Close-To-Nature Forestry

What is Close-To-Nature Forestry (CNF)?

Close-to-nature forestry is about managing a forest in a way that imitates nature, yet benefits humans more than no management would. It is considered very low impact and low maintenance as it is making use of natural processes “working with nature, not against nature”. Close-to-nature forest management creates diverse, multi-functional and resilient forests. The idea originated from Germany, but is either entirely or in parts adapted throughout the world. Synonyms can be “natural forest management”, “integrated forest management” or “ecological forest management”.

Practicing CNF

CNF requires a forest manager to have a good and deep understanding of the forest. If research and historical data is lacking, it is often difficult to develop this kind of understanding. Furthermore forests managed this way are not having a growth rate as high as in traditional plantations – instead the provide many more ecosystem services. However, in many commercial plantations in the world production is the ultimate measure when choosing a management style.

Finally CNF, originating from Germany, is not a famous concept, yet. Many people simply haven’t heard of it.

Necessary Information for CNF

A forest manager should know the fundamentals of forest ecology, successional processes (for example if a forest naturally will be in an equilibrium stage), disturbance cycles, land use history, site conditions and the human influence on forests. It is, for example, important to know whether a forest is naturally simpler in structure (which can be induced by a lack of water) or whether the simplicity in structure derives from former degradation processes (when people collect fuelwood and with that natural regeneration of trees). While even in areas of the world where CNF has been practiced for a while science learns more and more about these factors and therefore can never give a complete answer, it is important to have a grasp of each of these aspects in order to judge a forest accurately.

An Example of CNF

You are the manager of a forest that based on research, natural disturbance cycles and undisturbed forests in reserves is determined to be an natural oak forest. Your most commercial species is pine but naturally only occurs in very small amounts. If there is no disturbance (which would be rather unnatural as your windthrow cycle is about every 120 years) the forest would change into a hemlock forest.

A traditional forester would…

…likely mostly or purely grow pines and regenerate them with a clear-cut. They bring the most money for their timber and are the fastest to grow.

A CNF manager would…

…recognize that, while pine brings the most money and hemlock is the “virgin forest” species, this forest ecosystem is dominated by disturbances and finds its semi-equilibrium in oak forests. He would try to keep a certain low percentage of pine, grow oak and optimize it’s quality through thinning techniques and also keep some hemlock as it would naturally occur in the forest as well. He may designate the commercial value to the pine and oak, though, and leave the hemlock only for ecosystem services like biodiversity.

 Of course, management decisions are more complex than this example as they also have to take into account the political, socio-economic and local conditions. The example above was just including ecological and economical considerations.

So what is BFS exactly doing in Miyun?

The current condition

Nearly all of the forests in the Miyun watershed have either naturally established on degraded lands and are still in the process of recovery or have been planted in the 70s and 80s with the help of large state programs like the Grain for Green program. Back then barren mountains were a common picture and caused a lot of erosion issues affecting the reservoir which is why the government eventually intervened.

These plantations are for the most part mono-cultures that are not truly reflecting the natural vegetation which would provide more ecosystem services and be more resilient. Many of the planted forests today are too high in density, resulting in high h/d (height/diameter) ratios which make the forests prone to wind-throw and reduce the understory and general biodiversity. To the right you can find a description of the species used for afforestation back then.

Our Vision

It is our vision to restore the native vegetation while providing a maximum of ecosystem services to the villagers owning the forest and the people downstream depending on clean water. This means that we will not 100% replicate the natural forest but transform it in a way that brings humans and nature maximum benefits. This can for example mean that fruit trees or plant communities that favor the growth of medicinal plants will be favored.

Below you will find the current composition of the forests and an set of species that occur in natural forests.

Improving Water

CNF turns plantations into natural forests. Research has shown that natural forests show greater resilience against many disturbances like wind-throw or pests through their multi-species, multi-age and multi-strata structure. Due to climate change the likelihood of more frequent and severe disturbances increases, making it more important to enhance the resilience of the local forests. If forests are severely damaged sediment flow and erosion can increase, decreasing the water quality. While this would also increase the overall quantity, it intensifies the flow variation, likely causing damages by flooding places during intense rain storms. Overall resilient natural forests secure a more modified, stable and high-quality supply of water.

Thinning

The main method of transforming the plantations into natural forests BFS is using is thinning. Through thinning techniques BFS is carefully opening up the canopy and therefore reducing the competition to improve the quality of the remaining trees and reestablish the forest understory. The thinning technique being used is called “target tree thinning”. Target trees that promise to become high quality trees in the future, are selected and the closest immediate competitors are removed.

In some areas BFS is also doing shelterwood and selection cuttings in order to regenerate the forest and establish more tree species of the natural forest composition, for example the Mongolian oak (Quercus mongolica) or the Oriental white oak (Quercus aliena). Often natural seed sources for these trees are lacking, so that BFS often underplants the forests it is applying these cuts on.

While BFS forest experts are marking the trees and amount to be cut, the local villagers who own the forest are trained in managing the forest in the process, so that in the future they can manage their forest themselves.

Pruning

To further improve the timber quality of the individual trees BFS also teaches local villages how to prune trees, especially the widely planted Chinese pine. Pruning is referring to the removal of the lower dead branches of a tree. There are many trees (often deciduous) that naturally self-prune, others have to be artificially pruned. Pruning trees improves the quality as there will be less knots in timber when the trees have matured which usually achieve higher timber prices. Pruning should be done when the tree is still young and only on the highest value segment of the tree.

The Logging Ban

The logging ban was instituted in 1992 in many forests designated as “Natural Protection Forests” and forbids the cutting of trees above a certain diameter. This was done to prevent large scale deforestation from happening in forests that are of special ecological importance. However, as shown earlier, especially planted monocultures can become too dense, reducing the light that reaches the understory and therefore reducing many important eco-functions. It is therefore important that such forests are managed. The local forest administration can give special cutting permissions, if it is proven to them that the actions are part of a forest management plan and not mere deforestation or forest degradation. As one of BFS’ goals is to enhance the eco-function of forests, it was possible to get such permits. BFS is now working on finding a way to get these permits to be more institutionalized so communities can manage forests that way on their own.