Long-term changes in the frost-free season on the Canadian prairies

2004 ◽  
Vol 84 (4) ◽  
pp. 1085-1091 ◽  
Author(s):  
Herb Cutforth ◽  
EG (Ted) O’Brien ◽  
Jason Tuchelt ◽  
Rick Rickwood
Keyword(s):  
Climate Change ◽  
Early Spring ◽  
Late Winter ◽  
Past Century ◽  
Canadian Prairies ◽  
Spring Frost ◽  
Growing Seasons ◽  
Spring Frosts ◽  
Agricultural Regions

The climate of the prairies has warmed over the past century, especially during late winter and early spring. Some regions of the prairies have warmed faster than others. Climate change has been documented to affect living systems in North America, such as promoting earlier phenological development and longer growing seasons. We examined weather records gathered at several long-term weather-recording sites across the agricultural regions of the Canadian prairies for evidence of trends in last spring frosts, first fall frosts, and frost-free durations. During the latter half of the 20th century, the trends were towards earlier last spring frost dates and towards longer frost-free seasons in the agricultural regions of the Canadian prairies. Across most of the prairies the trends towards later first fall frost dates were smaller and generally not significant. The largest changes have occurred in the central and northern agricultural regions of Alberta, whereas the least change occurred over much of southern Alberta and in southern Manitoba. Key words: Last spring and first fall frost dates, frost-free season, agroclimatic indices, climate change, Canadian prairies

Climate change in the semiarid prairie of southwestern Saskatchewan: Late winter–early spring

1999 ◽  
Vol 79 (3) ◽  
pp. 343-350 ◽  
Author(s):  
H. W. Cutforth ◽  
B. G. McConkey ◽  
R. J. Woodvine ◽  
D. G. Smith ◽  
P. G. Jefferson ◽  
...  
Keyword(s):  
Climate Change ◽  
Early Spring ◽  
Late Winter ◽  
Spring Temperature ◽  
Spring Frost ◽  
The Past ◽  
Spring Runoff ◽  
Key Words Climate Change ◽  
Spring Maximum

Long-term weather and hydrological data were analyzed to study climate change during late winter–early spring within an approximately 15 000 km2 area in the semiarid prairie near Swift Current, Saskatchewan. The climate has changed over the past 50 yr. Winter and spring maximum and minimum temperatures have warmed, snowfall amounts have decreased, and spring runoff has started earlier now than during past years. The percentage of precipitation as snow has decreased as temperatures have warmed. As well, even though temperatures have warmed, the date of the last spring frost has not gotten earlier with time. Key words: Climate change, semiarid prairie, winter and spring, temperature, snow, spring runoff

Phenological phases of pollination related to climate change

2021 ◽  
Author(s):  
Samuel Monnier ◽  
Michel Thibaudon ◽  
Jean-Pierre Besancenot ◽  
Charlotte Sindt ◽  
Gilles Oliver
Keyword(s):  
Climate Change ◽  
Pollen Season ◽  
Microscopic Analysis ◽  
Allergic Diseases ◽  
Early Spring ◽  
Late Winter ◽  
General Tendency ◽  
New Production ◽  
Start Date ◽  
Generic Term

