Can a forest have too many trees?

Trees, forests and climate protection

Like other plants, trees absorb carbon dioxide from the air and use solar energy and water to convert it first into glucose and later into various other substances.

Trees not only have a variety of functions in the ecosystem, they not only please us humans, they also counteract the greenhouse effect! 1 t wood (dry) has 1.8 t CO2 saved. Depending on the wood moisture and type of wood, 1 m³ of wood contains approx. 0.25 t of carbon, i.e. approx. 0.925 t of CO2 bound.

Forest protection is climate protection

The world's forests (all taken together) are the largest carbon sinks on the mainland. Their fate is closely related to climate change. On the one hand, as sources and sinks of carbon dioxide, they can contribute to the greenhouse effect or to the stabilization of the climate. On the other hand, the health of the forests is also affected by climate change.

Approx. 20-25% of the global CO2-Emissions are due to the destruction of forests - the cutting down of trees and the destruction of the former forest floors. Especially in forests on boggy ground, much more carbon is stored in the soil than in the trees themselves; this is also released in the event of clear-cutting or slash-and-burn.

Year after year, 13 million hectares of forest are currently being destroyed (predominantly tropical and boreal primeval forests) and as a result 6 billion tons of CO2 released. (In addition, the home of the people living there and the habitat of many plants and animals will be destroyed, but that is not the subject of this article.) Even if you offset reforestation and the natural regrowth of forest, the earth still loses over 7 million hectares of forest area every year .

Primeval forests are cut down to obtain wood or land. Wood is used to manufacture wood products such as furniture or construction timber, as well as cellulose, which is then used to make paper, paper tissues and similar products. The "land reclamation" is mainly used for agriculture, the areas are used as arable land or pasture for a few years, ultimately agricultural products such as soy (mainly used as fodder), palm oil (used as a raw material for the chemical industry and as "bioenergy") or beef.

Between 1990 and 2000, around 1.33 million km² of forest were destroyed worldwide. This is shown on the map above, where the size of each country shown stands for the forest area destroyed there. The map below serves as a comparison and shows the countries of the world in an appropriate manner. With the kind permission of

Preserving the existing forests is one of the most important and most efficient contributions to climate protection! Reforestation is only the second-best solution, because it takes centuries or millennia before the soil destroyed by the destruction of forests has regenerated itself and that as much carbon is bound as before the destruction of the primeval forest.

In addition, well-managed forestry can generate additional CO, at least in the medium term2 bind if the wood obtained is used for long-lasting products - e.g. for furniture or in house construction. In this way, 30 million t of CO are generated in Germany every year2 that is about 1/7 of the reduction commitments under the Kyoto Protocol. For the problems of German forestry see below.

Options for action ...

... for students

  • Collecting waste paper and consistently using products made from recycled paper: This is the simplest and at the same time most important possible course of action, because most of the wood is used by students in the form of paper (see page Paper).
  • Plant trees or support corresponding projects with donations or public relations work: The trees will be CO for several decades2 absorb from the air and bind in their biomass. In doing so, indigenous and "site-appropriate" trees should have priority, because they also provide food and shelter for the animal world.
  • Eat meat-free or "organic" more often: Tropical rainforests are being destroyed for beef from Argentina (for pasture areas for cattle) or for cattle fattened in Germany (for soy as fodder). We "reward" this with our purchase - or we opt for a healthy salad or meat from animals that are grown on the pasture at the (organic) farmer's.

... for other areas

  • If possible, wood should be used for high-quality and long-lasting products (and not for disposable products such as paper tissues, exercise books or magazines).
  • Products (e.g. furniture) made from tropical wood should not be bought unless they have the FSC label, which stands for environmentally friendly / sustainable forestry.
  • Residual / waste wood can be used energetically. 1 cubic meter of wood replaces approx. 220 liters of heating oil. Modern wood heating offers almost the same comfort as oil or gas heating.
  • The strategy of using palm oil as "biofuel" on a large scale must be abandoned.

Afforestation is climate protection

The increase in forest areas is currently the only available way of using biological means to CO2 from the atmosphere. Even those who plant only one or only a few trees contribute to climate protection.

Below are two tree-planting campaigns that you and your students can participate in. On the subject of paper you will find a link at the bottom of the page.

The United Nations Billion Trees Campaign

The Billion Trees Campaign of UNEP (United Nations Environment Program) propagates the worldwide tree planting as a contribution to the fight against climate change. The aim of UNEP is that 1,000,000,000 trees are planted worldwide every year (!).

In principle, this applies to everyone, regardless of the context in which they live. Individuals, citizens' groups and municipalities, but also companies and governments can contribute to the campaign within their sphere of influence. You can also support this cause in your schoolyard. Even if you are, for example, "only" an English teacher and can only invest an hour for the time being - then first translate the call for action from Achim Steiner, the Executive Director of UNEP, into German with your class and disseminate it on site (links at Seitenenede ).

In many countries around the world, regional or target group-specific campaigns have been set up that support the Billion Trees campaign. A good contact for your students is the German student initiative "Plant for the Planet", which has set itself the goal of planting 1,000,000 trees.

But there are also comparable initiatives at the "other end" of the world, e.g. "Trees for Survival" in New Zealand (see links at the bottom of the page).

