Betula papyrifera resistant to the borer but when grown in subideal conditions the defense mechanisms of the tree may not function properly. Chemical controls exist. It is the provincial tree of Saskatchewan and the state tree of New Hampshire. People sometimes vandalize the bark of this tree by carving into it with a knife or by peeling off layers of the bark. Both forms of vandalism can cause unsightly scars on the tree. Betula papyrifera Betula papyrifera (paper birch, also known as white birch and canoe birch) is a short-lived species of birch native to northern North America. Paper birch is named
Northern celestial hemisphere Northern celestial hemisphere The northern celestial hemisphere, also called the Northern Sky, is the northern half of the celestial sphere; that is, it lies north of the celestial equator. This arbitrary sphere appears to rotate westward around a polar axis due to Earth's rotation. At any given time, the entire Northern Sky is visible from the geographic North Pole, while less of this hemisphere is visible the further south the observer is located. The southern counterpart is the southern celestial hemisphere. In the context of astronomical discussions or writing about celestial cartography, this celestial hemisphere may also simply then be