scholarly journals Climate change and forest seed zones: Past trends, future prospects and challenges to ponder

2009 ◽  
Vol 85 (2) ◽  
pp. 258-266 ◽  
Author(s):  
Dan McKenney ◽  
John Pedlar ◽  
Greg O’Neill

Canada regenerates more than 400 000 ha of forest land annually through planting and seeding operations. Much of the stock for this effort is selected to be climatically suited to the planting site—a match that is often facilitated through the development of seed zones. However, if climate change proceeds as predicted, stock that is well matched under current climate will be growing in sub-optimal conditions within the next 20 to 50 years—in some parts of the country, trees may already be growing outside their optimal climates. To provide a sense of the magnitude of these changes, we present past and predicted future climate trends for Ontario and British Columbia seed zones. For Ontario, over the period 1950 to 2005, minimum temperature of the coldest month has already increased by up to 4.3°C, growing season has lengthened by up to 6 days, and precipitation during the growing season has increased by up to 26%. Changes were more pronounced across British Columbia’s Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) seed zones, with minimum temperature increasing by up to 8°C, a growing season extension of up to 30 days, and growing season precipitation increases of up to 40%. Projections for the end of the current century include: minimum temperature increase of 5°C to 10°C, growing season extension of 31 to 60 days, and growing season precipitation increases of 3% to 42% across the seed zones in both provinces. These changes are certain to have extensive impacts on forest ecosystems. We briefly discuss 3 forest management adaptation strategies intended to mitigate the negative impacts of climate change in Canada. Key words: climate change, seed zones, British Columbia, Ontario, Douglas-fir, seed transfer, assisted migration

2018 ◽  
Vol 115 (47) ◽  
pp. 11935-11940 ◽  
Author(s):  
Ethan E. Butler ◽  
Nathaniel D. Mueller ◽  
Peter Huybers

Continuation of historical trends in crop yield are critical to meeting the demands of a growing and more affluent world population. Climate change may compromise our ability to meet these demands, but estimates vary widely, highlighting the importance of understanding historical interactions between yield and climate trends. The relationship between temperature and yield is nuanced, involving differential yield outcomes to warm (9−29 °C) and hot (>29 °C) temperatures and differing sensitivity across growth phases. Here, we use a crop model that resolves temperature responses according to magnitude and growth phase to show that US maize has benefited from weather shifts since 1981. Improvements are related to lengthening of the growing season and cooling of the hottest temperatures. Furthermore, current farmer cropping schedules are more beneficial in the climate of the last decade than they would have been in earlier decades, indicating statistically significant adaptation to a changing climate of 13 kg·ha−1· decade−1. All together, the better weather experienced by US maize accounts for 28% of the yield trends since 1981. Sustaining positive trends in yield depends on whether improvements in agricultural climate continue and the degree to which farmers adapt to future climates.


2019 ◽  
Vol 15 ◽  
pp. 01011
Author(s):  
A. Nesbitt ◽  
S. Dorling ◽  
R. Jones

As cool climate viticulture rapidly expands, the England and Wales wine sector is winning international acclaim, particularly for its sparkling wines, and is attracting significant investment. Supported by warming climate trends during the growing season, wine producers are establishing new vineyards planted predominantly with Pinot Noir and Chardonnay. Grape-friendly weather conditions in 2018 led to a record harvest and may be a sign of good things to come. Long term (100-years) Growing Season Average Temperatures (GSTs) in south-east and south-central England have noticeably increased with 6 of the top 10 warmest growing seasons (April–October), over the last 100 years, occurring since 2005. However, weather and growing season conditions fluctuate markedly from year to year, meaning that yields and grape quality continue to vary significantly. Weather extremes are anticipated to become more frequent under future climate change, further threatening the stability of production. Current uncertainty over future climatic conditions during the growing season and their potential effects on viticulture in the UK exposes both existing producers and potential investors to unquantified risks and opportunities. The CREWS-UK climate resilience research project is generating actionable information on how climate change may affect the wine production sector, to support better decision-making and investment.


