We take trees for granted, don’t we? We all know they have roots, a trunk, branches and leaves and that they can be evergreen or deciduous. Perhaps we can identify an oak or an ash but on the whole they’re just part of the background (we’ll post a separate blog about tree identification). Trees have been around for 370 million years longer than humans and an oak tree can live up to 1000 years and a redwood 2000 years . They have provided us with fuel for heating and cooking, tools, weapons, furniture, shelter, paper, and medicines such as aspirin (from willow bark) and quinine (from the bark of the cinchona tree). Trees are woven into our mythology and belief systems from the Norse tree of life to the sacred fig in Hinduism. Trees are good for us and good for the environment...here are just a few reasons why we should all love trees.
Without trees, life as we know it could not survive. I won’t go into the mechanisms of oxygen production here but, in very simple terms, we breathe out carbon dioxide, trees take it in and give off oxygen which we in turn breathe in. Oxygen also comes from ocean algae and marine life so trees don’t do all the work but, in relative terms, we each need the equivalent of 7 or 8 trees in order to breathe for a year. Take trees away, and we would all feel like we were breathing thin air at the top of a mountain.
Trees are incredibly important for soil stabilisation and soil creation. We rely on this thin layer of soil for our food but seem determined to destroy it and we are losing topsoil at an unsustainable rate. Worst case scenario research suggests we have only 60 harvests left if we carry on as we are, although this claim is disputed. The important point here is that we are not looking after our topsoil and this must change.
Trees stabilise soil in several ways. Their root systems bind the soil, the tree as a whole acts as wind protection, the leaves and branches reduce the force of the rain striking the soil, and the tree absorbs the rain. Trees reduce the amount of water in the soil via transpiration but also increase the amount of water the soil can hold which helps prevent wind erosion. This also helps with flood mitigation because trees slow the flow of water to the ground and gives the soil chance to absorb the water rather than it just running off. Mature trees are particularly important for this.
Soil is created by weathering of the local bedrock but also by the decomposition of organic matter so it is important to leave dead and decaying trees wherever it is safe to do so. Living trees also provide nutrients to the soil via their roots. The shade provided by trees helps to moderate soil temperatures, and also provides shelter to wildlife and people.
Improved Air Quality
Air pollution is in the news more and more these days and was recently deemed to be a factor in the death of a young girl with asthma. It causes an estimated 7 million deaths across the world, and these figures are predicted to rise. Trees can help improve air quality, particularly in urban areas, by adsorption of sulphur dioxide and ozone, the interception of particulate matter from smoke, pollen and dust, and the emission of oxygen. As an aside, trees also help to provide a buffer to noise pollution.
It is increasingly recognised that spending time in nature is good for us, both physically and mentally. Walking in woodland, for example, lowers our blood pressure and reduces our stress levels. The Japanese call this shinrin-yoku or forest bathing. In urban areas, increased tree canopy coverage has been linked to reduced crime levels and reduced incidence of mental health issues. Trees also provide a buffer to noise pollution leading to quieter and calmer communities. It has also been shown that people recovering from illness or operations recover quicker if they can see trees.
Trees and forests are huge carbon sinks and therefore play an important role in the fight against climate change. Tropical forests are the ones that make the news and their rate of loss is frightening - 40 football fields worth every single minute. Temperate woodland such as that found in the UK is also vitally important though and young woodland can lock up 400+ tonnes of carbon per hectare in the trees, roots and soil.
Trees also help cool the air immediately surrounding them by providing shade and by transpiration cooling. This is particularly important in urban areas. Transpiration cooling is the process by which the tree releases water from its leaves and the surrounding air is cooled as the water changes from liquid to vapour.
Trees are both home and food source to a diverse range of creatures. A mature oak can be host to 2300 different species not including bacteria or microorganisms. Mammals, birds, butterflies, moths, beetles, bugs, bees, wasps, ants, spiders, crickets, flies, and other invertebrates all live on or in trees. Dead trees are also important as they support saproxylic life. Saproxylic invertebrates are those that are dependent on dead or decaying wood (or dependent on other organisms that are themselves dependent on dead wood) and there are over 2000 saproxylic species in the UK alone. See our blog on deadwood here.
Trees give us the air we breathe, protect our soils, help fight climate change, keep our air clean, contribute to increased biodiversity and help us to feel good. They need our protection, and we should appreciate them and care for them. Without them, we would be nothing.
How You Can Help
Plant trees - plant native broadleaf trees and heritage or local fruit trees
Protect trees - try not to cut down trees, especially old ones
Plant a Tiny Forest - a dense, fast-growing, native woodland
Support local environmental groups such as The WEG. In Worcester, The WEG have planted heritage fruit trees at Aconbury Orchard and help maintain Trotshill Community Orchard. We are planting over 250m of edible hedge at Aconbury and will be planting a diverse variety of native broadleaved species in Plantation Woods to replace the mono-culture of ash which is suffering from ash dieback disease.
The Hidden Life of Trees - Peter Wohlleben
Woodlands - Oliver Rackham