IMPACT OF WEATHER EXTREMES TO THE PHENOLOGICAL PHASES OF BROADLEAVED TREES

2017 ◽  
Author(s):  
Miriam VALKOVA
Keyword(s):  
Weather Extremes ◽  
Phenological Phases

scholarly journals Impact of Temperature and Wetness of Summer Months on Autumn Vegetative Phenological Phases of Selected Species in Fageto‑Quercetum in the Years 2011–2015

2017 ◽  
Vol 65 (3) ◽  
pp. 939-946 ◽  
Author(s):  
Jana Škvareninová ◽  
Darina Babálová ◽  
Ján Valach ◽  
Zora Snopková
Keyword(s):  
Tree Species ◽  
Quercus Robur ◽  
Meteorological Parameters ◽  
Prunus Avium ◽  
Weather Extremes ◽  
Moisture Index ◽  
Cherry Tree ◽  
Temperature And Precipitation ◽  
Leaf Colouring ◽  
Phenological Phases

The work presents the result of the drought impact on the onset and the development of autumn phenological phases of tree species (Quercus robur L., Carpinus betulus L., Prunus avium L.) in the central part of Slovakia. The selected autumn phenological phases of tree species were observed in the years from 2011 to 2015. From meteorological parameters we examined precipitation, number of tropical days, and their periods from June to August. We revealed distinct differences in air temperature and precipitation between the years, which affected the onset of individual phenological phases. Based on the calculations of the Thornthwaite moisture index and climatic water balance, the year 2014 was wet (except for June) with the shortest periods of tropical days. The extreme drought and the longest 13‑day period of tropical days in the year 2015 shifted leaf colouring of hornbeam and cherry tree by 16 and 22 days earlier and the leaf fall by 5 and 16 days earlier than the average of the period from 2011 to 2015. Oak was the least sensitive to the weather extremes, which was documented by a balanced course of the phenological phases with the lowest variation. The 5‑year‑long average onset of the autumn phenophases of oak and hornbeam was shifted by 1 – 4 days later and of cherry tree by 4 days earlier than the 25‑year‑long average.

Meteorologischer und phänologischer Jahresrückblick 2008 | Meteorological and phenological annual review for 2008

2009 ◽  
Vol 160 (5) ◽  
pp. 124-128
Author(s):  
Claudio Defila
Keyword(s):  
Spatial Pattern ◽  
New Records ◽  
Annual Review ◽  
Leaf Fall ◽  
Mild Winter ◽  
Intensive Research ◽  
Natural Processes ◽  
Height Dependence ◽  
Cold Snap ◽  
Phenological Phases

Although the year 2008 in Switzerland belongs to the ten to twelve warmest years since the beginning of measurements, the effects on the development of the vegetation were not very striking. An extreme excess of heat was never registered except in the winter months and in May. The mild winter simply had an effect on the flowering of the hazel, occurring early to very early. Besides this, most of the phenological spring phases were observed at the normal point of time. However, at some observation stations, a small number of phenological phases showed a completely unusual date of occurrence. These were observed very late or even extremely late (new records). Because of the fact that this phenomenon was not only observed at one single phenological phase, showing no spatial pattern and no height dependence, no explanation was found for this extraordinary behavior of these plants. This clearly reflects, despite intensive research on phenology during the last years, that many natural processes are until now not or not yet understood by man. According to the changing weather, the development of the vegetation showed neither a consistent nor an outstanding pattern in the summer. However, the early leaf-fall of the beech was quite striking, caused by the cold snap at the beginning of October. The year 2008 can be considered as a normal phenological year, except the early flowering of the hazel, the inexplicable records (late observations) and the early leaf-fall of the beech.

Essai d'application de modèles météorologiques au calcul du moment d'apparition de deux phases phénologiques | Application of Meteorological Models for the Calculation of the Beginning of Two Phenological Phases

2000 ◽  
Vol 151 (10) ◽  
pp. 385-397
Author(s):  
Bernard Primault
Keyword(s):  
Sunshine Duration ◽  
Fruit Trees ◽  
Swiss Alps ◽  
Winter Solstice ◽  
Phenological Data ◽  
Thermal Thresholds ◽  
The Mean ◽  
Two Parameters ◽  
Meteorological Models ◽  
Phenological Phases