Forests ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 27
Author(s):  
Enzai Du ◽  
Yang Tang

Climate change is exerting profound impacts on the structure and function of global boreal forest. Compared with their northern counterparts, trees growing at the southern boreal forest and the temperate-boreal forest ecotone likely show distinct responses to climate change. Based on annual basal areal increment (BAI) of Dahurian larch (Larix gmelinii Rupr.) plantations with similar ages, tree densities and soil nutrient conditions, we investigated the tree growth responses to inter-annual climate variations at an Asian temperate-boreal forest ecotone and nearby boreal sites in northeast China. Annual BAI changed nonlinearly with cambial age in the form of a lognormal curve. The maximum annual BAI showed no significant difference between the two bioregions, while annual BAI peaked at an elder age at the boreal-temperate forest ecotone. After eliminating the age associated trend, conditional regression analyses indicate that residual BAI at the boreal sites increased significantly with higher growing-season mean nighttime minimum temperature and non-growing-season precipitation, but decreased significantly with higher growing-season mean daytime maximum temperature during the past three decades (1985–2015). In contrast, residual BAI at the boreal-temperate forest ecotone only showed a positive and weak response to inter-annual variations of growing-season precipitation. These findings suggest distinct effects of inter-annual climate variation on the growth of boreal trees at the temperate-boreal forest ecotone in comparison to the southern boreal regions, and highlight future efforts to elucidate the key factors that regulate the growth ofthe southernmost boreal trees.


2002 ◽  
Vol 82 (4) ◽  
pp. 755-763 ◽  
Author(s):  
J. M. Caprio ◽  
H. A. Quamme

An iterative χ2 method applied to 60 yr of records in the Okanagan Valley of British Columbia (1930–1989) revealed that the main climatic factor limiting grape production (Vitis spp. and Vitis vinifera L.) was low temperatures (critical value range, ≤–6°C to ≤–23°C) occurring during late October, November, December and February. Daytime temperatures ≤–9°C during late November and early December benefited grape production, probably because it prevented vine de-acclimation. Detrimental effects of precipitation during late October were probably associated with the early movement of Arctic fronts into the region. Beneficial effects of precipitation in the form of snow were observed in January. During the pre-harvest growing season, except for a 2-wk period in July, high temperatures (≥26°C) were associated with good production, probably because warm temperatures are required for flower bud initiation and development. In contrast, higher-than-normal temperatures were not beneficial to production during the harvest year. Detrimental effects of high temperature were observed during July of the pre-harvest year and July (≥32°C) and early August of the harvest year (≥28°C). During the growing season, rainfall was sometimes unfavourable for grape production under irrigation, either because of associated cool weather or greater disease occurrence. Both temperature and precipitation were greater in the last 18 yr of the study than the prior 36 yr, especially during the late winter and early spring. The anticipated climatic change appears to favour grape production in the Okanagan Valley. Key words: grape, climate change, heat stress, winter injury


2016 ◽  
Vol 8 (1) ◽  
pp. 78-88
Author(s):  
Erika Bouchard ◽  
Zhiming Qi

Long-term trends in air temperature and precipitation under climate change were analyzed for two meteorological stations on the Island of Montreal: McGill (1872–1986) and Pierre-Elliott-Trudeau (P-E-T, formerly Dorval) Airport (1942–2014). A linear trendline analysis, the Mann–Kendall (MK) test and the two-sample Kolmogorov–Smirnov (KS) test were conducted to assess specific climate trends. On a 100-year basis, temperature increased 1.88°C (34%) and 1.18°C (19%) at the McGill and P-E-T Airport sites, respectively, while annual rainfall increased 23.9 mm y−1 (2.3%) and 138.8 mm y−1 (15%) over the same period. The frequency of 50% (every other year) and 95% (every year) annual maximum daily rainfall events showed decreasing trends for the McGill station, but increasing trends for the P-E-T Airport station. Growing degree-days and growing season length are prone to being influenced by climate change and are critical to managing agricultural activities in the Montreal region; both showed increasing trends. At the same time, the onset of the growing season occurred earlier as time progressed.


