Picea sitchensis in the context of Cupressus austrotibetica

Centurion is the name given to a single Eucalyptus regnans tree growing in Southern Tasmania, Australia. The tree was first measured by climber-deployed tapeline at 99.6 metres (327 ft) tall in 2008, and was subsequently re-measured to be 100.5 metres (330 ft) tall by ground laser in 2018. This discovery places E. regnans as the third-tallest tree species in the world after the coast redwood and the Himalayan cypress (which is generally much shorter), and taller than both the Sitka spruce and Coastal Douglas Fir.It was discovered in August 2008 by employees of Forestry Tasmania while analysing the data collected by LiDAR system used in mapping and assessment of state forest resources.

Dendroctonus micans, the great spruce bark beetle, is a species of bark beetle native to the coniferous forests of Europe and Asia. The beetles attack economically important spruce species including Picea abies (Norway spruce) and Picea sitchensis (Sitka spruce). The adults burrow into the bark of the trees and lay eggs there. The larvae feed on the phloem under the bark; they can girdle the tree if present in large enough numbers.

The species is a serious pest of commercial forestry, and is an invasive species in many regions where it is not native, such as the United Kingdom, France, Turkey, Georgia, and North America. While its main host is spruce, it also attacks coniferous trees of other genera, including firs such as Abies sibirica (Siberian fir); pines such as Pinus sylvestris (Scots pine); the Douglas-fir Pseudotsuga menziesii, and the common larch, Larix decidua. Biological pest control has been applied using a natural predator, the beetle Rhizophagus grandis, in several countries.

The Giant Forest, famed for its giant sequoia trees, is within the United States' Sequoia National Park. This montane forest, situated at over 6,000 ft (1,800 m) above mean sea level in the western Sierra Nevada of California, covers an area of 1,880 acres (7.6 km). The Giant Forest is the most accessible of all giant sequoia groves, as it has over 40 mi (64 km) of hiking trails.

Five of the ten most massive trees on Earth are located within the Giant Forest. The largest of these, the General Sherman Tree, measures 36.5 ft (11.1 m) across the base. The giant sequoia is the world's most massive species of tree and is one of the six species documented to grow to 300 ft (91 m) in height; the others are coast redwood, yellow meranti, Eucalyptus regnans, Douglas fir, and Sitka spruce. It is also among the longest-lived of all trees in the world.