The combination of constant warmth and abundant moisture of the tropical regions demonstrates a successful environment for many plants and animals.

by kapitoshka (student)

Sex and the tropics

The tropical forests have their origins almost 200 million years ago, during the early days of dinosaurs. The continents were huddled together in a giant super-continent called Pangea. Gradually the Pangea started breaking off giving rise to separate continents. Through the process of division and development of the territories the ecosystem also took its course of progression. Thus the forest monkeys that evolved in the old and new worlds, while coming from the same ancient stock and living similar lives are now anatomically quite distinct. Similarly, lemurs survived only on Madagascar, partly because the island had no large predators.

We also examine the evidence that Cactoblastis, cactus moth, has been rather successful in Australia, yet caused so many problems in North America. To capitalise the response we must note that Australia has no native cactus species, and so far the moth has not attacked any other type of plant. In areas where there are other native species of Opuntia, the exotic moth is destructive and unfavourable.

Classes of organisms introduced to regions beyond their original ranges are known to achieve much greater population densities in comparison with their origins. The pending explanation explores the fact of no predators occupying the newly attained territory. Although the motion carries then the introduction of predators and parasites in order to control the species.

Firstly one should reflect carefully on the actually area of the tropics. It is known to be a hot, moist biome found near Earth's equator. The world's largest tropical rainforests are in South America, Africa, and Southeast Asia. The combination of constant warmth and abundant moisture of the tropical regions demonstrates a successful environment for many plants and animals. Tropical rainforests contain the greatest biodiversity in the world. Over 15 million species of plants and animals live within this biome. One should be willing to concede that 7 per cent of the planets land surface contains at least half of all the species that live on the planet. Not only it is classified the epicentre of the world’s biodiversity. It is where the rainforests-the planets largest body of living matter-breathe.

*The hot and humid conditions make tropical rainforests an ideal environment for bacteria and other microorganisms. Because these organisms remain active throughout the year, they quickly decompose matter on the forest floor. In other biomes, such as the deciduous forest, the decomposition of leaf litter adds nutrients to the soil. But in the tropical rainforest, plants grow so fast that they rapidly consume the nutrients from the decomposed leaf litter. As a result, most of the nutrients are contained in the trees and other plants rather than in the soil. Most nutrients that are absorbed into the soil are leached ...

This is a preview of the whole essay

With too much depth and greatness to the area, latitudinal species have not been recognized for nearly a century but only recently have some of these polar equatorial trends have been discussed in any detail.

A few groups, such as marine infauna and fresh water invertebrates, appear not to follow this pattern but many plant and animal taxa display latitudinal gradients.

*Approaches to the study of the diversity gradient have so far been mainly of two types-the method of gross geographical lumping with comparison of the total species lists for a group and the approach by the synechological studies on the smaller scale comparing the diversity of a taxon through many different habitats *

Despite and barrier of insufficient ecological data or perhaps because of it, the notions as to the explanations for the ecological co-existence have produces six hypothesise:

The time theory

The common position if that all communities tend to diversify in time. Moreover the scientists claim general increase in the environment complexity as one proceeds towards the tropics which once again alights the importance and value of the tropical regions.

The theory of spatial heterogeneity

The more heterogenous the physical environment becomes, the more complex and diverse the plant and animal communities supported by the environment

The high variability of sexually-reproduced plants and animals allows species to adapt to changing environmental conditions. Plants can reproduce either sexually (through spores or seeds) or asexually (vegetatively). There is a geographic pattern to plant reproduction: in the temperate zones of the world, cold winters make it difficult for plants to reproduce vegetatively, while in the tropics vegetative reproduction is an option for both wild and cultivated plants. Many tropical cultivars, especially the are propagated vegetatively.

Competition hypothesis

Natural selection takes a greater course when the restriction to food types and habitat requirements are present and one can observe increased importance of competitive interaction.

Although Darwin’s ideas of natural selection remained controversial, for many sceptics the confirmation of his theories came only with the strange story of the comet orchid, the native of Madagascar. The orchid produces white waxy flowers that attract pollinating insects with a fragrance that is especially seductive after dark; but any insect alighting on the flower in the forest night will have great trouble finding its nectar, because it is hidden deep onside a narrow tube roughly 30 centimetres long.

For this orchid to be pollinated it required an insect with an extremely long proboscis, many times the length of its body. Another forty years later, in the depth of Madagascar jungle, a subspecies of the Morgan’s sphinx moth was found with just such tongue.

The predation hypothesis considers that there are more predators in the tropics and they hold down individual prey populations enough to lower the level of competition among them. This lowered level of competition then allows the addition and co-excistance of new intermediate prey types which in turn support new predators in the system.

Advanced tracking techniques such as molecular markers allow the scientist and study organism’s location, physiology, feeding and social behaviours hence that we able to closely observe the competition and predation factors.

The theory of climatic stability

Regions with stable climates allow the evolution of finer specializations and adaptations that do the areas of more erratic climate regimes, because of the relative constancy of resources.

Productivity stability

The energetic cost of maintenance of the habitat should be examined, followed by the study of the energy left for growth and reproduction of given habitat. Indeed, it is reasonable to expect greater production results in greater diversity and everything else being equal.

With the six hypotheses being drawn individually one should not escape the idea of the several of these mechanisms operating simultaneously. Furthermore, it would be futile if they did not.

The rainforests are priceless to the planets biodiversity, to science and to our profound sense of wonder about nature-

The Amazon manatee, a remote relative of the whale, is the largest of the animals that live in the greatest rainforest on Earth. This denizen of the flooded forests on the Rio Negro, was like the great whale, hunted almost to extinction in the mid 20th century to provide oil boiled down from its blubber.

Curare is one of the most potent and famous jungle poisons. The French scientist Charles Marie de la Condamine first spotted it in the use among Amazon Indians in the mid 18th century. Soon after it was discovered that it is in fact a mixture of chemicals prepared from the deadly bark of several trees, with snake venom and poisonous ants sometimes added for extra potency. Curare causes death by paralysing muscles until the animal stops breathing

The clove and nutmeg tree were found on the slopes of volcanoes and gave the name to the area-spice islands

It is one of the dogmas of the day that world would had a great amount of gain from protecting the rainforest.

For some the tropics are a biochemical laboratory of the stupendous potential. While today’s laboratories can synthesize new molecules at a pace unimaginable a few decades ago, nature provides the optimum starting points. The secrets of rainforests species offer a vast pharmacy of potentially extremely valuable chemicals.

For the sake of the species richness, diversity and evolution we must preserve biodiversity by protecting habitats from exploitation or degradation for there is much more yet to be discovered.

References: