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Screw Pine Trees |
In the immemorial times, Xishuangbanna was a part of the Ancient Mediterranean; because of the Himalayan orogenic movement in the geological history, the Ancient Mediterranean retreated westward and the place experienced a change from vast seas into yellow earth. But how could we prove what we said above? The witnesses of geological structures and the results from ancient living creature research are the most believable proofs. However, these are all "dead" witnesses, and sometime we cannot make the fact clear to people depending on them.
It is lucky that there are still many varieties of plants that can be used as living witnesses in Xishuangbanna, and the most representing ones are members of the
Rhizophoraceae family, which are still living by the seaside. In the rain forest, there are three members of this family, and they are separately mangrove, feather tree,
Carallia brachiata, and C. Inanceaefolia. In immemorial times, they all lived on the seaside. After the disappearing of the ancient Mediterranean, they did not leave Xishuangbanna. After many years of evolvement, the mangrove evolves into a member of the rain forests.
These three varieties of plants, after long-term adaptation, gradually change their habit of growing on seaside, and adapt themselves to the acid soil, the humid and dark forest environment. Their seeds also change the habits of growing roots when still growing on trees. It might be because reasons of the gene, because, in the lower part of the tree trunks, mangrove trees still have many aerial roots as supporting roots, which preserved their habits of breathing in the shoals.
 
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