22 families of Arachnida, 1 species of Reptilia, 4 species from 2 families of Amphibia, 33 species from 18 families of Aves. In addition, the checklist includes fall webworm parasitoids from 18 families of Insecta. Among continents, 128 predators and 76 parasitoids were...

Green ash is threatened with extirpation from emerald ash borer (EAB) attack. Because green ash has an extensive range, its restoration could require both breeding for EAB resistance and possible adaptation to a variety of environmental gradients. We assessed the growth and climate sensitivity of green ash from five Plant Hardiness Zones (PHZs) growing in a range-wide provenance test in Vermont. Although there tended to be greater growth among trees from the warmest PHZ (7), differences were rarely statistically distinguishable. For trees from all PHZs, growth was positively correlated...

Aim: Forest pathogens, insect pests and parasitic plants are among the most important disturbance agents in forested ecosystems. Understanding where pests occur and where they might occur in the future will be important for understanding their impacts on host trees, and planning for future pest outbreaks. Location: North America. Taxon: Insect pests, pathogens and parasitic plants of forest trees. Methods: Here, we develop and implement a framework to predict the contemporary distributions of 26 pest species that accounts for climate, host abundance and, for non-native species, their...

Urban foresters today are faced with an unprecedented challenge in the context of climate change and social crises: achieving sustainability and resilience goals while supporting diversity, equity, inclusion, and justice. Experience suggests that partnerships are needed with community members who can provide local knowledge, legitimacy, and action beyond one plan, one agency, or one grant program, to influence the structure and function of the urban forest.

Despite the recent increase in landscape conservation and the design processes agencies are undertaking, there remains an implementation gap due to an inability to evaluate general strategies and account for uncertainties faced by managers. We demonstrated how a decision support process (DSP), recently developed to inform landscape conservation design, can address uncertainties and complexities inherent in landscape conservation to facilitate long-term, large-scale conservation planning. We applied the DSP to landscape conservation efforts within conservation opportunity areas (COA) of...

Invasive species harm natural and managed ecosystems. Awareness and management of these species depends on effective education and outreach. Traditional common names, including those with geographic references, for many invasive pests may perpetuate slanderous terms or stigmatize people from that place. To create more inclusive invasive species educational materials, the University of Minnesota Extension’s Invasive Species Community of Practice developed guidelines for selection of common names. Suggested names were shared with others involved in invasive species communications, leading to...

Invasive herbivores that kill foundation tree species pose a major threat to forest ecosystem sustainability. One important foundation tree species in the interior western United States is quaking aspen (Populus tremuloides Michx.), which is threatened by recent outbreaks of an invasive insect, oystershell scale (Lepidosaphes ulmi Linn.; OSS). OSS outbreaks were first reported in 2016, when OSS began causing dieback and mortality of aspen in wildland forest settings in northern Arizona. Since then, OSS has been observed in other locations across Arizona and in other western states, and...

Quaking aspen (Populus tremuloides Michx.) ecosystems are highly valued in the southwestern United States because of the ecological, economic, and aesthetic benefits they provide. Aspen has experienced extensive mortality in recent decades, and there is evidence that many areas in Arizona, United States lack adequate recruitment to replace dying overstory trees. Maintaining sustainable levels of regeneration and recruitment (i.e. juveniles) is critical for promoting aspen ecosystem resilience and adaptive capacity, but questions remain about which factors currently limit juvenile aspen and...

Emerald ash borer (EAB), a beetle from Asia that feeds on ash trees, was discovered as the cause of extensive ash mortality in southeast Michigan and adjacent areas of Canada in 2002. It is thought that this destructive pest was introduced in the early 1990’s in infested solid wood packaging material originating in Asia. EAB feeds on ash species in the genus Fraxinus causing widespread ash mortality and significant economic, environmental, and social impacts. As of March 2024, EAB infestations in the U.S. were known in Alabama, Arkansas, Colorado, Connecticut, Delaware, District of...