Human dependence on plants
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Bold textHuman and Animal Dependence on Plants Our dependence on green organisms to produce the oxygen in the air we breathe and to remove the carbon dioxide we give off doesn’t stop there. Plants are also the sources of products that are so much a part of human society that we largely take them for granted. We know, of course, that rice, corn, potatoes, and other vegetables are plants ; but all foods, including meat, fish, poultry, eggs, cheese, and milk, to mention just a few, owe their existence to plants. Condiments such as spices and luxuries such as perfumes are produced by plants, as are some dyes, adhesives, digestible surgical stitching fiber, food stabilizers, beverages, and emulsifiers. Our houses are constructed with lumber from trees, which also furnish the cellulose for paper, cardboard, and synthetic fibers. Some of our clothing, camping equipment, bedding, draperies, and other textile goods are made from fibers of many different plant families. Coal is fossilized plant material, and oil probably came from microscopic green organisms or animals that either directly or indirectly were plant consumers. All medicines and drugs at one time came from plants, fungi, or bacteria, and many important ones, including most of the antibiotics, still do.
What of plants and Future?
The population of the earth already has exceeded 6 billion persons,
every one of whom needs food, clothing, and shelter in order to survive. To ensure survival, a majority of us eventually may need to learn not only how to cultivate food plants but also how to use plants in removing pollutants from water , in making land productive again, and in renewing urban areas. In addition, many more of us may need to be involved in helping halt the destruction of plant habitats caused primarily by the huge increase in the number of earth’s inhabitants. Although at present the idea that humanity may not be able to save itself from itself may seem radical, there are a few who have suggested that it might become necessary in the future to emigrate to another planet. If so, microscopic algae could play a vital role in space exploration. Experiments with portable oxygen generators have been in progress for many years. Tanks of water teeming with tiny green algae are taken aboard a spacecraft and installed so that they are exposed to light for at least part of the time. The algae not only produce oxygen, which the spacecraft inhabitants can breathe, but they also utilize the waste carbon dioxide produced by respiration. As the algae multiply, they can be fed to a special kind of shrimp, which, in turn, multiply and become food for the space travelers. Other wastes are recycled by different microscopic organisms. When this self-supporting arrangement, called a closed system, is perfected, the range of spacecraft should greatly increase because heavy oxygen tanks will not be necessary, and the amount of food reserves needed will be reduced. Inhabitants of undeveloped areas still use plants for food, shelter, clothing, and medicine and also in hunting and fishing. Today, small teams of botanists, anthropologists, and medical doctors are interviewing medical practitioners and herbal healers in remote tropical regions and taking notes on various uses of plants by primitive peoples. These scientists are doing so in the hope of preserving at least some plants with potential for modern civilization before disruption of their habitats results in their extinction. What is Biodiversity? 'Bio' means life. Biodiversity is the diversity or variety of life on Earth. In general, Ireland has a rich biodiversity for such a small island. For example, we have about 815 native seed plants (ones that produce seeds); about 1108 other seed plants (aliens) that have made Ireland their home; 584 different mosses, 78 types of fern; 3500 different fungi (mushrooms), 1250 lichens, over 12,000 species of insect (1400 of these moths, 33 types of dragonflies/damselflies and 34 types of butterfly), 28 species of land mammals, over 400 resident birds, one toad, one frog and one lizard. These figures are of species that live here all the year round. There are many animals that pass through Ireland (such as migrant birds), stopping to take a rest, or feed or reproduce. It is important that we preserve this richness by 'minding' the landscape and not just the individual organisms. We must hold on to this biodiversity, but that we try to enrich it. Why is biodiversity important? The richer the variety of life (biodiversity) on Earth, then the greater the chance that life will continue to inhabit the planet into the future. A rich biodiversity will also ensure a greater variety of food and medicine for us. Imagine if we only had one type of cereal, one type of bread, one type of meat, etc. Life would become boring indeed. There is the possibility that malnutrition could become a serious source of disease. Also, biodiversity is important because all living things depend on each other in some way. This dependence is not always obvious. For example, humans have a very fundamental dependence on plants: they produce the oxygen we inhale and in turn plants need the carbon dioxide we exhale. Lastly, plants and animals have a right to exist. Why should humans, the Earth's dominant species, decide what should live and what should die? In other words, there are ethical/moral reasons that biodiversity should be allowed to increase. Many religions promote the idea of biophilia (love of life); while a few believe that biodiversity is there for Man to exploit. What is a Habitat? It is a location that animals inhabit. A freshwater lake is a freshwater habitat. The main types of habitat in Ireland are described in the right column. Plants: their uses for human life Humans have always used plant in one capacity or another. Plants are becoming known more and more for their vital usage in many arenas, including medicinal purposes.
Plants are thought of mostly as growing and thriving in pleasant, sunny atmospheres; but many plants also can be found in areas that do not seen likely in promoting growth. All that is required for growth of plant life is air, sunlight, and soil. In Greenland, the Arctic poppy can be found, rising up out of massive layers of ice. Mountainsides are filled with large, colorful blooms, even when packed in heavy snow. On the other end of the temperate zone, many types of cacti are found in barren deserts that may go for many years with rainfall.
