Is a warmer world and elevated CO2 levels causing rainforests to recover and expand?

Question

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Recent Study States:

“There is emerging evidence of profound changes to the structure and function of tropical rainforests, both in northern Australia and elsewhere. The expansion of northern Australian monsoon rainforests parallels reports of expansion of tropical rainforest on the east coast of Australia and increased tree growth and biomass accumulation in tropical rainforests elsewhere in the world”.

“We consider it most likely that the expansion of rainforest patches is related to global climate change via increased rainfall and/or the CO2 ‘fertiliser effect’.”

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Answer 1

Congratulations for actually trying to read real science. You should pay a little more attention to the details, but this is a start.



The study you are referring to is not all that recent. It was published a couple years ago in Landscape Ecology.

http://www.springerlink.com/content/flr12164821742l7/



The lead author had already reported the same thing two years before that

http://onlinelibrary.wiley.com/doi/10.1046/j.1466-822X.2001.00252.x/abstract



The authors could not determine whether the increase in the Australian rainforest was due directly to the increase in CO2 or to the increased rainfall which is due to the increased water in the warming atmosphere. Either way, it is a benefit to the rainforests in Australia.



This increase can only happen in Australia or other county with environmentally sensitive politics. Australia protects the forest. They can grow if they are not cut down. And they are not cut down only if they are public land or if private owners are financially motivated to not cut them down. It is nonsensical to argue that we do not need environmental protections and to use as support success in protected environments. CO2 is good for trees in places that trees are not cut down and have increasing water available to support growth.



In the tropics, rainforests are being cut down at a rate of more than 50,000 square miles per year. It is nonsensical to argue that growth of protected Australian rainforest is good, but much more massive loss of tropical rainforests is not bad. If you are in favor of increasing plant life on earth, then you should be in favor of protections of that plant life. As is, there is no economic incentive for land owners to maintain the rainforests so they are being cut down. No small improvement in a few places can overcome the massive use of bulldozers.

Answer 2

How could it? Rainforests are already warm. And



"Soil in the tropical rainforests is very nutrient poor. The topsoil is only one to two inches (2.5 to 5 centimeters) deep."

http://library.thinkquest.org/C0113340/text/biomes/biomes.rainforest.soil.html







Is your question about Earth or about some hypothetical planet in another solar system?






<"The only reason plant life is so lush is because the plants store the nutrients in themselves rather than getting them from the soil."







That is so you, Maxx. If you don't like what you see, respond with an ad hom.







Everything Madd Maxx doesn't like is silly and dumb.







You must be losing your touch because you just made a true statement. Greenhouses also have plenty of water, which does not come from melting snow. (at least not in the greenhouse.) Greenhouses also have something known as fertilizer.

Answer 3

CO2 is absolutely beneficial for plant life. Without CO2 there would be no life on earth (plant or animal). But the impact CO2 has on plant life depends on what else is available for plant growth (water, nutrients, light, etc.) You think these things have no impact on plant growth? You think that the increase we see in human-emitted CO2 will all be offset by increased plant growth and will not result in climate change?



I can see where CO2 fertilization could help improve growth rates. Increase rain in tropical regions equals increased growth. Increased concentrations could help offset water deficiencies to some degree, depending on species. Same could be true of shade tolerance. This could have a huge impact on structure. Temperatures will increase most at high latitudes and altitudes, so I'd not expect the extreme warming in tropical forest areas. that we have seen at the poles for example.



However, many of the rainforest (not all) are in very nutrient-poor soils - the nutrient capital is in the organic matter growing on the soil. It the trees are stripped, the nutrients are done in just a few years. The effectively wash out and the soil desertifies. So, CO2 may not be the limiting factor. That means that increasing CO2 concentrations may not have a huge impact. That is why there is such a emphasis on preventive the loss of tropic forest ecosystems.





I read the paper using Baccheus's link ( I have access). The authors conclude that more rain, fire control and CO2 fertilization are the causes for the increase (this paper generates more test hypothesis for testing latter). After looking at some similar forest in other countries, they do not feel fire control is as important as more rain and CO2 fertilization. They cannot separate the two to consider the effect of each factor. It is back to LIMITING FACTORS - what limits forest growth in N. Australia the most. The authors DO NOT STATE that that all things being equal, increased CO2 from current levels has a profound positive affect on plant-life. In this study, the authors feel that increasing rainfall and/or CO2 fertilization increases forest growth. They do not/can not separate the two. The note that an adjacent arid savannah may become forested because it will become wetter, and the tendency for southern and eastern Australia to become drier may be offset by growth in the in this region, where it becomes wetter. CO2 fertilization will definitely help because in part, it allows water to be used more efficiently. The authors want to look specifically into what physiological mechanisms in the plant are most impacted by CO2 fertilization. That could give forest managers insights into what nutrients could be used to optimize the growth of these forest.



