Now that we’ve introduced the brain, let’s talk about intelligence or, more specifically, what makes you intelligent. Intelligence is a difficult term to define. It can mean different things to different people. In fact, the scientific community has been debating its meaning for a long time and there is still controversy over its exact definition and the ways to measure it. The “IQ” test was once regarded as the best way to measure intelligence.
However, there is now a general awareness of its shortcomings, namely, that it only tests specific branches of intelligence (see opposite). The important thing to bear in mind is that being intelligent is not only about excelling in a narrow academic field, or having a broad general knowledge, or even being good at spelling or math. All those things require a degree of intelligence but do not define intelligence. Rather, intelligence reflects a broader and deeper aptitude for understanding multiple things in one’s surroundings, for catching on, making sense of things, or figuring out what to do in any given circumstance. It’s about possessing the ability to analyze and evaluate, to imagine and invent, and, in practical terms, being able to apply and implement ideas successfully.
Source of Information : BRAIN TRAINING BOOST MEMORY, MAXIMIZE MENTAL AGILITY, & AWAKEN YOUR INNER GENIUS
2012年3月31日
2012年3月27日
What are neurons?
Neurons are the cells in the nervous system that transmit information by electrochemical signaling. They are the core components of the brain and the spinal cord. Specialized types of neurons, including sensory neurons and motor neurons, allow us to feel and act respectively. All neurons respond to stimuli, and communicate the presence of stimuli to the central nervous system, and then to the relevant part of the brain, which processes the information and sends responses to other parts of the body for action. Each neuron is connected to approximately 10,000 others by frondlike tendrils. The dendrites are the “receivers,” and axons, the “transmitters.” The neurons are not actually joined together but touch each other. When neurons communicate, the gaps at the touch points are filled with with neurotransmitters, chemicals that carry pulses or “electrical messages.” The myelin sheath acts as an insulator and increases the speed and efficiency of the pulses.
Source of Information : BRAIN TRAINING BOOST MEMORY, MAXIMIZE MENTAL AGILITY, & AWAKEN YOUR INNER GENIUS
Source of Information : BRAIN TRAINING BOOST MEMORY, MAXIMIZE MENTAL AGILITY, & AWAKEN YOUR INNER GENIUS
2012年3月23日
The limbic system
Inside the ridges and grooves of each hemisphere lie a set of structures forming what is known as the limbic system. This system includes the amygdala, hypothalamus, thalamus, and hippocampus. These parts activate our emotions, appetites, instincts, pain and pleasure sensations, and other drives that are essential to survival. The amygdala
activates emotional responses, such as fear or euphoria, while the hypothalamus is the control center for brain-to-body, body-to-brain messages, causing, for example, blood pressure to rise when we are agitated. The thalamus receives auditory and visual sensory signals and relays them to the outer layer of the brain, known as the cerebral cortex, where the information is processed. The hippocampus is critical to learning and remembering spatial layouts. At the very back of the brain lies the cerebellum, which handles movement and balance and, along with the brain stem, is the part of the brain that evolved first, inherited from our primeval ancestors. It keeps us alive by controlling our involuntary body functions, including breathing and digestion.
Source of Information : BRAIN TRAINING BOOST MEMORY, MAXIMIZE MENTAL AGILITY, & AWAKEN YOUR INNER GENIUS
activates emotional responses, such as fear or euphoria, while the hypothalamus is the control center for brain-to-body, body-to-brain messages, causing, for example, blood pressure to rise when we are agitated. The thalamus receives auditory and visual sensory signals and relays them to the outer layer of the brain, known as the cerebral cortex, where the information is processed. The hippocampus is critical to learning and remembering spatial layouts. At the very back of the brain lies the cerebellum, which handles movement and balance and, along with the brain stem, is the part of the brain that evolved first, inherited from our primeval ancestors. It keeps us alive by controlling our involuntary body functions, including breathing and digestion.
Source of Information : BRAIN TRAINING BOOST MEMORY, MAXIMIZE MENTAL AGILITY, & AWAKEN YOUR INNER GENIUS
2012年3月19日
Brain power
Your brain is the most sophisticated object in the known universe. Millions of messages
are speeding through your nervous system at any given moment, enabling your brain to receive, process, and store information, and to send instructions all over the body.
Your brain is capable of so much more than you might give it credit for. Just take a moment to consider all the things made by human beings. From the earliest tool, such as
a pickax, to the modern skyscraper, and from the largest dam to the smallest microchip—the human brain is where all of these objects were first conceived. Undoubtedly, the brain is the most powerful tool at mankind’s disposal.
