If we destroy them, we destroy ourselves!”) Destroying the world’s forests would indeed be catastrophic, but it would not result in our suffocating. Of course, the forests of the world provide far more benefits than just capturing carbon — and the wholesale destruction of forests does far more harm than just releasing carbon dioxide into the atmosphere. This can lead to the misconception that the extracted CO2 is completely destroyed. Some of the biomass is underground, including tree roots, fungus, other microorganisms, and the myriad little critters that live in the soil. However, a very high percentage of the sugar is simply converted into cellulose — or in the case of woody plants, cellulose and lignin. Some of these compounds, such as starches and fats, require nothing more than the atoms already present in sugar — carbon, hydrogen, and oxygen. Once the forest is mature, trees die and as they die they give back the carbon they sequestered. What is true is that a tree contains a large quantity of carbon-based compounds. 4. However, the first three models all have serious weaknesses — including a failure to address the reason that plants absorb carbon dioxide, and a tendency to produce scientific misconceptions. 2. We have now examined six popular mental models that attempt to explain the relationship between trees and carbon dioxide — each model consistent with the basic concept that trees remove carbon dioxide from the air: 1. 6. Without trees dying you can’t have new growth in trees – in a mature forest. Furthermore, that causes the trees to die off. This can be expressed, for example, as tons of biomass per acre (or in metric tons per hectare). Another weakness, common to all of the first three models, is the implication that trees are the only green plants that remove carbon dioxide from the air. Like Model 1, this model is very easy to understand — which is certainly an advantage. Inter state form of sales tax income tax? In fact there are two distinct transport systems. This mental model equates forests — especially tropical forests — to a set of lungs, allowing the planet to “breathe”. All Rights Reserved. Biomass is any material that consists either of living tissue, or tissue that had once been living. How will understanding of attitudes and predisposition enhance teaching? A surprisingly wide range of compounds are produced, including starches, fats, proteins, and many other classes of molecules. On this basis then, trees are just a temporary store. This model usually mentions that oxygen is given off as a waste product of photosynthesis. There are two such former sinks: 1) Our fossil fuel reserves — oil, gas, and coal — are the remnants of ancient swamps in which large amounts of plant material accumulated without decomposing. When trees die do they release stored up carbon dioxide? Therefore vegetation, soil, and oceans are the three major carbon sinks — but each is capable of returning carbon dioxide to the atmosphere, depending upon current conditions. 2) This model avoids the question of “Why do trees do this? Even though Model 2 is better than Model 1, it still has several weaknesses: 1) Like Model 1, this model avoids the question of “Why do trees do this? Model 5 — Green plants create biomass; animals and decomposers break it down. There are extensive areas of peatlands in the world, where the density of carbon storage is as great as in tropical forests. The underlying idea is that trees constantly absorb and store CO2. But at night the opposite happens — oxygen enters through the pores, and carbon dioxide escapes — a phenomenon that Model 3 does not explain, or even acknowledge. Despite the helpful emphasis on gas exchange, this model has several weaknesses: 1) Like Models 1 and 2, this model (in its simplest, most common form) avoids the question of “Why do trees do this? This concept has recently grown quite popular — because forests help offset some of the human-caused increase in atmospheric carbon dioxide. If we can slow down or reverse the worldwide reduction in the number of trees, then this will help to slow the increase in atmospheric CO2. Fire races through a forest, burning the dead forest litter — and in the case of a crown fire, then also consuming parts of living trees. The first three models listed below are the simplest — which makes them quite popular — but they are also the mostly likely to lead to scientific misconceptions. And second, destroying a forest tends to release a lot of carbon dioxide into the atmosphere in a short period of time. First, there are fewer trees to remove carbon dioxide from the air. The ocean is also a major carbon sink, because carbon dioxide is soluble in water. However, a tree does not actually store most of those organic molecules — at least not in the popular sense of the word “store”, which implies that unused material has been set aside for possible later use. In fact there are several mechanisms by which carbon dioxide is returned to the air even while the tree is alive — including the metabolism of sugars by plant cells, and the annual shedding of leaves by deciduous trees. What’s in it for the trees?” This oversight sharply limits the value of the model — because answering this question opens the door to several important insights about the relationship between trees and CO2. It’s not hard to find wacky ideas about science on the internet — bizarre concepts that stand out because they are so far removed from reality. 4) This model diverts much of the attention away from the reduction of atmospheric carbon dioxide, shifting the attention to the production of oxygen. And a third advantage is the implication that carbon dioxide will return to the atmosphere if the tree is destroyed. Is evaporated milk the same thing as condensed milk? One system moves sugar water down from the leaves to the roots, and the other system moves mineral water up from the roots to the leaves. Every living cell needs energy to survive — and for most plant and animals cells, this energy is delivered as sugar. However, if you consider the organic carbon stored in soils, then the picture becomes more complicated. But what does it really mean when we say “trees absorb carbon dioxide”? Instead, the sugar is converted into other organic compounds that are useful to the plant. What is the birthday of carmelita divinagracia? The key point here is that in a typical ecosystem, such as a forest or grassland, all of the biomass is originally created by plants. 3) This model implies that any carbon dioxide “absorbed” by the tree remains locked away until the tree dies. Unlike some of the other models, this model offers no explanation as to what happens to the CO2 that has been removed. But if a forest has the equivalent of lungs, then where are these lungs? In fact, some non-forest ecosystems — such as peat bogs — are extremely good at removing carbon dioxide from the air. But the rest of the biomass consists almost entirely of energy-rich carbon-based compounds. When combined, these last three models can provide a powerful understanding of the relationship between trees and carbon dioxide. Both of these processes result in a steady rain of calcium carbonate settling to the bottom of the ocean, forming thick layers of marl that eventually become limestone and related rocks. However, when the sun is shining, the chloroplasts in the leaves and other green surfaces do just the opposite — and they do it at a much faster rate. Each of the six mental models provides a concise — but different — explanation of what this phrase means. 3) Furthermore, by failing to explain what happens to the carbon, this model can promote the misconception that carbon dioxide is completely eliminated by conversion to oxygen. However, because the lung model is clearly a metaphor, it is easy to understand that trees do the opposite of what animal lungs do. Model 6 — The forests of the world are a huge carbon sink. By using the term “mental model”, we can focus on what happens in the mind of a person who learns and interprets a concept. The upshot is that every cell in a plant constantly consumes oxygen and gives off carbon dioxide — just as animal cells do. (Decomposer organisms play a key role, consuming some of the stored energy while breaking down the organic compounds.). When decomposers eat up those sugars, they release the carbon i, When trees die do they release stored up carbon dioxide. How long does it take to cook a 23 pound turkey in an oven? Trees absorb and store carbon dioxide. In fact, worldwide there is more organic carbon in the top meter of soil than in all the above-ground biomass, including tropical forests.