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Effects of enhanced co2 on tropical forest growth

More clouds could cause higher temperatures at night as the clouds keep warm air from escaping into space. In deforested areas however it could cause not only hotter temperature but also less precipitation as there are less trees to give off water in transpiration.

Plants, animals and bacteria and fungi in the soil all play vital roles in the carbon cyclethe circulation of carbon between air, land, water and life forms, both plant and animal. Terrestrial vegetation uses 60 billion metric tons of carbon a year to grow, producing oxygen in the process.

Carbon dioxide is soluble in water and constantly being exchanged between the air and water. To grow plants remove carbon dioxide through the air via photosynthesis to produce energy and build tissue.

  1. Instead of improving the air we breath by adding oxygen it is now believed that the forest itself is neutral. Yet, she also cites numerous examples of how higher temperatures might reduce tropical forest productivity through declined rates of net CO2 assimilation or enhanced rates of respiration, which is, of course, equivalent to assuming the exact opposite.
  2. If they are driven by global warming, a vicious cycle of warmer temperatures and droughts could conceivably lead to a large-scale transformation of the forest over a period of decades.
  3. Plants, animals and bacteria and fungi in the soil all play vital roles in the carbon cyclethe circulation of carbon between air, land, water and life forms, both plant and animal.

Respiration by bacteria and fungi that feed on organic matter returns carbon dioxide to the atmosphere. Some carbon is removed from the system and stored for as long as millions of years locked up in ocean depths or crustal rock and as coal, oil and natural gas. Rainforest Weather Compared to the changing weather conditions in temperate forest, the condition in tropical rainforests remains pretty much the same: The main variations are the rainfall amounts which often time change between the wet and dry season.

Rainforests receive anywhere from 80 inches to extremes of inches of rain a year. Generally, a third of the rain evaporates, a third is absorbed by roots and greenery and third runs off. Even during strong thunderstorms sometimes little rain penetrates the canopy and reaches the ground.

Instead it is absorbed by plants and collects in pools in the leaves and branches in the upper reaches of the rainforest. The heat in the tropics is strong enough to melt the paint on the walls of steel hulled ships.

The shade provided by all the trees in the rainforest, however, keeps the temperatures lower than they otherwise would be. The humidity though makes being in the forest very uncomfortable for many people.

GLOBAL WARMING AND THE RAIN FOREST

The temperature and humidity are relatively constant at ground level in the tropical rainforest, but varies in the upper branches of the trees. Nadkarni, Academic Press] Carbon cycle Effects of Global Warming on the Rainforest In rainforests global warming could actually cause a cooling trend in the day as more clouds might be generated by a warming affect.

More clouds could cause higher temperatures at night as clouds keep warm air from escaping into space. This in turn could cause more rain. In deforested areas however global warming effects of enhanced co2 on tropical forest growth cause not only hotter temperature but also less precipitation as there are less trees to give off water by transpiration. Studies have shown that even pristine areas untouched by deforestation, logging and other human intrusions are showing changes.

One study published in Nature found that tree growth patterns during the past 20 years have been dramatically different growth patterns in previous year period, with large trees in the Amazon rainforests growing more quickly and smaller trees growing more slowly.

Global warming could set off a chain reaction with deforestation resulting in more carbon dioxide in the atmosphere and the increased heating causing the rainforest to dry and shrink resulting in even more carbon dioxide in the atmosphere.

Deforestation, Global Warming and Climate Trees absorb sunlight, warming the earth but their ability to absorb carbon dioxide and generate clouds has a net cooling effect. Deforestation and the burning of the tropical rainforest contributes to global warming mainly by using up oxygen and giving off carbon dioxide during the burning process.

Instead of improving the air we breath by adding oxygen it is now believed that the forest itself is neutral. The amount of oxygen trees give off during photosynthesis is roughly equal to the amount used up through the decay of organic material. The main source of carbon dioxide the greenhouse affect in the world today is the burning of the fossil fuels such as coal and oil.

The effect of deforestation on rain fall may be more alarming.

It is estimated, for example, that half of the water that falls on Amazonia is generated by the forests in Amazonia. The forests gives off water as respiration. If there are no forests the water either seeps into the ground or runs of into river. The decreased surface area of the water means that less is available for evaporation. In areas that have been cleared the humidity drops and hot winds start to rustle leaves that have never felt a breeze before.

