Tree-free fiber compositions and uses in containerboard packaging

A containerboard packaging material comprising:

• at least one paper linerboard layer including 50%-95% by weight tree-based pulp material;
• and
• at least one fluted medium layer including tree-free pulp material, wherein the tree-free pulp material is present in the medium layer in an amount of from about 80% to about 100%, the tree-free pulp material including
• a first tree-free pulp material selected from the group consisting of corn stover, straw, other land-based natural fibers, and combinations thereof and present in an amount of from about 10% to about 60%, and
• a second tree-free pulp material selected from seaweed and present in an amount of from about 5% to about 30%.