Nature Notes December 2017

 
Nature Notes

The recent cold weather here in the maritime north Atlantic island of Great Britain has sent nature running for cover.  Like us, most other animals, plants, fungi and microbes prefer to take refuge in locations warmer than average for the time of year where they usually live. 

You may say that plants and fungi do not move, yes?  Well, actually, most plants are large enough to move bits of their life-support systems between warm and cold parts of their extensive bodies.  That is, during the summer, when the air temperature is above 10o Celsius, most of the activity is above ground and the green bits grow large and bright, usually culminating in producing some kind of seeding fruit.  However, during the winter, these plants recede into the ground where, just about 10 centimetres down, the soil remains at about 10o Celsius.  The roots continue to grow, and some plants produce tubers, others corms which are really subterranean stem tissue; others produce bulbs, which are really compressed white leaf material.  During winter, the tissue above ground either goes dormant or dies off completely, leaving a powerful refugium below ground.  We often like to eat those in the form of carrots (root), potatoes (tubers), Chinese water chestnut (corm) and onion (bulb).  Even the seeds are usually hiding in leaf litter or below ground, and we eat those in the form of rice, beans and bread.

Fungi are also below ground, indeed the largest living organisms on the planet are probably fungi which include individuals spreading out underground for sometimes several hectares.  Fungi only come above ground to produce tiny airborne spores from their mushroom fruiting bodies, which drift on the wind into new habitats to make new fungi.

Animals, on the other hand, have the ability to fly into refugia such as caves (bats) or dig into the ground (tortoises), crawl under tree bark (earwigs) or swim to the bottom of ponds (frogs).  Many birds (e.g. cuckoos) and butterflies (painted ladies) fly to warmer countries, others move to warmer habitats (blue tits to gardens and reed-beds, peacock butterflies to garden sheds and tree stumps).  We humans too prefer to stay indoors and keep warm.  However, when the sun shines and the temperature rises out we and they all come again and life continues.

Dr Martyn Stenning