“Walsterben 2.0.” – “Forest dieback 2.0” – Forests under pressure

Background: Forest health declines again

Greta Thunberg, the Swedish climate activist and initiator of the “Fridays For Future” movement, warned us: “Our house is on fire” and spoke out in front of the World Economic Forum in Davos1. In fact, one can currently get the impression that climate change is becoming noticeable for humans and animals . The hot summer of 2018 in large parts of Europe, the hottest July since the weather began to record 2, as well as the current forest fires in the Arctic, spreading in Siberia and Alaska over an area of ​​10,000 football fields3. In the recently published IPCC special report, particular attention was paid to our land use: the global temperature rise on mainland has already reached 1.53 degrees Celsius (global 0.87 ° C). Agriculture, forestry and other land use (AFOLU) accounted for around 13% of CO2, 44% of methane (CH4) and 82% of nitrous oxide (N2O) emissions from human activities in the period 2007–2016 globally, which accounts for 23% (12.0 ± 3.0Gt CO2 eq. per year) of the total anthropogenic net greenhouse gas emissions4. The targets set in the 2015 Paris Climate Agreement, to reduce global warming to well below 2 degrees, if possible even to 1,5 degrees compared to pre-industrial times5, seem difficult to meet, since the industrialized nations are not taking effective steps in a timely manner to reduce greenhouse gas emissions significantly.

Agriculture and forestry are particularly affected by the persistent drought and extreme heat waves. The forests in Germany are doing poorly, at the same time forests and moors are one of the most effective weapons against global warming. The ETH Zurich came to the conclusion, that a worldwide reforestation on an area of ​​0.9 billion hectares would be possible and that two thirds of the CO2 emissions caused by humans could be absorbed. This would be the most effective measure against climate change6. Ethiopia intends to plant up to 4 billion trees by the end of October 20197. Likewise, voices in Europe and Germany are increasing in favor of afforestation8.

There are around 90 billion trees in German forests. Year after year, more grows back than is taken. Never, since the beginning of sustainable forestry 300 years ago, has the wood supply been as large as it is today. Around 2.5 billion tons of carbon are currently bound in forests. However, the frequent weather extremes severely affect the stocks. At the beginning of last year, Hurricane “Friederike” was followed by a drought summer, from which the forests have not yet recovered. Now it is dry and hot again. This weakens the trees and makes them susceptible to diseases and pests, such as the bark beetle, which reproduces almost explosively. Large areas of spruce and pine are dying, beech and oak trees are also affected. In 2018, 32 million cubic meters of damaged wood were generated. This year, there will be at least another 35 million. Dead wood and fallen trees must be removed from the forest as quickly as possible, so that the bark beetles cannot spread any further. Additionally, the dry wood also increases the risk of forest fires.

Alone the costs of removing the damage is estimated at two billion euros. Because there is so much damaged wood on the market, prices have fallen dramatically. After the Second World War, mainly spruce trees were planted in monocultures. They grow quickly and wood was badly needed in large quantities. Spruces thrive best in a humid and cool climate. They only develop shallow roots, which is why they dry up quickly in droughts and often cannot withstand storms. Mixed forests with different deciduous and conifer species are much more stable. In the future, resilient tree species will have to be planted, that can cope with less water and higher temperatures in the long term – such as red oak, Japanese larch, northern coastal fir or sweet chestnut, for example, which are not originally found in Germany. The largest turnover usually comes from spruce9. According to the third national forest inventory from 2012, spruce accounts for 26% of the forest stands (conifers 55%) and is one of the most important woods for forestry10.

A study by Swiss scientists from the “Forest and Climate Change” research program by the Federal Office for the Environment (FOEN) shows that spruce has genetically adapted to its very local conditions and will be extremely difficult to adapt to the speed of climate change 11.

Innovation: Expansion of forest value chains

Already in the 1980s, a debate about forest dieback erupted, which gave the environmental movement in Germany a great boost. Researchers found thinning tree tops and yellowed needles. At that time. The cause was the high level of air pollution caused by sulfur dioxide (SO2). When contacted with water, SO2 reacts to form sulfurous acid and thus acidifies the soil, which consequently can release fewer nutrients to the plants. In addition, poisonous aluminum ions were released, which additionally polluted the groundwater. Politicians reacted; power plants had to reduce their emissions into the environment significantly12.

Today, the problem has recently become a more difficult task. Forests can only adapt to the climatic changes of the next few years to a limited extent, while higher ecosystem services will be required of them in the future. The challenge in the near future will be to mitigate damage in the forests caused by extreme weather and prolonged periods of drought, and at the same time switch to sustainable forestry, which provides the raw material wood in its broad application to sustainable value chains.

Recently, new innovations have been on the advance, for example in the field of agriculture and forestry, in the field of biodegradable plastics and, most recently, in the textile industry. Soon, these components could be promising building blocks for a cascading economy –  a value chain which interconnects ecosystem services and economic interests.

One way of rethinking agriculture and forestry is agroforestry. Agroforestry is a form of land use in which perennial wood plants (trees, shrubs, palms, bamboo, etc.) are deliberately planted on the same area on which agricultural crops are grown and / or animals are kept. These elements can be combined either in a spatial arrangement or in a chronological sequence. In agroforestry systems there are usually both ecological and economic interactions between the various components13. Agroforestry, with its diverse manifestations (including tree cultivation, floor cultivation, forest pasture), enables the area yields to be doubled or quadrupled compared to traditional shifting cultivation (change of cultivation area) and allows to move to permanent farming. Agricultural sustainability increases with agroforestry from approx. 20 people / km2 to over 40. The system is relatively labor-intensive and capital-intensive, so we are talking about a low-input system and therefore corresponding to the conditions of the autochthonous population14.