Humans are very dependent upon plant life; without it, all would perish. Plants provide fuel, food, clothing, and even shelter, either directly or indirectly. The dependence upon corn and wheat, major parts of life-giving nutrients, is not in doubt; but without grasses and grains that sustain livestock, which feed and clothe humans, they, too, would perish. USES FOR PLANTS: FOOD The chief food plants in North America are cereal grains. The major types of grain crops include wheat, corn, rice, oats, barley, and rye. Next are legumes, such as peas, beans, soybeans, and peanuts. For centuries, people have used the herbs and spices derived from plants as seasonings for their food. Pepper and nutmeg are two examples of seasonings derived from dried fruit, while others such as sage and rosemary come from leaves. A common baking spice, cinnamon, is found in the stem of the plant. Even beverages come from plant life. By steeping plants in hot water, coffee, tea, and cocoa are produced. Nature makes many other beverages naturally, such as fruit juices, cider, and milk. CLOTHING Much of our clothing comes from the plants found in nature, such as cotton, the foremost fiber used to manufacture clothing. Synthetic fibers, too, such as rayon, are produced from plants; the cellulose required to manufacture the rayon is found in the cell walls of plants. PAPER Papyrus, a grasslike plant, was used more than four thousand years ago in the first endeavor, by Egyptians, to make paper. It is from this plant that paper has derived its name. The Chinese, around 100AD, invented a method of manufacturing paper that is still in use today. The fibers from the plant are placed in water, reduced to but a pulp. After the water has been sieved off, the remaining pulp is pressed, then allowed to dry to yield a very thin sheet of paper. Almost any plant that is found to be high in cellulose is considered excellent for making the pulp which produces paper, the most common today being trees such as aspen and pine varieties. SHELTER In many parts of the world wood is used for creating proper shelter against the elements. Items found in the wooded structures we call home are also made with wood, a plant product. Furniture, for example, is made up mainly of wood and cloth, from the fibers of plants. Walls in homes may be decorated with wallpaper, and many paints are derived from plant extracts. FUEL Green plants, which lived on the Earth very long ago, are the origin for the coal, oil, and gas that humans use for heating and cooking purposes. Compression and heat have converted these plants into fossil fuels. In Ireland, a common fuel is peat, which is formed by the same process as coal. The oldest form of fuel is wood, burned to create heat for warmth and for cooking. MEDICINES In ancient cultures, medicine men used the extracts from plant life to soothe and relieve aches and pains. In the very beginnings of Botany, doctors in both Europe and America researched herbs in their quest to cure disease. Many of the plants that were discovered by ancient civilizations are still in use today. The leaves of willows, which contain a compound very similar to aspirin, were chewed by Native Americans to relieve aches and pains. A major treatment in heart disease is digitalis, which is found in foxglove. The cinchona tree, found in South America, yields from its bark quinine, used to fight malaria. Even today plants are being discovered that yield important and much needed medicines. The periwinkle plant was discovered to have vincristine, a medicine that is effectively used to fight leukemia in children. Many other plants have proven invaluable as sources of vitamins, an important part of growth and proper development. As detailed above, plant life is a very vital part of human life; without plants, both land and sea dwelling, human life could not be sustained. Human dependence on plants
The two principal groups of living organisms are plants and animals. From the very early phase of evolution both the communities have lived together side by side in an intimate association to form the biotic environment or biosphere. In a stable ecosystem the plants and animals form a delicate nutritional interdependence which with minor fluctuations is rebalanced fairly rapidly. In addition to their nutritional interdependence biotic population of an ecosystem have various other types of interdependence like reproduction, protection etc. The various ways of interdependences among the member populations of an ecological community have led to various specializations in structure and function. In a large number of cases such specialization of the population in a community are even more propound, for a community contains not only free living population but also organisms of different species that live together in more or less permanent physical contact. These associations are instances of symbiosis, an expression of the most intimate form of communal life. A brief survey of the interdependence between plants and animals is presented below. Nutritional interdependence
Plants and animals are intimately connected with respect to their nutritional interdependence. Due to the presence of chlorophyll nutritionally plan is art self supporting bodies. They can synthesize complex organic food substances out of water and carbon dioxide gas and utilizing the energy of sunlight. In an ecosystem the green plants act as producers. Animals like grasshopper, bees, squirrels, sheep, goats etc. are nutritionally dependent upon green plants because they depend on continued supplies of ready-made food substances usually from green plant sources for their energy and growth. Green plant eaters are called herbivores. Animals which do not feed directly on plant materials but rather on animals (cat, dog, lions etc.) arc called carnivores. Carnivores are indirectly dependent upon plants for their food and energy, because carnivores eat the herbivores. If there were no plants in an ecosystem there would not be any herbivores left to feed the carnivores. So carnivores would die of starvation. Insectivores or insect feeding plants get their nitrogen from insects. These plants are provided with specialized organs for entrapping and capturing insects. A trapped insect is digested for its proteins by the proteolytic enzymes. Organic wastes and dead remains of animals are decomposed by the soil microbes like bacteria and fungi. They decompose the organic materials into their inorganic constituents. Similarly, the microbial fauna (animals) present in the soil also decompose the dead remains of plant origin. In this way the soil becomes rich in inorganic materials. These inorganic materials are again absorbed by the plants. In this way the inorganic substances rotate in nature.[1] Carbon dioxide-oxygen interdependence
