When thinking about biodiversity loss, imagine a natural forest. It has a rich variety of trees, shrubs, grasses, mosses, lichens, fungi, animals, and microbes. It’s a highly complex ecosystem which provides many “services”, including those well-known, such as the prevention of soil erosion, the production of oxygen, and the trapping of the greenhouse gas, carbon dioxide. Because of its diversity, a natural forest is resilient. It can bounce back from the onslaught of many destructive factors.
Now imagine that a timber company clears it. It’s logged off, and most of the remaining vegetation (shrubs, etc.) is burned or otherwise removed. Then, in place of the previous forest, trees are re-planted on what essentially is now a timber company “plantation”. Usually, only one or two species are grown. Undergrowth (mostly shrubs) is kept to a minimum, or eliminated completely. In other words, biodiversity has been greatly reduced. In addition, pesticides often are used. Some portion of them find their way into the soil, where they negatively impact any number of necessary soil microbes and fungi. This is a bare bones description of how “forest monoculture” operates.
Which of the two forests – the original, or the monoculture “plantation” – do you think will be more resilient? Which one will shelter and nourish a wider variety of organisms? Which will contribute more to soil fertility? [Artificial fertilizers generally are not good for soil microbes or soil structure. They, along with herbicides and other pesticides, commonly are used on tree plantations.] Which one will better prevent soil erosion? Which one will better resist tree-boring or leaf-eating beetles (which are usually specific to each species of tree)? You get the idea.
Consider, too, the following. Humans cut down (worldwide) an estimated fifteen billion trees per year, and re-plant only five billion. About half the forests which once covered almost half Earth’s land surface are now gone. Only approximately one-fifth of our planet’s old growth forests remain undisturbed and in pristine condition. In general and globally, we simply are not sustainably managing a crucial natural resource.
Forests have been called the “lungs” of the world. Luckily for us, they work differently than do animal lungs. Trees take in CO2 and “breathe” out O2. It’s usually easy to take adequate oxygen for granted, but we really shouldn’t. All green plants should be fully appreciated and valued as absolutely necessary to life on Earth. [A possible exception to that would be noxious weeds, such as various thistles & mesquites – both of which are injurious – and poisonous/deadly nightshade.] Arguably, trees should be at the top of the list of green plants to be revered. If for no other other reason, because they provide us with oxygen and are necessary carbon “sinks” (and that’s critical to the climate problem). It has been estimated that deforestation accounts for approximately 20% of the increase in atmospheric carbon dioxide.
