Native Forest Restoration
A Trial of Planting Methods
Introduction
Forever Trees and the planting trial explained in this paper are passion projects of Mandy Richards and John Etherington. Having spent 30 years in the adventure travel industry we have seen so much damage caused by deforestation around the world. Now we are on a mission to get involved in restoring and re-establishing land back to native forest here at home in Nelson and around the world!
We are all aware of our world's changing climate and that global deforestation is a major contributor. There are currently somewhere close to 3 trillion trees on our planet. Sadly this is only about 45% of the number of trees there were here prior to human industry. Furthermore, our planet is currently losing around 10 million hectares of forest every year. That is an estimated 15 billion trees cut down each year, and more than 41 million trees lost every day. It is estimated that about 5 billion trees are planted annually, but this means that there is still a net loss of around 10 billion trees every year.
In Aotearoa, New Zealand - our country was once more than 80% covered in native forest. In 2023 we are down to only 33%, less than 50% of how it was prior to human intervention. This is devastating considering that New Zealand native forests and related ecosystems are an important part of the biodiversity and habitat for many of New Zealand's endangered species. Here at home in Whakatu, Nelson, we have experienced an almost total loss of lowland podocarp forest through conversion to agriculture, horticulture and urbanisation.
The main drivers for deforestation globally are forest conversion to agriculture and horticulture. While in this paper we are focused on forest loss it is also interesting to note that the loss of wild grassland, shrubs and wetland is even greater than the loss of forest.
What are the consequences of Native Forest loss?
Forests are most commonly lost when land is converted to agriculture and horticulture. When this happens:
Native forests are a climate mediator, with the trees and the humus that form on the forest floor providing simple shade and cooling of the earth’s surface. Deforestation leads to subsequent warming of the land and is a major contributor to climate change.
Humus-rich forest soil has as much as five times greater water retention than soil in the open. Deforested land losses this moisture, increasing land and air temperatures, and drying the earth's surface. The heating and drying of the earth together exacerbate the warming of the climate.
Native forests have giant root systems - with trees working together to hold each other up and also provide land stability. When a forest disappears so does the root system stabilising it. Loss of forest also leads to changes in the microbiome of the soil so that the soil’s ability to retain water is significantly reduced. So when forest is lost, water retention is reduced, leading to increased flooding, and erosion, and combined with the reduced stability leads to land slipping and slumping - sometimes of significant size.
All types of forests store tonnes and tonnes of carbon through a number of complex systems that build on each other. Leaf mulch helps to sequester carbon and provides a habitat for mycelium, insects and bacteria. This forms rich dispersal networks that feed the trees around them. We know that trees sequester tonnes of carbon from the atmosphere, but we might be surprised to learn that much of the carbon sequestration happens much deeper in the soil. Fungal networks work with tree roots to exchange minerals that they break down for simple sugars that trees produce through photosynthesis. 55% of the global carbon stored in vegetation is stored in the world’s forests, and 45% of that is stored in the soil. It’s easy to see how important forests are for sequestering the increasing volume of carbon that humans emit, and how deforestation leads to a significant reduction in carbon sequestration resulting in an increase in atmospheric carbon.
Reduction in native forests has a direct impact and loss of habitat and biodiversity. It is no wonder that we are living in a time of mass extinction of wild species. In 2023 New Zealand has more than 4,000 native species at risk of extinction.
As the total amount of native forest cover is reduced - the proportion of forest margin (or surface area) of the remaining forest increases. Forest margins are far more vulnerable to invasive exotic pests and weed species. This means that a greater proportion of the native forest that remains is at greater risk of browsing and weed inundation. This further reduces habitat for native species and biodiversity.
Removal of native forests also leads to a drastic reduction in the number of plant species producing seed, meaning that native tree species become reduced and threatened.
There are also many other non-scientific but equally positive benefits that native forest has on human physical and mental health that come with living close to nature... Higher available oxygen levels, access to recreating in nature which has untold mental and physical health benefits and access to natural medicines.
The evidence of the effects of global deforestation is persistent and increasingly catastrophic. Forests provide ecological benefits that are essential to life on planet Earth and are the greatest defence against climate change that we have. It is clear to us that putting an end to global deforestation and turning things around to start increasing the world’s forest cover is the most urgent and important challenge of our generation.
The world needs more trees. Let's get started!