Your brain works around the clock. It generates more electrical impulses each day than all the mobile phones in the world. You have billions of tiny brain nerve cells interacting with each other in permutations that have been estimated to equal 1 with 800 zeros behind it. (To make that remotely graspable, the number of atoms in the world—one of the smallest material things we can get a fix on— is estimated to be 1.33 with 48 zeros after it.)
Your brain runs on less power than your refrigerator light. That’s about 12 watts of power. During the course of a day your brain uses the amount of energy contained in a small chocolate bar, around 230 calories. Even though these facts might make the brain sound efficient, in relative terms, it is an energy hog. Your brain accounts for merely 2 percent of the body’s weight, but consumes 20 percent of the body’s total energy. Your brain requires a tenth of a calorie per minute merely to survive. Your brain consumes energy at ten times the rate of the rest of the body per gram of tissue. The majority of this energy goes into maintenance of the brain.
Source of Information : BRAIN TRAINING BOOST MEMORY, MAXIMIZE MENTAL AGILITY, & AWAKEN YOUR INNER GENIUS
are speeding through your nervous system at any given moment, enabling your brain to receive, process, and store information, and to send instructions all over the body.
Your brain is capable of so much more than you might give it credit for. Just take a moment to consider all the things made by human beings. From the earliest tool, such as
a pickax, to the modern skyscraper, and from the largest dam to the smallest microchip—the human brain is where all of these objects were first conceived. Undoubtedly, the brain is the most powerful tool at mankind’s disposal.
Your brain works around the clock. It generates more electrical impulses each day than all the mobile phones in the world. You have billions of tiny brain nerve cells interacting with each other in permutations that have been estimated to equal 1 with 800 zeros behind it. (To make that remotely graspable, the number of atoms in the world—one of the smallest material things we can get a fix on— is estimated to be 1.33 with 48 zeros after it.)
Your brain runs on less power than your refrigerator light. That’s about 12 watts of power. During the course of a day your brain uses the amount of energy contained in a small chocolate bar, around 230 calories. Even though these facts might make the brain sound efficient, in relative terms, it is an energy hog. Your brain accounts for merely 2 percent of the body’s weight, but consumes 20 percent of the body’s total energy. Your brain requires a tenth of a calorie per minute merely to survive. Your brain consumes energy at ten times the rate of the rest of the body per gram of tissue. The majority of this energy goes into maintenance of the brain.
Source of Information : BRAIN TRAINING BOOST MEMORY, MAXIMIZE MENTAL AGILITY, & AWAKEN YOUR INNER GENIUS
2012年3月17日
Lake Chad Is Shrinking
Lake Chad lies next to the Sahara in western Africa. This shallow lake (16–26 feet; 5–8 m) has been shown in air surveys and satellite imagery to expand and shrink with intermittent droughts that occur in the region. Since 1960, however, Lake Chad has not followed this pattern; rather the lake has shrunk to one-tenth of its normal size. Villagers from countries bordering Lake Chad—Nigeria, Chad, Cameroon, and Niger—have
relied on the lake’s fish for generations, but the steady downward trend spells disaster for an area of the world already burdened by hunger and water stress. One resident told the BBC in 2006, “Survival becomes a real problem here because we have no means of other livelihood. We solely depend on the water, and when there’s not enough we have a serious problem.” Bata Ndahi, director of Nigeria’s Lake Chad Research Institute, added, “The water is moving farther and farther away. We believe desertification has contributed most to the demise of Lake Chad.” The villagers who once depended on fish cannot reach the water, so they have turned the exposed land over to planting crops that do not supply enough protein for the human diet.
The Lake Chad Basin Commission (LCBC) now includes representatives from the four bordering countries plus the Central African Republic to devise ways to save Lake Chad. The ambitious program intends to return the 373,360-square-mile (967,000-km2) area to near its former size by starting new types of water management, shoreline care, water efficiency in the surrounding cities, and by studying an aquifer that has potential to supply water during drought. The LCBC realizes that desertification has made Lake Chad’s future questionable, but years of water inefficiencies and damming rather than drought may have caused the worst abuse to the lake. LCBC director Wakil Bakar told the BBC, “It’s going to be a massive project, but the end result is what we’re after. This lake has to be saved. We know the benefit. We know how people have suffered. All the countries—Chad, Niger, Cameroon, Nigeria—we know what we have lost. It’s going to
be a huge benefit to all of us.” The Lake Chad restoration project therefore faces dual challenges: restoring a severely damaged ecosystem and returning a healthy water system to an area decimated by desertification.
