  Lithium abundance derived in metal-poor main sequence stars is about three
times lower than the value of primordial Li predicted by the standard Big Bang
nucleosynthesis when the baryon density is taken from the CMB or the deuterium
measurements. This disagreement is generally referred as the lithium problem.
We here reconsider the stellar Li evolution from the pre-main sequence to the
end of the main sequence phase by introducing the effects of convective
overshooting and residual mass accretion. We show that $^7$Li could be
significantly depleted by convective overshooting in the pre-main sequence
phase and then partially restored in the stellar atmosphere by a tail of matter
accretion which follows the Li depletion phase and that could be regulated by
EUV photo-evaporation. By considering the conventional nuclear burning and
microscopic diffusion along the main sequence we can reproduce the Spite
plateau for stars with initial mass $m_0=0.62 - 0.80 M_{\odot}$, and the Li
declining branch for lower mass dwarfs, e.g, $m_0=0.57 - 0.60 M_{\odot}$, for a
wide range of metallicities (Z=0.00001 to Z=0.0005), starting from an initial
Li abundance $A({\rm Li}) =2.72$. This environmental Li evolution model also
offers the possibility to interpret the decrease of Li abundance in extremely
metal-poor stars, the Li disparities in spectroscopic binaries and the low Li
abundance in planet hosting stars.
