Treesearch

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...

The five-needle pines have been an important part of the landscape of North America, but they have been severely affected by the introduction of white pine blister rust (causal agent: Cronartium ribicola). However, most of these species have one or more types of some inherent resistance to this exotic disease, such as major gene resistance (complete resistance), and some forms of partial resistance. Longestablished provenance trials in western white pine (WWP, Pinus monticola), established with unselected populations, allow us to investigate and compare genetic variation in our native...

Genetic variation in needle traits (number of rows of stomata, areal density of stomata, and density of stomata in a row, as well as needle length and needle width), seedling height growth, and early measures of blister rust (causal agent: Cronartium ribicola) resistance were examined among 22 openpollinated families of whitebark pine (Pinus albicaulis) from Crater Lake National Park (CLNP) in Oregon. Needle traits were examined for both the adaxial and abaxial sides. Needle traits were also assessed for 19 of 22 parent trees from CLNP. The adaxial side of the needle on average had more...

Provenance tests of 49 populations of whitebark pine (Pinus albicaulis) revealed moderate genetic differentiation for growth potential (growth under conditions approaching physiological optimum). Moderate genetic differentiation was also detected for survival after more than 10 years under warm-dry climate in the field but not for unconditional expected height, which was considered the best available predictor of fitness. Height was considered unconditional because survival over multiple years was explicitly included in the analysis. Genetic divergence for growth potential and survival was...

Southwestern white pine (Pinus strobiformis, syn. Pinus flexilis var. reflexa) is a high elevation five-needle pine. Pinus strobiformis occurs in mixed species stands across a range of elevations and forest types in western Texas, southwestern Colorado, and throughout New Mexico and Arizona (USA), and continues along the mountains south to central Mexico (Alexander et al. 1984; Looney and Waring 2013; Moreno-Letelier and Piñero 2011; Steinhoff and Andresen 1971) (fig. 1). This species, like all species of North American five-needle pines, is susceptible to infection and mortality from the...

Needle dimensions and stomate densities were measured for 300 seedlings representing a stratified sampling of 30 families of whitebark pine (Pinus albicaulis) from California, Oregon, Washington, Idaho, and Montana (USA), and British Columbia (Canada). The seedlings were selected from a larger common garden trial examining white pine blister rust (WPBR) resistance of 225 families from populations representing much of the geographic range of whitebark pine. The objective was to examine variation in needle characteristics, including needle width, number of stomata, and stomate density, and...