The LCBC’s plans have not yet saved Lake Chad. Little progress has been made in stopping the lake from disappearing, and the region struggles with poverty, food, and water conflicts, and wars in neighboring countries. In 2008 Nigerian President Umaru Yar’Adua expressed his concern to the Voice of America: “Over the next four decades, it is projected that the present population of 30 million will increase by almost 100 percent, resulting in 30 to 50 percent more water drawn. . . . Already the region is water-stressed. Unless urgent action is taken, the situation could escalate to crisis proportions, further diminishing Lake Chad’s capacity to be of value to those whose livelihood depends on it.” Unless the LCBC project succeeds, Lake Chad may become one of history’s worst victims of drought and desertification.
Lake Chad has not yet disappeared forever, and the LCBC’s plan still has a chance to work. The plan contains the following main directives: (1) establish coordination among national agencies that work on the project; (2) strengthen regional policies on water use; (3) recruit local communities by providing incentives and education; (4) develop water conservation methods; and (5) solicit funds from donors. These objectives are general and contain no specific details on how water conservation will be implemented in the area or how a water system infrastructure will be built. Without these details and quick action, Lake Chad’s future remains very much in doubt.
Source of Information : Green Technology Conservation Protecting Our Plant Resources
relied on the lake’s fish for generations, but the steady downward trend spells disaster for an area of the world already burdened by hunger and water stress. One resident told the BBC in 2006, “Survival becomes a real problem here because we have no means of other livelihood. We solely depend on the water, and when there’s not enough we have a serious problem.” Bata Ndahi, director of Nigeria’s Lake Chad Research Institute, added, “The water is moving farther and farther away. We believe desertification has contributed most to the demise of Lake Chad.” The villagers who once depended on fish cannot reach the water, so they have turned the exposed land over to planting crops that do not supply enough protein for the human diet.
The Lake Chad Basin Commission (LCBC) now includes representatives from the four bordering countries plus the Central African Republic to devise ways to save Lake Chad. The ambitious program intends to return the 373,360-square-mile (967,000-km2) area to near its former size by starting new types of water management, shoreline care, water efficiency in the surrounding cities, and by studying an aquifer that has potential to supply water during drought. The LCBC realizes that desertification has made Lake Chad’s future questionable, but years of water inefficiencies and damming rather than drought may have caused the worst abuse to the lake. LCBC director Wakil Bakar told the BBC, “It’s going to be a massive project, but the end result is what we’re after. This lake has to be saved. We know the benefit. We know how people have suffered. All the countries—Chad, Niger, Cameroon, Nigeria—we know what we have lost. It’s going to
be a huge benefit to all of us.” The Lake Chad restoration project therefore faces dual challenges: restoring a severely damaged ecosystem and returning a healthy water system to an area decimated by desertification.
The LCBC’s plans have not yet saved Lake Chad. Little progress has been made in stopping the lake from disappearing, and the region struggles with poverty, food, and water conflicts, and wars in neighboring countries. In 2008 Nigerian President Umaru Yar’Adua expressed his concern to the Voice of America: “Over the next four decades, it is projected that the present population of 30 million will increase by almost 100 percent, resulting in 30 to 50 percent more water drawn. . . . Already the region is water-stressed. Unless urgent action is taken, the situation could escalate to crisis proportions, further diminishing Lake Chad’s capacity to be of value to those whose livelihood depends on it.” Unless the LCBC project succeeds, Lake Chad may become one of history’s worst victims of drought and desertification.
Lake Chad has not yet disappeared forever, and the LCBC’s plan still has a chance to work. The plan contains the following main directives: (1) establish coordination among national agencies that work on the project; (2) strengthen regional policies on water use; (3) recruit local communities by providing incentives and education; (4) develop water conservation methods; and (5) solicit funds from donors. These objectives are general and contain no specific details on how water conservation will be implemented in the area or how a water system infrastructure will be built. Without these details and quick action, Lake Chad’s future remains very much in doubt.
Source of Information : Green Technology Conservation Protecting Our Plant Resources
2012年3月14日
Conservation Farming
Conservation agriculture, or conservation farming, resembles sustainable agriculture because it follows principles that conserve natural resources and minimizes the ecological footprint of raising crops or food animals. An ecological footprint is the amount of land and water needed to provide a population with resources to sustain life and dispose of wastes.
