Treesearch

White pines exhibit both qualitative and quantitative resistance to white pine blister rust, which is caused by the fungal pathogen Cronartium ribicola (Sniezko et al. 2014). Species from several western U.S. States have a major gene at low frequencies that confers virtual immunity to the disease; and most also show heritable quantitative variation in infection frequency, as well as the ability to abort or heal infections that do occur (Kinloch et al. 2012). Here, we summarize extensive data from different tests, some previously published, showing the magnitude and pattern of variation in...

Five hundred whitebark pine (Pinus albicaulis) parent trees from 80 populations were collected from throughout the range of whitebark pine, and are to be deployed in long-term field tests to screen for resistance to blister rust. The objective is to identify individuals to provide resistant seed for restoration of the species now undergoing catastrophic population declines throughout most of British Columbia (BC), Canada. Two series of four test sites, each with half of the open-pollinated families, are to be deployed across the range in BC with the first series to be established in 2015...

The need for predictions of flow time-series persists at ungauged catchments, motivating the research goals of our study. By means of the Sacramento model, this paper explores the use of parameter transfer within homogeneous regions of similar climate and flow characteristics and makes comparisons with predictions from a priori parameters. We assessed the performance using the Nash-Sutcliffe (NS), bias, mean monthly hydrograph and flow duration curve (FDC). The study was conducted on a large dataset of 73 catchments within the eastern US. Two approaches to the parameter transferability...

Western white pine (WWP, Pinus monticola) is a wideranging, long-lived native conifer species in western North America. It is highly susceptible to the introduced fungal pathogen Cronartium ribicola, causative agent of white pine blister rust (WPBR). The impacts of the blister rust have reduced the incidence of WWP in natural ecosystems and have led to reluctance in using the species in both restoration and reforestation. Research and operational programs to develop genetic resistance to WPBR have been ongoing for more than five decades, with regional programs based in Oregon (USA), Idaho...

Naturally occurring genetic diversity is the material upon which much of the biodiversity we attribute to forested ecosystems is based. The structuring of genetic diversity within natural populations of forest trees results from the interplay of numerous evolutionary forces, such as genetic drift, migration, and natural selection. Landscape genomics is concerned with testing hypotheses about how these interacting evolutionary forces change over geographical space and time to shape naturally occurring patterns of this diversity. Here, I will use a landscape genomic approach to illustrate...

Mexican white pine (Pinus ayacahuite) and Central American white pine (P. chiapensis) are two of the largest tree species in the highlands of Mexico and Central America. Pinus ayacahuite occurs from northern Mexico to central Honduras as three varieties: brachyptera, veitchii, and ayacahuite. Its southernmost variety, P. ayacahuite var. ayacahuite, is the most threatened of the three in its native environment. Pinus chiapensis has a smaller geographic range than P. ayacahuite, from central Mexico to western Guatemala. Many of the remnant populations of P. chiapensis are endangered throughou...

Korean pine (Pinus koraiensis) is an important species for timber as well as pine nut production in Korea. The selection of "plus" trees began in 1959 and seed orchards have been established with grafts and seedlings propagated from these selected individuals. There are 300 “plus” trees and 100 ha seed orchards of P. koraiensis in Korea. Further, 244 open-pollinated families are being tested at four 18.5-ha sites. The main purposes of this study were: (1) to investigate the correlation among cone, seed, and growth traits of P. koraiensis; (2) to examine the possibility that such traits...

Three species of stone pines are native to Russia: Siberian stone pine (Pinus sibirica), dwarf Siberian pine (P. pumila), and Korean pine (Pinus koraiensis). Genetic differentiation by allozyme loci placed P. sibirica in one clade with European stone pine (P. cembra), whereas the Far Eastern species P. pumila and P. koraiensis represent another lineage more closely associated with the Asiatic white pines that have winged seeds: P. armandii, P. parviflora, and P. wallichiana. Molecular data on the large divergence of sibirica-cembra and pumila-koraiensis clades are supported by analysis of...

Climate change is a major concern for forest managers involved in ecological restoration, in part because they are responsible for planting trees that will be components of a healthy and resilient ecosystem for the next 100 to 200 years. Anticipated changes in climate include changes in temperature, precipitation, and length of the growing season. Trees locally adapted to their native climate may not be able to survive or grow in novel climates. Current afforestation strategies may thus require the use of seeds from populations already adapted to future climates.

Growth rhythm represents the timing of annual plant growth and development in relation to the environment. Growth rhythm that is well synchronized with the local climate is understood to confer adaptation in plant species. Rapid ongoing climate change threatens to desynchronize growth rhythm for many plant populations, yet knowledge of how plant populations undergo selection on growth rhythm and how they will respond is limited. Therefore, to evaluate phenotypic selection on growth rhythm, seedlings from 49 populations of whitebark pine (Pinus albicaulis), representative of the interior...