Arborglyphs, dendroglyphs, silvaglyphs, or modified cultural trees are carvings of shapes and symbols into the bark of living trees. Although most often referring to ancient cultural practices, the term also refers to modern tree-carving. Love carvings Carving names and initials into trees is a common practice among lovers; the carvings can last for decades, as a symbol of the permanence of the couple's love. This practice would appear to date back up to the classical era, with Callimachus writing in his Aetia, "But graven on your bark may ye bear such writing as shall declare 'Cydippe beautiful'" (fragment 73). It also appears in the Eclogues of Virgil: "Resolved am I in the woods, rather, with wild beasts to couch, and bear my doom, and character my love upon the tender tree-trunks: they will grow, and you, my love, grow with them." This carving was also practised in Renaissance England, as evidenced by the writings of William Shakespeare (in As You Like It, 1599) and John Evelyn (in Sylva, 1664). Damage to trees Carving in the bark may damage the tree, by allowing diseases or pests to enter the tree. Bark acts as a protective layer similar to the way skin does in humans, keeping pests and harmful bacteria out of the organism. Breaking the protective layer not only allows disease in, but it may also cause cellular damage if the cut penetrates below the bark, disrupting its ability to transport nutrients through xylem and phloem. Owing to the fungal systems that link some trees, disease may even spread to surrounding trees. Culturally significant dendroglyphs People around the world have carved designs in trees imbued with cultural or spiritual significance. These include Aboriginal Australian peoples, including in present-day New South Wales, Western Australia, and Northern Territory. In parts of Latvia and Estonia, some rural-dwelling people carve a cross on a certain tree after someone dies. In the western United States, there are incised drawings on aspens known as arborglyphs, made by shepherds and hunters, and there are carvings made by the Chumash people depicting astronomical features. Australasia Boabs in Western Australia In 2021, a collaborative project to find and trace histories etched in boab trees in the Kimberley region of Western Australia was launched. Researchers from four universities are working with Aboriginal communities and using photogrammetry to record 3D images of carvings on the huge trees, in the first systematic survey