Treesearch

Much of the information available on successional modeling for whitebark pine (Pinus albicaulis) communities is based on research conducted in an ecosystem influenced by maritime conditions (Pacific Northwest). The Greater Yellowstone ecosystem (GYE; Wyoming, Montana, and Idaho, USA) is subjected to more continental climatic conditions and as a result, the dynamics of whitebark pine populations in the GYE may in fact be very different from those of maritime populations. Recent survey work in the GYE shows establishment is common with variable recruitment of young trees in the understory of...

In some Rocky Mountain treeline ecotones, whitebark pine (Pinus albicaulis) serves as a tree island initiator more frequently than Engelmann spruce (Picea engelmannii) or subalpine fir (Abies lasiocarpa). Tree island initiation begins with a solitary krummholz tree, which provides sufficient leeward protection so that another tree may become established, resulting in a tree island. More trees may establish on the lee side over time. Whitebark pine mortality from white pine blister rust (pathogen: Cronartium ribicola) reduces opportunities for such facilitation. Will declines in whitebark...

During the naturalization process of white pine blister rust (WPBR, caused by Cronartium ribicola), susceptible pine genotypes will be selected against, along with any traits that are associated with those genotypes, potentially causing a shift in the suite of traits in the post-selection population compared to the native population. Consequently, identifying associated traits with WPBR resistance is critical for effective restoration planning, especially in a changing climate. We sought to determine whether complete resistance to WPBR in limber pine (Pinus flexilis) is associated with...

North America is a secondary center of diversification of the genus Pinus. Most of these speciation events are fairly recent, producing a pattern of widespread shared polymorphism and fuzzy species boundaries. Among five-needle pines, the relationships among Pinus flexilis, Pinus strobiformis, and Pinus ayacahuite have been particularly difficult to determine. To understand the speciation process and the phylogenetic relationships in this species complex, we evaluated genetic and ecological differentiation using multilocus sequence data and ecological niche model comparisons. Our results...

Southwestern white pine (Pinus strobiformis, SWWP) is a component of dry and wet mixed-conifer forests in the southwestern United States and provides ecological function and diversity. The species is geographically limited to Arizona, New Mexico, parts of Texas, southern Colorado, and northern Mexico, but occurs on a wide range of habitats within its distribution. Historically, SWWP regeneration has not been well studied or monitored in mixed-conifer forests of the Southwest, although our understanding of the species’ ecology is increasing. Introductions of Cronartium ribicola, the...

Mountain pine beetle (Dendroctonus ponderosae) and white pine blister rust (causal agent: Cronartium ribicola) are causing extensive crown dieback and mortality in limber pine (Pinus flexilis) in the central and southern Rocky Mountains. Ecologically valuable limber pines often grow in fragile ecosystems where few other trees can grow. The combined effects of mountain pine beetle, white pine blister rust, dwarf mistletoe (Arceuthobium cyanocarpum), and climate change could greatly reduce the biodiversity of these ecosystems. Current status and long-term monitoring of limber pine trees and...

Extending from the Canadian province of Alberta to the Transverse Volcanic Plateau of Mexico, Pinus strobiformis is part of a species complex with two geographically adjacent, but nonsympatric, species, namely P. flexilis and P. ayacahuite. Pinus strobiformis is classified as being of least concern and at lower risk according to the guidelines of the International Union for the Conservation of Nature and Natural Resources (IUCN) Red List (IUCN 2014). In Mexico, this frequent tree species is protected and included in Mexican Regulation NOM-059-2010. Pinus strobiformis appears to have broad...

Climate-based predictions of species distributions provide information for understanding impacts of climate change. However, species distribution models do not include land management zones as input. Improving understanding of geographic shifts will require consideration of management zones where certain activities could facilitate or impede responses to climate change. For instance, assisted migration to overcome dispersal barriers could be challenged in areas designated for “untrammeled” character (e.g., wilderness). Alternatively, large tracts of land with uninterrupted disturbance...

Fungal species in the genera Armillaria and Desarmillaria (Physalacriaceae, Agaricales) are well known for their symbiotic relationships with Gastrodia elata and Polyporus umbellatus, important components of traditional medicine in Asia. In addition, some species in these genera cause Armillaria root disease, which has had a negative economic impact by damaging and destroying urban, horticultural and forest trees. Five species within Armillaria and Desarmillaria have been previously reported in South Korea, based primarily on basidioma morphology: A. cepistipes, A. gallica, A. mellea, A....

Downed woody material (DWM) is a key component in forest ecosystems with age, structure, and disturbance described as primary factors that influence DWM dynamics. In particular, much emphasis is placed on large coarse woody debris (CWD). Fine woody debris (FWD) (less than 7.62 cm diameter), duff, and litter also contribute to carbon stocks, provide habitat, add to nutrient cycling, and are often the most available fuels for fire, yet are regularly overlooked in studies describing the forest floor. Throughout the middle montane zone within the Intermountain West region USA, interior...