Steven Kiiskila, Crop Manager, Arbutus Grove Nursery

Steven Kiiskila, RPF, PAg is the Crop Manager at Arbutus Grove Nursery. Each year his team grows 20 million container forestry seedlings composed of up to 25 species, from Fort St. John to southern Oregon, and all places in between. For the past 25 years he has worked in various positions in the reforestation industry throughout Western Canada. He loves the combination of art and science used to grow forest seedlings, and the fact that seedlings always teach him something new. One of his favourite sayings borrowed from UBC Professor Bunnell is: “Growing trees is not rocket science, it’s much harder.” He has a MSc. in Forest Biology from the University of Victoria, a BSc. in Agriculture, horticulture major from the University of Guelph, and a Horticulture Diploma from Olds, College. www.linkedin.com/in/steven-b-r-kiiskila/

Presentation Abstract

Seedling Stocktypes for Hot, Dry Sites

Steven Kiiskila, Crop Manager, Arbutus Grove Nursery, North Saanich, B.C.
In recent years, planting sites are getting warmer and drier, resulting in decreasing seedling survival. To try and maximize establishment on these hot, dry sites, new seedling stocktypes are being proposed. The idea is to create a stocktype that mimics natural seedlings growing in hot, dry environments. Morphological attributes that offer drought resistance include: a low shoot-to-root ratio, a low height to diameter ratio, a long plug which places the roots deeper in the soil profile, and waxy needles. Seedling physiological attributes which improve drought tolerance include cell wall osmotic adjustment which can be manipulated in the nursery through drought stress. Nursery culture also influences seedling establishment through nutrient status, as seedlings with optimal nutrition at planting have been shown to have greater initial root growth. The ideal stocktype would initially favour root over shoot growth after planting, thus have fewer shoot primordia (e.g. smaller and/or fewer buds). While this can be measured in the lab, it is not certain if such a seedling can be grown while still achieving other desirable traits such as a thick stem and solid root plug. As well, new root growth prior to bud flush can be determined in the lab under controlled conditions via a Root Growth Potential (RGP) test. But, just how to increase the amount of new root growth upon planting via previous nursery culture merits further investigation, although nursery blackout exerts an influence, as does stock handling.