Tree Forms and Structure: Part 3 2018 Volume 24 issue 3

Tree Forms and Structure:Part 3

The expansive panoramas of the southwestern deserts have made visiting these landscapes “bucket list” items for people the world over. Big skies, vast open spaces and unobstructed views to distant horizons are a key element of the unique beauty of this often austere environment. A part of this openness is due to the modest stature of most native desert tree species. Characterized by multiple trunk growth forms, these trees rarely reach 40’ in height and are dispersed so as to allow each tree adequate space to capture the precious water that seasonal rains provide.

Multiple Trunk Elm Tree

Ulmus parvifolia

In the best examples of desert-adapted landscape designs, landscape architects feature these trees to help capture the sense of the natural desert and exploit their stature to preserve the view of the surroundings. In some respect, these multiple trunk tree forms are what distinguish desert landscape designs from traditional/ornamental landscape that include Elms, Oaks and Pistache. While it’s true that most traditional species typically grow as single trunk trees, multiple trunk forms are observed in nursery and propagation methods can increase the number produced. A greater availability of multiple trunk forms of these species would offer landscape designers the option to integrate desert-adapted and traditional trees without either looking out of place.  Such a blending of tree types, sharing a similar structure, would create landscapes that showcased the best of both types of trees and make for a more complex, more lush environment. Further, greater availability of multiple trunk traditional tree species expands the palette by offering landscape architects a variety of forms when using these trees, perhaps in ways not previously considered.

Multiple Trunk Oak Tree

Quercus virginiana

Examples of multiple trunk forms of Elms, Oaks and Pistache can be found in developed landscapes. They have been largely overlooked as they are few in number and do not always visually appear as we expect. There is clearly a place in the landscape for such trees and the opportunity to more seamlessly intersperse them with desert adapted species provides an additional advantage. Tree spacing and distribution, relative to other landscape elements, will require care and consideration as each group of trees bring different qualities to the build environment. Moving forward the creativity and imagination of the landscape architecture community will develop additional approach to arid adapted landscape designs with the incorporation of a new generation of traditional tree forms.