Many factors affect forests include logging, urban sprawl, human-caused forest fires, acid rain, invasive species, and the slash and burn practices of swidden agriculture or shifting cultivation. The loss and re-growth of forest leads to a distinction between two broad types of forest, primary or old-growth forest and secondary forest.
There are also many natural factors that can cause changes in forests over time including forest fires, insects, diseases, weather, competition between species, etc. The World Resources Institute recorded that only 20% of the world's original forests remained in large, intact tracts of undisturbed forest. More than 75% of these intact forests lie in three countries - the boreal forests of Russia and Canada and the rainforest of Brazil.
Old-growth forests contain mainly natural patterns of biodiversity in established seral patterns, and they contain mainly species native to the region and habitat. The natural formations and processes have not been affected by humans with a frequency or intensity to change the natural structure and components of the habitat. Secondary forest contains significant elements of species which were originally from other regions or habitats.
Smaller areas of woodland in cities may be managed as Urban forestry, sometimes within public parks. These are often created for human benefits.
Rainforests are forests characterized by high rainfall, with definitions based on a minimum normal annual rainfall of 68 to 78 inches. The monsoon trough, alternatively known as the intertropical convergence zone, plays a significant role in creating the climatic conditions necessary for the earth's tropical rainforests.
Rainforests cover 2% of the earth's surface, or 6% of its land mass. They originally covered at least twice that area. Tropical rainforests are the earth's oldest living ecosystems. Fossil records show that the forests of Southeast Asia have existed in more or less their present form for 70 to 100 million years.
Around 40% to 75% of all biotic species are indigenous to the rainforests. It has been estimated that there may be many millions of species of plants, insects and microorganisms still undiscovered in tropical rainforests.
Tropical rainforests have been called the "jewels of the earth" and the "world's largest pharmacy", because over one quarter of natural medicines have been discovered there. Rainforests are also responsible for 28% of the world's oxygen turnover, processing it through photosynthesis from carbon dioxide and storing it as carbon through biosequestration.
The undergrowth in a rainforest is restricted in many areas by the poor penetration of sunlight to ground level. This makes it easy to walk through undisturbed, mature rainforest. If the leaf canopy is destroyed or thinned, the ground beneath is soon colonized by a dense, tangled growth of vines, shrubs and small trees, called a jungle.
There are two types of rainforest, tropical rainforest and temperate rainforest.
Tropical rainforests are rainforests in the tropics, found in the equatorial zone (between the Tropic of Cancer and Tropic of Capricorn). Tropical rainforests are present in Southeast Asia (from Myanmar (Burma) to Philippines, Indonesia, Papua New Guinea and northeastern Australia), Sri Lanka, sub-Saharan Africa from Cameroon to the Congo (Congo Rainforest), South America (e.g. the Amazon Rainforest), Central America (e.g. Bosawás, southern Yucatán Peninsula-El Peten-Belize-Calakmul), and on many of the Pacific Islands (such as Hawai).
Temperate rainforests are rainforests in temperate regions. They occur in North America (in the Pacific Northwest, the British Columbia Coast and in the inland rainforest of the Rocky Mountain Trench east of Prince George), in Europe (parts of the British Isles such as the coastal areas of Ireland and Scotland, southern Norway, parts of the western Balkans along the Adriatic coast, as well as in the North West of Spain and coastal areas of the eastern Black Sea, including Georgia and coastal Turkey), in East Asia (in southern China, Taiwan, much of Japan and Korea, and on Sakhalin Island and the adjacent Russian Far East coast), in South America (southern Chile) and also in Australia and New Zealand.
More than half of the world's species of plants and animals are found in the rainforest. Rainforests support a very broad array of fauna, including mammals, reptiles, birds and invertebrates. Mammals may include primates, felids and other families. Reptiles include snakes, turtles, chameleons and other families; while birds include such families as vangidae and Cuculidae. Dozens of families of invertebrates are found in rainforests. Fungi are also very common in rainforest areas as they can feed on the decomposing remains of plants and animals. Many rainforest species are rapidly disappearing due to deforestation, habitat loss and pollution of the atmosphere.
On January 18, 2007, FUNAI reported also that it had confirmed the presence of 67 different uncontacted tribes in Brazil. The province of Irian Jaya or West Papua in the island of New Guinea is home to an estimated 44 uncontacted tribal groups. The tribes are in danger because of the deforestation, especially in Brazil. Central African rainforest is home of the Mbuti pygmies, one of the hunter-gatherer peoples living in equatorial rainforests characterized by their short height (below 59 inches, on average).
Tropical and temperate rainforests have been subjected to heavy logging and agricultural clearance throughout the 20th century and the area covered by rainforests around the world is shrinking. Biologists have estimated that large numbers of species are being driven to extinction, possibly more than 50,000 a year. A quarter or more of all species on earth could be exterminated within 50 years due to the removal of habitat with destruction of the rainforests. Four-fifths of the nutrients in the rainforests are in the vegetation. This means that the soils are nutrient-poor and become eroded and unproductive within a few years after the rainforest is cleared.
Another factor causing the loss of rainforest is expanding urban areas. Littoral rainforest growing along coastal areas of eastern Australia is now rare due to ribbon development to accommodate the demand for seachange lifestyles.
The forests are being destroyed at a rapid pace. Almost 90% of West Africa's rainforest has been destroyed. Since the arrival of humans 2000 years ago, Madagascar has lost two thirds of its original rainforest. At present rates, tropical rainforests in Indonesia will be logged out in 10 years and Papua New Guinea in 13 to 16 years. All the primary rainforests in India, Bangladesh, Sri Lanka and Haiti have been destroyed already. The Ivory Coast rainforests have been almost completely logged. The Philippines lost 55% of its forest between 1960 and 1985; Thailand lost 45% of its forest between 1961 and 1985.
Rainforests support 90,000 of the 250,000 identified plant species. Scientists estimate that there are at least 30,000 as yet undiscovered plants, most of which are rainforest species. A typical four square mile patch of rainforest contains as many as 1,500 species of flowering plants, 750 species of trees, 125 mammal species, 400 species of birds, 100 of reptiles, 60 of amphibians, and 150 different species of butterflies. In one study, one square meter of leaf litter, when analyzed, turned up 50 species of ants alone.
Many of the foods we eat today originated in rainforests: avocado, banana, black pepper, Brazilian nuts, cayenne pepper, cassava/manioc, cashews, chocolate/ cocoa, cinnamon, cloves, coconut, coffee, cola, corn/maize, eggplant, fig, ginger, guava, herbal tea ingredients (hibiscus flowers, orange flowers and peel, lemon grass), jalapeño, lemon, orange, papaya, paprika, peanut, pineapple, rice, winter squash, sweet pepper, sugar, tomato, turmeric, vanilla, and Mexican yam. The wild strains still in the rainforests of many of these plants provide genetic materials essential to fortify our existing agricultural stock. Many other rainforest plants have great promise to become other staple foods.
The uneven distribution of wealth and land is one major factor in the destruction of tropical forests. The World Bank estimates that of the 2.5 billion people now living in the tropics one billion exist in absolute poverty.
Mountains cover about 27 percent of Earth's surface. They inspire awe and cultural lore, and directly influence the patterns of settlement and movement by humans and wildlife. Despite some degree of protection due to their inherent inaccessibility, mountain regions are still fragile ecosystems threatened by human-related impacts such as animal agriculture, logging and erosion, acid deposition, and climate change.
For many wildlife species, these impacts are problematic. Wolverines, for example, depend on cold snow-pack to den and store food. As this resource becomes less permanent due to warming, wolverine populations may become physically and genetically isolated – leading to decline of the species.
Scientists and conservationists have long recognized the importance of mountains for both biodiversity and human well-being. To achieve effective and lasting protection of wildlife and resources such as water, mountains have to be pre-eminent in our thinking and implementation of conservation measures.
Mountain species are threatened by human-related impacts that cause isolation. As natural landscapes continue to become fragmented, habitat "islands" limit the ability of wildlife populations to move among ecosystems.
Climate change also has impacts on high elevation environments. In fact, impacts in mountain ecosystems may be greater than any other after those in the Arctic. Scientists have determined that it is important for conservationists to see climate change not as one of numerous independent variables acting on species survival in mountain landscapes, but as an exacerbating force over the many direct human alterations to these areas.
