Daisen Forest Rewilding
Conducting Forest Rewilding Projects in Daisen Town for the Benefit of the Whole Environment
Selective thinning of single-species tree plantations and replanting with a range of native tree species
Forming partnerships with travel agencies and the local community
Collaborations with Environmental Universities
Offering Tree Planting Activities and Experiences
Introduction
Sustainable Daisen NPO’s core mission is to protect the Japanese giant salamander and its unique habitat in the Nawa River Basin of Mount Daisen, Tottori Prefecture Japan. This requires considering the whole mountain ecosystem: the rivers, forests, farmland and villages.
Sustainable Daisen’s “Daisen Forest Rewilding” project aims to increase the health of the region’s wooded areas for the benefit of all animal species including the Japanese giant salamanders. Cedar and cypress plantations will be thinned out through selective felling and a mixture of native deciduous trees will be planted in their place. Tree guards crafted from wood from the felled trees will be installed in order to protect the saplings from damage caused by browsing animals such as deer.
Mixed forests are able to hold more water than coniferous plantations and therefore reduce and delay the amount of rainfall entering the rivers during torrential rains and typhoons. Generally speaking, mixed forests also have higher levels of biodiversity which is beneficial for all forms of wildlife up and down the food chain.
Working with local craftspersons, timber mills, forestry groups and landowners, the timber extracted from the forest will be used to create original products or sold to create revenue which will be split between the landowners and Sustainable Daisen NPO at a rate agreed upon between the NPO and landowner.
Torrential rains are an increasing problem for Japan and August 2021 saw western to eastern Japan experience record-heavy rain. As the largest animal living in Japan’s waterways, such heavy rains are particularly dangerous for Japanese giant salamanders. Many are washed downstream at high speed and as a result many are injured or die as they are smashed against debris in the water, rocks and concrete river reinforcements. For those salamanders that survive, nearly all are prevented from returning upriver by man-made barriers such as weirs and dams. Although Sustainable Daisen’s primary goal is to work with Tottori Prefecture to install bypass slopes to enable free movement back up the river for the salamanders, we also consider restoring the health, species diversity and overall biodiversity of Daisen Town’s forests as an essential task.
Expert advice and guidance
On January 22nd 2022, representatives of Sustainable Daisen met with Professor Nemoto of Tottori Environmental University to discuss the Daisen Rewilding Project and Save the Japanese Giant Salamander campaign. Professor Nemoto pledged the support of his class and offered to bring his students to our pilot rewilding site. He and his students will do an assessment “health check” of our initial rewilding area and offer advice on what species to plant, where to plant them and at what densities. Professor Nemoto is confident that a number of his students will seek further involvement with the project.
Further discussions with Professor Nemoto and Professor Kobayashi (a leading Japanese giant flying squirrel researcher) have taken place. Exciting collaborative projects are being planned between Sustainable Daisen and Tottori Environmental University. Watch this space!
Initial planting area - Anfield Woods, Nihonmatsu, Daisen Town
Anfield Woods is an approximately 15,000㎡ plantation consisting largely of Japanese cedar (Cryptomeria japonica). It was planted approximately 50 years ago and seems to have received little, if any, management since. Around the edge of the plantation there are some large and magnificent individual cedar trees. However, the interior is quite dark and the trees are thin, small and in some cases already dead. Accessibility is good. A small stream begins within the woods and eventually joins into the Shimoichi River. It is approximately 2kms from the source of the Higashidani River and approximately 3.5km from the source of the Nawa River. Both of these rivers represent important Japanese giant salamander habitats.
On the advice of experts, a select number of trees will be removed from the centre of the plantation and replaced with saplings of suitable deciduous trees that are native to the area.
Update! Further talks with other local land owners are underway and are progressing well. Watch this space!
“Rewilding” programme by planting of saplings funded by donations and sponsorship
Sustainable Daisen plans to work with travel agencies in order to help achieve sustainable travel by having each of the travel agency’s customers contribute towards the planting of native deciduous saplings. Our project is unique in that such charitable action will not only be of benefit to the general health of the destination country’s environment, but it will also directly support the conservation of one of Japan and the world’s most important and unique animals, the Japanese giant salamander.
We are able to offer individual tree plaques(made from wood offcuts) bearing the donators name which can be photographed in-situ and delivered digitally if desired.
Additionally, we plan to offer the chance for customers of our travel agency partners to come to the area and plant a tree for themselves.
What are the problems with artificial cedar and cypress plantations and why are mixed forests considered better for the environment?
Below is a basic summary of the issues surrounding artificial cedar and cypress forests found throughout Japan.
1. Artificial cedar and cypress forests have little to no water-holding capacity
The decaying leaves of trees such as beech, sawtooth oak and Japanese chinquapin, which grow in the low and mid-elevations of Japan, form a humus on top of the soil. Over a long period of time, this humus accumulates on the surface of the mountainside making the wooded slopes essentially like a thick sponge. This acts as a natural sponge dam to retain rainfall, even when it rains heavily.
On the other hand, coniferous tree leaves such as those from cedar and cypress do not become humus when they fall because of the high oil content of their leaves.
In artificial forests planted with cedar and cypress, the decaying leaves cannot hold rainwater, so the vast majority of the rain flows directly into the river.
2. Cedar and Japanese cypress have shallow roots which weaken the ground
The roots of broad-leaved trees such as Mizunara oak, sawtooth oak and beech grow deep into the ground. In contrast, the roots of coniferous trees such as Japanese cedar and Japanese cypress tend to spread out horizontally. As a result, the ground in artificial forests of coniferous trees such as cedar and cypress is much weaker than that of natural forests of broad-leaved trees, and heavy rains can easily cause landslides and mudslides.
Recently, we can often see images on TV of landslides and mudslides caused by torrential rains. Almost all of these landslides and mudslides occur in man-made forests planted with cedar and cypress.
3. Artificial coniferous plantations are “wildlife dead zones”
If you step into an artificial forest you may notice that they are often eerily quiet. This is because coniferous forests, generally speaking, support less biodiversity. This is due to a range of factors including soil acidity, the absence of humus and the lack of fruits and nuts. A byproduct of this is that “pest” animals such as wild boar, deer, macaques and bears are increasingly encroaching onto farmland in search of food and causing conflict with humans. In biodiverse areas such as deciduous and mixed forests there is more for these animals to eat so they are less likely to cause destruction to crops and property.
Why are single-species conifer plantations so common in Japan?
As the situation worsened for Japan in World War II, fuel shortages became more acute and vast tracts of woodland were cut down on mountains all over the country in order to secure firewood and charcoal.
As part of the post-war reconstruction efforts, cedar and cypress saplings were planted in the shaved mountains all over Japan under the slogan "plant and grow". The aim of the project was to earn foreign currency by planting large numbers of cedar and cypress trees for export as timber, and to secure the building materials needed for post-war reconstruction. The saplings could be obtained for free and citizens could receive money for planting them. This resulted in a kind of “planting frenzy” and goes some way to explaining why so many plantations have been abandoned or poorly managed.
Donation
Your donation allows us to carry out our vital work of conserving and protecting the Japanese giant salamander. For a detailed breakdown of our fund-raising goals, please visit our “Save the Japanese Giant Salamander Campaign” page