Expectation: A large, healthy mature city tree that provides shade and cooling, absorbs a significant amount of CO2 and provides habitat for flora and fauna.
Reality: An urban tree that has been weakening for years and will eventually die, resulting in no climate benefits at all.
Unfortunately, we often see this happen in practice. A hole is dug, and a small tree is planted in an urban environment with the expectation that it will grow into a large, mature tree. What many people seem to forget is that planting an urban tree requires tools to meet the expectation.
The Pressure on Urban Square Meters
In recent decades, the pressure on urban square meters has increasingly intensified. Every meter in the urban environment is intensively used by above- and underground infrastructure, traffic, and events. Creating a smart balance between green, grey and blue is a growing challenge and is becoming increasingly important.
Obstacles and Hurdles for City Trees
The conditions in the urban environment are far from optimal for a tree to grow old healthily. Several factors such as limited space, poor water infiltration, pollution, limited availability of nutrients and soil compaction reduce the growth and lifespan of the tree. As trees keep growing, they eventually run into all kinds of hurdles and obstacles that inhibit growth.
Soil Compaction and Underground Infrastructure
Particularly soil compaction and underground infrastructure are problematic for urban trees, as these are the main causes of roots being unable to anchor themselves properly in the soil and limiting the supply of water, air and nutrients to the roots. This causes a weakened tree and increases the likelihood of failure or blowing over in storms or strong winds. In the end, a valuable investment is lost because a large, mature tree yields significantly more climate benefits than new plantings.
Crucial Factor for City Trees
If there is one crucial factor in the development and health of both new and existing urban trees, it is the rootable space they have at their disposal. Roots simply need space to grow, so that the tree can stabilise and absorb nutrients from the soil. If this growth is inhibited by a lack of rootable space, the tree will weaken faster, be more susceptible to diseases and pests and eventually die. Especially in the case of existing urban trees, which provide many climate benefits, contribute to the aesthetic character of a place and provide social cohesion, this is a real waste. That is why it is essential to make existing trees future-proof by giving them the right tree pit design.
Underground Rootable Volume for Trees
The TreeParker tree bunker system is an innovative technique for creating an optimal rootable space for both new and existing urban trees. The TreeParker system consists of units that are attached to each other. One TreeParker unit consists of a deck, four posts and two frames. Because there is plenty of space between the posts, the TreeParker system can easily be filled with the right tree substrate for the respective tree species. As the system is applied under the pavement and strong enough to carry the heaviest traffic loads, the tree no longer suffers from soil compaction.
Water, Air, and Stability for the Tree
The TreeParker system not only consists of units, but also features aeration tubes, root ball anchoring (with new planting) and root guiding panels. The aeration tubes are there to provide the tree with sufficient aeration. The root ball anchoring ensures that the tree root ball is stably anchored using solid ties attached to concrete mesh or via ground anchors in the ground. The root guiding panels have the function to guide the tree roots perpendicularly downwards, allowing them to continue growing horizontally under the panel. This prevents the tree from causing root pressure in the pavement. In addition, the system is often connected to a storm drain so the tree can better absorb water and is less likely to suffer from drought.
Making Expectations a Reality
The traditional way of planting trees – dig a hole and plant a tree – is history in the urban environment. Urban trees simply encounter too many hurdles and obstacles to grow old healthily. To still get the necessary rootable volume to thrive among urban infrastructure, the TreeParker system is deployed. Both for new plantings and for existing trees. In this way, trees get the chance to grow old healthily in the city and expectations become reality!