Seasonal development of Scots pine under climatic warming: effects on photosynthetic production

2005 ◽  
Vol 35 (9) ◽  
pp. 2092-2099 ◽  
Author(s):  
Heikki Hänninen ◽  
Pasi Kolari ◽  
Pertti Hari
Keyword(s):  
Solar Radiation ◽  
Computer Simulations ◽  
Scots Pine ◽  
Frost Damage ◽  
Frost Hardiness ◽  
Seasonal Development ◽  
Climatic Warming ◽  
Present Climate ◽  
First Approximation ◽  
Photosynthetic Production

In boreal conditions under climatic warming, photosynthesis will start earlier in the spring than it does in the present climate. As a first approximation this phenomenon would increase the annual photosynthetic production of boreal conifers, as they can use the high amounts of incoming solar radiation prevailing during spring to a greater extent than in the present climate. However, the recovery of photosynthesis is accompanied by a simultaneous dehardening of the needles. Thus, climatic warming may also cause a premature dehardening of the needles during spring. This may result in needle losses caused by frost damage; so climatic warming may also decrease the annual photosynthetic production of boreal conifers. Using computer simulations with ecophysiological models, these counteracting effects of climatic warming on photosynthetic production were studied in Scots pine (Pinus sylvestris L.) trees growing in southern Finland. The results show that because of our insufficient understanding of the environmental regulation of frost hardiness, it is not possible to conclude which one of the two potential effects will dominate under climatic warming. This finding calls for further empirical development and testing of the frost hardiness models.

Computations on Frost Damage to Scots Pine Under Climatic Warming in Boreal Conditions

1995 ◽  
Vol 5 (1) ◽  
pp. 42-52 ◽  
Author(s):  
Seppo Kellomaki ◽  
Heikki Hanninen ◽  
Marja Kolstrom
Keyword(s):  
Scots Pine ◽  
Frost Damage ◽  
Climatic Warming

Development of freezing tolerance in roots and shoots of Scots pine seedlings at nonfreezing temperatures

1998 ◽  
Vol 28 (4) ◽  
pp. 557-565 ◽  
Author(s):  
Aija Ryyppö ◽  
Tapani Repo ◽  
Elina Vapaavuori
Keyword(s):  
Plasma Membrane ◽  
Low Temperature ◽  
Scots Pine ◽  
Fine Roots ◽  
Day Treatment ◽  
Growing Season ◽  
Frost Damage ◽  
Frost Hardiness ◽  
Pine Seedlings ◽  
Extracellular Resistance

The hardening of hydroponically cultured Scots pine (Pinus sylvestris L.) seedlings and their recovery after freezing was studied at the end of the second growing season (LD), after 3 weeks of short day treatment (SD), after a gradual decrease in temperature to 5°C over 4 weeks (H1), and after 4 weeks at 5°C (H2). Frost hardiness was determined by several methods and the recovery as survival of the seedlings. The highest frost hardiness was achieved in the distal parts of needles (-21 to -27°C) and in the proximal parts of needles (-18 to -25°C), followed by woody roots (-7 to -9°C), the 1-year-old and current stem (-8°C), and the fine roots (-5°C), all at the end of H2. Hardening of needles was induced by SD, but the stem and woody roots started to harden later, as a response to low temperature. As a result of frost treatment during LD and SD, potential plasma membrane roman H+-ATPase activity of roots decreased as electrolyte leakage increased and extracellular resistance decreased, but this relationship was lost during H1 and H2. The present study demonstrates the lack of hardening capacity in the fine roots of Scots pine seedlings at nonfreezing temperatures and the increased mortality of the young seedlings having frost damage on roots.

The relationship between multiple leaders and mechanical and frost damage to the apical meristem of Scots pine seedlings

1990 ◽  
Vol 20 (3) ◽  
pp. 280-284 ◽  
Author(s):  
Jarmo K. Holopainen
Keyword(s):  
Scots Pine ◽  
Apical Meristem ◽  
Dry Weight ◽  
Frost Damage ◽  
Night Temperature ◽  
Shoot Dry Weight ◽  
Frost Injury ◽  
Pine Seedlings ◽  
Before And After ◽  
Multiple Leaders

The responses of young Scots pine seedlings to mechanical apical meristem damage before and after 4 nights exposure to minimum night temperatures of −2.2 and −6.7 °C in controlled environment growth chambers were compared with control seedlings that were subjected or not to apical meristem damage and exposed to a minimum night temperature of 12 °C. The feeding damage caused by Lygus bugs was simulated by piercing the apical meristem of young pine seedlings with a hypodermic syringe needle and injecting a small drop of distilled water into the wound. At −6.7 °C increased numbers of dead seedlings were found. The proportion of seedlings with multiple leaders greatly increased after piercing, and about half of the seedlings subjected to the apical meristem damage had multiple leaders. The proportion of seedlings with multiple leaders and the number of leader shoots per seedling did not differ among seedlings subjected to apical meristem damage before or after the frost exposure. Short and twisted primary needles occurred in the basal parts of the new shoots in the seedlings with multiple leaders. Seedlings with necrotic needles were most often found after exposure to the night temperature of −6.7 °C. Shoot dry weight and length were significantly lower in seedlings subjected to apical meristem damage after frost exposure than in seedlings subjected to apical meristem damage before frost exposure or to no frost exposure. The results suggest that an increased reduction in growth is to be expected if Lygus bug attacks occur on pine seedlings that already suffer from frost injury.

