scholarly journals The effects of climate change on the flowering phenology of alder trees in southwestern Europe

2021 ◽  
Vol 42 ◽  
pp. e67360
Author(s):  
Jesús Rojo ◽  
Federico Fernández-González ◽  
Beatriz Lara ◽  
Verónica Bouso ◽  
Guillermo Crespo ◽  
...  
Keyword(s):  
Climate Change ◽  
Alnus Glutinosa ◽  
Flowering Phenology ◽  
Warming Trend ◽  
Reproductive Phenology ◽  
Positive Trend ◽  
Black Alder ◽  
Start Date ◽  
Temperate Trees ◽  
Short Period

Global warming impacts plant phenology and the effect of climate change will be more intensely experienced at the edges of a plant's distribution. This work focuses on Iberian alder's climatic range (Alnus lusitanica Vít, Douda & Mandák). The Iberian Peninsula constitutes the Southwestern edge of the global chorological distribution of European black alder (Alnus glutinosa (L.) Gaertn. s.l.), and some of the warmest and driest conditions for the alder population are located in the center of Spain. The critical temperature-relevant periods that regulate the reproductive phenology of alder were analyzed using a statistical-based method for modeling chilling and forcing accumulation periods in temperate trees. Our results reveal that autumn chilling was the most important thermal accumulation period for alder in a Mediterranean climate while forcing requirements are satisfied in a short period of time. Autumn temperatures were significantly correlated with the timing of flowering, and chill units during this season directly influence start-dates of alder flowering. A positive trend was observed in pollen seasons' timing, meaning a slight delay of alder flowering in central Spain. It coincided with autumn warming during the period 2004-2018. If this warming trend continues, our results predict a delay in the start-date of flowering by around 3-days for every degree increase in maximum autumn temperatures according to the most optimistic emission scenarios.

scholarly journals Local differentiation of flowering phenology in an alpine-snowbed herb Gentiana nipponica

Botany ◽  
2011 ◽  
Vol 89 (6) ◽  
pp. 361-367 ◽  
Author(s):  
Yuka Kawai ◽  
Gaku Kudo
Keyword(s):  
Genetic Regulation ◽  
Thermal Conditions ◽  
Growth Period ◽  
Local Area ◽  
Flowering Phenology ◽  
Reproductive Phenology ◽  
Transplant Experiment ◽  
Reciprocal Transplant Experiment ◽  
Thermal Requirement ◽  
Short Period

Phenological events of alpine plants are strongly influenced by the seasonal thermal conditions at the local scale that are caused by heterogeneity in snowmelt time. Populations in late-snowmelt locations suffer from a short period for seed maturation, in which rapid flowering that occurs soon after snowmelt (i.e., a low thermal requirement for flowering) is advantageous. To test the possibility of local adaptation of flowering phenology, we compared reproductive phenology, the preflowering period, and the thermal requirement for flowering of the alpine-snowbed species Gentiana nipponica Maxim. between populations inhabiting early- and late-snowmelt sites within a local area. Plants in the late-snowmelt population showed a shorter preflowering period than in the early-snowmelt population; nevertheless, they often failed to set fruit owing to the short growth period. To test the plasticity and genetic regulation of flowering phenology, we performed a reciprocal transplant experiment between early- and late-snowmelt populations. Although the preflowering period showed clear plastic responses depending on the transplanted habitats, the lower thermal requirement for flowering was retained in plants originating from the late-snowmelt populations, even after transplantation. Therefore, habitat-specific differentiation of flowering phenology was genetically determined between these local populations.

scholarly journals Climate Change in Rwanda: The Observed Changes in Daily Maximum and Minimum Surface Air Temperatures during 1961–2014

2021 ◽  
Vol 9 ◽  
Author(s):  
Jean Paul Ngarukiyimana ◽  
Yunfei Fu ◽  
Celestin Sindikubwabo ◽  
Idrissa Fabien Nkurunziza ◽  
Faustin Katchele Ogou ◽  
...  
Keyword(s):  
Climate Change ◽  
Time Scales ◽  
Surface Air Temperature ◽  
Warming Trend ◽  
Temporal Variations ◽  
Least Square ◽  
Daily Maximum ◽  
Spatial And Temporal Variability ◽  
Positive Trend ◽  
Minimum Surface