Conservation farming today includes four main aspects that work together to reduce ecological footprint: water conservation, soil conservation, efficient tilling methods, and low environmental-impact fertilization methods. Sustainable agriculture may be considered to be stricter than conservation farming with respect to ecological footprint because, unlike sustainable methods, conservation farming accepts the following:
» meat production
» some water-inefficient crops
» monoculture
» seasonal crops
» use of prime cropland
» some use of pesticides and herbicides
Conservation farming aims to convert traditional inefficient food production methods into methods that are both sustainable and efficient. For instance, traditional farming of 20 to 50 years ago often included the following characteristics: several passes over the fields with tilling equipment before sowing seeds; preemptory weed control with heavy doses of herbicide; fertilizer use at inefficient levels; and acceptance of any crop yields. Today conservation farming uses more efficient tillage and soil conservation methods. In the 1970s farmers cultivated their soils at least four times and often as 10 times before planting. Conservation farmers have found this overcultivation to be unnecessary, not to mention a waste of manpower, fuel, equipment, and soil. In weed control, conservation farming borrows from sustainable methods by using ground cover plants and natural methods (birds, small mammals) to combat weed growth.
Conservation farming uses both organic and inorganic fertilizers to return nutrients to the soil between each growing season. Organic fertilizers come from plant or animal materials such as manure. Green manure consists of cut crops that are plowed back into the soil to replenish some nutrients for the next crop. Green manure also includes compost, which is decomposed plant material that has been broken down by microbes on a site away from the fields, and may then be applied to fields like any other fertilizer. Brown manure consists of solid wastes from cattle, horses, sheep, or poultry, and even urine, which contains nitrogen in the form of urea. Inorganic fertilizers produced by chemical companies provide a set amount of nitrogen, phosphorus, and potassium to the soil with each application. Conservation farming makes use of both types of fertilizer; organic fertilizer provides a slow-release spectrum of plant nutrients, and inorganic fertilizer provides a fast-release influx of nutrients most likely to be depleted from soil each season.
Crop rotation conserves fertilizer by planting different types of crops on the same land every other year. Crops such as corn or cotton deplete nitrogen from the soil, so rotation with legumes the next year helps return nitrogen to the soil. Legume plants contain bacteria-filled nodules on their roots that draw in nitrogen from the atmosphere and convert it to a usable form for plants, a process called nitrogen fixation. In addition to recycling nitrogen, crop rotation reduces erosion by keeping a crop on each field rather than letting the field lie fallow (unplanted) for a season.
Drought and desertification put pressures on conservation farming, often in the issue of water conservation. Different irrigation systems offer more or less efficiency to watering fields, as already discussed. But what happens if there is no water at all? The “Desalination of Water” sidebar discusses one option in world water conservation.
Source of Information : Green Technology Conservation Protecting Our Plant Resources
Conservation farming today includes four main aspects that work together to reduce ecological footprint: water conservation, soil conservation, efficient tilling methods, and low environmental-impact fertilization methods. Sustainable agriculture may be considered to be stricter than conservation farming with respect to ecological footprint because, unlike sustainable methods, conservation farming accepts the following:
» meat production
» some water-inefficient crops
» monoculture
» seasonal crops
» use of prime cropland
» some use of pesticides and herbicides
Conservation farming aims to convert traditional inefficient food production methods into methods that are both sustainable and efficient. For instance, traditional farming of 20 to 50 years ago often included the following characteristics: several passes over the fields with tilling equipment before sowing seeds; preemptory weed control with heavy doses of herbicide; fertilizer use at inefficient levels; and acceptance of any crop yields. Today conservation farming uses more efficient tillage and soil conservation methods. In the 1970s farmers cultivated their soils at least four times and often as 10 times before planting. Conservation farmers have found this overcultivation to be unnecessary, not to mention a waste of manpower, fuel, equipment, and soil. In weed control, conservation farming borrows from sustainable methods by using ground cover plants and natural methods (birds, small mammals) to combat weed growth.
Conservation farming uses both organic and inorganic fertilizers to return nutrients to the soil between each growing season. Organic fertilizers come from plant or animal materials such as manure. Green manure consists of cut crops that are plowed back into the soil to replenish some nutrients for the next crop. Green manure also includes compost, which is decomposed plant material that has been broken down by microbes on a site away from the fields, and may then be applied to fields like any other fertilizer. Brown manure consists of solid wastes from cattle, horses, sheep, or poultry, and even urine, which contains nitrogen in the form of urea. Inorganic fertilizers produced by chemical companies provide a set amount of nitrogen, phosphorus, and potassium to the soil with each application. Conservation farming makes use of both types of fertilizer; organic fertilizer provides a slow-release spectrum of plant nutrients, and inorganic fertilizer provides a fast-release influx of nutrients most likely to be depleted from soil each season.
