The project’s machinery group focuses on how to handle reductions in stem density and which machines can be used for soil preparation, planting, and sowing.
The machinery group has exchanged experiences with LIFE 4Forest’s German partner – Schleswig-Holsteinische Landesforsten (SHLF) – to learn about the mechanical methods developed in Germany for soil preparation and sowing. Simon Russell from SHLF has been a great help and is also a member of the machinery group.
In April 2025, the machinery group held a machine demonstration in Denmark covering these themes and trials on Danish soil. Christian S. Ramsgaard from Salten Langsø Forest Administration, also a member of the machinery group, hosted the event and provided the demonstration sites.
A key part of converting from monoculture to close-to-nature forestry is mixing more tree species into the stand, either by sowing or planting, which makes it highly relevant to have a closer look at these aspects.
>>Read: What do we know about conversion close-to-nature forest management.
Mini tractors with mulcher and plow
The machinery group presented two examples of how a compact, remote-controlled crawler mini-tractor equipped with a disc plow and sowing tools can handle soil preparation and sowing.
The mini-tractor is primarily designed for forestry. The two models demonstrated were an MDB GREEN CLIMBER and a Pfanzelt Moritz fr75
The Disc plow - new to many
The MDB equipped with a disc plow offers a new way to prepare soil by creating narrow strips across the terrain without stressing the soil with heavier machines and vibrations. It weighs about 1.5 tons and can be operated remotely by a single forest worker. It has a 70 hp diesel engine and is fully off-road capable, even on slopes.
Soil preparation can be challenging during conversion to close-to-nature forestry, where navigation between old permanent trees, removal of unwanted natural regeneration, and ensuring growth in new layers with new species are required. This machine provides a good solution.
At SHLF, they have mounted a sowing unit on top of the plow, enabling soil preparation and sowing in one operation. According to Simon Russell, this solution is a useful tool for introducing new species into the stand. However, very small seeds pose challenges—but the Germans have found a solution, as described later in this article.
Rotary tiller with integrated sowing
With the Pfanzelt Moritz FR75, LIFE 4Forest’s German partner demonstrated a rotary tiller with integrated sowing. This is a slightly heavier machine, weighing just over 2 tons.
Mulcher and flail mower
Both machines can be fitted with a mulcher, typically featuring a fast-rotating rotor with hammers or flails that shred branches, wild vegetation, and stems into small fragments. They can also be equipped with a flail mower, which uses rotating flails or knives to cut and shred grass, weeds, shrubs, and small unwanted trees.
A hole in a bottle cap as a “seeder”
When tree seeds are very small, mechanical sowing can be difficult. This applies to species like Douglas fir, widely used in conversion to close-to-nature forestry. Like larch, its seeds are the size of a pinhead.
The Germans have devised a low-tech solution: drill a 10 mm hole in the cap of a plastic bottle, fill it with seeds, tape it to a stick, and when sowing on prepared soil, shake the bottle upside down as if sprinkling salt on an egg.
Sowing – A Tool in the Conversion Toolbox
The advantage of sowing is that it requires a relatively small investment, especially when there are an excess of seeds. This is particularly true for introducing beech. It can be a good supplement to planting. Simon Russell recalls Esben Møller Madsen calling it “forestry with a piggy bank.” If it fails, the economic loss is far smaller than with planting. Sowing is not a substitute for planting but can be combined with it to make the forest more resilient.
>>Read: The Germans showing the way for close-to-nature forest management
Planting with a modified drill
In many cases, planting bare-root or containerized seedlings is the preferred method for introducing new species into stands undergoing conversion. To preserve root structure, SHLF uses a modified power drill with soil drills of various diameters. The drill was adapted in Denmark.
By applying a modified drill, plants can be planted in a way that preserves the three-dimensional structure of the roots. Maximum 15 cm is used (Jiffz 7 or Quickpot 24). Photo: Jan Østergaard.
Next machinery demonstration
The group also aims to reduce economic and biological risks by developing cost-effective methods for reducing stem density in a stand.
During the conversion phase (from traditional to close-to-nature forestry), extensive natural regeneration often occurs, which can lead to high costs for reducing stem numbers. Dense, even-aged self-seeding of species such as Sitka spruce, Norway spruce, and larch typically does not provide the desired mixture of stable tree species in multiple layers sought in close-to-nature forestry. This will be the theme of the group’s next machinery demonstration in spring 2026.