Sure, you could argue that Tessa is the princess of the alfear race who supposedly descends from the elven race, and as such they are really close with nature related stuff, which is why the alfear are always born with water, wood or wind affinities while the elite among the royalty, have a chance to be born with "nature" affinity, which is a variant resulting of the combination of water and wood affinities.
And among the royalty, Tessa is considered to be the one with the highest potential ever, so based on the previous, one would be inclined to believe that such is the reason as to why those trees are acting subservient towards the alfear princess.