Crop rotation conserves fertilizer by planting different types of crops on the same land every other year. Crops such as corn or cotton deplete nitrogen from the soil, so rotation with legumes the next year helps return nitrogen to the soil. Legume plants contain bacteria-filled nodules on their roots that draw in nitrogen from the atmosphere and convert it to a usable form for plants, a process called nitrogen fixation. In addition to recycling nitrogen, crop rotation reduces erosion by keeping a crop on each field rather than letting the field lie fallow (unplanted) for a season.
Drought and desertification put pressures on conservation farming, often in the issue of water conservation. Different irrigation systems offer more or less efficiency to watering fields, as already discussed. But what happens if there is no water at all? The “Desalination of Water” sidebar discusses one option in world water conservation.
Source of Information : Green Technology Conservation Protecting Our Plant Resources
2012年3月9日
Irrigation
Irrigation is the process of supplying water to crops by artificial means. Each farming region’s terrain, precipitation, soil drainage, and type of crops determine the amount of water a farming operation needs. Irrigation worldwide has increased as the population has grown and as desertification has taken over previously healthy cropland. The FAO has stated that from 1950 to today, a period in which the world population went from 2.5 billion to 6.5 billion people, irrigated area doubled and water withdrawals tripled. Though irrigation helps agriculture meet the increasing demand for food, it also contributes to desertification if not done the correct way.
Farmers in arid and semiarid regions obtain irrigation water from surfaces waters, such as lakes, rivers, and ponds. This water must usually be carried long distances from its source to the fields. Underground water supplements surface waters, and in some instances it serves as the sole water supply. If irrigation draws water out of the ground quicker than nature replaces it, an overdraft occurs. In an overdraft the land above the aquifer may sink. In Europe water officials have used this process to their advantage. Workers drill deep wells alongside rivers, and the wells draw water from saturated soils close to the riverbank. Soil and gravel partially clean the water as it filters through on the way from the river to the well. Only very severe droughts interfere with this method of water purification. More about this topic is found in the “Drought” sidebar.
Irrigation of severely dry land must include precautions so that water does not simply rush over the ground’s surface and take soil but never reach the crops’ roots. Irrigation water may be supplied by the following systems: sprinkler systems; field-flooding; filling furrows between crop rows with water; subirrigation (in which water from ditches or porous vessels percolates into the soil); or drip irrigation. Drip irrigation offers the most efficient water delivery approach, especially in water-precious dry parts of the world. Drip irrigation periodically delivers small amounts of water to the soil above root systems through small tubes. Drip irrigation provides the three following advantages: (1) reduced total water requirements; (2) slow release that prevents large losses by evaporation; and (3) adaptation to hilly or flat terrain.
Improper irrigation causes unneeded damage to lands already threatened by desertification. First, repeated irrigation that does not allow the soil to absorb the water can cause salinization as salts slowly accumulate in the soil. Salinization, as mentioned earlier, further reduces the soil’s quality and leads to more desertification. Farmers who try to remove salinization with water may create a second problem from irrigation—waterlogged soil.
Waterlogged soil eventually raises the water table and kills plant roots. At the same time, soil microbes cannot carry out their normal metabolism so they do not degrade organic matter. Both salinization and waterlogging have become serious problems in parts of the world suffering desertification.
Source of Information : Green Technology Conservation Protecting Our Plant Resources
Farmers in arid and semiarid regions obtain irrigation water from surfaces waters, such as lakes, rivers, and ponds. This water must usually be carried long distances from its source to the fields. Underground water supplements surface waters, and in some instances it serves as the sole water supply. If irrigation draws water out of the ground quicker than nature replaces it, an overdraft occurs. In an overdraft the land above the aquifer may sink. In Europe water officials have used this process to their advantage. Workers drill deep wells alongside rivers, and the wells draw water from saturated soils close to the riverbank. Soil and gravel partially clean the water as it filters through on the way from the river to the well. Only very severe droughts interfere with this method of water purification. More about this topic is found in the “Drought” sidebar.
