Greening project Lentepark district

Greening project Lentepark district

1. Outline of the problem

Water is extremely important for life on earth and for human survival. But with that precious water come great challenges. In highly built-up environments such as our village centres, for example, insufficient rainwater reaches the water table due to the lack of open space. This puts our ecosystem under pressure (ecosystem= natural system consisting of organisms and their environment and the interactions between the two; one cannot do without the other to survive). Combine that with climate change and you see even more problems coming our way. For example, we can have to deal with water shortages in extremely dry periods. In case of excessive rainfall, our sewers will not process the water in time and there is a risk of flooding. And then there's the "heat island effect." This term refers to the temperature difference between the highly built environment and the much less paved surrounding countryside. After all, paved surfaces such as bricks, asphalt, concrete, crushed stone store more heat and release it slowly back into their environment.

More water and greenery in the highly built-up environment could provide the necessary cooling and contribute to the proper functioning of our ecosystems. I can already hear you thinking 'we have our Buggenhout forest, our forest municipality is green, right?', but buggenhout's climate plan exposes a lot of pain points, which we as humans will suffer the negative consequences of. So instead of pumping out the rainwater and draining it through our sewers, we should start looking at the lake as an essential part of our environment and try to hold it as much as possible where it ends up. The way to achieve this is to focus on greening and softening at district level.

A first project that we have worked on from the green service is where we are now, the Spring Park. This district was built in the 70s in different phases. 50 years ago, people did not have the knowledge we have today about tree species and location requirements. Knowledge about tree management has also evolved enormously in 50 years. It was therefore high time to take a closer look at this district and to develop an adapted tree plan for this.

2. Greening project Lentepark district

The points of attention in the development of this greening project were:

• Maximum preservation of healthy trees
• Greening where possible, in the most biodiverse way possible
• First step towards softening in Buggenhout
• Maximally involving the neighbourhood in this project in order to create support

118 trees were preserved and 90 trees were uprooted (These were trees in a very poor condition, severely damaged or had virtually no chance of future because of the wrong tree species for the location in which they were planted in the past.)

A total of 158 new trees were planted. When choosing these trees, the available above- and underground growth space was initially considered. In addition, the focus was on contributing to biodiversity and species were chosen that are expected to be 'climate-proof'. (The most commonly planted species are Sorbus (mountain ash), different varieties of Carpinus betulus (hornbeam) depending on the available space, 2 varieties of Acer campestre (field maple or Spanish barge).)

3. Tree mirrors

The tree mirrors in the streets were planted with an underplanting. An underplanting ensures that the tree mirrors are not entered, so that no compaction of the subsoil can occur. This not only allows rainwater to infiltrate better, but also keeps the growing conditions for the tree in an optimal condition. Different types of underplanting were used, so that in addition to the amenity value for humans, the alternating flowering ensures that pollen and pollen are available to the insects for a longer period of time.

4. Softening in function of rainwater infiltration

Initially, softening was not included in the project. Nevertheless, this was taken into account in the further elaboration and eventually 445m² of concrete paving stones and stones were removed and transformed into a plant compartment. In these zones, rainwater will be able to infiltrate better into the soil.

By the way, did you know that pebbles or gravel ensure that approximately 40% of the rainwater cannot infiltrate into the subsurface, but flows off? A lawn ensures that 10% of the rainwater cannot infiltrate. A planting with different plant species ensures that the soil is also rooted to different depths, so that rainwater can best infiltrate. It is therefore best to provide a herb layer, a shrub layer and a tree layer in your garden.

5. Future trees

This neighborhood park was also taken care of. New paths were built at a slightly modified location. In this way, the pavement that was in the root zone of the plane tree was removed to the maximum. In this neighborhood park several new trees were replanted, with 2 new future trees (Tilia cordata and Carpinus betulus). These are trees that we provide in such a way that they can grow into large full-fledged trees that can stand for a long time and grow very old. Why is it just as important to provide future trees: A large tree has a much larger leaf mass, so there is more shade and evaporation. In this way, they contribute to the fight against the warming of built-up space. In addition, they capture more particulate matter, retain more CO² and produce more oxygen than their small counterparts. Finally, they also provide more living space and food for different organisms.

6. How rainwater helps store and infiltrate.

The existing park was located in a spherical shape, so that during heavy rainfall a lot of water simply flowed to the sewer system. Outside the root zone of the trees where the ground level was preserved, the park was re-profiled: It was partly laid out in a bowl shape, with a maximum depth of -0.50cm below the existing ground level. Almost immediately after construction we could see that this wadi works. During heavy rainfall, water enters this basin that slowly infiltrates into the subsurface. In addition, this has become an extra watering hole for numerous animals.

Where no plants were planted in this neighborhood park, a biodiverse lawn mixture was sown. This herb-rich grass mixture not only requires much less maintenance, because of the variety of herbs and grasses in this mixture, the roots go much deeper than a classic lawn, in other words a winwin for rainwater infiltration and for biodiversity.

Explanation: Veerle De Buyser, Green Service Local Government Buggenhout

Plan and follow-up: Green Service Local Government Buggenhout

Jurgen Vermeulen