<p>Knowledge:</p><p>Rising CO2 levels and climate change may be resulting in some shift in the geographical range of certain plant species, as well as in increased rate of photosynthesis. Many plants respond accordingly with increased growth and reproduction and possibly greater pollen yields, that could affect allergic diseases among other things.</p><p>The aim of this study is the evolution of aerobiological measurements in France for 25-30 years. This allows to follow the main phenological parameters in connection with the pollination and the ensuing allergy risk.</p><p>Material and method:</p><p>The RNSA (French Aerobiology Network) has pollen background-traps located in more than 60 towns throughout France. These traps are volumetric Hirst models making it possible to obtain impacted strips for microscopic analysis by trained operators. The main taxa studied here are birch, grasses and ragweed for a long period of more than 25 years over some cities of France.</p><p>Results:</p><p>Concerning birch but also other catkins or buds’ trees pollinating in late winter or spring, it can be seen an overall advance of the pollen season start date until 2004 and then a progressive delay, the current date being nearly the same as it was 20 years ago, and an increasing trend in the quantities of pollen emitted.</p><p>For grasses and ragweed, we only found a few minor changes in the start date but a longer duration of the pollen season.</p><p>Discussion:</p><p>As regards the trees, the start date of the new production of catkins or buds is never the 1<sup>st</sup> of January but depends on the species. For example, it is early July for birch. For breaking dormancy, flowering, and pollinating, the trees and other perennial species need a period of accumulation of cold degrees (Chilling) and later an accumulation of warm degrees (Forcing). With climate change these periods may be shorter or longer depending of the autumn and winter temperature. Therefore, a change in the annual temperature may have a direct effect on the vegetal physiology and hence on pollen release. It may also explain why the quantities of pollen produced are increasing.</p><p>The Poaceae reserve, from one place to another and without any spatial structuring, very contrasted patterns which make it impossible to identify a general tendency. This is probably due to the great diversity of taxa grouped under the generic term Poaceae, which are clearly not equally sensitive to climate change.</p><p>Conclusion:</p><p>Trees with allergenic pollen blowing late winter or early spring pollinate since 2004 later and produce amounts of pollen constantly increasing. Grasses and ragweed have longer periods of pollination with either slightly higher or most often lower pollen production.</p>

scholarly journals Changes in the Occurrence of Late Spring Frost in Poland

Agronomy ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1835
Author(s):  
Dariusz Graczyk ◽  
Małgorzata Szwed
Keyword(s):  
Time Series ◽  
Air Temperature ◽  
Growing Season ◽  
Significant Trend ◽  
Similar Time ◽  
Spring Frost ◽  
Late Spring Frost ◽  
Low Probability ◽  
Spring Frosts ◽  
Agricultural Regions

Trends in the appearance of the last spring frost for three thresholds of minimum daily air temperature at the height of 2 m and near the ground were examined for six meteorological stations located in two agricultural regions in Poland. For most time series, the last spring frost, calculated as a consecutive day of the year, showed a statistically significant trend indicating its earlier appearance from 1.6 to about 3.5 days per decade. The date of the last spring frost was also calculated in relation to the ongoing growing season. In this case, few statistically significant changes in the dates of the last frosts were found. The probability of the last spring frost on a specific day of the calendar year and the day of the growing season was also examined for two periods: 1961–1990 and 1991–2020. For low probability levels corresponding to the early dates of the last spring frost, the last frost usually occurred much earlier (6–14 days) in 1991–2020. With the probability levels of 80–90% describing the late occurrence of the last frost with a frequency of once every 5–10 years, at some stations, the last spring frosts occurred at a similar time for both periods.

The productivity of breeding ewes grazing on lucerne or grass and clover pastures on the tablelands of Southern Australia. III. Lamb mortality and weaning percentage

1984 ◽  
Vol 35 (5) ◽  
pp. 709 ◽  
Author(s):  
JR Donnelly
Keyword(s):  
Early Spring ◽  
Practical Significance ◽  
Cold Weather ◽  
Late Winter ◽  
Maternal Weight ◽  
Risk Of Death ◽  
Probability Of Death ◽  
The Difference ◽  
Stocking Rates

Weaning percentage and perinatal mortality of lambs born in late winter or early spring to Merino and Border Leicester x Merino ewes grazing at several stocking rates on lucerne or phalaris-clover pastures were measured over 2 years. Weaning percentages for mature crossbred ewes declined linearly from 136 lambs per 100 ewes joined when stocked at 9 ha-1 to 100 for those at 18 ha-1. For mature Merino ewes, the values were 109 and 70 respectively. Weaning percentages were similar on lucerne and phalaris pastures, although 8% more lambs were born to ewes grazing on phalaris; higher mortality in lambs born as multiples eliminated the difference. Death from exposure during the first 3 days of life was the most important cause of lamb losses. For lambs born as singles to Merino ewes the probability of death from exposure was up to 0.4, and reached 0.6 for lambs born as multiples. For single and multiple lambs born to crossbred ewes equivalent probabilities were 0.25 and 0.4 respectively. These probabilities were reduced if maternal weight was high at lambing, the reduction being of practical significance in very cold weather, particularly if the proportion of multiple births was high. Under mild conditions, where the probability of death from exposure was low, reductions in mortality from high ewe weight at lambing were of little consequence. Long-term weather records kept at the experimental site near Canberra show that a high risk of death in new-born lambs is likely from early June to mid-September. Throughout this period deaths from exposure could be expected to exceed 30% in lambs born as multiples to Merino ewes.