The distribution of biodiversity in mountain ecosystems is determined by such things as elevation and slope. These variables and the relative intactness of these ecosystems is likely to be a critical factor in maintaining the health of mountain species in the face of climate change.
"Dead zone" is a more common term for hypoxia, which refers to a reduced level of oxygen in the water. Hypoxic zones are areas in the ocean of such low oxygen concentration that animal life suffocates and dies, and as a result are sometimes called "dead zones."
One of the largest dead zones forms in the Gulf of Mexico every spring. Each spring as farmers fertilize their lands preparing for crop season, rain washes fertilizer off the land and into streams and rivers.
Less oxygen dissolved in the water is often referred to as a “dead zone” because most marine life either dies, or, if they are mobile such as fish, leave the area. Habitats that would normally be teeming with life become, essentially, biological deserts.
Hypoxic zones can occur naturally, but scientists are concerned about the areas created or enhanced by human activity. There are many physical, chemical, and biological factors that combine to create dead zones, but nutrient pollution is the primary cause of those zones created by humans.
Excess nutrients that run off land or are piped as wastewater into rivers and coasts can stimulate an overgrowth of algae, which then sinks and decomposes in the water. The decomposition process consumes oxygen and depletes the supply available to healthy marine life.
Dead zones occur in many areas, particularly along the East Coast, the Gulf of Mexico, and the Great Lakes, but there is no part of the world that is immune. The second largest dead zone in the world is located in the U.S., in the northern Gulf of Mexico.
In general, oil spills can affect animals and plants in two ways: from the oil itself and from the response or cleanup operations. Understanding both types of impacts can help spill responders minimize overall impacts to ecological communities and help them to recover much more quickly.
Spilled oil can harm living things because its chemical constituents are poisonous. This can affect organisms both from internal exposure to oil through ingestion or inhalation and from external exposure through skin and eye irritation. Oil can also smother some small species of fish or invertebrates and coat feathers and fur, reducing birds' and mammals' ability to maintain their body temperatures.
What Creatures Are Most Affected by Oil Spills?
Since most oils float, the creatures most affected by oil are animals like sea otters and seabirds that are found on the sea surface or on shorelines if the oil comes ashore. During most oil spills, seabirds are harmed and killed in greater numbers than other kinds of creatures. Sea otters can easily be harmed by oil, since their ability to stay warm depends on their fur remaining clean. If oil remains on a beach for a while, other creatures, such as snails, clams, and terrestrial animals may suffer.
What Measures Are Taken When an Animal Comes in Contact with Oil?
Most states have regulations about the specific procedures to follow. Untrained people should not try to capture any oiled bird or animal. At most U.S. spills, a bird and/or mammal rehabilitation center is set up to care for oiled animals.
What Type of Spilled Oil Causes the Most Harm?
The type of oil spilled matters because different types of oil behave differently in the environment, and animals and birds are affected differently by different types of oil. However, it's not so easy to say which kind is worst.
First, we should distinguish between "light" and "heavy" oils. Fuel oils, such as gasoline and diesel fuel, are very "light" oils. Light oils are very volatile (they evaporate relatively quickly), so they usually don't remain for long in the aquatic or marine environment (typically no longer than a few days). If they spread out on the water, as they do when they are accidentally spilled, they will evaporate relatively quickly.
However, while they are present, light oils present two significant hazards. First, some can ignite or explode. Second, many light oils, such as gasoline and diesel, are also considered to be toxic. They can kill animals or plants that they touch, and they also are dangerous to humans who breathe their fumes or get them on their skin.
In contrast, very "heavy" oils (like bunker oils, which are used to fuel ships) look black and may be sticky for a time until they weather sufficiently, but even then they can persist in the environment for months or even years if not removed. While these oils can be very persistent, they are generally significantly less acutely toxic than lighter oils. Instead, the short-term threat from heavy oils comes from their ability to smother organisms. Over the long-term, some chronic health effects like tumors may result in some organisms.
Also, if heavy oils get onto the feathers of birds, the birds may die of hypothermia (they lose the ability to keep themselves warm). We observe this same effect if sea otters become oiled. After days or weeks, some heavy oils will harden, becoming very similar to an asphalt road surface. In this hardened state, heavy oils will probably not harm animals or plants that come in contact with them.
In between light and heavy oils are many different kinds of medium oils, which will last for some amount of time in the environment and will have different degrees of toxicity. Ultimately, the effects of any oil depend on where it is spilled, where it goes, and what animals and plants, or people, it affects.
Trillions of cigarette butts are littered annually and their metal contaminants are endangering marine environments. Littered cigarette butt metals are leaching into aquatic ecosystems and potentially entering the food chain.
Cigarette butts are the most common form of litter found in the marine environment, with an estimated 5 trillion or so discarded outdoors around the globe every year. Research has shown that metals can leach from cigarette butts. To gain an understanding of the potential implications, levels of metals in cigarette butts were recently monitored at nine different locations along the north part of the Persian Gulf in the Bushehr seaport coastal areas.
The metals assessed included cadmium (Cd), iron (Fe), arsenic (As) nickel (Ni), copper (Cu), zinc (Zn) and manganese (Mn) from discarded cigarette butts in the top 10 cm of sediment and deposited at the tidal mark on the beaches. The metal content was measured twice, with a period of 10 days in between, to gauge the potential impact of marine currents on levels. But there was little significant change in levels between the two assessments, irrespective of where the samples had been taken.
Metal content is likely to vary according to the cultivation and growth of the tobacco leaf and the application of pesticides and weed killers. Additional metals may be added during cigarette manufacture and/or during the application of brightening agents on the wrapping paper.
Cigarette filters, which are made of cellulose acetate, may act like other plastics in providing a conduit to transport metals in marine environments. The response of animal and plant life to metal content is highly variable. Whereas elevated concentration of heavy and trace metals in water and soils can adversely affect some species, contamination may increase the metal tolerance of other organisms.
Considering the estimated amount of cigarette butts littered annually (4.95 trillion), the release of metals from littered cigarette butts in the marine environment may increase the potential for acute harm to local species and may enter the food chain.
More research is needed to understand fully the leaching behavior of metals from cigarette butts into the marine environment. But from what we already know about the toxicity of discarded cigarette butts in the marine and coastline, it's obvious we need to decrease the environmental hazards of cigarette butts in these areas.
The prairie grasslands ecoregion is often referred to as a “duck factory” because it produces roughly 50% of America’s ducks even though it occupies only about 10% of total duck breeding territory. Duck species such as northern pintails and mallards form mating pairs and breed in the scattered wetlands of this region.
Ducks seem to prefer the smaller wetlands because the isolated ponds allow each pair to have its own space. In fact, ducks already inhabiting a small pond may chase away other ducks in order to protect their territory.
Mallards, pintails, and blue-winged teals are all dabbling ducks, which means they feed in the shallow wetland waters by dipping their heads just below the water surface to eat plants, insects, and small fish. Diving ducks, like the redhead, dive into the deep water to feed on the bottom of the pond.
Ducks often prefer to nest near the wetlands and ponds of the prairie grasslands region in order to feed on the plentiful resources available there. They also prefer this area because the tall grass habitat provides protection from predators.
Agriculture and other activities have decreased the total amount of grassland in the prairie grasslands region, and scientists have found that as the grassland diminishes and the habitat becomes fragmented, predators destroy more duck nests. Part of the reason for this increase in predation is that predators such as foxes and crows are better able to see nests in less grassy and more fragmented areas.
The number of ducks that breed successfully in the prairie grasslands region depends on the wetland conditions that year. In the past, lower duck populations have resulted from unusually dry years with fewer wetland areas.
Wetlands in the prairie grassland region are likely to be affected by forecasted changes in climate, but the magnitude of the impact is uncertain. Scientists initiated a study to examine how prairie grassland wetlands might respond to climate change. Model simulations determined that a warmer climate of only a few degrees Celsius increased the frequency and duration of droughts, and produced less favorable vegetation conditions in semi-permanent wetlands for most of the region. Climate scenarios using smaller temperature and rainfall changes resulted in geographic shifts in the locations of prairie grassland wetlands. During the model simulations, the scientists found that if rainfall increased with temperature, the location of the most productive wetlands would remain approximately the same. However, if precipitation remained stable or decreased, models predicted that most of the prairie grassland region would become too dry to maintain the wetland conditions.