Forest share

Another special campaign that takes account of the same goal is the "forest share" in Mecklenburg-Western Pomerania. The Tourism Association, the Ministry of Agriculture, Environment and Consumer Protection and the State Forestry Administration M-V call on vacationers to buy "forest shares" worth € 10.00 in order to get the additional CO2-Compensate the emissions of your vacation (trips, hotel use). With the income, a good 10 hectares of forest in various parts of the country are to be reforested and maintained (initially). If you want, you can also help with planting on certain dates. An attractive website provides detailed information about the campaign and the resulting forests.

Forest protection ...

Actions for the planting of forests or individual trees are ultimately only remedial environmental protection. The decisive factor is how the (still) existing forests are used or protected.

... in Germany?!

Responsible use of forests - only use as much as grows back - was the starting point of the discussion about sustainable development.

Around 1990 the forest in Germany was still a sink for CO2, i.e. there was more CO2 bound in the form of biomass when it was released through logging and the use of the wood. The wood stocks in the forest rose to approx. 320 m³ per hectare.

However, natural forests contain more than twice as much wood. Forest operations that work close to nature still have stocks of 550 m³ per hectare - and can still "harvest" good yields.

In the years since 2007, there has been heated debate about the future of German forests. The interests of economic use and forest protection collide. In 2005 the federal government (the Ministry of Agriculture) set up a charter for wood, according to which wood consumption should be increased. However, these rates of increase would mean that by 2020 a good 34 million m³ more wood would be consumed than will grow back ("wood gap").

Instead, environmental associations are calling for wood and wood products to be used more sparingly and thus to reduce wood consumption. Forests should be managed naturally, and at least 5% of the forest area should be left uncultivated (currently only around 1%). In addition, they criticize the fact that the game population is far too high and that the browsing hinders the natural regeneration of the forests.

On September 21, 2011 the federal government passed the "Forest Strategy 2020"; a 40% increase in logging is planned ...

... worldwide?!

The protection of the rainforests is a contribution to climate protection. As carbon stores, the tropical forests make an important contribution to maintaining the global climate. But forest protection means more than just securing a CO2Memory, it also ensures the preservation of the diversity of life. Indigenous peoples have saved these ecosystems from destruction through their forms of use, which is why the recognition and respect of their rights makes a direct contribution to the protection of the rainforests.

Climate Alliance sees the inclusion of forests in the global emissions trading system (REDD) as critical, as the generation of further certificates - here for the CO bound in trees and forest soils2 - it enables companies to emit greenhouse gases as before. With the introduction of REDD, the CO2-Reduction targets also softened. The indigenous peoples living in the rainforests fear that REDD will increase the threat to tropical forests. "Market-based climate protection instruments such as REDD have the potential to aggravate the situation of indigenous peoples. Their rights to free, prior and informed consent are difficult to enforce with forest protection and compensation agreements such as REDD, and the pressure on land rights is increasing accordingly," explains Thomas Brose, managing director of the Climate Alliance.

As an alternative, Climate Alliance calls for the heavily forested countries to be supported in developing their own forest strategies and implementing them with efficient control mechanisms. "The establishment and strengthening of indigenous organizations is an important instrument for the recognition of indigenous rights and thus also active rainforest and climate protection", says Silke Lunnebach, consultant for cooperation with indigenous peoples. "This is why Climate Alliance supports indigenous organizations in the Amazon region in South America."

Further measures to protect tropical forests are taking place in Europe: Climate Alliance municipalities undertake to refrain from using tropical timber from overexploitation and the EU has started an initiative against illegal tropical timber (FLEGT). "However, the legal framework that the EU has opted for in the law is inadequate. Legal is what is considered legal in the country of logging. Indigenous rights and conflicts over land rights in tropical countries do not play a role in the EU's considerations," comments Dr . Andreas Kress, advisor for forests and tropical timber in the Climate Alliance. "If the use of tropical wood is necessary, only certified wood with the FSC seal, which also takes social criteria into account, may be used."

Energy forests?

In the course of climate protection, the conversion of the energy supply from fossil to renewable energies plays an important role. Biomass - and also trees - can contribute to this. However, the forests should not be burned in the process.

The following technology was therefore developed under the heading "short rotation plantations": Fast-growing tree species are planted and "harvested" every 2 to 7 years for energetic use. The roots remain in the ground and the trees sprout again. One advantage of the technology is that a lot of energy-rich biomass can be generated with relatively little effort. However, from the point of view of nature conservation, this should not lead to large-scale monocultures either. The NABU is of the opinion that the cultivation of energy wood in comparison to arable crops such as rapeseed or maize an enrichment of nature and
Can represent landscape. NABU has drawn up recommendations for action for short rotation plantations (editorially adapted):

  • Plant in a variety of ways: Blocks with native trees such as hornbeam, ash, alder, hazel, quivering poplar or mountain ash as well as with different autochthonous willow varieties or poplar clones
  • Create irregular and varied structures, e.g. fields of different sizes, gaps in the stock, clearings, different row spacings, also piles of stones or solitary trees
  • Plant energy wood in strips, e.g. at the edges of water or as strips of fields
  • no clear cutting, but harvest different areas of the short rotation plantation in different years
  • In addition, e.g. hang up nesting boxes or set up waiting areas for birds of prey.


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