Irrigation of severely dry land must include precautions so that water does not simply rush over the ground’s surface and take soil but never reach the crops’ roots. Irrigation water may be supplied by the following systems: sprinkler systems; field-flooding; filling furrows between crop rows with water; subirrigation (in which water from ditches or porous vessels percolates into the soil); or drip irrigation. Drip irrigation offers the most efficient water delivery approach, especially in water-precious dry parts of the world. Drip irrigation periodically delivers small amounts of water to the soil above root systems through small tubes. Drip irrigation provides the three following advantages: (1) reduced total water requirements; (2) slow release that prevents large losses by evaporation; and (3) adaptation to hilly or flat terrain.
Improper irrigation causes unneeded damage to lands already threatened by desertification. First, repeated irrigation that does not allow the soil to absorb the water can cause salinization as salts slowly accumulate in the soil. Salinization, as mentioned earlier, further reduces the soil’s quality and leads to more desertification. Farmers who try to remove salinization with water may create a second problem from irrigation—waterlogged soil.
Waterlogged soil eventually raises the water table and kills plant roots. At the same time, soil microbes cannot carry out their normal metabolism so they do not degrade organic matter. Both salinization and waterlogging have become serious problems in parts of the world suffering desertification.
Source of Information : Green Technology Conservation Protecting Our Plant Resources
2012年3月6日
Drought
Drought is a period of dry weather with insufficient rainfall. Droughts are natural occurrences in climate cycles, and most plants and animals have mechanisms for getting through these periods unharmed. Prolonged droughts can, however, affect people and ecosystems. Severe water shortages cause lakes, ponds, and streams to dry up and may lower the water table as people draw water out of underground sources.
Droughts have an immediate effect on plant growth. This in turn harms food chains; predators have a harder time finding prey animals and fresh water sources. People, too, suffer in drought conditions, especially those living by subsistence farming. In addition to crop losses, soil conditions decline, and winds blow away precious topsoil. Droughts often occur in marginal areas that have already been subjected to desertification. Crop failures in areas burdened with poverty can lead to famine, which may force people to migrate and encroach on wildlife habitat. At the same time, drought degrades habitat conditions by reducing vegetation and altering entire food webs.
Certain technologies lessen the effects of drought, such as the development of drought-resistant plants, drought-resistant soil blends, ground cover plants to reduce evaporation, and rain-fed irrigation and other water conservation techniques. In impoverished areas, however, even these actions have been difficult to establish. In China, for example, the Gobi Desert expanded 20,240 square miles (52,400 km2) during a five-year period in the 1990s; today it has crept to within 100 miles (161 km) of the Beijing metropolis. Japan and Korea now suffer springtime dust storms that originate in China’s desert, a distance of about 2,000 miles (3,200 km).
Pat Mulroy, head of the Southern Nevada Water Authority, spoke to the New York Times in 2007 about water conditions in Las Vegas: “This country is going to have 100 million additional people in it in the next twenty-five to thirty years,” she said. “Tell me where they’re supposed to go. . . . Every community says, ‘Not here,’ ‘No growth here,’ ‘There’s too many people already.’ We have an exploding human population, and we have a shrinking clean-water supply. Those are on colliding paths. This is not just a Las Vegas issue. This is a microcosm of a much larger issue.” As Mulroy suggests, this condition could describe almost any other place in the world today.
In the United States, the National Oceanic and Atmospheric Administration (NOAA) uses a calculation called the Palmer Index to put a value on the severity of droughts. A zero value indicates normal conditions; negative numbers indicate drought, and positive numbers indicate ample rainfall. The Palmer Index relates to the local climate so that it can be as useful in the Mojave Desert as it is in Maine. The crop moisture index provides similar information but calculates conditions during short-term periods—weekly, for instance, rather than seasonally as in the Palmer Index. Farmers use the crop moisture index to assess the best times for planting and harvesting crops.
Resource wars is a new term for the possibility of increased warfare throughout the world over natural resources that are necessary for civilization. Resource wars have taken place in human history over gold, salt, diamonds, and oil. Today society confronts increasing conflicts over food and water, and drought will intensify the problem. Increased irrigation works well during short-term dry periods, but a constant reliance on water reserves threatens groundwater storage and leads to salinization. Climatologist Roger Pulwarty of the NOAA told the New York Times in 2007, “You don’t need to know all the numbers of the future exactly. You just need to know that we’re drying. And so the argument over whether it’s 15 percent drier or 20 percent drier? It’s irrelevant. Because in the long run, that decrease, accumulated over time, is going to dry out the system.” Resource wars over water may dominate the future the way conflicts over oil have affected the present.
