Treesearch

The landscape theory of food web architecture (LTFWA) describes relationships among body size, trophic position, mobility, and energy channels that serve to couple heterogenous habitats, which in turn promotes long-term system stability. However, empirical tests of the LTFWA are rare and support differs among terrestrial, freshwater, and marine systems. Further, it is unclear whether the theory applies in highly altered ecosystems dominated by introduced species such as the Laurentian Great Lakes. Here, we provide an empirical test of the LTFWA by relating body size, trophic position, and...

Balsam woolly adelgid (BWA), Adelges piceae, is an invasive insect colonizing true fir in North America. Following its recent range expansion into Utah, BWA has caused significant mortality of subalpine fir (Abies lasiocarpa). The first instar (crawler) is the only motile life stage and is responsible for dispersal among trees, usually by wind. Due to BWA’s small size, detection and monitoring is challenging. In this study, monitoring for dispersing crawlers using sticky cards was compared to a more labor-intensive bark sampling method in four northern Utah stands with the goal of identifyi...

Root disease caused by Armillaria spp. is among the leading causes of mortality and lost productivity in forests around the world (Kim et al. 2022). In the northern and western USA, A. solidipes (previously known as North American A. ostoyae) is considered the most damaging Armillaria root disease pathogen in coniferous forests (Lockman and Kearns 2016). In many regions, climate change is expected to result in an increasing likelihood of damage from Armillaria root disease as trees become more stressed from maladaptation to climate and extreme weather events (Murray and Leslie 2021; Kim et...

Western white pine (WWP; Pinus monticola) is a keystone species in moist forests of western North America that displays adaptation to ranging climates and resilience to native root diseases. Since Cronartium ribicola, the cause of white pine blister rust (WPBR), was introduced to North America in the early 1900s, WBPR has caused dramatic reductions in WWP across its native range. Although WPBR is well established throughout WWP’s range, observations have suggested some recent, naturally regenerated WWP stands in northern Idaho, USA display lower rates of WPBR incidence than was recorded...

Armillaria root disease, the most common forest root disease in western North America, affects all tree species to some degree and is one of the most complex forest problems to understand and effectively manage. In 1870, Robert Hartig, the father of forest pathology, was one of the first scientists to investigate the disease in Europe. A century later, after a long history of disease observation, research, and treatment, Lewis Roth, a professor of forest pathology at Oregon State University, highlighted the frustration associated with studying the disease by writing, “Armillaria has a...

Armillaria root disease is one of the leading causes of growth loss and mortality in coniferous forests of the western USA (Lockman and Kearns 2016; Kim et al. 2022). In 2019, a collaborative project was started to learn more about Armillaria root disease in the Intermountain Region (USDA Forest Service Region 4). Recent surveys suggested that Armillaria root disease was increasing on trees in Utah, particularly at higher elevations than was previously observed (John Guyon, per. comm.). Previous and subsequent surveys using DNA-based identification revealed that A. solidipes (formerly...

First of all, I am both very grateful and extremely humbled to receive the WIFDWC Outstanding Achievement Award, and, of course, I can easily recognize so many other candidates who are more deserving. However, I am extremely happy that Phil Cannon is a co-recipient of this award, because Phil and I have collaborated on diverse projects for about 25 years, and Phil is an exemplary recipient for this award. Unfortunately, I have little idea about what sort of topics I should address here, so I decided to include a bit on various topics.

Phellinus noxius, is a destructive, fast-growing pathogen that causes brown root rot disease of a very wide range of woody hosts (Cannon et al. 2022). Its devastating effects on fruit trees, cacao, ornamentals, coffee, and rubber have been documented across diverse global regions, such as Taiwan, Japan, Hong Kong, Southeast Asia, Australia, and various Pacific Islands (e.g., Guam, Saipan, Kosrae, Pohnpei, Palau, American Samoa, etc.) (Stewart et al. 2020; Cannon et al. 2022). To date, this pathogen has not been reported in some Pacific Islands and other U.S. states/territories (e.g.,...

Fusaria can be introduced into novel landscapes through latent-infected nursery stock and cause seedling mortality. Molecular tools can rapidly identify and track Fusarioid pathogens to mitigate novel pathogen introductions by informing both pathogen composition and pathogenicity of different Fusarium spp. Understanding the community structure and population genetics of Fusarium spp. is a prerequisite for developing robust primers to detect pathogenic species. Accessory chromosomes have been identified in fungi that house virulence genes that can be horizontally transferred among species...

Armillaria root disease (ARD) is among the largest causes of mortality and lost productivity in forests of the western USA (Lockman and Kearns 2016, Kim et al. 2022). In some forest areas of western North America, growth/volume losses between 16-55% have been attributed to ARD (Filip and Goheen 1984; Cruickshank 2011). Damage from ARD is expected to increase under climate change and extreme weather events (e.g., drought, temperature), because host tree stress can predispose trees to ARD (Klopfenstein et al 2009; Kim et al. 2021; Murray and Leslie 2021). Furthermore, ARD may predispose...