Treesearch

Plants resist herbivores using both constitutive and induced defenses. Limited resources and biosynthesis costs of anti‐herbivore compounds may impose tradeoffs between these modalities, but the evidence is conflicting. We postulated that biological and ecological scale may influence potential tradeoffs and analyzed constitutive‐induced relationships from genotypic to interspecific levels. We focused on one system, conifer phloem monoterpenes that resist bark beetle attack, to minimize variation from feeding guild or phylogeny. We examined 45 half‐siblings in common gardens (n = 763),...

Root diseases are a primary cause of reduced forest productivity, decreased carbon sequestration, and impaired ecosystem function (e.g., Lockman & Kearns 2016). Armillaria altimontana and A. solidipes (as A. ostoyae) are soil fungi that frequently co-occur (McDonald et al. 2000) and are found in association with western white pine (Pinus monticola). Armillaria solidipes is well known as a virulent primary pathogen on diverse conifers within inland western regions of the contiguous USA (e.g., Lockman & Kearns 2016). Armillaria altimontana is often considered as a weak or secondary pathogen...

The sudden interruption of recurring larch budmoth (LBM; Zeiraphera diniana or griseana Gn.) outbreaks across the European Alps after 1982 was surprising, because populations had regularly oscillated every 8–9 years for the past 1200 years or more. Although ecophysiological evidence was limited and underlying processes remained uncertain, climate change has been indicated as a possible driver of this disruption. An unexpected, recent return of LBM population peaks in 2017 and 2018 provides insight into this insect’s climate sensitivity. Here, we combine meteorological and dendrochronologica...

Datasheet report for Trirachys holosericeus (apple stem borer). Trirachys holosericeus, a highly polyphagous longhorned beetle, is native to southern Asia from Pakistan to the Philippines. It is a stem-boring pest in natural and planted forests and fruit trees. It attacks primarily hardwoods, and at least one conifer. Both healthy and stressed trees are attacked, often leading to crown dieback and possibly tree death after one or more years of infestation.

Many post-industrial U.S. cities have developed programs to promote the greening of publicly-owned vacant lots, including initiatives in which homeowners can purchase nearby lots and turn them into yards or community gardens. These initiatives can result in greener landscapes in marginalized communities, but we know little about the spatial patterns of vacant land disposition and whether demand for and sale of publicly-owned lots are stronger in gentrifying neighborhoods. We examined the Chicago Large Lot Program and used neighborhood sociodemographic, environmental, and safety factors to...

Austropuccinia psidii impacts numerous forest ecosystems world-wide by causing myrtle rust disease on many myrtaceous species, including guava (Psidium guajava), eucalypts (Eucalyptus spp.), rose apple (Syzygium jambos), and ‘ohi’a (Metrosideros polymorpha). First reported in 1884 on guava in Brazil, the rust has since been detected in tropical and subtropical areas worldwide. At least three biotypes of A. psidii have currently been identified (Stewart et al. 2017), including eucalypt and guava biotypes in Brazil, and the globally distributed pandemic biotype which infects multiple hosts....

Root diseases cause extensive damage to forests in the western USA (Blodgett et al. 2015). However, despite their abundance and economic impact (Lockman et al. 2016), we know very little about the identity and distribution of some pathogens responsible for these diseases. Our project addresses this knowledge gap by characterizing root pathogens in forests of the western USA (Kim et al. 2006) and has the potential to result in updated distribution maps, bioclimatic models, as well as first reports.

The forest pathology paradigm is shifting to include complex ecological interactions that contribute to disease development, such as 1) microbial communities associated with the soil or host plant that suppress or enhance disease; 2) invasive pathogens that are associated with new hosts in new environments; 3) host and pathogen populations that display different adaptation and ecological behaviors; 4) induced host resistance to disease that is derived from differential gene expression; and 5) other interacting environmental factors that influence biological processes related to plant disease.

Fusarium can cause significant damage within conifer nurseries across the United States. Several species of Fusarium, which are morphologically similar to F. oxysporum, are known to cause damping-off, including F. commune, F. fujikuroi, F. proliferatrum, and F. solani. Isolates of Fusarium spp. (ca. 431) were collected from Idaho, Oregon, Nevada, Washington, Nebraska, Michigan, North Carolina, South Carolina, and Georgia. Initial species identification was conducted based on colony morphology. Because F. oxysporum and F. commune have almost identical colony morphology with the exception...

Recent taxonomic investigation into genus Pyrrhoderma has determined that the genus currently contains six species, including Pyrrhoderma noxium (formerly Phellinus noxius), and one unnamed, but likely novel species (Zhou et al. 2018). Pyrrhoderma noxium is considered one of the most important pathogens in this genus due to its worldwide distribution in pan-tropical regions, including Asia, Australia, Africa, and Oceania. Pyrrhoderma noxium has a wide host range of over 200 plant species and causes mortality of >100 tropical tree species (e.g., breadfruit, mango) that are integral to...