These findings indicate that the duck factory is vulnerable to climate change, particularly under conditions of water stress.
Raccoons are intelligent, fascinating and highly adaptable mammals. As we destroy more and more wildlife habitat, we force animals like raccoons to come into closer contact with us. There's no need to panic or pay hundreds of dollars for trapping services because most problems can be easily resolved with some simple advice and household materials. Many conflicts occur in spring and summer when raccoons take advantage of cavities in human dwellings to raise their young. This is why it's vital to solve problems in a way that doesn't separate a mother from her cubs. Here are some solutions to common raccoon problems:
KEEPING RACCOONS OUT OF GARBAGE
Overflowing or uncovered garbage cans provide an open invitation to hungry raccoons. The simplest solution is to put out your garbage cans for pick-up in the morning, after the nocturnal raccoons have returned to their dens. If you must put out your garbage cans at night, get the kind of plastic garbage can with a tall (4' high) TWIST-ON lid which raccoons can't open. Another option is to build a simple wooden box outside for storing garbage cans. For easy access, the top should be hinged and have a latch in front secured with a snap hook.
RACCOONS IN DUMPSTERS
Often garbage disposal companies don't close dumpster lids after emptying them in the early morning hours. Raccoons are enticed by the food smells, jump in, and can't climb the slippery sides. This problem is easily resolved by putting some strong branches or plank-like pieces of wood in the dumpster so the raccoons can climb out. If your company leaves dumpster lids open all the time, post a sign telling employees that it's vital to keep the lid closed so animals don't become trapped inside.
DO DAYTIME RACCOONS HAVE RABIES?
Even though raccoons are considered nocturnal, mother raccoons sometimes nap in trees or forage during the day when they have nursing cubs which depletes their energy. Coastal raccoons take advantage of the tides and are often seen by day. Call your local animal control officer or police if an adult raccoon seen in daytime is acting at all sick or showing abnormal behaviors such as partial paralysis, circling, staggering as if drunk or disoriented, self-mutilating, screeching, or exhibiting unprovoked aggression or unnatural tameness. Otherwise, just leave the raccoon alone and keep people and companion animals away from the animal.
GETTING RACCOONS OUT OF ATTICS & CHIMNEYS
In spring and summer, mother raccoons often take advantage of chimneys and attics as denning sites for raising cubs. The easiest and best solution is to wait a few weeks for the raccoons to move out on their own. As soon as the cubs are old enough to go on nighttime outings with their mother, she will take them out of the chimney once and for all rather than continually carrying them back and forth. Mother raccoons clean their babies meticulously to avoid attracting predators. If you absolutely must evict the raccoon family, remember that raccoons look for quiet, dark and non-noxious smelling places to raise their young. By creating the opposite conditions, you can evict them using the following methods:
Eviction of Chimney Raccoons: Keep the damper closed and put a blaring radio (rock or rap music works best) in the fireplace. Then put a bowl of ammonia on a footstool near the damper. Apply these deterrents JUST BEFORE DUSK; mother raccoons won't want to move their cubs in broad daylight. Be patient, it may take a few days for the mother to move her young. Once you inspect and make sure all the raccoons are gone, promptly call a chimney sweep to install a mesh chimney cap (the best kind has a stainless steel top) and this situation will not recur.
Eviction of Attic Raccoons: Leave all the lights on and place a blaring radio and rags sprinkled with 1/4 cup of ammonia around the attic. You can also enhance the deterrent effect by adding cayenne pepper or the commercial repellent Repel around the attic and also hanging an electrician's drop light over the denning area. Apply these deterrents JUST BEFORE DUSK; mother raccoons will not want to move their cubs in daylight. Be patient, it may take a few days for the mother to move her young. Once the raccoons are gone, promptly seal any entry hole and this situation will not recur.
RACCOONS EATING CAT FOOD
If you leave food outside all the time, you will attract raccoons and other animals. The solution is to feed the cats only at a certain time in the morning or midday, then take away any uneaten food. The cats will get used to the schedule and modify their behavior accordingly.
RACCOONS COMING THROUGH CAT DOORS
No self-respecting raccoon is going to ignore a free buffet! The best solution is to feed your cats indoors and not use a cat door at all. There are strong, electrically controlled doors that you can purchase which only let your designated animals in.
RACCOONS & POND FISH
It is difficult to have a delicacy like fish in an area and expect raccoons not to take notice! The best solution is to maintain a higher water level (at least 3 feet deep) and stack cinder blocks, large rocks, or ceramic pipes in the bottom of the pond so the fish can escape from the raccoons and take refuge.
RACCOONS DESTROYING LAWNS
The raccoons are going after the grubs in your lawn. If you keep your lawn well watered, this exacerbates the problem since it drives the grubs to the surface layer of the soil. The good news is that the grubbing activity, although unsightly, does not permanently damage the lawn. A long-term, ecological solution is to apply the product "Milky Spore" to the soil. This natural bacteria will spread and get rid of the grubs, but it takes a long time to work (1+ years). Don't use chemical pesticides due to their toxic effect on the environment, people and animals.
RACCOONS IN THE CHICKEN COOP
The only answer is to reinforce your chicken coop so the raccoons cannot have access to the chickens. Heavy gage welded wire should be used and another layer of finer mesh put over it to prevent raccoons from being able to reach through. Although an inconvenience, once an animal pen is well reinforced and maintained, there will be no more problems.
Trapping is rarely a solution to wildlife nuisance problems. As one animal is removed, another from the surrounding area will soon take his place. The answer is to exclude the animal from the food or nesting source that is attracting him.
Nuisance wildlife control companies charge a fee -- sometimes hundreds of dollars -- for problems that homeowners can often resolve themselves. In addition, when animals are trapped during birthing season, starving babies may be left behind. Homeowners are then horrified to find a foul odor emanating throughout their house. Animals should never be trapped under extreme conditions, such as on sunny rooftops, in rain, snow, sleet, or other bad weather which will cause the animals to suffer and die.
Don't trap unless an animal is stuck somewhere and can't get out or poses an immediate threat to humans or domestic animals. If you do hire a nuisance trapper, ensure that humane practices are followed and no animals are orphaned in the process.
MAKING SURE RACCOONS ARE GONE
Most attics contain clutter, making it hard to verify if the raccoons are gone. Before sealing any entry hole, stuff it first with newspaper and see if the paper stays in place for 3 successive nights. If so, the den is vacated. After sealing the entry hole with hardware cloth, make sure no raccoons are left behind by leaving a sardine or marshmallows in the attic and check if the food is uneaten after 24 hours, or sprinkle flour in front of the entry hole and check for footprints of a raccoon trying to get out.
For over one hundred years, gas and oil production on public lands has caused harm to species and ecosystems and contaminated air, soil, and water. The manufacturing and drilling of oil results in public lands becoming fragmented, driving wildlife away and harming habitats. At the same time, fires, oil disasters and other pollutants result in the contamination of water reserves, both on the surface and underground. By building roads to connect to drilling sites, human activity in previously unharmed areas skyrockets, leading to littering, increased poaching, roadkill, and fires. What’s more, it becomes easier for foreign species to take over and overwhelm the native fauna and flora. Perhaps most importantly, by allowing the gas and oil industry to develop further our reliance on fossil fuels is strengthened, producing greenhouse gasses and facilitating global warming.
Massive environmental value is hidden in our oceans and public lands, ranging from clean water to clean air, and natural ecosystems providing essential habitat for some of our most endangered species. But fossil fuel is valuable monetarily, which is why the government is selling public lands to anyone willing to pay the highest bid. Corruption and greed plagues the decision making process of how to best manage our public lands and waters.
Our climate is at a crucial point. Unless we overcome our dependence on fossil fuels by 2050, we will be facing extreme phenomena such as flooded coasts, human health disasters and massive extinctions of wild species. Climate change is happening now, not tomorrow. With global warming set to boost the rate at which wildlife is pushed to extinction, there is no better use for our oceans and public lands than providing safe haven to species and protection of their ecosystems.
Despite the alarming messages, the government keeps sacrificing these habitats to the oil and gas industry, to which they have leased over 67 million acres – 55 times more land than the Grand Canyon National Park. More than 25 percent of all greenhouse emissions in the country comes from these leases, while some of our most valued lands are being destroyed.
