Thursday, September 19, 2019

Carnivorous Plants Essay -- essays research papers

Carnivorous Plants In a world where plants are at the bottom of the food-chain, some individual plant species have evolved ways to reverse the order we expect to find in nature. These insectivorous plants, as they are sometimes called, are the predators , rather than the passive prey. Adaptions such as odiferous lures and trapping mechanisms have made it possible for these photosynthesizers to capture, chemically break-down and digest insect prey (and in some cases even small animals.) There is no reason to fear them though. The majority are herbaceous perennials, usually only 4 to 6 inches high, and nothing like the plant in "Little Shop of Horrors". Almost all carnivorous plants have a basically similar ecology and several different species are often found growing almost side by side. They are most likely to be found in swamps, bogs, damp heaths and muddy or sandy shores. Drosophyllum lusitanicum from Portugal and Morocco is the one exception, it grows on dry gravelly hills. Like other green plants, carnivorous plants contain the organic pigment chlorophyll. This pigment helps to mediate a chemical process called photosynthesis. This converts light energy into the chemical bond energy of carbohydrate which is utilized as cellular energy, plant growth and development. Water, carbon dioxide, nutrients and minerals are also needed for survival. In wetlands, where stagnate water contains acidic compounds and chemicals from decaying organic matter many plants have a difficult time obtaining necessary nutrients. It is in these nutrient poor conditions that some plants evolved different ways of obtaining nutrients. The ability of carnivorous plants to digest nitrogen -rich animal protein enables these plants to survive in somewhat hostile environments. The evolution of carnivorous plants is speculative due to the paucity of the fossil record. It is believed that plant carnivory may have evolved millions of years ago from plants whose leaves formed depressions that retained rain water. Small insects would sometimes fall into these water reservoirs and drown, eventually being decomposed by bacteria in the water. The nutrients from the insects would be absorbed by the leaf. The deeper the leaf depression the more insects that could be drowned. This would have creat... ... as frogs and small rodents. Nepenthes are unique amongst carnivorous plants as the only dioecious genus, which means there are separate male and female plants. These plants are very endangered and several species or extinct. Some species of Nepenthes are sold for hundreds of dollars to collectors and are involved in illegal overseas trade. The growing of carnivorous plants has become very popular in recent years. Unfortunately the endangered status of many species does not stop collectors from risking high fines and field collecting them. This has had seriously impact on many species, but collectors are not the biggest problem facing carnivorous plants. In the USA and other developed countries wetlands are considered useless and are being drained and developed on. At present it is estimated that only 3-5% of carnivorous plant habitat remain in the US. Another problem is that fires are put out before they spread even though many plants, such as the Venus fly trap, benefit from periodic burns. Habitat destruction from slash and burn agriculture, however, does not benefit any of the carnivorous plants and is also causing a great deal of the extinctions.

No comments:

Post a Comment

Note: Only a member of this blog may post a comment.