You must consider limiting factors. You cannot extrapolate from N. Australia rain forest to the entire world based on 1 study, especially if you really do want to know why CO2 fertilization may or may not work elsewhere, without considering limiting factors. Stop being stupid and learn a little science.



This research supports the facts that climate is changing, forests will be impacted (in a good way for N. Australia, not clear if good in E. or S. of the country)

Answer 4

I think yes. I live in eastern South Carolina and have observed that the forests around hear are growing thicker by the year. I cannot image how people 250 years ago could cut their way through the forest of today. I went to Jamestown Va last year. The common theme that I heard was " in the late 1700's these wooded areas were wide open areas". Jefferson build his home on this hill for the long view for his enjoyment. Today there is no view because of trees. As the world gets warmer, the forest will take over and put a natural brake on further global warming. Nature is more powerful than man.

Answer 5

Rain forest soil tends to be shallow, thin and depleted in nutrients. The basic life cycle of a rain forest tree involves a tree growing, dieing and then becoming the nutrient base for the next tree. In a rain forest that's been logged the soil quickly washes away, and if it's planted in grass so cattle can graze the soil usually depletes anyway...eventually what's left is an iron rich hard pan...pretty much good for nothing. Also, a good deal of the 'rain' in a rain forest is self produced...the trees suck up water and then expel it into the atmosphere producing micro climates that result in severe rainfall....which is sucked up by the vegetation and...so on. Rain forests are a bit like closed systems in that regard.



So, the idea that given a reduced soil, but a lot of CO2 and rain will result in a new rain forest is an idea with a lot of science left out. A depleted area with a lot of rain will be an eroded mess long before a jungle will take root. Possibly some low lying gullies and washes could accumulate enough viable soil to begin such a process, but we're talking geological time before that kind of small area could spread out over millions of square miles. Besides...any new rain forest would probably be cut down any way. It's a nice thought, but....fugetaboutit..it ain't gonna' happen!

Answer 6

source or GTFO



the main problem is deforestation is removing rainforest faster than it can grow. I'm yet to see any evidence of increased growth in aussie rainforest, and I still haven't since you don't feel it necessary to post a source. Seriously maxx, did you just make this up or did you read it somewhere? Post your f*cking source or don't post at all. How hard can it be, and why do you need to be told EVERY time?



EDIT: What's really sad maxx is you don't even know what a source is. Science has sources without urls, you don't need a link to tell us where it's from. This is the source: Bowman, et al. (2010). Has global environmental change caused monsoon rainforests to expand in the Australian monsoon tropics? Landscape Ecology 25:1247-1260.



So yes, I recall seeing this before. As others have stated, and I have done previously CO2 is only beneficial to NPP in a forest ecosystem if rainfall and nutrients are sufficient. Here are a few more sources for you to browse.



Waring, R.H. (1985). Imbalanced forest ecosystems: Assessments and consequences. Forest Ecology and Management, 12:93-112. http://www.sciencedirect.com/science/article/pii/0378112785900787



Knohl & Veldkamp (2011). Indirect feedbacks to rising CO2. Nature 475:177–178. http://www.nature.com/nature/journal/v475/n7355/full/475177a.html



Lindroth et al. (). Long-term measurements of boreal forest carbon balance reveal large temperature sensitivity. Global Change Biology 4:443–450. http://onlinelibrary.wiley.com/doi/10.1046/j.1365-2486.1998.00165.x/abstract;jsessionid=FFF2A0C13D1108A139244EA9FAD21E11.d04t02?userIsAuthenticated=false&deniedAccessCustomisedMessage=



Anyway, how is deforestation not relevant to your question? You asked "Is a warmer world and elevated CO2 levels causing rainforests to recover and expand" and I stated that deforestation is occurring faster than regrowth, ie there is no net gain of forest area. Perhaps you should load your question with more specific elements if you want to disregard the relevent facts. Have fun reading.

