What is 'Holon'?
‘Holon’ is a little known word but one used to describe the endemic ‘micro’ ecosystem each tree provides.
It is also something we don’t consider enough when thinking about tree planting and in particular the random introduction of non native species.
A holon describes all the interacting organisms and biodiversity that are associated with a tree’s own ecosystem. In this way we can think of an individual tree as a fully functioning ecosystem — a group of symbiotic organisms and plants shaped by climate and environment.
It has taken many insects and smaller organisms hundreds of thousands of years to adapt and live in, on, or under certain tree species. Hence the connections to true native species is always so strong. Trees emit all sorts of compounds that can be toxic to many organisms and the capacity to evolve and adapt takes millennium. Each species of tree supports a different unique mix of local biodiversity.
All this biodiversity works in harmony and balance to create a tree’s healthy biome. It’s only a lack of balance that cause the conditions for disease and illness.
When non native species are thoughtlessly introduced, there can often be a dramatic affect and lessening of biodiversity and balance — the tree being mildly toxic to the native biodiversity and they can’t evolve with the tree.
This aspect isn’t given enough consideration with tree planting and forest creation. We tend to look at the tree and it’s climatic tolerance and not consider the effects on the local holon and biodiversity!