scholarly journals Canada's Plant Hardiness Zones and Extreme Minimum Temperature Zones

2014 ◽  
Author(s):  
D W McKenney ◽  
J H Pedlar ◽  
K Lawrence ◽  
P Papadopol ◽  
K Campbell ◽  
...  
2006 ◽  
Vol 86 (2) ◽  
pp. 511-523 ◽  
Author(s):  
Daniel W. McKenney ◽  
Michael Hutchinson, Pia Papadopol ◽  
Kathy Campbell ◽  
Kevin Lawrence

Hardiness zones are widely used in North America to support the trade of plants and recommendations on local use of perennial plant species. In Canada, two zonation approaches are in use, a made-in-Canada model that integrates seven climate variables and the United States Department of Agriculture’s (USDA) extreme minimum temperature map/model. In this paper we develop and present several extreme minimum temperature models for the 1961–1990 and 1971–2000 climate normal periods and annual models for the winter seasons of 1961 through 2000. These models are similar in nature to the USDA plant hardiness model/map. We compare these models with a recent update of the Canadian plant hardiness zones developed with the same mathematical interpolation techniques (thin plate smoothing splines). Individual Canadian zones typically span five to nine USDA equivalent sub-zones in total, although most of the area (>75%) of each zone generally spans 3–4 USDA sub-zones. We note that there is no simple transformation of one zonation approach to the other, but values for both systems can now be obtained for any location in Canada using an internet mapping tool. Over the period of 1961–2000 extreme minimum temperature has been trending upward in most provinces. These trends may be affecting plants in some locations, but a lack of survival and/or hardiness data is a significant impediment to assessing this. Variation in extreme minimum temperature over the 1961 to 2000 period was greatest in western North America, particularly interior British Columbia. Key words: Climate mapping and trends, spatial analysis, ANUSPLIN


2008 ◽  
Vol 65 (spe) ◽  
pp. 54-59 ◽  
Author(s):  
Roger D. Magarey ◽  
Daniel M. Borchert ◽  
Jay W. Schlegel

Plant hardiness zones are widely used for selection of perennial plants and for phytosanitary risk analysis. The most widely used definition of plant hardiness zones (United States Department of Agriculture National Arboretum) is based on average annual extreme minimum temperature. There is a need for a global plant hardiness map to standardize the comparison of zones for phytosanitary risk analysis. Two data sets were used to create global hardiness zones: i) Climate Research Unit (CRU) 1973-2002 monthly data set; and ii) the Daily Global Historical Climatology Network (GHCN). The CRU monthly data set was downscaled to five-minute resolution and a cubic spline was used to convert the monthly values into daily values. The GHCN data were subjected to a number of quality control measures prior to analysis. Least squares regression relationships were developed using GHCN and derived lowest average daily minimum temperature data and average annual extreme minimum temperatures. Error estimate statistics were calculated from the numerical difference between the estimated value for the grid and the station. The mean absolute error for annual extreme minimum temperature was 1.9ºC (3.5ºF) and 2/3 of the stations were classified into the correct zone.


2012 ◽  
Vol 51 (2) ◽  
pp. 242-264 ◽  
Author(s):  
Christopher Daly ◽  
Mark P. Widrlechner ◽  
Michael D. Halbleib ◽  
Joseph I. Smith ◽  
Wayne P. Gibson

AbstractIn many regions of the world, the extremes of winter cold are a major determinant of the geographic distribution of perennial plant species and of their successful cultivation. In the United States, the U.S. Department of Agriculture (USDA) Plant Hardiness Zone Map (PHZM) is the primary reference for defining geospatial patterns of extreme winter cold for the horticulture and nursery industries, home gardeners, agrometeorologists, and plant scientists. This paper describes the approaches followed for updating the USDA PHZM, the last version of which was published in 1990. The new PHZM depicts 1976–2005 mean annual extreme minimum temperature, in 2.8°C (5°F) half zones, for the conterminous United States, Alaska, Hawaii, and Puerto Rico. Station data were interpolated to a grid with the Parameter-Elevation Regressions on Independent Slopes Model (PRISM) climate-mapping system. PRISM accounts for the effects of elevation, terrain-induced airmass blockage, coastal effects, temperature inversions, and cold-air pooling on extreme minimum temperature patterns. Climatologically aided interpolation was applied, based on the 1971–2000 mean minimum temperature of the coldest month as the predictor grid. Evaluation of a standard-deviation map and two 15-yr maps (1976–90 and 1991–2005 averaging periods) revealed substantial vertical and horizontal gradients in trend and variability, especially in complex terrain. The new PHZM is generally warmer by one 2.8°C (5°F) half zone than the previous PHZM throughout much of the United States, as a result of a more recent averaging period. Nonetheless, a more sophisticated interpolation technique, greater physiographic detail, and more comprehensive station data were the main causes of zonal changes in complex terrain, especially in the western United States. The updated PHZM can be accessed online (http://www.planthardiness.ars.usda.gov).