Answer 7

"@Trevor: " Increasing levels of CO2 and other GHG’s has to result in a greater retention of heat, this is governed by the laws of thermodynamics and quantum mechanics, like it or not there’s no escaping it." This statement is true in isolation with CO2 the only variable changing like in lab conditions. However, in the climate system there are feedbacks (both positive and negative) since there are many variables and processes interacting. In nature there are plenty of examples where the positive addition of a variable results in negative feedbacks being more powerful. I'm not saying this is the case with CO2 in the atmosphere I'm just saying it's not impossible and it would not break any laws of physics." Charitably, your "rebuttal" to Trevor is flawed. You can't have a feedback of any kind overpowering a nonexistent effect. Some feedback might be possibly overpower increased heat retention from CO2, but that does not negate the fact that CO2 increase MUST increase heat retention. You appear to be doing your best to muddy up scientific thinking. If enough people point out that your reasoning is flawed, we may get increased scientific understanding - but it doesn't erase your original attempt, just the negative effects.

Answer 8

You say "...all things being equal" but all things are not equal. This particular rainforest may expand with increased rainfall and increased CO2, but others are being slashed and burned out of existence. And just as there may be increased rainfall in tropical rainforests (which apparently you now accept), there will be other places with decreased rainfall, and as others have said CO2 may not be the limiting factor in a plant's growth--I would think that rarely it is. If you don't believe this statement, build yourself a little greenhouse where you can control the amount of CO2. Make it 2 or 3 times Earth's present value if you like. Now put a plant in there and don't water it. How do you think that plant will do? By your reasoning that plant should thrive; personally I think it will wither and die.



EDIT: There's nothing wrong with my logic. Tropical rainforests are decreasing in area at a rate I've heard quoted as 6000 acres per hour, much of that to slash and burn operations. Any individual plant may very well grow faster with more water and CO2, but that doesn't mean that the rainforests overall are increasing in area--they certainly are not. Once someone takes a saw or bulldozer and takes down a tree, it doesn't really matter how much CO2 is in the air or how much water they get, they're going to die.



I have never disputed that plants may grow faster if they have adequate water and increased CO2. The problem with is that in the mid-latitudes, where much of the world's food is grown (in contrast to the tropical rainforests), crops are threatened by having LESS rain due to global warming. We've already seen farmers let orchards die and let their fields go fallow because they did not have enough water for irrigation. They didn't say "Oh, look how much faster my crops are growing with all this extra CO2," because without water it doesn't matter how much CO2 is in the air.



My logic is that without water plants die--do you really want to dispute that? Even your own link credits increased rainfall as the possible reason one particular rainforest is expanding.

Answer 9

From what I see, yes it has. Unfortunately, most rain forests have been suffering from deforestation at such a rate that this might not even be measurable. Since CO2 Since there is such an immense amount of CO2 polluting our atmosphere, this could indeed be good for the rain forests and humans.



Studies have shown that while younger trees react to an increase in CO2 and experience faster growth, older trees send the excess CO2 to the roots and twigs rather than using it for growth. So the younger trees are then removing more CO2 and helping to clean the planet.

Answer 10

Actually, I think you'll find that, where rainforests are expanding, it's because we stop cutting them down. Tropical rainforests grow like fracking weeds, *when we let them*. I don't think global warming is to any significant degree changing what areas tropical rainforests can or will spread to, or how fast they grow. The main limiter on tropical rainforests is, and for at least the past several decades has been, us cutting them down.



One important thing you don't seem to have figured out. Plants (and other organisms) need a lot of different things. Generally speaking, there will be some limiting factor (food, or water, or sunlight, or certain nutrients, or whatever). With only very minimal exceptions, you can increase the other factors all you want without changing the population or growth rate of that organism, because they'll still be limited by that same limiting factor. And for most plants in "natural" conditions (not greenhouses with a "perfect" supply of nutrients and water), CO2 is not, not, not, not the limiting factor.

Answer 11

it seems to me fires and droughts were the news in the past few years. nature does not recover that fast, but it can be destroyed faster. Ask the australian farmers where hey think climate is going. The CO2 fertilizer effect is no match for human deforestation.

Answer 12

This is a quote from an article written by Rutan on Global warming.



Atmospheric Carbon Dioxide was likely 18 times today‟s concentration, during the Cambrian period when life‟s diversity was at its greatest expansion (red circle). It was 4 times the current level when the dinosaurs were killed by an asteroid. The only other extended time CO2was low, (like today) was a period 300 million years ago.



It is an extensive article which the warmies ignore rather than attack because it is pretty much bullet proof since he uses the IPCC's original figures and shows where they changed them to concoct GW.



http://rps3.com/Files/AGW/EngrCritique.AGW-Science.v4.3.pdf



I hope this link works.

Answer 13

yes

edit

Rainforests are already warm

tell that to the rain forest in Panama that is above 5000 feet and I know this because i watched Cody trying to survive barefoot freezing to death on the great show Dual Survivor