I would be interested to know if after a full cycle of forest plantations of Pinus sp without fertilization, if they could recover the initial level of nutrients (e.g. by atmospheric deposition) or if that level is never recovered.
This is a question, that has a long tradition to be investigated in forestry. There are plenty of articles available. However the answer very much depends on factors like site conditions (e.g. weathering of bedrock, nutrient availability in the soil, climate conditions...), which part of the trees are harvested (e.g. whole-tree, only saw timber, belowground biomass...), on time (e.g. rotation/ production time, thinning cylcle...) and on considering only the direct loss throug harvesting (e.g. taking stem, branches, needles away...) or also indirect losses (e.g. postharvesting trough changes in decompostion rates (e.g. run of with water, more light on the ground...) and of course on the type of harvesting regime (continuous cover forestry, clear cut system...). Some forst models deas with all these problems (nutrient driven...) others not. Difficult to give you the exact answer to your question. For a start, take a look at google.scholar... with "tree harvesting nutrient loss".
Sebastian
Sebastian Hein, Thanks for your reply! First allow me to make some clarifications. Certainly there are many lines of research that considered this issue, however, I have not seen one that considers the entire cycle. Most of them leave uncertainty !!
Regarding the question I mean afforestation short cycle, eg Pinus sp, with planting of 1600 trees per hectare, frequent thinnings to reach 300 plants per hectare at the end of the cycle of 20 years. At that time clearcutting is made and left in the ground the remains of the cup. Throughout the cycle of no fertilization planting is done.
Given these conditions, it is possible that the site reaches the original level of nutrients? There are several studies that mention that atmospheric depositions could cover the amount of nutrients exported during harvest. It will be possible?
Hi,
You can find the review I made for radiata pine on page 182 of 'Sustainable Management of radiata pine plantations' FAO forestry paper 170'. It is available on-line or can be downloaded through my Research Gate site. In Table 10.2 the data is presented on a mean annual basis, with the 'Other inputs' line being rainfall for P and cations.
Although there are many variables involved, stem-only harvesting is usually OK in the long term on many sites. Weathering rates, erosion, leaching losses and N fixation etc, as well as rainfall needs to be considered. Weathering is often more important than rainfall inputs for P and cations.
Some researchers have also developed models that can be run to see if there are trends over several rotations, but of course they are only so good as the data used to develop them and assumptions made.
Don
Dear Rodolfo,
Maybe this article is useful to know the percentage of nutrient loss with the Pinus sp.: http://www.jstor.org/discover/10.2307/1936402?sid=21106065681653&uid=4&uid=2&uid=3738792
Respect the inputs or nutrient recovery by atmospheric deposition, it is possible depending of the location of your plantation, e.g. if this is near an industrial area you can have more inputs of heave metals by atmospheric deposition, and you can test it analysing the nutrient concentration in the wood, or you can make a dendrochemical study to have a historical record of the nutrient inputs in this ecosystem. In the Amazon region is tested the inputs of nutrients like P by the aerosols coming from the Sahara Dust, you can check a recently study Here.
Saludos,
Darwin
http://www.nasa.gov/content/goddard/nasa-satellite-reveals-how-much-saharan-dust-feeds-amazon-s-plants/#.VP39-i5ggZx
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