Both our national and natural heritage pay a high toll. The nation’s public lands are industrialized, coastlines and pristine rivers are contaminated, underprivileged communities are undermined, and wildlife is pushed closer towards extinction. For every new fossil fuel lease, the world is burdened with additional climate disruption.
There is nothing rational in a policy that allows for the destruction of natural heritage so that more climate pollution can be produced. The federal fossil fuel leases in our oceans and on our public lands are unacceptable and need to stop. If we did this, we would spare the atmosphere of 450 billion tons of pollution. Vast areas of public lands, wildlife habitat and oceans would be saved in the process.
The Potential Greenhouse Gas Emissions of U.S. Federal Fossil Fuels report showed that by putting an end to the federal fossil fuel leases, we would prevent 450 billion tons of carbon pollutants from becoming potential greenhouse emissions. This comprises over 25 percent of the total emissions that are permitted, should the world adopt a target to prevent global warming from surpassing 2 degrees Celsius which would cause catastrophic consequences to humans and natural ecosystems worldwide.
It is impossible to stop climate change with the regulation of tailpipes and smokestacks alone; extracted fossil fuels are intended to be burned, so any policy aspiring to counter climate change should limit the fossil fuel supply. There is no better place to start this process than our oceans and public lands, which harbor significant biological and ecological value.
Like most endangered creatures, the giant panda has had to bear the brunt of man's frantic quest for development. No place embodies this phenomena more starkly than China, of which this furry animal is a native. The panda population in the plains of China have completely vanished over the millennia, and the only giant pandas remaining are those found in the Qinling Mountains of the Sichuan, Shaanxi and Gansu provinces of Central China. These rain-soaked forests are at elevations from 5,000 to 8,000 feet and are generally covered in clouds and mist.
An adult male panda can weigh over 350 lbs, the female 275 lbs, and measure from 2 to 3 feet in height up to its shoulders. With its huge round white-colored body, two black patches around the eyes, black ears and stout black legs, the panda looks very much like an over-bloated raccoon.
The breeding age of the pandas starts from about 4 to 8 years and remains reproductive up to the age of 20. The female gives birth between 95 to 150 days, and the panda cub is probably one of the most difficult creatures to raise. Almost blind, hairless and pink, the baby is 1/900th the size of its mother. The cubs remain without eyesight for a period of six to eight weeks and are just able to move around after three months.
Bird meat, rodents, carrion and grass form a part of the animal's diet, but these are secondary. Their primary diet is bamboo, which is available in plenty in the Qinling Mountains. The panda's huge round face is suggestive of a powerful set of jaws which itself is an adaption to a coarse diet such as the bamboo. The flowers of the bamboo have more nutrition than the stems. Re-flowering of the bamboos is a slow natural process and there is a fragile balance between it and the slow reproductive rate of the pandas – something that has evolved over a million years in these mountains.
Changes in climate threatens to upset this delicate balance. It presents a genuine threat to the habitat of the panda. A 3 to 4 degree rise in temperatures could easily wipe out half the bamboo forests and leave the panda starving. Scientists opine that owing to the serious damage to the ozone layer, a fallout of China's manic industrialization drive, temperatures could rise up to such a point that there would be none of these precious bamboo forests left after 50 to 100 years. While bamboo could be cultivated in other areas, it would have none of the nutritional value of the Qinling mountain bamboo. There's still plenty of bamboo being cultivated in China, but for the panda to move out of its habitat in search of its vital food will put it in direct confrontation with humans.
Poaching is another menace, and pandas have been captured over the years for exhibition in private zoos. Their pelts fetch a high price in the illegal wildlife trade. Giant pandas sometimes end up in traps laid for other animals and receive grievous injuries. The Chinese government has put in place strict penalties for panda poaching that entails a ten-year sentence and confiscation of property.
Authorities in the Shaanxi Province enacted a regional law in 2007 that marked the Qinling Mountains as a protected zone. The law also states that all development projects in the vicinity of the zone will be assessed for their impact on the ecology and bio-diversity of the region. The Natural Forest Protection Project, implemented by the Chinese Government, has gone a long way in securing a future for the pandas.
Despite these efforts, China has been criticized for showing little interest in true conservation. The Chinese government rents pandas to zoos around the world. Few pandas have been born in zoos, and only a handful of those have been released into the wild; the majority of which did not survive. The enormous amount of money spent on panda breeding programs has been criticized, as the money could be used much more effectively by saving wild habitats.
Zoo pandas suffer the same stresses all wild animals face in captivity. They are moved from zoo to zoo, usually more for political and economic reasons rather than genetic management. Their natural habitat can never be truly simulated, leading to changes in behavior, prolonged inactivity, health problems, stereotypical behavior and lower levels of immunity creating higher susceptibility to illness and disease.
Animal advocates argue that the pandas' welfare should be put above propaganda and profits; pandas should be put in refuges out of the public eye to eliminate the stress they endure due to such exposure.
Wildlife organizations have had an impact by establishing panda natural reserves and conservation programs. Integrating reserves with forest farms and bamboo corridors enable pandas to forage for more food and come into contact with new breeding mates.
A 17 percent rise in the panda population has been witnessed in the past decade. From a count of 1,596 individuals in 2003, it has risen to 1,864. Of these, though, 50 pandas are condemned to captivity in 18 zoos spanning 13 countries.
People commonly perceive mountains as pyramid-shaped masses that steadily narrow as they slope upward. But researchers have found they actually have four principal shapes. Not only are pyramid-shaped mountains in the minority, but most ranges increase in area at higher elevations. Besides reshaping the mountains in our mind's eye, these findings could lead scientists to reconsider conservation strategies for mountain species.
The four principal shapes of mountain ranges include: diamond, pyramid, inverted pyramid and hourglass. For all the range shapes except pyramid, land availability can be greater at higher elevations than it is farther down the mountainside. Yet, people's idea that land area steadily shrinks as a mountain rises is so entrenched that it has come to guide conservation plans and research. This needs to change.
A majority of mountain ranges studied (39 percent), such as the Rocky Mountains, are diamond-shaped. This means that land-area increases from the bottom until the mid-elevation range before contracting quickly. Hourglass-shaped mountain ranges such as the Himalayas make up 23 percent of ranges. Land area in these types rises slightly then decreases at mid-elevations before increasing sharply at higher elevations. The nearby Kunlun Mountains of China are representative of the 6 percent of ranges worldwide that take the form of inverse pyramids which gradually expand in area as elevation increases before, like the hourglass ranges, suddenly widening toward their peaks.
As mountain species move to higher elevations to escape rising global temperatures, they are expected to face a consistent loss of territory – as well as an increase in resource competition. That all but ensures their eventual extinction. But while this risk exists in pyramid-shaped ranges, many species in other range types might in fact benefit from seeking higher altitudes if they move to an elevation with more land area than the one they left.
Research is needed to more precisely identify those elevation zones where species will encounter territory losses and potentially become more threatened as they move upward. The limited resources that exist for conservation could then be targeted to those species.
Animals that could benefit from an increase in elevation may still face other threats – habitat loss, food availability and exposure to existing animals and diseases, for instance. Even the range shapes themselves provide unique areas of concern. Hourglass-shaped ranges such as the Himalayas present a "bottleneck" at mid-elevation that could become overwhelmed with species moving upslope from more expansive lower elevations.
Not every elevation holds equal value for limited conservation resources. Some gradients, and some portions of gradients, will be more important than others. Protecting land within an elevational bottleneck, for example, is critical. That is where species will be greatly pressured, and often long before they reach the mountaintop.
Surviving in an environment of continuous threat and stress is a serious challenge for most living species. Living organisms, in whatever form, need to adapt to changes in the weather, climate and all sorts of changes in the environment. Add to this the natural calamities in the form of floods, storms, fires and volcanic bursts and their aftermath. When new lifeforms enter their ecosystems, pressure on existing species mount.
Dangers can be parasitic or predatory in nature. Challenges to adaptation can be in the form of diseases or the very complexity of biological changes themselves.
After millions of years of adapting to their environments, animals faced a new kind of threat - the advent of human beings. The effect of humans on the planet has been profound and has threatened the existence of all kinds of organisms to a degree that has caused scientists to believe that the Earth is beginning to witness extinction on a mass scale.
Being a a part of nature, the dangers arising from human actions are extensions of natural threats. But the threats from mankind are within human control and can be curbed by changes in behavior. Humans are in a position to realize the consequences of their actions on the environment and can easily make changes in behavior that would affect the future health of the planet in a positive way.