In the debate about sustainable land use, as recently presented in the IPCC special report, the question of the forest resource also arises. By shifting fossil fuels to renewable raw materials, the forest ecosystem is gaining in importance.

The so-called liquid wood ARBOFORM offers a diverse way of using wood. The research project that made the development of this substance possible, started at the Fraunhofer Institute for Chemical Technology. In 1998, TECNARO GmbH was finally founded, bringing liquid wood to the market. The company recently moved into a new production facility in Ilsfeld, where it intends to start the production of the revolutionary material as bioplastic granules.

Standard plastics such as ABS, PE, PP, PS as well as technical plastics such as polyamides (PA 6, PA6.6, PA12) have already been successfully substituted, thus enabling versatile applications15.

An additional field is the fashion industry, which leaves the largest carbon footprint after the oil industry16. Estimates show that the textile industry is responsible for 20% of the world’s wastewater, 10% of CO2 emissions, 24% of all insecticides used and 11% of all pesticides17. Wood has fiber structures that make it possible to develop yarn for fashion.

The young company wijld from Wuppertal pursues a completely different approach and simply makes fashion out of wood, which, compared to cotton and sheep’s wool, uses resources much more ecologically. According to the manufacturer, the wood fiber shirts save 1,000 liters of water, 150 ml of chemicals in the form of pesticides and fertilizers and around 600 g of CO² due to the shortened transport route alone.

Potential: More wood, more good

The volume of agricultural waste is estimated at 10 to 14 km³ 18. That is an average of 42.5 t of new biomass per hectare annually. In a comparable dimension, production in natural forests is offset by the degradation of biomass (dead wood, leaves, etc.), so that there is no net increase or decrease. The biomass produced annually in the forests alone contains 25 times the energy of the crude oil extracted annually19.

A tree, for example an average 80-year-old beech with a height of 25 meters, has a dry mass of 12 tons of wood. About 6 tons of carbon are bound in it. The amount of energy in the wood of this beech corresponds to about 6000 liters of heating oil. A living beech tree also generates the oxygen requirement for 10 people, an ecosystem service that is never billed, but is the most essential for people and animals.

Wood is still one of the most versatile materials and will continue to gain in importance in the future, both as a renewable raw material and as a CO2 sink.

If we do not rethink forestry, the condition of the forests will continue to deteriorate. We can still counter this with clever, innovative ideas and use the forests for ourselves.

This could also interest you: innovative material straw.


1Deutschlandfunk (25.01.2019)

2Copernikus Klimawandeldienst

3ZDF (20.07.2019) Rekordtemperaturen – In der Arktis brennt es weiter

4IPCC (2019): Climate Change and Land

5BMU (2015):

6ETH Zürich (04.07.2019): Wie Bäume das Klima retten könnten

7Der Standard (06.08.2019): Weltrekord: Äthiopien will bis Oktober vier Milliarden Bäume pflanzen

8Agrarheute (26.04.2019): EU-Kommissar Hogan schlägt Initiativen zur Aufforstung vor

9Welt (06.08.2019): Kranker deutscher Wald. Eine Bestandsaufnahme

10Baumwaldinventur (2012)

11Sonnenseite (21.08.2017): Klimawandel: Fichte vom aussterben bedroht

12Focus (04.06.2012): War das Walsterben nur falscher Öko-Alarm?


14Spektrum (2001): Lexikon der Geographie: Agroforstwirtschaft

15Tecnaro: The Biopolymer Company

16Ellen Mc Arthur Foundation (2017): A New Textiles Economy: Redesignings Fashion Futures

17Forbes (04.06.2018): Can Fashion Be Sustainable?

18Deutschlandfunk (08.11.2009):

19Craig Morris (2006): Zukunftsenergie–Die Wende zum nachhaltigen Energiesystem.


Agrarheute (26.04.2019): EU-Kommissar Hogan schlägt Initiativen zur Aufforstung vor


Agrarheute (01.08.2019): CDU/CSU-Minister fordern 800 Millionen Euro für den Wald


Baumwaldinventur (2012)


Bundesministerium für Umwelt, Naturschutz und nukleare Sicherheit


Copernikus Klimawandeldienst


Craig Morris (2006): Zukunftsenergie–Die Wende zum nachhaltigen Energiesystem.

Heise Zeitschriften Verlag, Hannover 2006, S. 39 ff.

Der Standard (06.08.2019): Weltrekord: Äthiopien will bis Oktober vier Milliarden Bäume pflanzen


Deutschlandfunk 25.01.2019


Ellen Mc Arthur Foundation (2017): A New Textiles Economy: Redesignings Fashion Futures



ETH Zürich (04.07.2019): Wie Bäume das Klima retten könnten


Focus (04.06.2012): War das Walsterben nur falscher Öko-Alarm?


Forbes (04.06.2018): Can Fashion Be Sustainable?


IPCC (2019): Climate Change and landSonnenseite (21.08.2017): Klimawandel: Fichte vom aussterben bedroht

Spektrum (2001): Lexikon der Geographie: Agroforstwirtschaft


Tecnaro: The Biopolymer Company


Vogt (1999): Definition Agroforst


Welt (06.08.2019): Kranker deutscher Wald. Eine Bestandsaufnahme



ZDF (20.07.2019) Rekordtemperaturen – In der Arktis brennt es weiter