The coming Tree Week, held by Tree Council in Ireland, is a week full of activities from tree planting and arts to woodland walks and webinars. This event prompted me to learn more about Irish native tree species. I decided to go for a walk to the largest native hardwood forest in Ireland - Vale of Clara Nature Reserve, Co. Wicklow.
The first tree that emerges above the others is an oak - tall, powerful, with beautiful branches and many different mosses and lichens growing on the bark. It was hard for me to identify them exactly because the trees were still dormant.
The oak trees started to grow in Ireland after the Ice Age and quickly became one of the dominant trees across the island. Due to their enormous size and strength, oaks have been considered Irish national trees and historically had economic and cultural importance.
The mature trees produce acorns - fruits popular amongst red squirrels and jays, due to the high amount of protein, carbohydrates and fats. Both animals hide the treats in the ground for later, as supplies. Very often, they forgot where the acorn was hidden and this is how they contributed to the spreading of the young oaks.
If the seedlings are lucky, they will grow up to 30m in height and 30-90cm in diameter each year, with the first 10-15 years of development being the most intense growth period. The characteristic broad leaves, with wavy edges, can play a special role in the development of tiny Gall Wasp larvae. The female wasp lays eggs onto the leaves, forcing the host tree to produce a tissue around the egg, forming a safe environment for the larva to pupate, a cherry gall, often noticed on the underside of the oak leaves.
The second tree, that I recognised straight away during my walk was birch. The bright, white bark can peel in thin sheets, allowing for a quick expansion of the trunk. Birch has a great ability to absorb pollution and once it sheds its bark, the pollutants are removed. As the tree becomes mature, thick and dark patches appear near the ground, to protect the trees from fire.
Birches are considered pioneers, growing easily on any type of soil, empty fields and planes. This is due to its astonishing ability to spread light seeds with the wind.
During this time of the year, it is easy to observe specific growths on the twigs of the tree. These are called "witches brooms" and occur due to the fungal infection, making the tree lose leaves from the affected areas faster during the Autumn.
The fresh, green leaves in spring are diamond-shaped and are usually pointed. Research suggests, that the leaves of birch, due to the small hair can very easily trap the pollution particles. Some of the tree's leaf buds are now starting to burst with yellow-greenish colours, making the forest look especially fresh this time of the year.
Another tree that is waking up after a long winter is a willow. Instead of developing leaves, the tree produces flowers in early spring, making it one of the most important sources of food for native bees, which are now waking up after hibernation. There are 100 species of native bees in Ireland, one species of the honey bee, 21 bumble bees and 78 species of solitary bees. Bees are the most important pollinators of crops and native plants and studies show that bees are worth 53 million a year to the economy!
Willow is dioecious, meaning that the male and female flowers grow on separate trees. The greyish catkins, the male flowers, become yellow when ripe with pollen.
Willow prefers damp grounds and wetlands and it is usually found around river banks and temporarily flooded areas. Willow can be easily propagated from cuttings. This is due to the high amounts of plant hormone - indolebutyric acid, that stimulates root growth.
There are many other native tree species around Ireland like pine, alder, mountain ash or yew. For more information on those trees, you could check the interesting website here.
For those interested in trees, not only in native Irish trees, I would recommend a great book about trees from different parts of the world: Around the World in 80 Trees by Jonathan Drori.
"Around the world in 80 trees" by Jonathan Drori