Turning tree planting challenges into growth
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By Kim Deans
When we plant a tree and it dies, there are a few ways we can choose to respond. We can decide that it didn’t work, give up and not try again. We can decide to continue trying the same thing, planting more of the same types of trees in the same ways, expecting different results. Or, we can get curious, see feedback (not failure) and question into the reasons the tree failed to survive.
Our 20-year journey of re-establishing trees on land where trees were cleared for tin mining in the early 1900’s has presented plenty of challenges, which have provided abundant opportunities to learn and try methods to improve our success growing trees. Observing trees we have planted and nurtured growing and the landscape transforming as shelter, habitat and aesthetics improve inspires us to continue. We remain curious to see what is possible, even when there are times we wonder if it might be easier to start the process again somewhere else.
Some of the insights we are learning that are helping us to improve the success of our tree planting efforts are:
Natives might not be the best option
Our first tree planting project began with a trip to the local forestry nursery to discuss suitable trees for our site. We came home with a range of natives we were informed would be most suitable for our light, sandy granite soils and climate. Only three trees of one species (Eucalyptus nicolii) survived the first frosty winter and have gone on to be much appreciated paddock trees. Those trees we lost felt like a failure initially however we can now see this differently. Instead of failure, they kickstarted us on a learning journey and made us more determined to figure out how we could help trees to survive here.
Alongside these first few natives, we also began planting deciduous trees and found these much easier to establish on our site. Elms and Oaks do particularly well here and have survived fire and drought much better than Eucalypts and Pines. Pines have also been easier to establish than natives.
Our learning experiences mean that we have not embarked on any funded tree planting projects which require natives to be planted. We would much prefer to see good results from our efforts than waste money on what experience has shown us is not yet working in our context.
Understanding successional dynamics is essential
Ecosystems naturally evolve over time towards increasing complexity, they are never static. Landscape succession starts when bare ground is covered by algae, lichen and mosses who can handle extreme environments without soil. These organisms trap moisture and dust so soil building processes commence. Gradually over time other plants and organisms join the community, early pioneer plants with shallow root systems cover the ground, over time soil organic matter builds and annual grasses appear and continue building soil until the system can support perennial grasses which over time gradually move towards woody shrubs and trees.
Understanding this process gave me an aha moment around tree planting. I realised that we had been planting trees into a soil that in terms of successional dynamics was a low successional grassland with a bacterially dominant soil food web. Yet trees thrive in a more fungal soil (the soil food web evolves alongside the vegetation). We have improved the success of our tree planting efforts by incorporating wood chip mulches to encourage a more fungal soil for trees and inoculating tree plantings with a handful of soil and leaf litter from underneath similar trees to inoculate them with beneficial micro-organisms.
Have a succession plan for trees in the landscape
Losing mature trees here following fire/drought/flooding as well as facilitating whole farm planning workshops have shown me that we need a succession plan for the trees in our landscapes. While trees live for much longer than humans, individual trees are not going to live forever.
Agricultural systems where landholders have a routine of killing all tree regrowth create a situation where there is no younger vegetation coming along to replace older trees when they are inevitably lost. A healthy agricultural ecosystem will include vegetation of a range of ages and stages, not solely older, isolated paddock trees.
In one farm planning workshop location a severe storm came through when soils were saturated by recent rainfall and landholders reported that many isolated, mature paddock trees were destroyed by the storm. This created widespread loss of habitat, shelter and biodiversity across this region in one night.
Mature trees cannot be replaced by new plantings
Trees take time to grow, and a tiny newly planted seedling cannot instantly replace a mature tree in terms of any of the multitude of services they provide that are greater than money can buy. Prioritising conserving mature trees in our landscape is just plain commonsense.
Trees are community minded
Rather than looking for ways to force trees to grow and survive in isolation, we are curiously learning ways to plant trees with community in mind to create an environment where they thrive. Planting trees in groups, experimenting with concepts we have learned from syntropic agroforestry and nurturing ecosystems so trees can be part of functioning ecological communities and communicate with each other via complex fungal networks is now our focus.
Embrace multipurpose plantings
Our choice of trees can contribute towards increasing climate resilience in landscapes. Deciduous trees can be more fire retardant, with less volatile oils and more moisture in their leaves. In 2019 we had many deciduous trees survive a fire followed by prolonged drought, many dropping their leaves early in the season due to stress. In typical Australian style, this weather event was followed by flooding rains and waterlogging. Since then, many of the older Eucalypts in the landscape have been gradually dying off or falling over. Incorporating fodder trees as well as fire retardant trees are priorities for us. In dry times we have supplemented our stock with elm leaves.
Grazing management can be more effective than planting trees
Over time rotationally grazing sheep and cattle to allow adequate rest and recovery between grazing here has made it possible for native tree regeneration to occur with no additional effort from us. Another valuable benefit gained by using grazing management a tool for soil and ecosystem restoration.
It’s SO worth the effort, landscapes are much more liveable with trees in them
You only need to walk under a tree on a hot day to appreciate the benefits trees offer us in terms of temperature regulation. As part of my whole farm planning teaching material, a few years ago we recorded some temperature readings of soil surface temperatures to illustrate how effective trees and living groundcover are in terms of temperature regulation. These images below were the result.
The shelter from trees pays dividends year-round and in all types of agricultural production systems, with research in Australia(1) indicating crop yield improvements of 25% and pasture growth improvements of 20-30%. Livestock production improves greatly in the presence of shelter due to improved lamb survival, and growth rates of sheep and cattle.
Legacy
Planting trees and tree conservation leaves an incredible legacy. Our tree planting journey has also been inspired through seeing the legacy of trees planted and bushland protected by Angus’s ancestors in and around Christchurch in New Zealand. While we can’t be attached to the outcome, it would be pretty cool if we can leave a tree legacy that ends up being appreciated by future generations.
“The true meaning of life is to plant trees, under whose shade you do not expect to sit” – Nelson Henderson
References:
Further reading
Tree Planting into Alien Environments, a blog by Angus Deans
Learn practical tree planting skills from Angus Deans at an upcoming workshop as part of the New England Garden Festival in Armidale, November 2-3, 2024
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