SOLAR PUMPED LASER BASED ON COMPOSITE TITANIUMSAPPHIRE ACTIVE MEDIUM

2018 ◽  
Vol 20 (5) ◽  
pp. 321-323
Author(s):  
Sh. Payziyev ◽  
Kh. Makhmudov ◽  
S. Bakhramov ◽  
A. Kasimov
Keyword(s):  
Laser Radiation ◽  
Pump Power ◽  
Solar Radiation ◽  
Solar Energy ◽  
Computer Simulations ◽  
Active Element ◽  
Radiation Energy ◽  
Laser Radiation Energy ◽  
Optimal Geometry ◽  
Concentrated Solar Radiation

On the basis of the active element of Ti3+:Al2O3, the possibility of converting solar energy into laser radiation energy is investigated. By the computer simulations, it was shown the possibility of reducing the threshold pump power by choosing the optimal geometry of the crystal parameters for end-pumping scheme of concentrated solar radiation.

scholarly journals Analysis of the potential use of Trombe walls in Brazil: design recommendations

2020 ◽  
Vol 5 ◽  
pp. 4
Author(s):  
Fernando Antonio de Melo Sá Cavalcanti ◽  
Rosana Maria Caram
Keyword(s):  
Solar Radiation ◽  
Computer Simulations ◽  
Thermal Performance ◽  
Natural Ventilation ◽  
Solar Heating ◽  
Heating And Cooling ◽  
Heated Air ◽  
Trombe Wall ◽  
Potential Use ◽  
Passive Strategy

In this paper, the thermal performance of a standard environment was evaluated based on the use of a Trombe wall with different configurations and types of use, as the potential for using this passive strategy is still little studied in Brazil. This device is capable of absorbing energy from solar radiation by heating the air in this greenhouse and this heated air can be directed to the interior or exterior of the building depending on the purpose. This air can be used to heat the room or cool it by means of natural ventilation. The analysis of this research was based on a series of computer simulations using the EnergyPlus software, version 7.0 in order to quantify and classify the thermal performance of a standard environment equipped with this component, under the various construction configurations. Both for heating and cooling environments. The use of Trombe walls improved the thermal comfort of users in buildings located in Brazil, depending on the climate where they are located, promoting natural ventilation and passive solar heating, allowing the potential of this device to be investigated in the most diverse Brazilian regions.

scholarly journals A case of severe frost damage prior to budbreak in young conifers in Northeastern Ontario: Consequence of climate change?

2009 ◽  
Vol 85 (3) ◽  
pp. 453-462 ◽  
Author(s):  
Rongzhou Man ◽  
Gordon J Kayahara ◽  
Qing-Lai Dang ◽  
James A Rice
Keyword(s):  
Climate Change ◽  
Cold Hardiness ◽  
Shoot Elongation ◽  
Frost Damage ◽  
Weather Data ◽  
Climatic Warming ◽  
Closed Canopy ◽  
Time Requirements ◽  
Spring Frosts ◽  
Understory Trees

In spring 2007, young planted and natural conifers suffered extensive needle and bud injury near Hearst and Kapuskasing in northeastern Ontario. Damage was observed on all species of conifers up to 20 years old and 8 m in height. Taller trees, especially those in the overstory, and young understory trees protected by a closed canopy had less damage. The damage was caused by earlier than normal loss of cold hardiness followed by late spring frosts according to damage observations, weather station data, and calculated thermal time requirements for budbreak and cold hardiness of conifers. During May 19 to 21, 2007, minimum temperatures were recorded between -8°C and -9°C, and before this period, temperatures were warm enough to induce early dehardening and loss of trees' cold hardiness. According to the historical weather data for Kapuskasing, estimated budbreak time has become earlier since 1918 and freezing temperatures during budbreak and shoot elongation (between growing degree days 100 and June 15) have become more frequent since 1980. If the trend towards earlier budbreak is due to climate change, then the type of frost damage we observed in northeastern Ontario in 2007 could become more common. We discuss implications of such events and suggest research needed to understand the risk of frost damage with climatic warming and to reduce damage. Key words: conifer frost damage, mature needle and bud (or needle/bud) mortality, early dehardening and budbreak (or dehardening/budbreak), climatic warming

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