This is far from a new idea and there is a plethora of information on ancient and modern techniques to use wildlife to help lessen the risk of tree threats.
Managed trees and woodland attracts wildlife, the more wildlife the more chance that the predators; from mammals to the microfauna of the phyllosphere or rhizosphere will help defend their habitat – which is the tree itself.
But as so often too much emphasis on the innovative and usually costly techniques post infection are publicised before trying out basic, very basic, tricks to bolster the health of a forest or non woodland tree.
The problem for many tree professionals is a simple one, if we were to wait around for the research to be done, (as it should be and more, much more is needed), the problem in many locations can easily become much greater very quickly. A fundamental shift in tree management and establishment be it urban or rural locations, a single tree or a forest, has to be made now to protect for the future.
Recent research from the US on Soil Profile Rebuilding to combat against compaction was great to read, whilst similar methods which vary according to the practitioners own preference and the site specific factors are relatively common in Europe to have referenced material and an acronym is incredibly beneficial. What could be better is to start to encourage the use of techniques and materials to help create as rich, and therefore populated with beneficial microbes and fungi, a planting medium as possible.
In the Mediterranean forests and estate gardens of Southern France there have been many informal trails of using soils which have been managed to increase soil microfauna as much as possible towards a supplement when planting. The soil samples are taken from sites of different natural woodland types and whilst we don’t know what the samples contain, nor the mix for planting, the trees (matching natural habitat to tree type) treated appear to respond better to drought conditions, and other stresses, to their neighbours – only time will really tell.
We tend to easily forget just how susceptible soil is to certain contaminants, and some of these contaminants are actually believed to be of assistance (like milk or urine). combined with the all too common mistake that trees always require lots and lots of water, which in consolidated soils in particular can be fatal – any and all techniques to diffuse / disperse contaminants are of benefit and help increase oxygen levels. Tree roots and the rhizosphere micro fauna and fungi need oxygen! Therefore techniques, based on very ancient knowledge, of simply introducing vertidrains or similar help tremendously, any small hole backfilled with pea gravel which are dug through consolidated layers (bearing in mind soil shear zones, clay smearing and other types of sub surface consolidation are as bad as surface compaction), and assist with surface water run off also.
Therefore at the same time as any works to improve soil conditions for the health of the tree, both existing or new, it seems absurd not to incorporate the simple and easy techniques to provide as much homing as we possibly can for invertebrates, from buried bamboo canes to upside down clay pots within a vertidrain core. Ideas on a postcard – as I am hoping to produce a list of all techniques (both for the tree itself and the root system).
Riparian woodland, River Exe, Exeter