The more solar energy and water, the more biomass. A greater amount of light and heat and water enable a greater primary production (npp). That is why most of the world’s forests and biomass are in the tropics, where it is bright and warm all year round and it rains a lot. Tropical forests have been calculated to contain up to 70% of the global biomass. Similarly, most of the biodiversity, 75%, is concentrated in tropical forests.
Net primary production means how much new biomass, or more precisely phytomass, plants produce per year in a certain area. In the tropics, the net basic production is about 2-3.5 kg/m2 and in the northern coniferous forests, on average, 0.4-1 kg. In the tundra and desert, only about 0.01-0.4 kg. This is only the amount of carbon, otherwise the biomass is double due to water and other weight. 600 Gt of carbon is bound in the entire biosphere, of which about 80%, or 450 Gt, is phytomass, i.e. plant biomass, and about 90% of this is in forests, most of it in trees. Forests cover only 30% of the Earth’s land surface. Tropical forests cover about 10 million m2 or 10% of the earth’s land surface, only about 3% of the entire earth’s surface. The biosphere sequesters around 60-70 Gt of carbon per year, of which the seas account for only 5 Gt and most of it is the result of carbon sequestration by forests. The carbon sink of tropical forests is about 40%, 25-30 Gt.
From this we can see how enormously important a carbon sink tropical forests are. The biomass of the northern forests is up to 10% of the global biomass and their area is up to 14 million m2. A boreal forest grows large over time, much more slowly than a tropical forest. Growth is slowed down by the cold and dark winter. However, their biomass gradually increases and they are a very important global carbon store. Boreal forests are an area of intensive forestry and their carbon stock and biomass have been reduced by half due to forestry and oil and gas drilling etc. Old-growth forests over 300 years old have decreased considerably: in southern Finland, for example, there are less than 1% of old-growth forests left. Just a few centuries ago, half of the area of southern Finland was covered with old-growth forests. Finland’s forests are no longer a carbon sink, but a source of carbon, according to the Finnish Natural Resource Agency. The main reason is clear-cutting and the fact that forests are converted into paper, cardboard and other short-term products, from which the carbon soon returns to the atmosphere.
The bioeconomy, where the forest is used intensively, is a mistake. The boreal forest cut down after clear-cutting is a source of carbon for 30 years, even if the forest grows a little. This is because wind and rain carry carbon from the soil with them. The carbon in the soil is a much larger carbon store than even the forest. The forest always binds more carbon to the soil when rotting wood, leaves and needles become soil. A forest does not need felling to be a carbon sink. When a forest ages, its carbon sequestration never stops. For example, the University of Helsinki has a lot of research on the subject. Old forests bind carbon indefinitely, because they too always have new growing trees replacing the dead ones, and above all, in old forests, new soil is constantly created, in which carbon is bound from decaying biomass. The best way to increase carbon sinks and stores is to protect forests.
About 75% of the world’s species are endemic to tropical forests. Up to 2/3 of the world’s flowering plants live in rainforests. An endemic species means a species that occurs only and only in a certain place, for example only in a certain cloud forest on a mountainside. When rainforests are destroyed, a huge number of endemic species disappear. Even small logging can destroy numerous rare species. Natural cover and species cover are the worst in tropical forests. In Brazil, right-wing populist President Bolsonaro’s extractive policy, which aims to aggressively seize pastures and fields and exploit natural resources, was extremely damaging. The same has been seen in many other countries. Exactivist and colonial exploitation of natural resources have led to great destruction. In Africa and Asia, the main reason for the loss of rainforests is often the collection of firewood and the clearing of fields and pastures, also the mining industry and oil drilling. In Indonesia, the main reason is the lack of oil palm plantations. In South America, in addition to the clearing of grazing land, the biggest threat is logging, most of which is illegal. In the tropics, the forest is often lost permanently when the thin soil is washed away by the rains. What remains is a laterite desert. 37,000 km2 of rainforests are lost every year, i.e. an area almost the size of Estonia. In ten years, an area of rainforest the size of Finland or Germany will disappear. This is alarming. At this rate, all rainforests will have disappeared completely in 250 years.
Even in Finland, logging is currently often extractive, and in the Saami region, and also in other ways, one can talk about colonialism when a large forest company comes and cuts down the nearby forests beloved by the villagers. The amount of deforestation in Finland has doubled in a couple of decades. At the same time, the biodiversity of the forests has weakened and the biomass has decreased. Although we have a lot of forest in terms of surface area, 70%, most of our forests are young and poor in terms of diversity. Germany and France have less than a third of the forest in terms of area, but they have more forest than Finland measured in cubic meters of wood. The reason is that they have a lot of old forest. In Finland, the old forests have mostly been cut down, with the exception of Northern Lapland. Biodiversity and especially the number of individuals of many species have fallen sharply downwards: sedges have halved, as have blueberries, in a few decades. About 10% of the forests species are endangered.
A prosperous and healthy forest is a diverse, mosaic-like patchwork of different habitat types, different ages and layers. There are trees of all ages and lots of dead rotting wood. A diverse forest is more resilient to external threats such as storms, wildfires, and insect invasions because of its high levels of connectivity, symbiosis, and interaction. The forest works as a system and as a whole. In 2016, it was even proven that the strong trees in the forest help the weaker ones by giving them sugars via symbiotic mycorrhizal fungi. It has also been observed that trees warn each other about pests etc. In Finland and many other countries with intensive forestry, the vast majority of forests are no longer like this, but more or less tree-like. The only function of the wood field is to produce wood cubes for the needs of the forest industry. Biodiversity and the ecosystem services that depend on it are collapsing. Forests, e.g. clean the air of impurities, produce oxygen, bind carbon, cool the climate in many ways, e.g. by evaporating water, participate in the water cycle, purify water, prevent floods, provide nests and eco-chambers for pollinators, birds and other animals, enable tourism and provide mushrooms and berries…
Ecosystem services are directly proportional to biodiversity, and the destruction of the forest therefore backfires on humans, also financially. The short-sighted pursuit of profits is neither sustainable nor financially profitable in the long term. The value of ecosystem services is billions of euros. When ecological capital is consumed, it can no longer be converted into economic capital and profits. The most reasonable and sustainable forestry would be the method of continuous cover forestry and focus on wood construction and carpentry products instead of bulk and pulp. In the method of continuous cover forestry, the focus is on the functionality of ecosystem services and only big trees are felled here and there. With a time span of 40 years (or more), this is also the most economically profitable when measuring the number of wooden cubes.
When the forest is healthy, people also benefit the most. Unsustainable forestry is sawing one’s own branch from under oneself. Forests and especially trees play a key role in climate work both as carbon sinks and stores, but also in adapting to a changing climate, for example preventing floods and cooling the air temperature. Forests and trees are protectors of the world, like elves from The Lord of the Rings.
Daniel Elkama
More on the subject
https://www.worldwildlife.org/threats/deforestation-and-forest-degradation
Ecoblogi - A Blog by Daniel Elkama 
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