dogoonsen
Atlantic, rainfall.
In the early Miocene, about sixteen to twelve million years ago, most of the plains on our planet (most of Europe and Asia, virtually all of Africa and both Americas) were covered by an endless tent of lush green forests. But nothing is forever under the moon, and even the continents do not stand still. The climate gradually changed, ice caps grew at the poles, global cooling 'dried up' the territories adjacent to the equator, and the Miocene tropical rain forest gradually shrank. Yet it has survived almost to this day.
The tropical rain forest grows in zones of humid non-seasonal equatorial climate with an average annual temperature of 22-28° (or at least where winter is not below 18°), an annual rainfall of at least 1,500 millimeters and a relative humidity of at least 50%. What does it represent? Some researchers distinguish almost 12 tiers in the vertical structure of rain forests, but it is more like 4-5.
The uppermost tier consists of trees over 30 meters tall, with crowns that don't close up (which is why a tropical rain forest often has such a "jagged" appearance from a distance). The second tier is the real "roof" of the forest, at a height of 25-30 meters. Then comes the layer of low trees (from 10 to 15 meters) and the surface layer with young growth, bushes, etc. There is also an inter-tier vegetation, the most curious representative of which (at least for a European) is lianas.
One of the most characteristic features of the rain forest is its exceptional biotic richness, while the huge variety of fauna is maintained mainly due to the diversity of the flora: the number of tree species only per one hectare of forest reaches a hundred (not to mention lianas, epiphytes and grasses). It is curious that such an amount of biomass usually exists on completely infertile, bare soils, from which all the active substances are washed out. At the same time, there is plenty of fresh organic matter: these are fallen leaves, branches, seeds, fruits, etc. But higher plants cannot "eat" this directly, and they enter into symbiosis with mycorrhizal (living on the roots) fungi - hence the dominant surface root system. Of course, these shallow roots are incapable of anchoring a giant tree in soil (which is, moreover, practically non-existent), so the largest trees grow plank-shaped roots that adhere to the trunk and somewhat resemble rocket stabilizers. Such roots sometimes extend downward from the trunk at a height of several meters, and fall to the ground three to four meters from the main trunk.
The wet Atlantic forest that once covered a large part of the southern American continent has almost completely disappeared, leaving only isolated islands with the total area of barely a hundred thousand hectares. One such islet is a small reserve in eastern Brazil, part of Bahia's Green Gold Project. Photo by ALAMY/PHOTAS
Getting to Brazil is not easy. A three-hour flight to Paris, then more than 10 hours to Rio de Janeiro, another hour and a half to Salvador, the capital of the state of Bahia. However, my three journalist colleagues and I flew even farther, to the tiny town of Ituberu. In fact, the main purpose of our visit to Brazil this time was to visit the gewea plantations and the reserve where they are trying to restore the Atlantic rain forest. The six-seater "mosquito"-airtaxi had been making loops between the low clouds for half an hour and landed on a cleared of vegetation earthen strip, jutting right into the river bed, on which the rushing pirogue was visible from afar. Selva was waiting for us.