Many years ago, a model was elaborated to calculate the«beginning of the vegetation's period», based on temperatures only (7 days with +5 °C temperature or more). The results were correlated with phenological data: the beginning of shoots with regard to spruce and larch. The results were not satisfying, therefore, the value of the two parameters of the first model were modified without changing the second one. The result, however, was again not satisfying. Research then focused on the influence of cumulated temperatures over thermal thresholds. Nevertheless, the results were still not satisfying. The blossoming of fruit trees is influenced by the mean temperature of a given period before the winter solstice. Based on this knowledge, the study evaluated whether forest trees could also be influenced by temperature or sunshine duration of a given period in the rear autumn. The investigation was carried through from the first of January on as well as from the date of snow melt of the following year. In agricultural meteorology, the temperature sums are often interrelated with the sunshine duration, precipitation or both. However,the results were disappointing. All these calculations were made for three stations situated between 570 and 1560 m above sea-level. This allowed to draw curves of variation of the two first parameters (number of days and temperature) separately for each species observed. It was finally possible to specify the thus determined curves with data of three other stations situated between the first ones. This allows to calculate the flushing of the two tree species, if direct phenological observation is lacking. This method, however, is only applicable for the northern part of the Swiss Alps.

scholarly journals Climate Change, Weather, Housing Precarity, and Homelessness: A Systematic Review of Reviews

2021 ◽  
Vol 18 (11) ◽  
pp. 5812
Author(s):  
Mariya Bezgrebelna ◽  
Kwame McKenzie ◽  
Samantha Wells ◽  
Arun Ravindran ◽  
Michael Kral ◽  
...  
Keyword(s):  
Climate Change ◽  
Systematic Review ◽  
Natural Disasters ◽  
Green Infrastructure ◽  
Temperature Extremes ◽  
Weather Extremes ◽  
Positive Effects ◽  
Increased Risk ◽  
Review Of Reviews ◽  
The Impact

This systematic review of reviews was conducted to examine housing precarity and homelessness in relation to climate change and weather extremes internationally. In a thematic analysis of 15 reviews (5 systematic and 10 non-systematic), the following themes emerged: risk factors for homelessness/housing precarity, temperature extremes, health concerns, structural factors, natural disasters, and housing. First, an increased risk of homelessness has been found for people who are vulnerably housed and populations in lower socio-economic positions due to energy insecurity and climate change-induced natural hazards. Second, homeless/vulnerably-housed populations are disproportionately exposed to climatic events (temperature extremes and natural disasters). Third, the physical and mental health of homeless/vulnerably-housed populations is projected to be impacted by weather extremes and climate change. Fourth, while green infrastructure may have positive effects for homeless/vulnerably-housed populations, housing remains a major concern in urban environments. Finally, structural changes must be implemented. Recommendations for addressing the impact of climate change on homelessness and housing precarity were generated, including interventions focusing on homelessness/housing precarity and reducing the effects of weather extremes, improved housing and urban planning, and further research on homelessness/housing precarity and climate change. To further enhance the impact of these initiatives, we suggest employing the Human Rights-Based Approach (HRBA).

Major weather-related risks to crop performance along the Australian wheat belt for recent past and longer-term historical weather records

2021 ◽  
Author(s):  
Gennady Bracho Mujica ◽  
Peter Hayman ◽  
Victor Sadras ◽  
Bertram Ostendorf ◽  
Nicole Ferreira C. R. ◽  
...  
Keyword(s):  
Grain Yield ◽  
Extreme Events ◽  
Extreme Weather Events ◽  
Yield Reduction ◽  
Recent Past ◽  
Weather Extremes ◽  
Crop Failure ◽  
Weather Events ◽  
Australian Wheat ◽  
Historical Past

<p>Extreme events, such as drought, heat and/or frost are among the major weather-related causes of yield reduction and crop failure worldwide. Changes in the frequency and intensity of such weather extremes affect the shape and scale of yield distributions. Wheat growers, in Australia, are particularly vulnerable to climate due to its high variability. Risks of both, extremely high or low temperatures and water stress occurring simultaneously or at different crop stages within the growing season (May-October, e.g. frost mid-season, drought during the season and heat towards the end) often lead to yield reductions, or sometimes even to crop failure. In this study, we focused on assessing the frequency and impact of these relevant extreme weather events (i.e. drought, heat and frost) affecting wheat production in Australia. Specifically, we used a widely used and calibrated crop model (APSIM) to simulate wheat grain yield, and determine probability density functions (PDFs) of grain yield and crop failure. Chances of crop failure due to these extreme events are explored for the recent past (1991-2020) and the longer-term historical past (1901-1990). Key adaption strategies to minimise the impacts of these extreme events, and reduce crop failure risk are assessed in this study, including early sowing and cultivar choice. Our findings are in line with recent studies, indicating that drought and heat are major risk factors contributing to reduced yields or crop failure. However, due to the timing, frequency and impacts of frost events on wheat productivity, frost also remains a relevant risk for the wheat industry in Australia.</p>

scholarly journals Effects of bromeliad flowering event on the community structuring of aquatic insect larvae associated with phytotelmata of Aechmea distichantha Lem. (Bromeliaceae)