On the Biology and Fishery of the Canadian Atlantic Halibut, Hippoglossus hippoglossus L.

1958 ◽  
Vol 15 (6) ◽  
pp. 1269-1311 ◽  
Author(s):  
F. D. McCracken
Keyword(s):  
Nova Scotia ◽  
Deep Water ◽  
Early Spring ◽  
Large Female ◽  
Late Winter ◽  
Atlantic Halibut ◽  
Large Numbers ◽  
Water Edge ◽  
Mature Fish

Exploratory fishing in the northern Gulf of St. Lawrence in 1945 and 1946 and off western Nova Scotia in 1947 caught 739 halibut, of which 229 were tagged and released. About 590 fish from the commercial fishery of the two regions were also examined.Larger, older halibut were caught in the northern part of the Gulf of St. Lawrence than off western Nova Scotia. Tagged halibut recaptures, size and age composition of commercial landings, and differences in rate of growth suggest generally separate stocks in the two regions.Younger, immature halibut were most available in shallower water; larger, mature fish usually in deep water. Most halibut were caught at temperatures between about 3° and 9 °C. Seasonal, inshore, relatively shallow water halibut fisheries in the northern part of the Gulf of St. Lawrence and off western Nova Scotia occur as the bottom water warms. Large female halibut predominate in such catches.Mature halibut, about 9 to 11 years and older, must spawn in late winter and early spring, probably along the deep-water edge of the banks. Mature halibut grow slowly though the females exceed the mature males and reach a much larger size. The faster-growing, immature halibut of both sexes grow at about the same rate.Halibut landings from ICNAF Subareas 3 and 4 which were at a low level between 1940 to 1948 increased sharply to about 13 million pounds in 1950. More recent landings approximate the long-term annual average of about 5 million pounds. Changes in the level of landings are related to changes in the magnitude of the Canadian fishery which, since 1940, has produced most of the halibut from Subareas 3 and 4.Offshore and inshore fisheries specifically for large halibut produce most of the landings. Catches of halibut taken incidentally in other fisheries contribute little by weight but take large numbers of small, faster-growing individuals. With a continuation of present fishing practices and intensities an annual yield of about 5 million pounds may be expected to continue, but some increased yield might result from controlling the incidental catches of younger halibut. Ways and means of effecting such control should be explored.

scholarly journals Effects of Climate Change on Epidemics of Powdery Mildew in Winter Wheat in China

Plant Disease ◽  
2017 ◽  
Vol 101 (10) ◽  
pp. 1753-1760 ◽  
Author(s):  
Xiuli Tang ◽  
Xueren Cao ◽  
Xiangming Xu ◽  
Yuying Jiang ◽  
Yong Luo ◽  
...  
Keyword(s):  
Climate Change ◽  
Relative Humidity ◽  
Powdery Mildew ◽  
Winter Wheat ◽  
Weather Conditions ◽  
Early Spring ◽  
Long Term Effects ◽  
Temperature Changes ◽  
Disease Epidemics

