deletions | additions       diff --git a/untitled.html b/untitled.html  index 510a572..704e24b 100644  --- a/untitled.html  +++ b/untitled.html 
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author = {R. J. Howard and M. A. Ferrari and D. H. Roach and N. P. Money},  title = {Penetration of hard substrates by a fungus employing enormous turgor pressures.},  journal = {Proceedings of the National Academy of Sciences}  }" data-bib-key="Howard_1991" contenteditable="false">Howard 1991, and also to widen existing cracks in mineral grains and rock fragments. The results of physical weathering is an increase in mineral surface area exposed to the soil solution.
 hydrolysis (or carbonation when carbonic acid is the main proton donor). Biotic processes have a strong influence on the soil solution pH via the exudation of protons in exchange of positively charges nutrients as NH4+ and K+, the exudation of organic acids and the release of CO2 into the soil solution.

Organic acids like oxalic acid and citric acid, not only contribute to proton-driven weathering. Their deprotonated anions (in this case oxalate and citrate) interact in a similar way as protons and hydroxide with the mineral crystal lattice. In fact, many of the deprotonated anions of organic acids are stronger weathering agents than protons and hydroxide. They behave as strong complexants with metals including Al3+, a central element in most mineral crystal lattices.

To understand the effect of mycorrhizal fungi, we first need to determine what is the limiting step in the dissolution process. 

  class="ltx_title_section">Fungal weathering in the lab

From lab to field

Conclusions