Human Threats To Animals
Destruction of habitat and fragmentation: Destruction and fragmentation of animal habitats for the purpose of agriculture, urban development, building of hydro-electric projects and other self-serving uses are major threats to the Earth’s wildlife.
Effects on global climate: Large scale emissions from fossil fuel burning and excessive flaring of gas have wrought serious damage to the Earth's atmosphere, especially the ozone layer, causing climate changes in many parts of the globe.
Introduction of new and invasive species: Loss of endemic species have been caused by introduction of new species into their ancient habitats.
Hunting and poaching: Hunting animals for sport and poaching them for profit as part of the illicit wildlife trade are among the major threats to wildlife.
Effects of pollutants: Industrial wastes, fertilizers, and pesticides have infiltrated and consumed entire habitats of all forms of living creatures and organisms.
Accidents: Loss of habitat causing animals to venture onto freeways and other manmade obstacles is also a common occurrence. More birds are being killed by a growing traffic in aviation and from colliding into windows.
Watching the many species of birds that inhabit your ecosystem is a fun and fascinating pastime the whole family can enjoy together. Winter is the best time to feed birds as they need the food more than at any other time of year and you will typically see a greater number and variety of birds at bird feeders. Many interesting birds from the north fly south in winter, and in spring many species return home from lands in the south, providing a great variety of species to see.
You don’t need to spend money on food or feeders to attract birds to your yard. If you can leave a small area of your yard un-mowed, you can attract a lot of birds. They eat the seeds from the grasses and weeds and use the area for cover as well.
Employing a feeder grants the ability for close study of birds. While all feeders draw birds, those that keep the bird feed dry and free of mold are best. Moldy seeds are bad for bird health. Place feeders either near a window or fairly far away to help prevent birds from colliding with windows when startled. The most common feeder is a hopper or house feeder, usually made of windows of clear plastic that feed seed to a perching surface. These feeders attract cardinals, nuthatches, chickadees, grosbeaks, buntings and titmice. One without a lot of perching surface minimizes use by house sparrows or starlings. The most important thing is to keep feeders clean by washing with bleach water every few weeks. Washing with bleach water prevents the spread of disease.
Although slightly more expensive, bird food with black oil sunflower seeds attract a wide variety of desirable birds. A suet feeder attracts woodpeckers, nuthatches, chickadees and bluejays. Some birders push suet or peanut butter into crevices in bark or in the cracks of old stumps to attract birds. Witnessing a northern flicker or red-bellied woodpecker feeding at close range sears a delightful memory into the mind of a youngster. Woodpeckers love dead branches on trees. Leave a dead branch on a tree to attract woodpeckers if it is safe to do so.
It is important to provide water for birds in winter too. Place the water in a spot in the yard that receives sun as its rays will melt some water for birds on even the coldest days.
A good guide book is essential for identifying birds. Looking up unfamiliar birds and learning about their distinguishing characteristics is part of the fun of birding. Modestly priced binoculars now have coated lenses and other features that make them acceptable choices for bird watching. Don’t get zoom binoculars for birding. You tend to lose clarity at high magnification. A wide angle pair lets in more light and makes it easier to find birds.
Bird watching is a good way to introduce kids into the outdoors and spark awareness of our natural world. Backyard birding is a family-friendly way to enjoy wildlife viewing. Plus, it is just plain fun.
Coral reef ecosystems are complex, dynamic, and sensitive systems. Although they are geologically robust and have persisted through major climactic shifts, they are however, sensitive to small environmental perturbations over the short-term.
Natural And Human Influences
Slight changes in one component of the ecosystem affect the health of other components. Changes may be attributed to a number of causes but generally fall into two categories, natural disturbances and anthropogenic disturbances. Distinguishing between natural and anthropogenic disturbance is not always simple because the impacts of human actions may not be seen until well after the action has occurred, or may not be seen until it is coupled with a natural disturbance. Also, some events that appear to be natural may have been influenced by human actions. Impacts may be direct or indirect and may be compounded where several occur. For these reasons, it is often difficult to make cause-and-effect linkages when reef degradation is observed.
Coral reef ecosystems are naturally variable and experience natural disturbances that vary on both temporal and spatial scales. Natural disturbance events that affect coral reefs include tropical storms, outbreaks of a coral predators, disease, extended periods of elevated or low water temperatures, and extremely low tides.
Although these events disturb the reefs and may kill a significant amount of coral, they are part of a natural cycle that reefs experience and the reef ecosystem may benefit in other ways. The destruction caused by a hurricane, for example, opens space for reef organisms that had been excluded by larger and longer lived corals. Hurricanes also flush out accumulated sediment within the reef and create more substrate for organisms to settle and grow on.
A healthy reef ecosystem will eventually recover from natural disturbance events. However, when these natural disturbances occur to a reef system that has been impacted by human activities, the reef system may have a reduced or even no capacity to rebound. A natural disturbance acting synergistically with accumulated human impacts may result in destruction that is not reversed in the same time frame it naturally would occur.
Coral reefs around the world have experienced major recent natural disturbances. These natural events may have been influenced by human activities.
A recent World Resources Institute report estimates that nearly 60 percent of the world's reefs are threatened by increasing human activity. The expanding human population and its activities may impact coral reef health in a number of ways.
Development, urbanization, and agriculture lead to increases in freshwater runoff, polluted runoff, sedimentation, and nutrient inputs. Growing industry and automobile usage cause an increase in emissions contributing to the green house effect and chemical deposition from air to water. Commercial and private vessel traffic mean the possibility of fuel leaks or spills, vessel groundings, and anchor damage.
Harvest of reef resources is also taking a toll on the health of coral reef ecosystems.
Overfishing on reefs leads to an unbalanced ecosystem, allowing more competitive or less desirable organisms to become dominant. Fishing methods such as the use of explosives and poisons severely harm reefs and reef organisms.
Harvest of coral skeleton for souvenirs depletes healthy corals or substrate where coral larvae might have settled.
Increased tourism in areas of coral reef habitat contributes to increased pressure from scuba diving, recreational fishing, and vessel traffic.
Kelp forests grow predominantly on the Pacific Coast, from Alaska and Canada to the waters of Baja California. Tiered like a terrestrial rainforest with a canopy and several layers below, the kelp forests of the eastern Pacific coast are dominated by two canopy-forming, brown macroalgae species, giant kelp (Macrocystis pyrifera) and bull kelp (Nereocystis leutkeana).
Conditions Required for Growth
Kelp forests grow along rocky coastlines in depths of about 2 m to more than 30 m (6 to 90+ ft). Kelp favors nutrient-rich, cool waters that range in temperature from 5o to 20o C (42o to 72o F). These brown algae communities live in clear water conditions through which light penetrates easily.
Kelp recruits most successfully in regions of upwelling (regions where the ocean layers overturn, bringing cool, nutrient-rich bottom waters to the surface) and regions with continuously cold, high-nutrient waters. Because the amount of dissolved inorganic nitrogen decreases significantly in marine waters warmer than 20oC, kelp experiences reduced or negative growth rates in warm water.
Kelp survival is positively correlated with the strength of the substrate. The larger and stronger the rock on which it is anchored, the greater the chance of kelp survival. Winter storms and high-energy environments easily uproot the kelp and can wash entire plants ashore.
Unique Characteristics of Kelp Plants
Instead of tree-like roots that extend into the substrate, kelp has "anchors" called holdfasts that grip onto rocky substrates. From the holdfasts, kelp plants grow toward the water's surface. Gas bladders called pneumatocysts, another unique feature of kelp, keep the upper portions of the algae afloat. A giant kelp plant has a pneumatocyst at the base of each blade. In contrast, a bull kelp plant has only one pneumatocyst that supports several blades near the water's surface.
Giant kelp is a perennial (it lives for several years) while bull kelp is an annual (it completes its life cycle in one year). Both types of kelp have a two-stage life cycle. They exist in their earliest life stages as spores, released with millions of others from the parent kelp, the sporophyte. The spores grow into a tiny male or female plant called a gametophyte, which produces either sperm or eggs. After fertilization occurs, the embryos may grow into mature plants (sporophytes), completing the life cycle.