Powdery mildew is a highly destructive winter wheat pathogen in China. Since the causative agent is sensitive to changing weather conditions, we analyzed climatic records from regions with previous wheat powdery mildew epidemics (1970 to 2012) and investigated the long-term effects of climate change on the percent acreage (PA) of the disease. Then, using PA and the pathogen’s temperature requirements, we constructed a multiregression model to predict changes in epidemics during the 2020s, 2050s, and 2080s under representative concentration pathways RCP2.6, RCP4.5, and RCP8.5. Mean monthly air temperature increased from 1970 to 2012, whereas hours of sunshine and relative humidity decreased (P < 0.001). Year-to-year temperature changes were negatively associated with those of PA during oversummering and late spring periods of disease epidemics, whereas positive relationships were noted for other periods, and year-to-year changes in relative humidity were correlated with PA changes in the early spring period of disease epidemics (P < 0.001). Our models also predicted that PA would increase less under RCP2.6 (14.43%) than under RCP4.5 (14.51%) by the 2020s but would be higher by the 2050s and 2080s and would increase least under RCP8.5 (14.37% by the 2020s). Powdery mildew will, thus, pose an even greater threat to China’s winter wheat production in the future.

Assessment of recent environmental changes in New Brunswick (Canada) lakes based on paleolimnological shifts in diatom species assemblages

2006 ◽  
Vol 84 (1) ◽  
pp. 151-163 ◽  
Author(s):  
M. Anne Harris ◽  
Brian F. Cumming ◽  
John P. Smol
Keyword(s):  
Climate Change ◽  
New Brunswick ◽  
Environmental Changes ◽  
Environmental Data ◽  
Species Assemblages ◽  
Past Century ◽  
Diatom Species ◽  
Long Term Effects ◽  
Recent Climate

New Brunswick lakes are subjected to multiple environmental stressors, such as atmospheric acid deposition and climate change. In the absence of long-term environmental data, the impacts of these stressors are not well understood. Long-term effects of environmental change on diatom species assemblages were assessed in the sediments of 16 New Brunswick lakes using paleolimnological approaches. A regional trend of increasing Cyclotella stelligera Cleve & Gunrow and decreasing Aulacoseira species complex was recorded in most lakes. Detailed paleolimnological analyses of Wolfe, Cundy, and West Long lakes revealed varying degrees of species change, with assemblage shifts beginning ca. 1900 CE (common era). These species trends are not consistent with acidification. However, linear regression of mean July temperature with time for two New Brunswick historical instrumental temperature records revealed statistically significant warming over the past century. The shift from heavily silicified tychoplanktonic Aulacoseira species to small planktonic diatom species, such as C. stelligera, is consistent with paleolimnological inferences of warming trends recorded in several other lake regions of the Northern Hemisphere. These assemblage shifts are likely due to recent climate change and may be mediated by reduced ice cover and (or) increased thermal stability (decreased lake mixing) during the open water period.

Frost-seeding of summer turnip rape in the subarctic

1992 ◽  
Vol 72 (3) ◽  
pp. 713-723
Author(s):  
Stephen D. Sparrow ◽  
Charles W. Knight
Keyword(s):  
Early Spring ◽  
Frozen Soil ◽  
Market Quality ◽  
Good Seed ◽  
Hordeum Vulgare L ◽  
Plant Populations ◽  
Turnip Rape ◽  
Spring Frost ◽  
Growing Seasons ◽  
Seed Yields

Previous research has indicated that spring-planted summer turnip rape (Brassica rapa L.) can produce good seed yields with high oil content in subarctic Alaska. However, short growing seasons often prevent seeds from reaching full maturity, resulting in high proportions of green seeds and lowered market quality. In an attempt to allow summer turnip rape seedlings to begin growth earlier in the growing season, we planted the seeds in frozen soil in late fall and early spring. Fall seeding of summer turnip rape always resulted in low plant populations, low seed yields, and high percentages of green seeds. Percentages of green seeds were highly variable and early spring seedings did not result in significantly lower percentages of green seeds than conventional (May) seedings. The effects of early spring frost-seeding on plant populations and seed yields were variable but only rarely did early spring seeding produce significantly higher seed yields than conventional seeding. Planting into barley (Hordeum vulgare L.) stubble resulted in poor stands which produced low seed yields. This study did not indicate any advantage from fall planting of summer turnip rape. Results from spring frost-seeding were not consistent; therefore, this practice cannot be recommended until these inconsistencies are better understood.Key words: Frost-seeding, summer turnip rape, subarctic, Alaska

scholarly journals Long-term trends in the body condition of parents and offspring of Tengmalm’s owls under fluctuating food conditions and climate change

