The Importance of Pioneer Trees for Forest Gardens and Other Purposes

Pioneer species play a crucial role in ecosystem restoration.

Spring nature background with amazing alder catkin blooming
VICUSCHKA / Getty Images

As we seek to improve our gardens and farms for the benefit of the planet, wildlife, and humanity, we should consider pioneer trees and other pioneer plants – and think about the crucial role they can play in ecosystem restoration.

Pioneer trees and plants are those which are typically the first to colonize an area of land that has been damaged or degraded – the species that appear when nature is allowed to reign. Usually, these are hardy and vigorous native species, perfectly adapted to the climate and conditions in your area.

Why Pioneer Trees Are Useful

Pioneer trees can be very useful in ecosystem restoration because of the various services and yields they can provide. Of course, most trees and shrubs will be beneficial – for the role they play in carbon sequestration and in the water cycle.

As resilient and hardy pioneers, however, certain species can also provide particular benefits that make it easier to establish more woodland or further vegetative cover on a piece of land.

They can:

  • Play a role in nitrogen fixation. 
  • Stabilize the soil, improve soil aeration and prevent erosion.
  • Provide organic matter to create humus/mulches.
  • Create windbreaks or shelterbelts to improve environmental conditions on the site.
  • Give canopy cover and shade, which enables understorey plants to become established.

Choosing Pioneer Trees

Choosing pioneer trees and plants for your garden or land involves careful thought. 

These trees and plants will be very different in a temperate woodland environment, for example, than in a tropical rainforest setting, or in a desert. So it is not possible to give a list of species that will work well in any setting. But wherever you live, looking at a list of native plant species and their properties can often be a good place to start. Making this decision also involves looking at what already grows well in your area. Observation is key.

Bright green immature scrub oak in the ashes from a fire
Immature scrub oak trees emerge after Lightner Creek fire in Durango, Colorado. KaraGrubis / Getty Images

Nitrogen Fixing Pioneer Trees (and Shrubs)

Amongst the most important and crucial pioneers for almost any site are those that have formed a symbiotic relationship with bacteria in their root rhizomes and play a crucial role in accumulating atmospheric nitrogen. These plants and trees enrich the soil and are commonly referred to as nitrogen fixers.

In temperate climate zones, alders are one of the most useful nitrogen fixing pioneer trees. As pioneers, alders can quickly establish even in poorer soils, and even in areas where there is extreme exposure. They enrich the soil with nitrogen and build soil humus over time as their leaves fall. (Acacias are often amongst the useful pioneer trees in arid warm climate zones. And in many climate zones, there are also a range of other nitrogen-fixing trees and shrubs that can be considered.)

Incorporating nitrogen-fixing trees or other nitrogen-fixing plants into a woodland or other ecosystem helps the nitrogen cycle to function as it should. It can improve degraded land by replenishing nitrogen in damaged soils, and can help to maintain and improve soil fertility over time.

Deep-Rooted Pioneer Trees

Other helpful pioneer trees and pioneer plants are those that have deep roots. Deep-rooted plants are beneficial because the roots help to stabilize soil, improve soil aeration and prevent soil erosion. Deeper rooted species can also be beneficial in drawing water and nutrients from deeper below the ground, and also for storing water within the landscape.

Fast-Growing Trees For Organic Matter Generation

Pioneer trees that serve one of the above functions can also be great for quickly generating organic matter. As deciduous pioneer trees drop their leaves, they provide a steady stream of organic material, which builds and improves the soil, and which can be utilized as other parts of the land are managed and new growing areas established.

Pioneer Trees for Shelterbelts/Windbreaks

Since pioneer species are resilient and well suited to local conditions, they can often be used to prepare the ground for other planting not only through improving the soil and its fertility but also by mitigating environmental extremes – such as strong winds. By considering the use of pioneer trees on parts of a site, you can create a design that creates more sheltered conditions for other needs.

Creating Canopy Cover

Of course, planting pioneer trees on a degraded site or one that does not live up to its full potential also often allows some degree of canopy cover to be established. The shade created can reduce moisture losses, and allow a greater diversity of plants and animals to thrive.

Pioneer trees can be important in the first stages of the creation of an agroforestry or forest garden system, or in establishing native woodlands and rewildling. Pioneers come first, then the settlers – all the other plants you want to include within the system.

These real pioneers are truly inspiring. And their importance to land restoration and ecosystem establishment should not be overlooked.