Giant kelp can live up to seven years. Factors such as the severity of winter storms may affect its life span. Its average growth (in spring) is 27 cm/day (~10 inches/day), yet it may grow up to 61 cm/day (2 ft/day). The average growth of bull kelp is 10 cm/day (~4 inches/day).
The Kelp Forest Ecosystem
A host of invertebrates, fish, marine mammals, and birds exist in kelp forest environs. From the holdfasts to the surface mats of kelp fronds, the array of habitats on the kelp itself may support thousands of invertebrate individuals, including polychaetes, amphipods, decapods, and ophiuroids.
California sea lions, harbor seals, sea otters, and whales may feed in the kelp or escape storms or predators in the shelter of kelp. On rare occasions gray whales have been spotted seeking refuge in kelp forests from predatory killer whales. All larger marine life, including birds and mammals, may retreat to kelp during storms or high-energy regimes because the kelp helps to weaken currents and waves.
Perhaps the most familiar image of kelp forests is a picture of a sea otter draped in strands of kelp, gripping a sea urchin on its belly. Both sea otters (Enhydra lutris) and sea urchins (Strongylocentrotus spp.) play critical roles in the stable equilibrium ecosystem. Sea urchins graze kelp and may reach population densities large enough to destroy kelp forests at the rate of 30 feet per month. Urchins move in "herds," and enough urchins may remain in the "barrens" of a former kelp forest to negate any attempt at regrowth. Sea otters, playing a critical role in containing the urchin populations, prey on urchins and thus control the numbers of kelp grazers.
The aquatic biome includes habitats around the world dominated by water. Aquatic ecosystems are divided into two main groups based on their salinity—freshwater habitats and marine habitats.
● Freshwater habitats are aquatic habitats with low levels of salt, less than one percent. They include rivers, lakes, streams, ponds, swamps, wetlands, bogs and lagoons.
● Marine habitats are aquatic habitats with salt concentrations of more than one percent. They include oceans, seas and coral reefs.
Some habitats exist where saltwater and freshwater mix together. These include mud flats, mangroves and salt marshes. Aquatic ecosystems support a diverse assortment of animals including fishes, amphibians, reptiles, mammals, birds and invertebrates.
When evaporated sea water falls as rain, it flows down mountain streams creating rivers and lakes. Rain water feeds freshwater rivers, which then flows back into the sea. Streams, rivers and lakes are home to countless animal species.
The two main types of freshwater habitat are rivers and lakes. Lakes are often fed by streams or rivers. They can also be enclosed areas where species live that are found nowhere else on the planet. Rivers usually contain large animals able to cope with strong currents, as well as animals such as crabs and birds that feed on the fish within the water.
Freshwater rivers provide habitat to a wide variety of species including fish, amphibians, reptiles, insects, birds and mammals. An extraordinary number of fish species inhabit streams and rivers.
Freshwater lakes are also home to a vast variety of wildlife. Some species spend their entire lives in one area. Others visit momentarily to eat and drink. Many species are specially adapted to life in particular lakes. Large mammals, including zebras, primates, giraffes and deer, visit lakes to drink.
Many freshwater habitats have been drastically affected by human activities. Chemicals and pesticides contaminate the water, as well as waste water. Animals and plants that inhabit the water can be affected, as are the animals that eat them.
Oceans create the largest habitat in the world. Countless animal species inhabit the planet's oceans which cover over 75% of the earth.
The two main types of ocean habitat are coastal, inshore habitats found around land, and open ocean habitats that stretch around the planet.
More animal species live in the rich, shallower waters than the deep sea, though animals live throughout the oceans.
The ocean landscape is as vast and varied as on land, featuring underwater continental shelves, mountains, valleys, volcanoes, trenches and plains.
Warmer, coastal waters around the globe are home to the majority of species. These areas feature more food sources than the deep ocean. Smaller aquatic animals often inhabit the shallower regions. Coastal waters provide them with a variety of places to hide, with fewer large predators. Larger animals tend to prefer deeper regions beneath the waves along the continental shelves.
Plankton -- microscopic plants and animals, fish eggs and animals in their larvae form -- provide a plentiful food source for many marine animals. Tiny fishes and crustaceans, to the largest animal on the planet, the blue whale, feed on this vital food source.
The two largest threats to ocean habitats are over-fishing and pollution. Pollution from the land and air accumulate in the sea with devastating effects to many plant and animal species. Over-fishing threatens many species with extinction.
Coral reefs are the richest habitats on the earth. Found along the coastlines, they provide habitat to countless plant and animal species including fish, reptiles, invertebrates, echinoderms and crustaceans. Coral reefs are located in the tropical and sub-tropical coastal regions where it is always warm, day and night, year-round.
The two main types of coral reef habitats are soft coral reefs and hard coral reefs. Soft corals are animals that move through the water, eventually settling. Hard corals are the reef-building corals that are hard coral shells left behind when corals die.
The largest coral reefs are located along the south-west coast of Africa, in the Caribbean and all around Australia, south-east Asia and the coastal regions of the South Pacific Ocean.
So rich in life and biodiversity, coral reefs are home to an incredible variety animal species able to survive together with little competition for food. Animal species that inhabit coral reefs vary tremendously in shape, size and color. Sea urchins, starfish and crustaceans are invertebrates that call coral reefs home. Sea snakes hunt small fish and eels in the coral reefs. Eels and seahorses are among the many fish species. Sharks do not live permanently in coral reefs, but visit often in search of prey. Sea turtles also make frequent trips to coral reefs in search of food.
The threats to coral reefs and coastline wildlife include commercial fishing, pollution and storms. Dredging involves dragging fishing nets across the sea bed, destroying coral reefs in the process. Many animal species that inhabit coral reefs are on the brink of extinction. Sea storms, such as tsunamis, can also reek havoc on coral reef environments.
Wetlands are found throughout the world, often in more temperate regions where vegetation grows quickly. These large areas of water contain a wealth of plants and are broken up by small islands of land. Wetlands include swamps, marshes, fens and bogs. Many wildlife species are specifically adapted to wetland environments, including fish, amphibians, birds, mammals, reptiles and insects.
The two main types of shallow watery areas are swamps and wetlands. Swamps are usually located in forested areas. Trees, such as mangrove trees, survive in salt-water conditions and require ample space for their roots. Wetlands are usually near large rivers or estuaries that flood when river banks burst from a lot of rain.
Mangrove swamps are one of the richest habitats on the planet. Numerous animals species live above and below the water's surface. Many animal species that live in mangrove forests are found nowhere else on earth. The mangrove tree's enormous roots provide shelter to small fishes, amphibians and reptiles and provide a way for the animals to get in and out of the water. Larger animals have ample fish to feed on.
Large aquatic birds such as heron spear fish with long beaks in wetland habitats. Salt-water swamps contain snapping turtles, crabs, crocodiles and alligators. Amphibians and reptiles inhabit the water's edge. Many insects live, and lay their eggs, in wetland habitats...providing food for frogs and lizards.
The main threats to wetlands are deforestation and pollution. The animals in wetland habitats are specifically adapted to their environment and are vulnerable to toxins in the water and air.
Islands form when land breaks away from large land masses or volcanoes erupt on the sea floor. They are found throughout the world. Their isolated nature results in unique wildlife species, often different from their counterparts living in mainland habitats. Some island animal species have developed completely separately from mainland species.
Numerous habitats including forests, wetlands, deserts and tundra can be found on different islands. Limited in size and resources, ecosystems on islands are fragile and easily disturbed. Human activity and the introduction of new species on islands has caused much harm, making many species endangered or extinct. With nowhere else for them to go, the loss of habitat or food sources is particularly damaging to island animals.
Lemurs live only on the island of Madagascar, the tree kangaroo only in Papua New Guinea, the kiwi only in New Zealand and the orangutan only on the Indonesian islands of Borneo and Sumatra. Separated from the mainland, these species have adapted to their isolated environments. The kiwi and the kakapo birds have adapted to a flightless lifestyle since there were no large predators on the islands to flee from. The introduction of predators by humans threatens their survival. Orangutans suffer from mass deforestation in south-east Asia and the exotic pet trade.
A breaking point has been reached in conserving the fragile habitats of islands. Without immediate action to save these precious ecosystems, many species will be lost forever.
The world's great deserts were formed by natural processes interacting over long intervals of time. During most of these times, deserts have grown and shrunk independent of human activities.