2014 ◽  
Vol 6 (2) ◽  
pp. 124 ◽  
Author(s):  
Chongyi E ◽  
Hongchang Hu ◽  
Hong Xie ◽  
Yongjuan Sun

The study of temperature change and its elevation dependency in the source region of the Yangtze River and Yellow River have been insufficient owing to the lack of adequate observation stations and long-term climatic data. In this study five temperature indices of 32 stations from 1961 to 2007 in and near the source region are used. The 32 stations all have experienced significant warming; the warming amplitudes are higher than the mean warming amplitude of the Qinghai-Tibetan plateau. The warming amplitudes and the numbers of stations showing significant warming trends in mean minimum temperature and extreme minimum temperature are higher than that of the mean maximum temperature and extreme maximum temperature. The elevation dependency of climatic warming and the amount of significant warming stations are not obvious; the influence of human activity and urbanization may be higher. The warming amplitudes of 26 stations above 3000 m tend to be uniform, and there is no significant law at 6 stations below 3000 m. On the contrary, the ratio of stations showing significant warming in minimum temperature above 4000 m is far less than that of the stations below 4000 m.


2014 ◽  
Author(s):  
D W McKenney ◽  
J H Pedlar ◽  
K Lawrence ◽  
P Papadopol ◽  
K Campbell ◽  
...  

2014 ◽  
Author(s):  
D W McKenney ◽  
J H Pedlar ◽  
K Lawrence ◽  
P Papadopol ◽  
K Campbell ◽  
...  

2009 ◽  
Vol 39 (7) ◽  
pp. 1346-1356 ◽  
Author(s):  
Jianbang Gan ◽  
James H. Miller ◽  
Hsiaohsuan Wang ◽  
John W. Taylor

We identify species–environment relationships to predict the occurrence of Chinese tallow ( Triadica sebifera (L.) Small) on forestlands in the southern US, where it has emerged as the most pervading, stand-replacing, alien tree species. Tallow invasions are more likely to be observed on low and flat lands, areas adjacent to water and roadways, sites recently harvested or disturbed, younger stands, and private forestlands. The winter extreme minimum temperature tends to restrain tallow northward migration. Increases in both range and severity of tallow invasions are predicted with a warming climate trend, and the situation could be worse if the warming is coupled with an increased frequency and intensity of disturbances. Monitoring and mitigation strategies are proposed to assist this region and other countries threatened by tallow invasions.


2021 ◽  
Vol 24 (5) ◽  
pp. 519-527
Author(s):  
Jung Nam Suh ◽  
Yun-Im Kang ◽  
Youn Jung Choi ◽  
Kyung Hye Seo ◽  
Yong Hyun Kim

Background and objective: This study was conducted to establish a Plant Hardiness Zone (PHZ) map, investigate the effect of global warming on changes in PHZ, and elucidate the difference in the distribution of evergreen trees between the central and southern region within hardiness Zone 7b in Korea. Methods: Mean annual extreme minimum temperature (EMT) and related temperature fluctuation data for 40 years (1981 to 2020) in each of the meteorological observation points were extracted from the Open MET Data Portal of the Korea Meteorological Administration. Using EMT data from 60 meteorological observation points, PHZs were classified according to temperature range in the USDA Plant Hardiness Zone Map. Changes in PHZs for each decade related to the effects of global warming were analyzed. Temperature fluctuation before and after the day of EMT were analyzed for 4 areas of Seoul, Suwon, Suncheon, and Jinju falling under Zone 7b. For statistical analysis, descriptive statistics and ANOVA were performed using the IBM SPSS 22 Statistics software package. Results: Plant hardiness zones in Korea ranged from 6a to 9b. Over four decades, changes to warmer PHZ occurred in 10 areas, especially in colder ones. Based on the analysis of daily temperature fluctuation, the duration of sub-zero temperatures was at least 2 days in Seoul and Suwon, while daily maximum temperatures were above zero in Suncheon and Jinju before and after EMT day. Conclusion: It was found that the duration of sub-zero temperatures in a given area is an important factor affecting the distribution of evergreen trees in PHZ 7b.


2014 ◽  
Author(s):  
D W McKenney ◽  
J H Pedlar ◽  
K Lawrence ◽  
P Papadopol ◽  
K Campbell ◽  
...  

2012 ◽  
Vol 22 (1) ◽  
pp. 6-19 ◽  
Author(s):  
Mark P. Widrlechner ◽  
Christopher Daly ◽  
Markus Keller ◽  
Kim Kaplan

The accurate prediction of winter injury caused by low-temperature events is a key component of the effective cultivation of woody and herbaceous perennial plants. A common method employed to visualize geographic patterns in the severity of low-temperature events is to map a climatological variable that closely correlates with plant survival. The U.S. Department of Agriculture Plant Hardiness Zone Map (PHZM) is constructed for that purpose. We present a short history of PHZM development, culminating in the recent production of a new, high-resolution version of the PHZM, and discuss how such maps relate to winterhardiness per se and to other climatic factors that affect hardiness. The new PHZM is based on extreme minimum-temperature data logged annually from 1976 to 2005 at 7983 weather stations in the United States, Puerto Rico, and adjacent regions in Canada and Mexico. The PHZM is accessible via an interactive website, which facilitates a wide range of horticultural applications. For example, we highlight how the PHZM can be used as a tool for site evaluation for vineyards in the Pacific northwestern United States and as a data layer in conjunction with moisture-balance data to predict the survival of Yugoslavian woody plants in South Dakota. In addition, the new map includes a zip code finder, and we describe how it may be used by governmental agencies for risk management and development of recommended plant lists, by horticultural firms to schedule plant shipments, and by other commercial interests that market products seasonally.


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