Case Study Barnard Park
Barnard Park Micro-Forest. Barnard Park, Islington, London N1 0ER.
Completed March 2022
Installation
The Brief
To plant a micro-forest of 400m2 in a corner of the Barnard Park to encourage biodiversity into what was a ‘tired’ area of grassland used mainly by dog walkers.
The Challenge
To mimic nature and grow a forest, quickly, in very poor ground conditions in very poor soil.
Our survey to the area chosen found between 300 – 400mm depth of compacted, waterlogged soil that previously consisted of houses which had been bombed and subsequently demolished during the war.
We wanted to engage with the local community to help plant the trees and educate them on biodiversity.
The Approach (Design & logistics)
We carried out a survey of trees that grew well in a 15-mile radius and those that would have been in typically found in the area since the last Ice Age.
We chose high, mid and low canopy cover trees with shrub underplanting.
The rate of planting to be at 3-4 cell grown trees per m2.
Soil preparation consisted of spreading 150mm depth of mineral enriched topsoil over the area followed by injecting high pressure air up to depths of 1mtr to break up the subsoil and any hardcore from the old buildings.
Biochar, Mycorrhiza and organic nutrients were subsequently injected to maintain the de-compaction and ameliorate the soil.
The cell grown trees were planted with worms were added to aid the re-generation of the soil both of which contribute to the high success rate of the trees – over 90%.
The Results / Outcome
The results were very impressive with the 50% of the trees over 1.5m tall after the first 12 months and, despite the exceptionally hot summer, only a 5% failure rate.
The abundance of perennials and grasses that nature provided free of charge was an unexpected benefit and more than made up for the small quantity of trees lost.
These perennials have attracted a host of insects whilst the trees establish.
Children from the local school helped plant the trees. As the top layer of soil had been imported and the trees were cell grown, it was a relatively simple task to plant. They loved handling the worms.
At rates from £80.00 per m2 this is a simple, cost effective way to attract biodiversity, sequester carbon and other pollutants whilst bringing countless other wellbeing benefits
The Future Plan
We will be carrying out biodiversity sweeps as the forest matures.
With data on the biodiversity benefits and pollution sequestration these micro-forests are an ideal way for developers to tackle the biodiversity net gain requirement that becomes law in November 2023
With a minimum size requirement of the size of a tennis court (200m2) to properly support an ecosystem, these micro-forests can complement any building development and help achieve carbon offsetting target of the build.
If space is limited, planting hedges 2.0m wide using the same system will produce similar results.