Green plants take in carbon dioxide gas from the air during photosynthesis. Carbon dioxide gas is given out by animals during respiration. Carbon dioxide being an injurious gas it should be removed from the air regularly. Plants do this job and thus purify the air. If the plants had not absorbed carbon dioxide the air would have been poisoned with Carbon dioxide so much so that life would have been impossible on the earth. Plants give out oxygen formed during photosynthesis. This oxygen is the source of oxygen used by animals in their respiration. In this way the carbon dioxide-oxygen balance of air is maintained by the plants.[2] Interdependence in pollination
Many insects like bees, butterflies, ants etc. visit flowers for collecting nectar and pollens. During the process they move from one flower to the other. While moving from one flower to another the sticky pollen grains produced in the male parts of flower adhere on their legs, wings, and antenna. When they visit another flower along with the pollen grains the pollen grains adhere on the sticky surface of stigma (female part). This is an act of transference of pollen grains from male to female flower, a process termed cross pollination. Thus insects help the flowering plants in pollination against nectar, the food of insect.[3] Interdependence in dispersal of seeds and fruits Animals play a vital role in the dispersal of seeds and fruits of flowering plants. The seeds for the purpose of dispersal develop various attachment structures like hooks or sticky hairs. With the help of these structures the seeds get attached on the bodies of visiting animals and are thus carried to distant places. Animals generally eat fruits. When the whole fruits eaten the seeds pass through the alimentary canal unchanged. The seeds are not digested during their passage through the alimentary tract, because they have a slimy covering which protect them from digestive enzymes. The seeds come out through the faeces are still able to germinate. This is how seeds spread out to distant places.[4] Interdependence In relation to aeration and nutrition
Earthworm contributes immensely to the betterment of soil and the healthy growth of crops. The earthworm lives in the soil and feed on decaying vegetation. While in soil it moves here and there for food forming burrows. Thus, the worm loosens the soil particles and forms countless channels inside the soil. These channels are readily tilled up with air making the soil airy. The burrows help quick exit of rain water from the base of the roots, enabling the plants to grow more rapidly. Leaves and other vegetables are consumed by the worm. The faecal matter of the worm adds minerals and humus to the soil and thus increases the fertility and productivity of soil.[5] Interdependence on shelter and defence
Some insects like beetle, wasps, moth etc. protect their offspring by depositing eggs on plant parts and later initiating the formation of a gall around the eggs. Here the female insect first lays its eggs on any soft portion of plant body. The cells around the eggs start dividing and ultimately cover the whole mass of eggs forming a gall. The eggs remain safe within the gall. The development of egg takes place within the gall taking nourishment from the gall. Ultimately immature insects come out of the gall through pores. Beetles live within leaftents during day time to avoid attack by birds. They make the tent with the help of silk thread secreted by their silk glands. At night they come out of the tent and destroy aphides and other plant pests. Sometime ant’s nests are built in underground stems, in hollow stems of trees, thorns, fruits and leaves. In certain aroids having underground corms it is found that some dangerous ants take shelter within the compartments of the corm. These ants protect the corm from man and animals. In a species of South American Acacia, (A. sphaerocephala) the spiny stipules, are hollow and serve as shelters for the ants. Simultaneously the leaflets secret food for the ants which accumulate at the tip of leaflets forming a structure called Belt's corpuscles. The plant keeps ready both food and shelter for the troops of bodyguard. The common Indian apt Oecophylla webs the leaves of mango, litchi, the spesia and other plants into a nest, using the silken threads produced by the larva. This ant ferociously attacks those who intrude into the tree on which it has made its nests. This mutual interdependence of plants and animals for protection against attack by enemies is termed Myrmecophily (G. Myrmeco-ant, philos-love) i.e., love of ants.[6] Symbiosis
The term symbiosis is used to describe a situation when organisms live together and benefit mutually by their association. An example of symbiosis between a plant and an animal is offered by the green Hydra (Chlorohydra vuidissuma). Here the alga Zoochlorella lives in a symbiotic association within the ectodernal cells of the animal Chlorohydra. The alga use car bon dioxide and nitrogenous waste produced by the animal while the animal benefit by the oxygen and carbohydrates produced by the alga during photosynthesis. Similarly, the ciliate Paramaecium bursaria also harbour unicellular green algae within its cells. Bacteria present within the alimentary canal of animals are symbiotic in nature. Bacteria living within the stomach of Cow help to digest the food of Cow. Bacteria living within the large intestine of Rabbit also help food digestion. Bacteria living within the large intestine of man help digestion of waste. They secrete many vitamins (B12K) which helps man in their nutrition. The ant Mycetosoritis hartmani secure their food by growing gardens of a particular fungus in the underground nests. The fungus is nourished by leaves the ants collect, bring underground, and chew into nutrition pulp.[7]
