What causes tree bark to become darker?

Explanation:

Maybe how old the tree is? Like when it gets covered in dirt and stuff.

succession returns a disturbed

ecosystem to a more stable state. this is also classified into two (2) types:

primary succession and secondary succession. the primary succession arises when

a new land is transformed and a bare rock has been exposed providing an environment

that can be occupied for the first time. while, secondary succession occurs

when a previously occupied environment was disturbed that kills much of all its

community

explanation:

sodium i think the chemical element of atomic number 11, a soft silver-white reactive metal of the alkali metal group.