Paleodeserts, large sand seas now inactive because they are stabilized by vegetation, extend well beyond the present margins of core deserts, such as the Sahara. In some regions, deserts are separated sharply from surrounding, less arid areas by mountains and other contrasting landforms that reflect basic structural differences in the regional geology. In other areas, desert fringes form a gradual transition from a dry to a more humid environment, making it more difficult to define the desert border.
These transition zones have very fragile, delicately balanced ecosystems. Desert fringes often are a mosaic of microclimates. Small hollows support vegetation that picks up heat from the hot winds and protects the land from the prevailing winds. After rainfall the vegetated areas are distinctly cooler than the surroundings. In these marginal areas, human activity may stress the ecosystem beyond its tolerance limit, resulting in degradation of the land. By pounding the soil with their hooves, livestock compact the substrate, increase the proportion of fine material, and reduce the percolation rate of the soil, thus encouraging erosion by wind and water. Grazing and the collection of firewood reduces or eliminates plants that help to bind the soil.
This degradation of formerly productive land, desertification, is a complex process. It involves multiple causes, and it proceeds at varying rates in different climates. Desertification may intensify a general climatic trend toward greater aridity, or it may initiate a change in local climate.
Desertification does not occur in linear, easily mappable patterns. Deserts advance erratically, forming patches on their borders. Areas far from natural deserts can degrade quickly to barren soil, rock, or sand through poor land management. The presence of a nearby desert has no direct relationship to desertification.
Unfortunately, an area undergoing desertification is brought to public attention only after the process is well underway. Often little or no data are available to indicate the previous state of the ecosystem or the rate of degradation.
Scientists still question whether desertification, as a process of global change, is permanent or how and when it can be halted or reversed.
Desertification became well known in the 1930's, when parts of the Great Plains in the United States turned into the "Dust Bowl" as a result of drought and poor practices in farming, although the term itself was not used until almost 1950. During the dust bowl period, millions of people were forced to abandon their farms and livelihoods. Greatly improved methods of agriculture and land and water management in the Great Plains have prevented that disaster from recurring, but desertification presently affects millions of people in almost every continent.
Increased population and livestock pressure on marginal lands has accelerated desertification. In some areas, nomads moving to less arid areas disrupt the local ecosystem and increase the rate of erosion of the land. Nomads are trying to escape the desert, but because of their land-use practices, they are bringing the desert with them.
It is a misconception that droughts cause desertification. Droughts are common in arid and semiarid lands. Well-managed lands can recover from drought when the rains return. Continued land abuse during droughts, however, increases land degradation. By 1973, the drought that began in 1968 in the Sahel of West Africa and the land-use practices there had caused the deaths of more than 100,000 people and 12 million cattle, as well as the disruption of social organizations from villages to the national level.
In 1988 Ridley Nelson pointed out in an important scientific paper that off-road vehicles significantly increase soil loss in the delicate desert environment of the western United States. In a few seconds, soils that took hundreds of years to develop can be destroyed.
While desertification has received tremendous publicity by the political and news media, there are still many things that we don't know about the degradation of productive lands and the expansion of deserts. The desertification problem and processes are not clearly defined. There is no consensus among researchers as to the specific causes, extent, or degree of desertification. Contrary to many popular reports, desertification is actually a subtle and complex process of deterioration that may often be reversible.
In the last 25 years, satellites have begun to provide the global monitoring necessary for improving our understanding of desertification. Landsat images of the same area, taken several years apart but during the same point in the growing season, may indicate changes in the susceptibility of land to desertification. Studies using Landsat data help demonstrate the impact of people and animals on the Earth. However, other types of remote-sensing systems, land monitoring networks, and global data bases of field observations are needed before the process and problems of desertification will be completely understood.
At the local level, individuals and governments can help to reclaim and protect their lands. In areas of sand dunes, covering the dunes with large boulders or petroleum will interrupt the wind regime near the face of the dunes and prevent the sand from moving. Sand fences are used throughout the Middle East and the United States, in the same way snow fences are used in the north. Placement of straw grids, each up to a square meter in area, will also decrease the surface wind velocity. Shrubs and trees planted within the grids are protected by the straw until they take root. In areas where some water is available for irrigation, shrubs planted on the lower one-third of a dune's windward side will stabilize the dune. This vegetation decreases the wind velocity near the base of the dune and prevents much of the sand from moving. Higher velocity winds at the top of the dune level it off and trees can be planted atop these flattened surfaces.
Oases and farmlands in windy regions can be protected by planting tree fences or grass belts. Sand that manages to pass through the grass belts can be caught in strips of trees planted as wind breaks 50 to 100 meters apart adjacent to the belts. Small plots of trees may also be scattered inside oases to stabilize the area.
On a much larger scale, a "Green Wall," which will eventually stretch more than 5,700 kilometers in length, much longer than the famous Great Wall, is being planted in northeastern China to protect "sandy lands" deserts believed to have been created by human activity.
More efficient use of existing water resources and control of salinization are other effective tools for improving arid lands. New ways are being sought to use surface-water resources such as rain water harvesting or irrigating with seasonal runoff from adjacent highlands. New ways are also being sought to find and tap groundwater resources and to develop more effective ways of irrigating arid and semiarid lands.
Research on the reclamation of deserts also is focusing on discovering proper crop rotation to protect the fragile soil, and on understanding how sand-fixing plants can be adapted to local environments.
If we are to stop and reverse the degradation of arid and semiarid lands, we must understand how and why the rates of climate change, population growth, and food production adversely affect these environments. The most effective intervention can come only from the wise use of the best earth-science information available.
What is a greenhouse? A greenhouse is a house made of glass. It has glass walls and a glass roof. People grow vegetables and flowers and other plants in them. A greenhouse stays warm inside, even during winter. Sunlight shines in and warms the plants and air inside. But the heat is trapped by the glass and can't escape. So during the daylight hours, it gets warmer and warmer inside a greenhouse, and stays pretty warm at night too.
How is Earth a greenhouse? Earth's atmosphere does the same thing as the greenhouse. Gases in the atmosphere such as carbon dioxide do what the roof of a greenhouse does. During the day, the sun shines through the atmosphere. Earth's surface warms up in the sunlight. At night, Earth's surface cools, releasing the heat back into the air. But some of the heat is trapped by the greenhouse gases in the atmosphere. That's what keeps our Earth a warm and cozy 59 degrees Fahrenheit, on average. Greenhouse effect of Earth's atmosphere keeps some of the sun's energy from escaping back into space at night.
You might think 59 degrees Fahrenheit is pretty cold. Or, you might think that's warm. It depends on what you are used to. That temperature would melt all the Arctic ice. Yes, it's colder than 59 degrees in a lot of places, and hotter than 59 degrees in a lot of places, but 59 is the average of all of the places.
If the atmosphere causes too much greenhouse effect, Earth just gets warmer and warmer. The point is, if the greenhouse effect is too strong, Earth gets warmer and warmer. This is what is happening now. Too much greenhouse gases in the air are making the greenhouse effect stronger.
Why can't we just plant more trees? You might well wonder, because, after all, trees—like all plants—take in carbon dioxide and give off oxygen. Well, that might help a little. But, instead of planting more forests, some people are cutting them down and burning them to make more farm land to feed the growing human population. Animal agriculture produces more greenhouse gases than all transportation put together, a staggering 51 percent or more.
The ocean also absorbs a lot, but not all, of the excess carbon dioxide in the air. Unfortunately, the increased carbon dioxide in the ocean changes the water, making it more acidic. Ocean creatures don't like acidic water. Bleached out, unhealthy coral are just one example of what acidic water can do.
Don't clouds keep Earth cooler? Water in the atmosphere also acts as a greenhouse gas. The atmosphere contains a lot of water. This water can be in the form of a gas—water vapor—or in the form of a liquid—clouds. Clouds are water vapor that has cooled and condensed back into tiny droplets of liquid water. Water in the clouds holds in some of the heat from Earth's surface. But the bright white tops of clouds also reflect some of the sunlight back to space. So with clouds, some energy from the sun never even reaches Earth's surface. How much the clouds affect the warming or cooling of Earth's surface is one of those tricky questions that scientists are aiming to answer.
Here is a riddle—a serious one, not a joke: As the ocean warms up, more water evaporates into the air. So does more water vapor then mean more warming? And does more warming mean more water vapor? And ‘round and ‘round we go?