1997 ◽  
Vol 75 (5) ◽  
pp. 799-814 ◽  
Author(s):  
Marlow G. Pellatt ◽  
Rolf W. Mathewes ◽  
Ian R. Walker

Surficial sediment samples from 42 lakes, distributed from sea level to alpine elevations of coastal British Columbia and northwest Washington, were analyzed for pollen and spores. Pollen analysis revealed characteristic differences among the assemblages of the Coastal Western Hemlock, Mountain Hemlock, and Engelmann Spruce – Subalpine Fir biogeoclimatic zones (the Alpine zone is less clearly identifiable). Cluster analysis and detrended correspondence analysis (DCA) correctly group the sites according to their biogeoclimatic zones and also by geographic origin. DCA indicates a high correlation between the biogeoclimatic zones of the sample sites and annual precipitation (−0.89), January temperature (−0.77), annual temperature (−0.64), and growing-season precipitation (−0.68). Further analysis of the samples and eight environmental gradients using canonical correspondence analysis groups the pollen assemblages from the study sites into biogeoclimatic zones in relation to annual precipitation, growing-season precipitation, annual snowfall, annual temperature, and growing degree-days. These data are useful for testing whether or not postglacial pollen assemblages have modern analogues. Key words: modern pollen analysis, vegetation, ordination, multivariate statistical analysis, biogeoclimatic zones, British Columbia.


2020 ◽  
Vol 13 (07) ◽  
pp. 3234
Author(s):  
Roni Valter De Souza Guedes ◽  
Thiago Luiz Do Vale Silva

Os efeitos das mudanças climáticas sobre as principais variáveis atmosféricas locais é o objeto deste estudo, a partir de dados de 1961 a 2019 para a localidade do Recife-PE. A metodologia engloba uma análise exploratória e descritiva com distribuição de frequencia por faixas de intensidades pluviométricas e identificação de tendências em escalas temporais diversificadas em meses, quadras, estações, anos e décadas das variaveis precipitação, temperaturas e umidade do ar. Verificou-se redução das precipitações em algumas faixas intermediárias e aumento dos dias sem chuva, chuvas leves e chuvas intensas, com tendência anual da precipitação de diminuição ao longo das décadas. Observou-se também tendências de aumento das temperaturas máximas, mínimas e diminuição das umidades, com taxas diferenciadas entre os meses secos e chuvosos, com maiores variações nas estações de transição e indicativo de verões mais quentes e secos. A conclusão é que o clima do Recife está mudando alguns padrões climatológicos, com tendência de chuvas extremas durante a quadra chuvosa e provável aumento de ondas de calor fora do periodo chuvoso.  Descriptive Analysis of Precipitation, Temperature, Humidity and Climate Trends in Recife - PE A B S T R A C TThis study aims to describe and evaluate the changes and trends of meteorological variables in Recife - PE during the period from 1961 to 2019 and verify indications of climatic changes over the Region. The methodology includes an exploratory and descriptive analysis with frequency distribution by ranges of rainfall intensity and identifying trends in temporal scales of precipitation, temperatures, and air humidity. The results pointed a precipitation reduction in ranges between 10 to 70 mm, an increase in the number of days without rain, in rains below 10 mm, and rains with intensity above 100 mm, however, with a trend in the annual accumulated rainfall reduction in recent decades. There was an evident trend towards increasing maximum and minimum temperatures and decreasing relative humidity in the air, with different rates between the dry and rainy months, with emphasis on more significant variations in the transition seasons and indicative of hotter and drier summers, divergent behavior of the minimum temperature, stabilizing during the rainy season, and reduction in the last decade. Thus, the rate of increasing maximum temperature is more than 0.23ºC/decade, while the minimum temperature is rising 0.13ºC/decade, and the relative humidity is decreasing at a rate of 0.53%/decade. The local climate change at Recife registered different behaviors on seasonal scales and diversity in climatological patterns, with an increase in the concentration of extreme rainfall in the rainy season, a decrease in rainfall in the driest periods. Also, an increase in the probability of the occurrence of heatwaves.Keywords: Climate change, intensity frequencies, seasonal and decadal variations