Rwanda has experienced high temperature rising phenomena over the last decades and hence, highly vulnerable to climate change. This paper examined the spatial and temporal variations of daily maximum and minimum surface air temperature (Tmin and Tmax) and diurnal temperature range (DTR). It studied variables at monthly, seasonal and annual time-scales from 1961 to 2014. The study applied various statistical methods such as ordinary least-square fitting, Mann-Kendall, Sen’ slope and Sequential Mann-Kendall statistical test to the new reconstructed ENACTS dataset that cover the period from 1983 to 2014 while pre-1983s recorded data from 24 meteorological stations have been added to complete the lengthiness of ENACTS data. The January to February season did not show a significant trend at seasonal time-scales. The authors decided only to consider March-to-May, June-to-August and October-to-December seasons for further analyses. Topography impacts on temperature classified stations into three regions: region one (R1) (1,000–1,500 m), region two (R2) (1,500–2,000 m) and region three (R3) (≥2,000 m). With high confidence, the results indicate a significant positive trend in both Tmin and Tmax in all three regions during the whole study period. However, the magnitude rate of temperatures change is different in three regions and it varies in seasonal and annual scale. The spatial distributions of Tmax and Tmin represent a siginificant warming trend over the whole country notably since the early 1980s. Surprisingly, Tmin increased at a faster rate than Tmax in R3 (0.27 vs. 0.07°C/decade in March-to-May) and (0.29 vs. 0.04°C/decade in October-to-December), resulting in a significant decrease in the DTR. This is another confirmation of warming in Rwanda. The mutation test application exhibited most of the abrupt changes in the seasonal and annual Tmax and Tmin trends between 1984 and 1990. The present work mainly focus on the spatial and temporal variability of Tmin, Tmax and DTR in Rwanda and their relationship with elevation change, leaving a gap in other potential cause factors explored in the future.

scholarly journals Phenological responses to multiple environmental drivers under climate change: insights from a long-term observational study and a manipulative field experiment

2017 ◽  
Author(s):  
Susana M. Wadgymar ◽  
Jane E. Ogilvie ◽  
David W. Inouye ◽  
Arthur E. Weis ◽  
Jill T. Anderson
Keyword(s):  
Climate Change ◽  
Environmental Factors ◽  
Observational Study ◽  
Interspecific Variation ◽  
Flowering Phenology ◽  
Environmental Drivers ◽  
Reproductive Phenology ◽  
Biological Responses ◽  
Boechera Stricta

AbstractClimate change has induced pronounced shifts in the reproductive phenology of plants, with the timing of first flowering advancing in most species. Indeed, population persistence may be threatened by the inability to track climate change phenologically. Nevertheless, substantial variation exists in biological responses to climate change across taxa. Here, we explore the consequences of climate change for flowering phenology by integrating data from a long-term observational study and a manipulative experiment under contemporary conditions. Dissecting the environmental factors that influence phenological change will illuminate why interspecific variation exists in responses to climate change. We examine a 43-year record of first flowering for six species in subalpine meadows of Colorado in conjunction with a 3-year snow manipulation experiment on the perennial mustard Boechera stricta from the same site. We analyze shifts in the onset of flowering in relation to environmental drivers known to influence phenology: the timing of snowmelt, the accumulation of growing degree days, and photoperiod. At our study site, climate change is reducing snowpack and advancing the timing of spring snowmelt. We found that variation in phenological responses to climate change depended on the sequence in which species flowered, with early-flowering species flowering faster, at a lower heat sum, and under increasingly disparate photoperiods in comparison to species that flower later in the season. Furthermore, climate change is outpacing phenological change for all species. Early snow removal treatments confirm that the timing of snowmelt governs observed trends in flowering phenology of B. stricta and that climate change can reduce the probability of flowering, thereby depressing fitness. Shorter-term studies would not have captured the trends that we document in our observational and experimental datasets. Accurate predictions of the biological responses to climate change require a thorough understanding of the specific environmental factors driving shifts in phenology.