Clouds sometimes stop forming over barren tracts of land and rain patterns shift. Some deforested areas have already noted drops in rain fall, and, some believe, the process could feed on itself.

More frequent severe droughts like those in and risk turning the world's largest rain forest from a sponge that absorbs carbon emissions into a source of the gases, accelerating global warming, the report found. Stuart Grudgings, Reuters, February 3, ] Trees and other vegetation in the world's forests soak up heat-trapping carbon dioxide effects of enhanced co2 on tropical forest growth they grow, helping cool the planet, but release it when they die and rot.

The study, published in the journal Science, found that the Amazon drought caused rainfall shortages over a 1. It was also more intense, causing higher tree mortality and having three major epicenters, whereas the drought was mainly focused in the southwestern Amazon. Amazon fires As a result, the study predicted the Amazon forest would not absorb its usual 1. In addition, the dead and dying trees would release 5 billion metric tons of the gas in the coming years, making a total impact of about 8 billion metric tons, according to the study.

In comparison, the United States emitted 5. The combined emissions caused by the two droughts were probably enough to have canceled out the carbon absorbed by the forest over the past 10 years, the study found.

The Amazon drought dried up major rivers in the Amazon and isolated thousands of people who depend on boat transportation, shocking climate scientists who had billed the drought as a once-in-a-century event. The two intense dry spells fit predictions by some climate models that the forest will face greater weather extremes this century, with more intense droughts making it more vulnerable to fires, which in turn could damage its ability to recover.

Under the more extreme scenarios, large parts of the forest could turn into a savannah-like ecosystem by the middle of the century with much lower levels of animal and plant biodiversity. Although human-caused deforestation in Brazil has fallen sharply in recent years, scientists say the forest is still vulnerable. The jury is still out as to whether global warming will produce more drought. A crucial question is whether the droughts are being driven by higher levels of greenhouse gases effects of enhanced co2 on tropical forest growth are an anomaly, Lewis said.

If they are driven by global warming, a vicious cycle of warmer temperatures and droughts could conceivably lead to a large-scale transformation of the forest over a period of decades. Prolonged drought or damaging rains could destroy crops and cause malnutrition.

Scorched soil absorbs more heat and retain less water, increasing droughts. The study may also boost a U. If these forests are locking away more carbon than thought, such projects could become more valuable. David Fogarty, Reuters, July 11 ] Trees need large amounts of planet-warming carbon dioxide CO2 to grow, locking away the carbon in the trunks and roots.

But scientists have struggled to figure out exactly how much CO2 forests soak up in different parts of the world and a global total for how much is released when forests are cut down and burned. The study released on Friday in the latest issue of the U. The researchers found that forests soak up more than 10 percent of carbon dioxide from human activities such as burning coal, even after taking into account all of the global emissions from deforestation.

Canadell and an international research team combined data from forest inventories, models and satellites to construct a profile of forests as major regulators of atmospheric CO2. Greenhouse gas emissions from burning fossil fuels and deforestation are rising rapidly, with growth being largely driven by surging coal, oil and gas consumption in big developing nations.

The researchers found that in total, established forests and young regrowth forests in the tropics soaked up nearly 15 billion tonnes of CO2, or roughly half the emissions from industry, transport and other sources.

But the scientists calculated that deforestation emissions totaled David Fogarty, Reuters, July 11 ] REDD aims to reward poorer nations that preserve their carbon-rich rainforests with a market-based scheme in which carbon credits are given for every tonne of carbon locked away. Many REDD projects currently being developed focus on peat-swamp forests because these contain the most carbon. Tropical regrowth forests could represent a new investment opportunity, Canadell said.

For example, you can reward countries like Indonesia and Brazil for reducing their deforestation rate but what about countries like Guyana and Suriname that have maintained high forest cover. Leaders of poor tropical countries have argued that the cheapest way to combat not only deforestation but also global warming is for rich, developed countries to pay poor, tropical developing countries not to fell trees. In conjunction with REDD Google UK has released satellite images of rainforest areas on the Internet, allowing anyone with Internet access to compare images of the same places at different times to monitor deforestation and make sure countries involved with the REDD agreement and keeping their promises.

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