1993 ◽  
Vol 23 (3) ◽  
pp. 373-379 ◽  
Author(s):  
Richard W. Reich ◽  
Bart J. van der Kamp

The relationships between dieback severity of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), growing-season frosts, and invasion by canker pathogens in plantations >10 years old in central British Columbia are described. The coincidence of frosts and dieback events was determined by dissection and by mapping dieback damage in arid around frost pockets. Putative canker pathogens were isolated from bark and fruiting bodies. The timing of significant dieback events coincided with major growing-season frosts, as determined by the formation of frost rings. Damage was most severe in shallow depressions and valley bottoms. Early flushing trees were more severely affected than late flushing trees in two of three plantations. Seven weak canker parasites were isolated from dead Douglas-fir bark. Among these, Sclerophomasemenospora Funk was restricted to tissues killed by frost or other factors, while Leucocytosporakunzei (Fr.:Fr.) Munk and a Sirodothis sp. accounted for about 65% of isolates from recently killed bark. Outside frost prone areas, these fungi were common as small latent branch cankers, but caused no further discernable damage. Areas of high dieback hazard could be identified from topographic features seen on aerial photographs. Of the area of Douglas-fir plantations >10 years old, 4.7% was severely damaged by dieback. It is recommended that lodgepole pine (Pinusconforta Dougl.) be planted in frost-prone areas.


2010 ◽  
Vol 40 (2) ◽  
pp. 308-321 ◽  
Author(s):  
Hardy P. Griesbauer ◽  
D. Scott Green

How climate change will affect tree growth across species’ geographic and climatic ranges remains a critical knowledge gap. Tree-ring data were analyzed from 33 interior Douglas-fir ( Pseudotsuga menziesii var. glauca (Beissn.) Franco) stands spanning wide geographic and climatic conditions in the interior of British Columbia to gain insights into how within-species growth responses to climate can vary based on local environmental conditions over a broad climatic and geographic range, including populations growing at the species’ range and climatic margins. Populations growing in relatively warm and dry climates had growth patterns correlated mostly with annual precipitation, whereas populations growing in high-elevation wet and cold climates had growth patterns correlated with snowfall, winter and annual temperatures, and ocean–atmosphere climate systems. Populations growing at climatic extremes (e.g., coldest, driest, warmest) in each study region had the strongest responses to climate. Projected climate change may negatively influence Douglas-fir productivity across most of its range, and populations growing near the species’ climatic limits may provide early and strong indications of future responses.


1990 ◽  
Vol 20 (10) ◽  
pp. 1640-1647 ◽  
Author(s):  
Bart J. van der Kamp ◽  
John Worrall

A widespread and unusual form of damage was suffered by most buds above the putative 1988–1989 winter snow line on Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), Engelmann and white spruces (Piceaengelmannii Parry and P. glauca (Moench) Voss, respectively) and their hybrids, and subalpine and amabilis firs (Abieslasiocarpa (Hook.) Nutt. and A. amabilis (Dougl.) Forbes, respectively). By mid-June, on trees less than 30 years old, all tissues above the innermost bud scales, including the dome of the apical meristem, were dead, and a whorl of embryonic shoots arising from bud scale axils was developing. These shoots either produced a bud or developed into short stem segments during the 1989 growing season. The probable cause of the phenomenon was a warmer (1.0 to 3.6 °C above normal) October to December, and a very warm (2.9 to 4.7 °C above normal) January followed by a sudden cold snap with temperatures falling to −30 °C in early February.


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