scholarly journals Glossiness Evaluation of Coated Wood Surfaces as Function of Varnish Type and Exposure to Different Conditions

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 558
Author(s):  
Emilia-Adela Salca ◽  
Tomasz Krystofiak ◽  
Barbara Lis ◽  
Salim Hiziroglu
Keyword(s):  
Artificial Aging ◽  
Chemical Resistance ◽  
Heat Exposure ◽  
Value Added ◽  
Alnus Glutinosa ◽  
Practical Applications ◽  
Black Alder ◽  
Structural Differences ◽  
Wood Surfaces ◽  
Water Borne

The objective of this study was to evaluate the glossiness of black alder wood (Alnus glutinosa L.) samples coated with two varnish types as a function of exposure to dry heat and artificial aging. The chemical resistance of the coated samples to cold liquids was also evaluated. Based on the findings in this work, it appears that the varnish types and their structural differences influenced the overall glossiness of the coated samples. The UV varnish exhibited higher gloss values than those coated with the water-borne product within the range of silky gloss and silky matte grades. The heat exposure influenced the surface glossiness of the UV-coated samples more than the samples coated with water-borne varnish. The overall gloss values of the samples decreased with the exposure time to artificial aging, resulting in no layer cracks. The cold household liquids left less visible traces on the surfaces and alcohol was found to be the strongest agent. This study could have practical applications in the furniture industry to produce value-added furniture units according to their specific conditions of indoor use.

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 Predicted Effects of Climate Change on Winter Chill Accumulation by Temperate Trees in South Korea

2018 ◽  
Vol 87 (2) ◽  
pp. 166-173 ◽  
Author(s):  
YoSup Park ◽  
ByulHaNa Lee ◽  
Hee-Seung Park
Keyword(s):  
Climate Change ◽  
South Korea ◽  
Winter Chill ◽  
Temperate Trees

Changes in the Amplitude of the Temperature Annual Cycle in China and Their Implication for Climate Change Research

2011 ◽  
Vol 24 (20) ◽  
pp. 5292-5302 ◽  
Author(s):  
Cheng Qian ◽  
Congbin Fu ◽  
Zhaohua Wu
Keyword(s):  
Climate Change ◽  
Annual Cycle ◽  
Linear Trend ◽  
Surface Air Temperature ◽  
Mean Amplitude ◽  
Warming Trend ◽  
Ensemble Empirical Mode Decomposition ◽  
Surface Solar Radiation ◽  
Climate Change Research ◽  
Annual Cycles

Abstract Climate change is not only reflected in the changes in annual means of climate variables but also in the changes in their annual cycles (seasonality), especially in the regions outside the tropics. In this study, the ensemble empirical mode decomposition (EEMD) method is applied to investigate the nonlinear trend in the amplitude of the annual cycle (which contributes 96% of the total variance) of China’s daily mean surface air temperature for the period 1961–2007. The results show that the variation and change in the amplitude are significant, with a peak-to-peak annual amplitude variation of 13% (1.8°C) of its mean amplitude and a significant linear decrease in amplitude by 4.6% (0.63°C) for this period. Also identified is a multidecadal change in amplitude from significant decreasing (−1.7% decade−1 or −0.23°C decade−1) to significant increasing (2.2% decade−1 or 0.29°C decade−1) occurring around 1993 that overlaps the systematic linear trend. This multidecadal change can be mainly attributed to the change in surface solar radiation, from dimming to brightening, rather than to a warming trend or an enhanced greenhouse effect. The study further proposes that the combined effect of the global dimming–brightening transition and a gradual increase in greenhouse warming has led to a perceived warming trend that is much larger in winter than in summer and to a perceived accelerated warming in the annual mean since the early 1990s in China. It also notes that the deseasonalization method (considering either the conventional repetitive climatological annual cycle or the time-varying annual cycle) can also affect trend estimation.

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