Propagation of Twelve Alaska Native Plants by Summer Stem Cuttings

Twelve Alaska native plants were propagated from softwood and semi-hardwood stem cuttings collected from late June through August. Cuttings of new growth were treated with 0.3% indole-3-butyric acid powder and propagated in horticultural grade perlite and vermiculite (1:1 by vol) under intermittent mist with bottom heat [26C (79F)] in a greenhouse with a minimum night temperature of 15C (59F). After 6 weeks, cuttings were harvested and evaluated for rooting percentage and root quantity. Four species rooted poorly (< 25%) regardless of collection date: Siberian alder (Alnus viridis ssp. fruticosa), silverberry (Elaeagnus commutata), Bebb willow (Salix bebbiana) and shrub birch (Betula glandulosa). Best rooting (> 80%) occurred June 20 for: Beauverd spiraea (Spiraea stevenii), sweetgale (Myrica gale), and thinleaf alder (Alnus incana ssp. tenuifolia). Peak rooting for dwarf birch (Betula nana), feltleaf willow (Salix alaxensis), balsam poplar (Populus balsamifera), Labrador tea (Ledum groenlandicum) and littletree willow (Salix arbusculoides) was early to mid July. During peak rooting times, all successful species developed adequate root quantities for survival following transplanting.

Ectomycorrhizal colonization of greenhouse-grown Douglas-fir (Pseudotsuga menziesii) seedlings by inoculum associated with the roots of refuge plants sampled from a Douglas-fir forest in the southern interior of British Columbia

Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings were grown in the greenhouse in a sterilized mixture of forest soil and vermiculite, which had been inoculated with root fragments from one of six different ectomycorrhizal under story plant species (Arctostaphylos uva-ursi (L.) Spreng, P. menziessi, Salix bebbiana Bebb, Alnus viridis subsp. sinuata (Regel) Ä. Löve & and D. Löve (alder), Betula papyrifera Marsh. (paper birch), Populus tremuloides Michx.) and arbuscular mycorrhizal Calamagrostis rubescens Buckl. (pinegrass) sampled from a dry Douglas-fir forest in the southern interior of British Columbia. The overall objective of the present study was to investigate the inoculum potential of these ectomycorrhizal roots for colonizing Douglas-fir seedlings. A total of seven ectomycorrhizal morphotypes formed on the bioassay seedlings, which were colonized by all treatments except the control. Seedlings growing in soil inoculated with root fragments of Douglas-fir, Arctostaphylos, and paper birch had greater ectomycorrhizal richness and a higher percentage of colonized fine roots relative to the pinegrass and alder treatments. The community of ectomycorrhizal fungi that colonized the bioassay seedlings differed from that associated with some of the same refuge plants assessed in a previously reported field-based study at this site. Different ectomy corrhizal fungal colonization strategies and the retention of refuge plants are discussed in relation to the colonization of outplanted seedlings following clearcutting.Key words: ectomycorrhizae, refuge plants, inoculum potential, soil bioassay, Pseudotsuga menziesii.

Seasonal isolation as a reproductive barrier among sympatric Salix species

Differences in flowering phenology may be an important premating reproductive barrier between willow species. The seven sympatric species studied fall into two flowering groups within which there is substantial seasonal overlap: an early flowering group that includes Salix bebbiana Sarg., Salix discolor Muhl., Salix eriocephala Michx., and Salix petiolaris Smith, and a later flowering group that includes Salix amygdaloides Anderss., Salix exigua Nutt., and Salix lucida Muhl. The species flowering sequence was reasonably consistent over the 3-year period from 1984 to 1986. Thermal control over flowering phenology was related to cumulative growing degree-days. The inheritance of phenological responses in artificially produced F1 interspecific hybrids was intermediate between that of the parental species.

THE DIMORPHISM IN THE MALE COPULATORY ORGAN OF THE CHRYSOMELID ARTHROCHLAMYS BEBBIANAE BROWN

Arthrochlamys bebbianae Brown is a small chrysomelid that occurs rather commonly in the Ottawa District. It is one of a group of species that have been confused under the names Chlamys gibbosa (Fab.) and C. plicata (Fab.). Both its larvae, which are case-bearers, and its adults feed on the leaves and on the epidermis of the new growth of a willow, Salix Bebbiana Sarg. The speries appears to be monophagous, and it tends to occur in diffuse colonies.