[News] Forests Are Growing Faster, Ecologists Discover; Climate Change Appears to Be Driving

[Moontanman]

Forests Are Growing Faster, Ecologists Discover; Climate Change Appears to Be Driving Accelerated Growth

 

ScienceDaily (Feb. 2, 2010) — Speed is not a word typically associated with trees; they can take centuries to grow. However, a new study in the Proceedings of the National Academy of Sciences has found evidence that forests in the Eastern United States are growing faster than they have in the past 225 years. The study offers a rare look at how an ecosystem is responding to climate change.

 

Forests are growing faster, ecologists discover; Climate change appears to be driving accelerated growth

[Eclipse Now]

Yes, recent papers are saying that Co2 may be the culprit behind the infamous tree-ring discrepancies with global temperatures after the 1960's, leading to the infamous 'hide the decline' climategate allegations from denialists.

 

http://www.morrissuntribune.com/event/article/id/20026/

 

However, the general saying that 'Co2 will make plants grow faster and thus reduce the Co2' that Denialists often use is wrong for a number of reasons.

 

Generally speaking, human beings are cutting down forests faster than they can grow.

 

Increased global warming temperatures are responsible for other factors (pests, bugs, etc) that will retard growth. EG: The Canadian pine beetle.

YouTube - Climate Denial Crock of the Week - Don't it make my Green World Brown http://www.youtube.com/watch?v=vFGU6qvkmTI&feature=player_embedded

 

Other nutrient limits will cut in so that exponentially increasing Co2 does not mean exponentially increasing plant growth: see Leibig's law of the minimum.

 

Also:

Nitrogen limitation constrains sustainability of ecosystem response to CO2 : Nature

 

Climate myths: Higher CO2 levels will boost plant growth and food production - environment - 16 May 2007 - New Scientist

[Eclipse Now]

Yes, recent papers are saying that Co2 may be the culprit behind the infamous tree-ring discrepancies with global temperatures after the 1960's, leading to the infamous 'hide the decline' climategate allegations from denialists.

 

http://www.morrissuntribune.com/event/article/id/20026/

 

However, the general saying that 'Co2 will make plants grow faster and thus reduce the Co2' that Denialists often use is wrong for a number of reasons.

 

Generally speaking, human beings are cutting down forests faster than they can grow.

 

Increased global warming temperatures are responsible for other factors (pests, bugs, etc) that will retard growth. EG: The Canadian pine beetle.

 

Other nutrient limits will cut in so that exponentially increasing Co2 does not mean exponentially increasing plant growth: see Leibig's law of the minimum.

 

Also:

Nitrogen limitation constrains sustainability of ecosystem response to CO2 : Nature

 

Climate myths: Higher CO2 levels will boost plant growth and food production - environment - 16 May 2007 - New Scientist

[Turtle]

...

Generally speaking, human beings are cutting down forests faster than they can grow.

 

so maybe we can mitigate things a bit by reversing that trend? i liked the idea uncle al pitched years ago about farming more trees for lumber. makes jobs, sequesters carbon, provides homes. make your charcoal for the tera preta crops from the waste.

 

as to the tree rings, the limiting growth factor for a given stand is specific to the geography of that stand. those trees in the article can't grow faster without more water, regardless of the other limiting (or promoting as the case may be) factors. :rolleyes: :phones:

 

...As used in dendrochronology, this principle states that rates of plant processes are constrained by the primary environmental variable that is most limiting. For example, precipitation is often the most limiting factor to plant growth in arid and semiarid areas. In these regions, tree growth cannot proceed faster than that allowed by the amount of precipitation, causing the width of the rings (i.e., the volume of wood produced) to be a function of precipitation. In some locations, rainfall is not the most limiting factor. For example, in the higher latitudes, temperature is often the most limiting factor that affects tree growth rates. In addition, the factor that is most limiting is often acted upon by other non-climatic factors. While precipitation may be limiting in semiarid regions, the effects of the low precipitation amounts may be compounded by well-drained (e.g. sandy) soils.

Principles and Definitions

[Eclipse Now]

Agreed, but the morris tribunal article I linked to made the point that with Co2 tree leaves can have less stomata open, and so don't lose as much water when they 'breathe'... making them less susceptible to drought and water deprivation.

[Turtle]

Agreed, but the morris tribunal article I linked to made the point that with Co2 tree leaves can have less stomata open, and so don't lose as much water when they 'breathe'... making them less susceptible to drought and water deprivation.

 

can't read it without paying. :rolleyes: i'd say that the reaction you describe is likely variable depending on species. moreover, i think in order to grow, trees have to use the water, that is, transpire, and that simply retaining it is not a sufficient condition for increased growth.

 

...Transpiration is important because it maintains a supply of water to the cells – essential for the cell processes to continue. A tree takes up a lot more water than it actually needs and the excess is used to carry the dissolved minerals from the roots to the leaves. ...

Forestry Insights

 

my point again is that without an increase in available water, there will not be an increase in growth. for the area in the article we are discussing, i would want to look at the rainfall records. :eek: :phones: :evil:

[Eclipse Now]

nice quote there from forestry insights... OK, I'm with you totally on this one.

[Turtle]

nice quote there from forestry insights... OK, I'm with you totally on this one.

 

roger. i saved both those sources to fav's. :rolleyes: one other point from the dendrochronology site of Henri D. Grissino-Mayer is that a wider ring (and a larger diameter tree trunk therefore) do not necessarily translate to more carbon sequestered. the individual cells may be large or small, few or many, and so the wood more or less dense. a proper study of the growth rate then in regards carbon sequestration, at the maryland cite or elsewhere, requires either felling trees, :eek:, or using an increment borer to extract cores for microscopic study. :evil:

 

just one other note; i mentioned rainfall/precipitation records, but in addition i think you need good records of all water resources coming to the stand(s) such as streams, aquifers, springs, etcetera. :phones:

[maikeru]

so maybe we can mitigate things a bit by reversing that trend? i liked the idea uncle al pitched years ago about farming more trees for lumber. makes jobs, sequesters carbon, provides homes. make your charcoal for the tera preta crops from the waste.

 

These sound like sustainable, "green" jobs we need right now. It'd be a nice positive feedback loop.

[Eclipse Now]

Oh yeah, agriwaste => energy crops => biochar => =>syngas / synfuel => soil amendment => carbon sequestration => rural energy security as peak oil kicks in => rural jobs... it's win win win win win win win!

[maikeru]

Gogo biochar. :)

[Eclipse Now]

Phillip Adams interviews an Aussie expert that says we can store more carbon in the soils cheaper, just by changing fertiliser practices and bringing the soil back to life.

 

How much carbon can we store in soil? - Late Night Live - 4 February 2010