background bark cracked crevice fissured hard natural nature oak protection protective Quercus rough texture tree trunk crack fissure Pinus sylvestris scots pine thick American larch backdrop bole branch brown crust green gullies moss mossy peeling plant red pine rind root shellbark hickory structure structures sweet birch textures timber tree bark Tree Stump trees wood woody plant amphibian animal animals Camouflage frog India krayker Tree frog big conifer enormous huger large redwood Sequoia aussie Australia essential eucalyptus food fragrance fragrant habitat home koala oil sveres cut felled floor forest log rings twigs woodland aspen canada deciduous pale populus colors colours edges fronds palm trees pith shapes Castanea chestnut crevasse surface