Mr. Speaker, with regard to (a), hardiness zones are geographic areas associated with the probability of plant survival in relation to the average climatic conditions present.
NRCan scientists use two different approaches for delineating hardiness zones.
They use a made-in-Canada approach, first developed in the 1960s by Agriculture and Agri-Food Canada, revised and modernized by Natural Resources Canada in 2001 and again in 2010. The Canadian map delineates plant hardiness zones using seven relevant climate variables. See part b for the list of variables.
They use a hardiness zone map developed by the United States Department of Agriculture, USDA, that relies solely on extreme minimum temperature to delineate hardiness zones.
Both approaches are recognized and widely used by the horticultural community in Canada.
With regard to (b), the made-in-Canada system is based on statistical analyses of plant survival at test sites across the country and involves seven climate variables, each with a different weight or importance. Application of the formula yields an index that is used to determine a hardiness zone. The variables, in order of importance, are:
monthly mean of the daily minimum temperatures, in °C, of the coldest month, the minimum temperature factor;
mean frost-free period above 0°C in days, length of the growing season;
amount of rainfall from June to November, in mm;
monthly mean of the daily maximum temperatures, in °C, of the warmest month, maximum temperature factor;
a “winter factor” that reflects the stress caused to plants by loss of winter cold adaptation caused by above-freezing temperatures in winter, calculated using the monthly mean of the daily minimum temperatures of the coldest month and the total rainfall in January;
mean maximum depth of snow, in mm, a positive factor that reflects insulation of plants against cold;
and maximum wind gust, in km/h, over 30-year period, reflecting environmental stress.
With regard to (c), there are two new hardiness zones, 8b and 9a, that have emerged in Canada. Both are found on Vancouver Island, the warmest area of the country. These two new zones are the result of two factors: an increase in weather temperature; and an increased quantity of weather data, from 1930 to 1990, which incorporates a digital elevation model that captures the effect that topography has on plant hardiness. This important factor was not previously reflected in the Canadian hardiness zone map.
With regard to (d), yes the government explored using climate envelope models. Many are shown on the plant hardiness website at http://planthardiness.gc.ca. The aim of this work is to go beyond a single general map and develop range maps for individual species of trees, shrubs and perennial flowers.
With regard to (e), the work is made available at the plant hardiness website. A variety of knowledge transfer activities occur as opportunities arise, including presentations at conferences, journal articles, including in trade magazines, and posters.