Treesearch

A central tenet of landscape conservation planning is that natural communities can be supported by a connected landscape network that supports many species and habitat types. However, as the planning environment, ecological conditions, and risks and stressors change over time, the areas needed to support landscape connectivity may also shift. We demonstrate an approach designed to assess functional and structural connectivity of an established protected area network that has experienced landscape and planning changes over time. Here we present an approach designed to inform adaptive...

Landscape connectivity is increasingly promoted as a conservation tool to combat the negative effects of habitat loss, fragmentation, and climate change. Given its importance as a key conservation strategy, connectivity science is a rapidly growing discipline. However, most landscape connectivity models consider connectivity for only a single snapshot in time, despite the widespread recognition that landscapes and ecological processes are dynamic. In this paper, we discuss the emergence of dynamic connectivity and the importance of including dynamism in connectivity models and assessments....

The northern Rocky Mountains, the Great Basin, and the central Sierra Nevada are regions of North America where limber pine (Pinus flexilis James) and whitebark pine (Pinus albicaulis Engelm.) live in sympatry or close proximity. For those needing to distinguish between these two pine species in these areas of western North America, seed cones are the best visual identification aid. Limber pine has seed cones that measure 7-15 cm long and have persistent woody scales whereas whitebark pine has seed cones that measure 4-8 cm long and have tightly overlapping woody scales.

Many research studies and syntheses have suggested that prescribed fire (Rx fire) and wildland fire use fires (WFU) are perhaps the most effective tool for restoring whitebark pine ecosystems (Murray et al. 1995, Keane et al. 2012, Perkins 2015, Keane 2018). Rx and WFU fires can kill competing conifers; reduce surface and canopy fuels; and create attractive sites for nutcracker caching. They best mimic historical fire regimes, much better than mechanical thinnings and cuttings (Keane and Parsons 2010). However, the primary assumption of their application as a restoration tool is that the...

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...

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...