The Lowland Equatorial Monsoon Ecozone
The trees of the Amazon rainforest are much older than anyone previously believed – and some have been growing for at least 1,400 years, new measurements have shown. The finding, a great surprise, has implications for the management of the forest.
Trees in temperate regions can be dated by their rings, but the rings of tropical trees can be non-existent or irregular. So the ages of the trees have been guessed by observing how fast they grow and measuring the girth of the biggest ones. Now Dr. Joshua Schimel, of the University of California at Santa Barbara, has taken a more direct route, carbon-dating 20 trees of 13 species felled near Manaus in Brazil.
He and colleagues report in Nature that most of the trees were 500 to 600 years old, a couple exceeded 1,000 years and one was 1,400 years old. It turns out that growth rates vary greatly from species to species, and even within species depending on the precise conditions. Armed with this knowledge, loggers could leave slower growing species behind to maintain the canopy, harvesting only the faster growing ones.
The Times of London – 26th January 1998
5.10 ANIMAL SPECIES OF THE LEM RAINFOREST
As in all ecosystems, the animals without backbones ('invertebrates') vastly out-number the vertebrates, and of all the groups the Arthropods are most numerous (see 4.7). Populations of micro-arthropods in Nigerian tropical rainforests have been estimated to exceed 38,000 per m2 of surface soil.
One of the most conspicuous Arthropods is the ant, exploiting every level of the ecosystem of the tropical rainforest as individuals and in multitudinous drives, found at every level from deep under ground to the very top of the Silk Cotton Tree. They are extraordinarily active; it has been estimated that ants are responsible for eating 1% of all leaves of the tropical rainforest each year.
Of the vertebrate groups in the LEM natural ecosystem, the reptile and bird species would have been most numerous. The snakes alone will have included tens of species like the Black and Spitting Cobras, the Royal Python, the Puff Adder, and the Green Mamba. Fish would be next most numerous.
As discussed in chapter 2, the importance of mammals are often overstressed but they are nonetheless very meaningful to humans and their loss is significant.
Likely mammals of the LEM rainforest would include the following:
#PRIMATES
| Cercopithecus mona | ('Mona monkey') |
| Cercopithecus erythrogaster | ('White-throated monkey') |
| Cercopithecus nictitans | ('Putty-nosed monkey') |
| Cercocebus spp. | (the 'Mangabeys') |
| Colobus spp. | (the Colobus monkeys) |
| Pan troglodytes | (or Chimpanzee) |
| Perodicticus potto | ('Bosman's potto') |
| Galago demidovii | ('Lesser Bush Baby') |
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