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marek Kouba ◽  
Luděk Bartoš ◽  
Jitka Bartošová ◽  
Kari Hongisto ◽  
Erkki Korpimäki
Keyword(s):  
Climate Change ◽  
Snow Cover ◽  
Body Condition ◽  
The Body ◽  
Adult Survival ◽  
Late Winter ◽  
Study Population ◽  
Males And Females ◽  
Tengmalm's Owl

AbstractPhysical condition is important for the ability to resist various parasites and diseases as well as in escaping predators thus contributing to reproductive success, over-winter survival and possible declines in wildlife populations. However, in-depth research on trends in body condition is rare because decades-long datasets are not available for a majority of species. We analysed the long-term dataset of offspring covering 34 years, male parents (40 years) and female parents (42 years) to find out whether the decline of Tengmalm’s owl population in western Finland is attributable to either decreased adult and/or juvenile body condition in interaction with changing weather conditions and density estimates of main foods. We found that body condition of parent owl males and females declined throughout the 40-year study period whereas the body condition of owlets at the fledging stage very slightly increased. The body condition of parent owls increased with augmenting depth of snow cover in late winter (January to March), and that of offspring improved with increasing precipitation in late spring (May to June). We conclude that the decreasing trend of body condition of parent owl males and females is important factor probably inducing reduced adult survival and reduced reproduction success thus contributing to the long-term decline of the Tengmalm’s owl study population. The very slightly increasing trend of body condition of offspring is obviously not able to compensate the overall decline of Tengmalm’s owl population, because the number of offspring in turn simultaneously decreased considerably in the long-term. The ongoing climate change appeared to work in opposite ways in this case because declining depth of snow cover will make the situation worse but increased precipitation will improve. We suggest that the main reasons for long-term decline of body condition of parent owls are interactive or additive effects of reduced food resources and increased overall predation risk due to habitat degradation (loss and fragmentation of mature and old-growth forests due to clear-felling) subsequently leading to decline of Tengmalm’s owl study population.

Knowledge level and constraints in adopting the recommended mitigation strategies on climate change in Haryana

2020 ◽  
Vol 36 (2) ◽  
pp. 7-11
Author(s):  
Dilip S ◽  
, Joginder Singh Malik ◽  
R.N. Sheokand
Keyword(s):  
Climate Change ◽  
New Technologies ◽  
Mitigation Strategies ◽  
Knowledge Level ◽  
Advisory Services ◽  
Growing Seasons ◽  
Lack Of Information ◽  
High Knowledge ◽  
The Mean

The greatest influencer of agricultural productivity is the weather. Climate is typically defined as the normal weather, or more precisely, as the statistical explanation of important parameters in relations of the mean and variability over time scales extending from months to thousands or millions of years. Agriculture in India, as well as the respite of the world, is mostly reliant on the weather. Global warming has had an important impact on agriculture and its output. The shift in growing seasons and changes in agricultural zones have been exacerbated by rising temperatures. Changes in rainfall patterns, on the other hand, pose a severe threat to agriculture, affecting the country’s economy and food security. The sale of agricultural products such as fertilizers, agro-chemicals and tractors are also affected by the delayed or insufficient monsoons. As a result, the farmer’s income is impacted. The present study conducted during 2020-21 focuses on Knowledge level farmers on climate change and constraint experienced by the farmers in adopting recommended mitigation strategies in Hisar district. The majority of beneficiary farmers (48.89 per cent) had high knowledge level on Agro-met Advisory Services whereas majority of non-beneficiary farmers (67.76 per cent) had low knowledge level on Agro-met Advisory Services. Lack of technical skills and capacities for technology adoption, lack of awareness and sensitization about the creation and use of new technologies, non-availability of timely inputs, and lack of information about long-term mitigation strategies were the major constraints

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