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Mother nature's dynamic equilibrium

In the garden: Biodiversity and pollination are linked but different, writes Gerry Daly

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Bees hog the limelight — but moths, butterflies and many other animals are needed for pollination

Bees hog the limelight — but moths, butterflies and many other animals are needed for pollination

The Big Book of Blooms. Out now.

The Big Book of Blooms. Out now.

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Bees hog the limelight — but moths, butterflies and many other animals are needed for pollination

There has been a lot of interest expressed in recent years, and indeed months, about the nature and importance of biodiversity and pollination. However, although the two processes are linked, they are not interchangeable.

Biodiversity simply means the diversity of species in a particular locality, a country, city, town, countryside, even housing estate if one were minded to carry out the survey to determine which animals and plants were present.

This kind of recording is very valuable because it can document changes in species' populations, and these days, such repeated investigations generally show that biodiversity has been in decline since the ascent of mankind more than a million years ago, but acutely so in recent decades. These trends were established centuries ago and largely document the human pressure on land and resources.

While the theory of evolution presages a decline and extinction of species in their hundreds and thousands as better specimens, more successful in survival, take control of resources and space. This constant emergence of new species to replace older ones can adapt itself to the loss of older species, speeding up if evolutionary pressures are great and slowing down if the environment is kind, and the niche in which the animal or plant is comfortably ensconced does not change radically.

Due to the activities of mankind, particularly over the last century or so, large areas of land and oceans have been altered dramatically.

There are still some reservoirs of enormous biodiversity, such as the forests of Siberia, Canada, Australia, the catchment area of the Congo River and the great Amazon basin. In many of these areas, the extent of biodiversity and biodiversity change is largely unknown for want of research and study.

However, apart from these areas which are either too hot or cold for human survival, most other areas of land have been altered in some fashion over the centuries since the Middle Ages and in that time large areas of new land have been altered, largely for timber and plant production for food and amenity use.

So, how does this relate to your garden?

Gardens are very diverse, offering habitats suitable to a wide range of animal and plant life. Species from both cold and warm temperate regions thrive in mild Irish conditions. Gardens are planted with trees, shrubs, perennial flowers and annuals, ideal for different seeds and berries. The area of land under gardens is considerable and, if managed for wildlife and biodiversity, can make a significant contribution to the replacement of habitat lost due to road construction and housebuilding.

Pollination is essential for some fruits and other food crops. The natural advantage conferred on a plant species by means of pollination is to mix the genes of any particular species. This ensures less chance of a species becoming inbred and testing double positive for genetic diseases and disorders.

So, nature, again following evolutionary theory, finds the niche in plant life to reduce the production of unhealthy specimens.

To achieve pollination, in general, the pollen of two forms of a species must be swapped or at least delivered to one species of a crossbreeding pair.

There are two ways to do this: wind pollination and vector pollination. With wind pollination, as used by birch and pine, the pollen is light and dry, and travels long distances on strong winds. Vector pollination uses an insect, or other creature, to transfer pollen between flowers.

Bees are easily the most prominent of pollinating species but they are joined by many others, including hoverflies, bumblebees, solitary bees, beetles, weevils.

When there is a loss of a species or a reduction in its population, other species do their best to take over the niche vacated by the diminished pollinator.

Mother nature has a way of striking a balance by a process of dynamic equilibrium. Only when the shock to the system is very considerable is a new equilibrium required. While it is concerning that species are being lost, and biodiversity diminished, it is well to note that there is some facility in nature to adapt to just about anything, though not obviously to human-generated climate change.

 

READ ALL ABOUT IT: Young naturalists will love The Big Book of Blooms, a picture-led stroll through a flower garden with Yuval Zommer that includes gems like how to be a botanist or spot seven types of pollinators, and why some flowers are colourful and some scented. Grown-ups will learn plenty, too. Out now.

ON THE WING: Join Biodiversity Ireland's butterfly monitoring scheme and record how many you see in 15 minutes. For details, biodiversityireland.ie

STAYCATION: Bloom moves online this year, with a busy list of events such as cookery demos, panel discussions, Q&As, music and competitions - check it out on bordbiabloom.com

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