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Foster and Kreitzman - Seasons of Life - Plants deserve more respect!

Identifier

020335

Type of Spiritual Experience

Background

Systems - temperature, season, growth etc

Vernalisation is the process whereby a certain number of cold days – for example exposure to a cold winter – are needed before a plant will flower

The temperature drop is also used to develop cold acclimatisation changes....

Acclimation of biennial and perennial woody plants has been described as follows....

Leena Linden 2002

a combination of the photoperiodic effect and an acute response to cold.  The first stage is strongly affected by photoperiod.  In many woody plants, shortening days of autumn induce growth cessation, which is a prerequisite for cold acclimation.  Cells in the first stage of acclimation can survive temperatures well below 0 degrees centigrade, but they are not fully hardened.  The second stage of cold acclimation is induced by low temperatures, especially sub zero temperatures.  During this stage, plants undergo metabolic and or structural changes which lead to a considerable degree of cold hardiness.

 

A description of the experience

Seasons of Life – Russell G Foster and Leon Kreitzman

Plants deserve more respect!  They have neither eyes, nor brain nor nervous system, yet over the past hundred million or more years, the flowering angiosperms have developed a set of light sensitive receptors and a signalling system that, linked to an innate biological rhythm [system], enables them to know both the time of day and the time of year....

As Martin Lechowicz of McGill University has explained...

“Just knowing the time of the year is insufficient to evaluate the likely environmental conditions in the weeks or months ahead.  Lengthening days can cue the onset of spring, but not whether the spring will advance quickly or slowly, or be especially warm or cool.  Organisms thus use temperature and sometimes water regimes, to better estimate the progression of seasons in a given year and locality.  These climatic signals are useful cues for phenological events, but also not entirely reliable.  Changes in atmospheric calculation may indeed bring an earlier than usual onset to spring warming, but not necessarily prelude a late freeze”.

........ vernalisation is a protective adaptation that guards against plants initiating flowering too early in the year by … sensing and counting a period of cold temperatures

… as autumn fades, plants sense the falling temperatures of approaching winter and develop tolerance to the cold in a process known as cold acclimation.  Unlike vernalisation, when up to 40 or more continuous cold days may be needed in some species to institute the process, most plant species that can acclimatise to cold do so after a day or so of low temperatures.

The source of the experience

Foster and Kreitzmann

Concepts, symbols and science items

Symbols

Science Items

Activities and commonsteps

Activities

Commonsteps

References