Old trees = sustainable trees
As we are now enjoying the trees which the generations before us planted, we can let future generations enjoy a green legacy. That is why it is important to include trees in new (building) plans at an early stage. Not just to fill up the gaps, but as decisive elements in the outdoor space, with enough room to grow. Unfortunately, that still does not guarantee a long tree life. Town plans can change and hinder trees in their development, trees can be struck down by disease or, in the worst case, chopped down before they reach adulthood. It is important to stress the sustainability aspect of greenery. Old trees are sustainable trees, but trees which have the potential to be sustainable do not always grow old…
Budding red beech at the Fathers in Oirschot
Conditions for a future tree
To ensure a tree becomes sustainable, in the sense that future generations can enjoy them, a number of conditions have to be met.
• Start by selecting a good quality tree. A tree which has been replanted regularly and which has been able to develop a healthy root system. A tree with a well-formed crown, which has been skilfully pruned and supported.
• Also select a tree which has been cultivated in a sustainable manner. In the end, we want to create a green legacy. Sustainably cultivated trees are less vulnerable to external influences, because they have a stronger natural resistance to diseases and pests.
• Select a tree that suits its habitat. Don't only think of soil type, but also other factors such as wind, frost, pavement and humidity. More information about these issues can be found in the tree book 'Van den Berk on trees’.
• Select a species which has the potential of becoming old. In principle, these are the trees which grow more slowly. During growth, smaller cells are formed which harden better. The heartwood in the trees is harder and more durable.
• When the situation at the habitat suffers from the effects of climate change, then select a species which is expected to be more resistant to these effects. (See below)
• Select a location for the tree where it has enough room, both above and below ground. Take into account that a tree from the first growth category needs around a cubic meter of space underground per growth year.
• Make sure the tree is professionally planted. The location should be assessed beforehand, and if necessary the soil should be improved. The trees should also be properly anchored.
• Ensure proper support pruning during the first few years, for the formation of a beautiful, balanced crown. Support pruning is not necessary when a larger-sized tree is planted, in which case the crown has already been formed at the nursery.
There are, of course, many other factors we are unable to influence, but by adhering to these rules, you are giving your tree the best start for a green future.
Effects of climate change for trees:
A. Stronger solar radiation
B. Longer periods of drought
C. Heavy downpours
D. Fluctuations in the water table
E. Occurrence of diseases and pests
Some species with are resistant to these effects are:
• Metasequoia glyptostroboides (A.B.C.D.E)
• Celtis australis (A.B.C.E.)
• Ginkgo biloba (A.B.C.E.)
• Quercus palustris (A.B.C.D.E.)
• Platanus acerifolia (A.B.C.D.)
• Gleditsia triacanthos (A.B.C.E.)
• Pinus nigra nigra (A.B.E.)
• Pinus sylvestris (A.B.E.)