2017 ◽  
Vol 29 (0) ◽  
Author(s):  
Felipe Emiliano Amadeo ◽  
Juliana Déo Dias ◽  
Bianca Trevizan Segovia ◽  
Nadson Ressyé Simões ◽  
Fábio Amodêo Lansac-Tôha
Keyword(s):  
Growth Phase ◽  
Vegetative Growth ◽  
Beta Diversity ◽  
Aquatic Insect ◽  
Insect Larvae ◽  
Local Factors ◽  
Flowering Phase ◽  
Regional Factors ◽  
Aquatic Insect Larvae ◽  
Phenological Phases

Abstract Aim: We aimed to understand how aquatic insect larvae communities associated with bromeliad phytotelmata are affected by plant architecture, predators and resources (local factors), and by geographical distance (regional factors) in two different plant phenological phases. Bromeliad flowering results in plant structural changes, which favours insect dispersal. Considering that local and regional factors may affect the community of aquatic insect larvae, we expected that composition, beta diversity and the importance of those factors would differ in the vegetative growth and flowering phases. Methods We performed six samplings of the bromeliad associated fauna in 2010, three during the first semester - vegetative growth phase - and three during the second semester - flowering phase. In each sampling, we collected 12 plants along the rocky walls with similar location distribution, with a total of 72 bromeliads studied. Results Although beta diversity (PERMDISP) did not differ between vegetative growth and flowering, NMDS followed by ANOSIM showed that composition was significantly different in the distinct phenological phases. IndVal results showed that three Diptera morphospecies were discriminant of the vegetative growth phase. In addition, pRDA revealed differences in the relative contribution of local and regional factors to explain insect larvae community structure. During the flowering phase, local factors predominated, while during vegetative growth, regional factors were more important. Conclusion Differences in dispersal rates between the two phenological phases, likely due to adult insect pollination and further oviposition, influenced community structuring. Therefore, flowering events account for differences not only in the composition, but also in community structuring of aquatic insect larvae inhabiting the phytotelmata of Aechmea distichantha Lem. (Bromeliaceae).

scholarly journals Basal temperature and thermal sum in phenological phases of nectarine and peach cultivars

2011 ◽  
Vol 46 (12) ◽  
pp. 1588-1596 ◽  
Author(s):  
Adilson Pacheco de Souza ◽  
Sarita Leonel ◽  
Andréa Carvalho da Silva
Keyword(s):  
Degree Days ◽  
Phenological Stages ◽  
Phase Duration ◽  
Open Flower ◽  
Thermal Sum ◽  
Phenological Phases

The objective of this work was to evaluate basal temperature, thermal sum at different phenological stages, phenological phase duration, yield and seasonality of one nectarine and 14 peach cultivars, between 2006 and 2009. The considered phenological phases were: pruning-sprouting; sprouting-flowering, from swollen bud to open flower; flowering-fruiting, from petal fall to medium-sized fruit; and ripening. Minimum basal temperatures (Tb) obtained were: pruning-sprouting, 8°C, irrespective of the cultivars; sprouting-flowering, 10°C, except for 'Cascata 968', which required 8°C Tb; flowering-fruiting, 12°C, except for 'Oro Azteca', which required 14°C Tb; ripening, 14°C, except for 'Sunblaze', 'Diamante Mejorado' and 'Precocinho' with 12°C Tb. For most cultivars, the maximum basal temperatures were 30, 34, 34 and 28ºC for phases pruning-sprouting, sprouting-flowering, flowering-fruiting and ripening, respectively. 'Turmalina', 'Marli' and 'Tropic Beauty' showed average yields of 3,945.0, 3,969.3 and 3,954.0 kg ha-1, respectively, in 2009, while the nectarine 'Sunblaze' showed around 3,900 kg ha-1 in 2008 and 2009. The cultivars differed for their total cycle and for the accumulated thermal sums which varied, respectively, from 245 days and 1,881.4 degree-days for 'Oro Azteca', to144 days and 1,455.7 degree-days for 'Precocinho'.

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