Source of Information : Green Technology Conservation Protecting Our Plant Resources
Droughts have an immediate effect on plant growth. This in turn harms food chains; predators have a harder time finding prey animals and fresh water sources. People, too, suffer in drought conditions, especially those living by subsistence farming. In addition to crop losses, soil conditions decline, and winds blow away precious topsoil. Droughts often occur in marginal areas that have already been subjected to desertification. Crop failures in areas burdened with poverty can lead to famine, which may force people to migrate and encroach on wildlife habitat. At the same time, drought degrades habitat conditions by reducing vegetation and altering entire food webs.
Certain technologies lessen the effects of drought, such as the development of drought-resistant plants, drought-resistant soil blends, ground cover plants to reduce evaporation, and rain-fed irrigation and other water conservation techniques. In impoverished areas, however, even these actions have been difficult to establish. In China, for example, the Gobi Desert expanded 20,240 square miles (52,400 km2) during a five-year period in the 1990s; today it has crept to within 100 miles (161 km) of the Beijing metropolis. Japan and Korea now suffer springtime dust storms that originate in China’s desert, a distance of about 2,000 miles (3,200 km).
Pat Mulroy, head of the Southern Nevada Water Authority, spoke to the New York Times in 2007 about water conditions in Las Vegas: “This country is going to have 100 million additional people in it in the next twenty-five to thirty years,” she said. “Tell me where they’re supposed to go. . . . Every community says, ‘Not here,’ ‘No growth here,’ ‘There’s too many people already.’ We have an exploding human population, and we have a shrinking clean-water supply. Those are on colliding paths. This is not just a Las Vegas issue. This is a microcosm of a much larger issue.” As Mulroy suggests, this condition could describe almost any other place in the world today.
In the United States, the National Oceanic and Atmospheric Administration (NOAA) uses a calculation called the Palmer Index to put a value on the severity of droughts. A zero value indicates normal conditions; negative numbers indicate drought, and positive numbers indicate ample rainfall. The Palmer Index relates to the local climate so that it can be as useful in the Mojave Desert as it is in Maine. The crop moisture index provides similar information but calculates conditions during short-term periods—weekly, for instance, rather than seasonally as in the Palmer Index. Farmers use the crop moisture index to assess the best times for planting and harvesting crops.
Resource wars is a new term for the possibility of increased warfare throughout the world over natural resources that are necessary for civilization. Resource wars have taken place in human history over gold, salt, diamonds, and oil. Today society confronts increasing conflicts over food and water, and drought will intensify the problem. Increased irrigation works well during short-term dry periods, but a constant reliance on water reserves threatens groundwater storage and leads to salinization. Climatologist Roger Pulwarty of the NOAA told the New York Times in 2007, “You don’t need to know all the numbers of the future exactly. You just need to know that we’re drying. And so the argument over whether it’s 15 percent drier or 20 percent drier? It’s irrelevant. Because in the long run, that decrease, accumulated over time, is going to dry out the system.” Resource wars over water may dominate the future the way conflicts over oil have affected the present.
Source of Information : Green Technology Conservation Protecting Our Plant Resources
2012年3月3日
Threats to Grasslands
The grassland biome consists of land dominated by grasses instead of shrubs and trees. Grasslands go by various names in different parts of the world: In North America, grasslands are called prairies; in South Africa, they are velds; in Asia, they are called steppes; in Australia, rangeland; and in South America, the pampa. Two types of grasslands occur on Earth: temperate and tropical (also called the savanna). Temperate grasslands are found north of the tropic of Cancer and south of the tropic of Capricorn, while tropical grasslands occur near the equator.
Grasslands receive varied precipitation from season to season, ranging from deluges of rainfall to prolonged dry periods. The dry periods can be made worse for the ecosystem by overgrazing, the overuse of pesticides, invasive species, and the depletion of groundwater sources. The savanna’s shallow soil bakes in the hot dry seasons, and its porous consistency allows water to drain quickly, so even though savannas experience distinct dry and wet seasons, heavy downpours in a few concentrated regions must serve widespread ecosystems. Grazing, cutting, fires, and the trampling of the land by animals represent the greatest threats to grasslands, all of which lead to desertification. For example, elephants have been blamed for trampling large areas of African savanna that have turned into desert. Temperate grasslands have a wider temperature range than the savanna, but they receive slightly less rain. Savannas average 20–50 inches (51–127 cm) of rainfall per year; temperate grasslands receive 20–35 inches (51–89 cm).
