With climate-smart forest management, we are looking to spread risks. And to get new tree species into the forest, we plant many young (climate-smart) trees within the LIFE project. But there is another way to rejuvenate the forest... seeding. In Germany, it has also been practised for much longer and much more often, and to investigate in practice whether this option also catches on well in Dutch forests, project partner Bosgroep Noord-Oost Nederland sowed in Ubbinkbos and the Climate Forest example forest Boschoord at the end of March 2025.

Martijn Jansen is associated with LIFE Climate Forest as an expert member of Bosgroep Noord-Oost Nederland. He explains the different choices and measures ...

Abies grandis seed

Douglas seed

"In the different plots, we sow species that we would hardly expect there using natural rejuvenation. Depending on light conditions, we experiment with beech, sessile oak, pedunculate oak, silver fir, giant silver fir, douglas and giant life tree. A total of four plots, on two different estates, have been sown. In total, it covers a total area of nearly 3.5 hectares."

"The choice of these species was made based on the owners' objectives, such as more mixing, more foliage and a climate-resilient forest as well as to partly fulfil the wood production function of the forest. When working out the plans, we actually planned to sow more species such as tree hazel, alderberry and hornbeam. Unfortunately - at the moment - no seed of these was available for the trial."

"An important part of climate-smart forest management is spreading risk by enhancing mixing in forests and increasing structure. To date, we achieve these goals by encouraging natural rejuvenation and in the absence of the desired tree species, we realise this through planting. We see the prices of plants and labour rising sharply in recent years. Hence we take a broad view and look for alternatives. In Germany, they have already gained a lot of experience in recent decades with seeding when converting softwood to hardwood and reforesting large-scale calamity felling after the extremely dry years 2018, 2019 and 2020."

"After many positive stories in the literature and during field visits, we decided together with the owners to also experiment in our region. In Germany, practical observations have shown that at several locations where simultaneous sowing and planting have taken place, after only three years the sown tree has a much larger root system than the planted tree. We are closely following the development in our sowing trials and hope that the sown trees will eventually be more climate-robust than the planted ones. "

Forstraupe Moritz Fr75

"Why did we choose to conduct a trial of seeding new forest under screen of older trees in addition to replanting new trees? The seeding trial was done to gain experience with this method of forest rejuvenation under Dutch conditions. Depending on seed emergence, this could be a good alternative or complement to traditional planting. Depending on the emergence of the seed and how many plants can eventually reach maturity, it also seems to compete financially with planting. In addition, 'rutting' is not an issue. The machine weighs less than 1,500 kilos and is on caterpillars. So the soil pressure with this machine is minimal."

"We sowed at two concerned forest owners: Stichting Landgoed Ubbinkbos and (the Boschoord demo site of) Stichting Maatschappij van Weldadigheid. The Maatschappij van Weldadigheid is already committed in multiple actions by Climate Forest."

"In terms of tree species, the owner of Stichting Landgoed Ubbinkbos thought along. From the Forest Groups, we had recommended Abies alba, but the owner himself preferred grandis. In the end, we sowed seeds of beech, sessile oak, pedunculate oak, silver fir, giant fir, Douglas fir and giant live tree."

"Within LIFE Climate, we are still monitoring until 2027. But because we as a Bosgroep are also active in the regular management of the two owners involved, we can hopefully monitor the results of the seeding trials for a long time. There will also be a final symposium for LIFE Climate and that could be a great time to share our experiences regarding seeding."

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