The ornamental design for a treestandstabilizer, as shown and described.
FIG. 1 is a perspective view of a tree stand stabilizer showing my new design;
FIG. 2 is a left-side view of the tree stand stabilizer shown in FIG. 1;
FIG. 3 is a right-side view of the tree stand stabilizer shown in FIG. 1;
FIG. 4 is a rear view of the tree stand stabilizer shown in FIG. 1;
FIG. 5 is a frontal view of the tree stand stabilizer shown in FIG. 1;
FIG. 6 is a top view of the tree stand stabilizer shown in FIG. 2;
FIG. 7 is a bottom view of the tree stand stabilizer shown in FIG. 2; and,
FIG. 8 is a left-side view of the tree stand stabilizer shown in FIG. 1 when in a folded, storage configuration.
The dashed lines represent environment and form no part of the claimed design. The dash-dot-dash lines in FIG. 6 represent boundaries and form no part of the claimed design.