China’s grasslands provide examples of the varied forces that conspire to bring a sensitive ecosystem to disaster. From the 1950s to the early 1980s, Chinese leaders encouraged the development of self-sufficiency within the population along with food security. Farmers and ranchers migrated to the steppes to cultivate the land and release cattle to graze. Without adequate knowledge of grassland conservation, the steppes became overgrazed and turned into barren land. Droughts and soil erosion had been increasing in the vast China plateau at the same time. Until 1998 China had no national plan for recovering the steppes or preventing further desertification, and even since then only two national laws focus on land loss from desertification. Currently, global warming has accelerated glacier melt on China’s Qinghai-Tibet plateau. The melting causes large amounts of runoff to erode the plateau’s soil, to be followed by desertification.
By the late 1990s, massive sandstorms swirled across China’s plateau, burying barns, vehicles, and sometimes animals. China Daily reported that between April 14 and 18, 2006, 330,000 tons (299,375 metric tons) of sand landed on the city of Beijing after the wind swept it across thousands of miles of steppes. Efforts have begun to recover the land from the desert by replanting it, but progress has been slow and frustrating. Farmer Zhang Minqing, a resident of Sichuan Province, was quoted in the New York Times as saying, “Last year [2003] our first crop failed because we didn’t know what we were doing. We didn’t provide enough water and they all died.” Still, once farming rebounds in China, the land will stabilize and offer more hope for improved conditions.
Each year in March through May, the sandstorms in China roll east. Yang Weixi, the chief engineer at the Desertification Control Center, lamented in 2006, “Given the millions of square kilometers of desert in China, they will continue to be a source of sandstorms in the future, and we cannot cherish unrealistic expectations this problem will vanish overnight.” Once desertification has taken hold, it is very difficult to reverse.
Source of Information : Green Technology Conservation Protecting Our Plant Resources
Grasslands receive varied precipitation from season to season, ranging from deluges of rainfall to prolonged dry periods. The dry periods can be made worse for the ecosystem by overgrazing, the overuse of pesticides, invasive species, and the depletion of groundwater sources. The savanna’s shallow soil bakes in the hot dry seasons, and its porous consistency allows water to drain quickly, so even though savannas experience distinct dry and wet seasons, heavy downpours in a few concentrated regions must serve widespread ecosystems. Grazing, cutting, fires, and the trampling of the land by animals represent the greatest threats to grasslands, all of which lead to desertification. For example, elephants have been blamed for trampling large areas of African savanna that have turned into desert. Temperate grasslands have a wider temperature range than the savanna, but they receive slightly less rain. Savannas average 20–50 inches (51–127 cm) of rainfall per year; temperate grasslands receive 20–35 inches (51–89 cm).
China’s grasslands provide examples of the varied forces that conspire to bring a sensitive ecosystem to disaster. From the 1950s to the early 1980s, Chinese leaders encouraged the development of self-sufficiency within the population along with food security. Farmers and ranchers migrated to the steppes to cultivate the land and release cattle to graze. Without adequate knowledge of grassland conservation, the steppes became overgrazed and turned into barren land. Droughts and soil erosion had been increasing in the vast China plateau at the same time. Until 1998 China had no national plan for recovering the steppes or preventing further desertification, and even since then only two national laws focus on land loss from desertification. Currently, global warming has accelerated glacier melt on China’s Qinghai-Tibet plateau. The melting causes large amounts of runoff to erode the plateau’s soil, to be followed by desertification.
By the late 1990s, massive sandstorms swirled across China’s plateau, burying barns, vehicles, and sometimes animals. China Daily reported that between April 14 and 18, 2006, 330,000 tons (299,375 metric tons) of sand landed on the city of Beijing after the wind swept it across thousands of miles of steppes. Efforts have begun to recover the land from the desert by replanting it, but progress has been slow and frustrating. Farmer Zhang Minqing, a resident of Sichuan Province, was quoted in the New York Times as saying, “Last year [2003] our first crop failed because we didn’t know what we were doing. We didn’t provide enough water and they all died.” Still, once farming rebounds in China, the land will stabilize and offer more hope for improved conditions.
Each year in March through May, the sandstorms in China roll east. Yang Weixi, the chief engineer at the Desertification Control Center, lamented in 2006, “Given the millions of square kilometers of desert in China, they will continue to be a source of sandstorms in the future, and we cannot cherish unrealistic expectations this problem will vanish overnight.” Once desertification has taken hold, it is very difficult to reverse.
Source of Information : Green Technology Conservation Protecting Our Plant Resources
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