Description
Similar names: Tiny forests, Fast growing forests, Urban forests, Potential natural vegetation
The Miyawaki method is a reforestation technique that entails the growing of a forest within a few decades – instead of centuries – by taking into account the succession of plants and plant diversity that naturally occurs in forests. This method was first conceptualized in Japan by Dr. Akira Miyawaki and has been successfully implemented in areas with relatively high rainfall rates such as India, Malaysia, and South America. However, it has also been successfully practiced in other/locations/, such as the Mediterranean; the steppe zone of Jordan; and in the Persian Gulf region.
This technique is particularly effective as it imitates the structure of a mature forest. It aims at recreating all the different levels of vegetation and combinations of species that would naturally occur in a native forest without human intervention – defined as “potential natural vegetation”. Practitioners must carefully select the right indigenous vegetation best adapted to local conditions, and they need to commit to watering and mulching the seedlings during the first years of implementation of the intervention.
One of the advantages of using this technique is that it allows for the quick regrowth of a dense forest rich in biodiversity which is able to retain rainfall and create a cooling microclimate effect.
NOTE: The implementation of this technique can be expensive as it requires a lot of seedlings for a relatively small area. However, it allows to obtain a full functional forest in short times, with minimal maintenance needed.
PRE-CONDITIONS FOR IMPLEMENTATION
- Before establishing the forest, it is essential to verify that the site has all the biophysical requirements for the growth of trees and that the selected area will not cause any societal conflicts.
- For forests which are highly vulnerable to wildfires, this intervention should be applied with caution, taking into account the context of the specific forest. A less dense forest would be a better fit in those areas.
- This intervention can be time consuming at the very beginning (preparing the soil, watering, weeding, mulching, transplanting of seedlings)
- More successful if engaging the whole community
- Need access to water in the initial years to water the seedlings
- Expensive if seedlings, especially of good quality, are not available.
METHOD OF APPLICATION
MATERIALS
- Shovel
- Manure
- Seedlings
- chair
- Study the area and define the potential natural vegetation: identify native species found within about 20 km of the selected zone. A number between 50 and 100 different species is recommended. Such information can be gathered through asking local and indigenous peoples which tree species are naturally growing well in the area. The vegetation structure should start with the planting of fast-growing plants, followed by pairing these plants with perennial herbs and grasses, and finally, shrubs and trees of different heights. The minimum space needed to plant a Miyawaki forest is usually 92m2 for a dense forest in which about 250 saplings are planted. However, this can be as few as 12 m2 for a less dense forest.
- Rejuvenate the soil: trees need a lot of organic matter to grow, therefore, ensuring that the soil is well prepared for the intervention is a fundamentally important step. A pit should be dug, and the soil should be prepared by incorporating organic materials such as dead vegetation and manure. Sometimes, it is recommended to build a small hill with accumulated organic material (with a maximum slope of 30%), as this can imitate the increasing soil layer of a natural forest.
- Planting: saplings that are up to 80cm high should be planted, and a standard density of 3 plants per square meter is usually recommended in order to imitate a natural forest. However, this has to be adapted to the requirements of your area; a good rule of thumb is to imitate the density of the natural vegetation already occurring in the area or ask a local expert. The planting of the seedlings can be facilitated, and the watering reduced, by using the Planting pits intervention; hence, small pits containing soil and manure in which the sapling is planted.
- Mulching: After planting the trees, the ground should be covered with a thick layer of mulch which imitates fallen leaves on the forest floor. Though, one should be cautious to never apply the mulch in direct contact with the seedling - especially in humid areas - as doing so can cause rotting of the young plant. Once the trees have matured enough, they will self-mulch the soil with fallen leaves. This helps to protect the soil from water evaporation, whilst providing the soil with fertilizer and preventing weed growth.
- Maintenance: during the first 3 years of implementation, the plants will require occasional weeding and watering. After this period, the forest should be dense enough to prevent weeds from growing and to retain enough water to be self-sufficient.
The trees grow fast (3 ft or 1 m per year), with a survival rate of up to 90%, and have the capacity to capture more CO2 than monoculture plantations. For tutorials and more details about the method of application please click here.
COSTS
Estimation of costs & benefits of intervention
It is important to remember that the values differ consistently from country to country, mainly due to the cost of seedling’s production. The example given is based in India, where 3 months-old saplings are produced at a cost varying between Rs 10 and Rs 40 per plant.
Establishment cost | About Rs 300-Rs 350 per square foot of planting area (manure, seedlings, watering etc.) |
Labor time | 3-year commitment (for maintenance), more intensive in the first year |
Maintenance cost | zero after 3 years |
CASE STUDIES
Jordan:
One of the most interesting cases of Miyawaki forest can be found in Amman, Jordan. Click here to know more about it.
France:
Miyawaki forests are becoming popular also in Europe. Click here to know more about if from the Boomforest Association in France.
India:
Other than Afforestt institute and Forest Creators, the SayTrees Association illustrates some very good examples of Miyawaki forests in India.
Netherlands:
A tiny forest was created in Saanstad, The Netherlands, with the aim to better connect society, in particular children, and nature. Click here or here to know more about it.
Urban areas:
If you want to know more about urban forests around the world, here are two good examples: Example 1, Example 2
FIND OUT MORE
Links with videos for a more detailed step-by-step:
- Afforestt tutorial
- Afforestt methodology
- Extra step-by-step source
- Here you can find an example of one way of preparing the soil (however, it is important to evaluate if this method applies to your region before implementing it).