At night, clouds trap some of the heat from Earth's surface. Thus, it does not escape back into space. Or, since more water vapor means more clouds, will the fluffy white clouds reflect enough sunlight back into space to make up for the warming? During the day, clouds reflect the sun's energy back to space, before it has a chance to heat Earth's surface.
This cloud riddle has scientists scratching their heads and trying to figure it out.
Wetland conservation is aimed at protecting and preserving areas where water exists at or near the earth's surface, such as swamps, marshes and bogs. Wetlands cover at least 6% of the earth and have become a focal issue for conservation due to the 'ecosystem services' they provide.
More than three billion people, around half the world’s population, obtain their basic water needs from inland freshwater wetlands. The same number of people rely on rice as their staple food, a crop grown largely in natural and artificial wetlands. In some parts of the world, such as the Kilombero wetland in Tanzania, almost the entire local population relies on wetland cultivation for their livelihoods.
In addition to food, wetlands supply fiber, fuel and medicinal plants. They also provide valuable ecosystems for birds and other aquatic creatures, help reduce the damaging impact of floods, control pollution and regulate the climate. From economic importance, to esthetics, the reasons for conserving wetlands have become numerous over the past few decades.
The main functions performed by wetlands are water filtration, water storage, biological productivity, and habitat for wildlife.
Wetlands aid in water filtration by removing excess nutrients, slowing the water allowing particulates to settle out of the water which can then be absorbed into plant roots. Studies have shown that up to 92% of phosphorus and 95% of nitrogen can be removed from passing water through a wetland. Wetlands also let pollutants settle and stick to soil particles, up to 70% of sediments in runoff. Some wetland plants have even been found with accumulations of heavy metals more than 100,000 times that of the surrounding waters' concentration. Without these functions, the waterways would continually increase their nutrient and pollutant load, leading to an isolated deposit of high concentrations further down the line. An example of such a situation is the Mississippi River’s dead zone, an area where nutrient excess has led to large amounts of surface algae which use up the oxygen and create hypoxic conditions (very low levels of oxygen).
Wetlands can even filter out and absorb harmful bacteria from the water. Their complex food chain hosts various microbes and bacteria, which invertebrates feed on. These invertebrates can filter up to 90% of bacteria out of the water this way.
Wetlands can store approximately 1-1.5 million gallons of floodwater per acre. When you combine that with the approximate total acres of wetlands in the United States (107.7 million acres), you get an approximate total of 107.7 - 161.6 million million gallons of floodwater US wetlands can store. By storing and slowing water, wetlands allow groundwater to be recharged. And combining the ability of wetlands to store and slow down water with their ability to filter out sediments, wetlands serve as strong erosion buffers.
Through wetlands ability to absorb nutrients, they are able to be highly biologically productive (able to produce biomass quickly). Freshwater wetlands are even comparable to tropical rainforests in plant productivity. Their ability to efficiently create biomass may become important to the development of alternative energy sources.
While wetlands only cover around 5% of the Conterminous United States’s land surface, they support 31% of the plant species. They also support, through feeding and nesting, up to ½ of the native North American bird species.
Nearly all wetland conservation work is done through one of 4 channels. They consist of easements, land purchase, revolving land and monetary funding. In locations where wildlife habitat has been degraded and the land is for sale, wetland conservation organizations will seek to acquire it. Once purchased, the habitat will be restored and easements will be placed on land to perpetually protect resource values.
Our oceans are filled with items that do not belong there. Huge amounts of consumer plastics, metals, rubber, paper, textiles, derelict fishing gear, vessels, and other lost or discarded items enter the marine environment every day, making marine debris one of the most widespread pollution problems facing the world's oceans and waterways.
Marine debris is defined as any persistent solid material that is manufactured or processed and directly or indirectly, intentionally or unintentionally, disposed of or abandoned into the marine environment or the Great Lakes. It is a global problem, and it is an everyday problem.
There is no part of the world left untouched by debris and its impacts. Marine debris is a threat to our environment, navigation safety, the economy, and human health.
Most of all, marine debris is preventable.
Anything man-made, including litter and fishing gear, can become marine debris once lost or thrown into the marine environment. The most common materials that make up marine debris are plastics, glass, metal, paper, cloth, rubber, and wood.
Glass, metal, and rubber are similar to plastic in that they are used for a wide range of products. While they can be worn away - broken down into smaller and smaller fragments - they generally do not biodegrade entirely. As these materials are used commonly in our society, their occurrence as marine debris is overwhelming.
Debris typically comes from both land-based and ocean-based sources. Plastics are used in many aspects of daily life and are a big part of our waste stream. Derelict fishing gear refers to nets, lines, crab/shrimp pots, and other recreational or commercial fishing equipment that has been lost, abandoned, or discarded in the marine environment. Thousands of abandoned and derelict vessels litter ports, waterways and estuaries, creating a threat to navigation, recreation, and the environment.
How does marine debris move and where does it go? Wind, gyres, and ocean currents all impact how marine debris gets around. Floatable marine debris items, once they enter the ocean, are carried via oceanic currents and atmospheric winds. Factors that impact currents and winds, such as El Niño and seasons, also affect the movement of marine debris in the ocean. Debris items can be carried far from their origin, which makes it difficult to determine exactly where an item came from. Oceanic features can also help trap items in debris accumulation zones, often referred to in the media and marine debris community as “garbage patches.”
Wildlife entanglement and ingestion, economic costs, and habitat damage are some impacts of marine debris.
Marine debris is an eyesore along shorelines around the world. It degrades the beauty of the coastal environment and, in many cases, may cause economic loss if an area is a popular tourist destination. Would you want to swim at a beach littered in trash? Coastal communities may not have the resources to continually clean up debris.
Marine debris can scour, break, smother, and otherwise damage important marine habitat, such as coral reefs. Many of these habitats serve as the basis of marine ecosystems and are critical to the survival of many other species.
Wildlife Entanglement and Ghostfishing
One of the most notable types of impacts from marine debris is wildlife entanglement. Derelict nets, ropes, line, or other fishing gear, packing bands, rubber bands, balloon string, six-pack rings, and a variety of marine debris can wrap around marine life. Entanglement can lead to injury, illness, suffocation, starvation, and even death.
Many animals, such as sea turtles, seabirds, and marine mammals, have been known to ingest marine debris. The debris item may be mistaken for food and ingested, an animal's natural food (e.g. fish eggs) may be attached to the debris, or the debris item may have been ingested accidentally with other food. Debris ingestion may lead to loss of nutrition, internal injury, intestinal blockage, starvation, and even death.
Vessel Damage and Navigation Hazards
Marine debris can be quite large and difficult to see in the ocean, if it's floating below the water surface. Encounters with marine debris at sea can result in costly vessel damage, either to its structure or through a tangled propeller or clogged intake.
Alien Species Transport
If a marine organism attaches to debris, it can travel hundreds of miles and land on a shoreline where it is non-native. Invasive species can have a devastating impact on local ecosystems and can be costly to eradicate.
Marine debris, especially large and heavy debris, can crush and damage coral.
The world’s oceans are on the verge of collapse. The overexploitation of fish has tripled since the 1970s, rapidly depleting the seas of fish. About 90 percent of the world’s fish have now been fully or overfished, and a 17 percent increase in production is expected by 2025, according to the UN Food and Agriculture Organization (FAO).
The UN's The State of World Fisheries and Aquaculture (SOFIA) says that the state of the world's marine “resources” is not improving. Almost a third of commercial fish stocks are now fished at biologically unsustainable levels, triple the level of 1974. Some 31.4 percent of the commercial wild fish stocks regularly monitored by FAO have been overfished.
The situation in the Mediterranean and Black Sea - where 59% of assessed stocks are fished at biologically unsustainable levels - is alarming. This is especially true for larger fish such as hake, mullet, sole and sea breams. In the Eastern Mediterranean, the possible expansion of invasive fish species associated to climate change is a concern.
Globally, fish provide 6.7 percent of all protein consumed by humans. Some 57 million people are engaged in the primary fish production sectors, a third of them in aquaculture.
Fishery products account for one percent of all global merchandise trade in value terms, representing more than nine percent of total agricultural exports.
The depletion of the oceans' fish starts with consumer demand. You can make a difference by eliminating your consumption of seafood. The average person can save 225 fish and 151 shellfish a year by cutting seafood from their diet.