Living tree with greatest girth

The living tree with the largest base is a Montezuma cypress (Taxodium mucronatum) named El Árbol del Tule found in the town of Tule near Oaxaca, Mexico. The 35.4-m-tall (116-ft 1.7-in) tree has an immense, spherical crown that averages 45.3 m (148 ft 7.5 in) in diameter. In 2005, a tape stretched around the circumference at a height of 1.3 m (DBH; diameter at breast height) reads 36.18 m (118 ft 8.4 in), which translates to a diameter of 1,151.6 cm (37 ft 9.4 in). However, the trunk is strongly elliptical and has large buttresses, so the actual DBH cross-sectional area (as calculated from a 3D model of the tree base) is 71.44 m2 (768.97 sq ft), which translates to a functional diameter of 953.8 cm (31 ft 3.5 in).

The total stem volume of El Árbol del Tule is 645 m3 (22,778, making it the third largest tree species in the world after the giant sequoia (Sequoiadendron giganteum) and coast redwood (Sequoia sempervirens).

The Tree of One Hundred Horses, a European chestnut (Castanea sativa) on Mount Etna in Sicily, Italy, had a circumference of 57.9 m (190 ft) in 1780, giving it the record for greatest tree girth ever. But unfortunately, due to abuse over the years, this tree is now in three widely separate pieces.

Generally speaking, the largest girths are attributed to African baobab trees (Adansonia digitata), with measurements of 43 m (141 ft) recorded. However, measurers need to make sure that it is indeed one mass (as the Montezuma is) rather than several trees fused together. El Árbol del Tule and baobabs grow on flat ground, so the difference between the cross-section area of the footprint (at ground level) and breast height (1.37 m – the height most people use to compare diameters) is small. However, giant conifers of both Sequoia and Sequoiadendron can grow on slopes (sometimes very steep slopes), so that the difference between the footprint and the horizontal diameter measurement is great. The Boole Tree Sequoiadendron provides a good example – the difference between high point of ground and low point of ground is 3.5 m (11 ft 5.8 in), so there is a great difference between the footprint area (87.14 m2/937.97 sq ft - greater than that of El Árbol del Tule) and the horizontal area at high point of ground (63.33 m2/681.68 sq ft - less than that of El Árbol del Tule).