sweet auburn | 2026 volume i
Did you know? Mount Auburn is home to over 5,000 trees, with Sugar Maple( acer saccharum), Flowering Dogwood( Cornus florida) being the taxa with the highest representation.
Water Availability.
The daily and seasonal availability of water is a critical environmental factor affecting the distribution of trees. The ability of soils to absorb and retain water has a direct impact on the type of vegetation and trees that can grow in a given location. Those soils that retain the least water will support only xeric forests, whose trees are adapted to very dry conditions. A different set of trees is adapted to mesic conditions, where the soil rarely dries out. The wettest habitats, those with standing water, harbor trees with shallow root systems or other adaptations for soggy soils.
Soil Composition.
The pH of the soils, often correlated with the history of the soils and the regional geology, has a significant impact on the vegetation growing there. In addition, some trees are better than others at tolerating the presence of heavy metals in soils. Often it is possible to determine the composition of soils just by looking at the types of trees that grow there.
Disturbance.
Changes to habitats can happen on a daily or seasonal basis, or they can be gradual, occurring over long periods of time. If change is steady over time, trees can often adapt to these changes. However, change can also be rapid, unexpected, or severe. Some trees tolerate natural disturbances better than others. Variation in tolerance for shade, drought, fire, and windthrow will determine the range of environments a tree can inhabit. Increasing human disturbance of natural
habitats is testing the tolerance of tree species. Air pollution in the form of acidic fog and rain can affect tree growth and mortality. The introduction of non-native plants, especially invasive vines such as Kudzu, English Ivy, Oriental Bittersweet, and Japanese Honeysuckle, can also influence the survival and growth of trees.
Pests and Diseases.
A major element of human-caused disturbance is the introduction of insects from outside of North America. The Gypsy Moth, Asian Longhorned Beetle, Emerald Ash Borer, and Wooly Adelgids are among the insects that have attacked many of our native tree species. In fact, the latter two species have had a significant impact on the collections at Mount Auburn. The Emerald Ash Borer was identified for the first time at the Cemetery in 2014. At that time, there were 17 ash trees in the collection; only 7 remain today. When the Hemlock Wooly Adelgid arrived in the 1990s, Mount Auburn had 380 hemlock trees. Today, there are 108 specimens remaining, under constant care by the arborists.
All trees are subject to disease and predation from native pests and herbivores, but where species of trees and pests have evolved together the native pests do not kill or even substantially harm the trees. It is the unexpected blights from outside North America that do the most damage. Non-native fungi and other pathogens have decimated populations of certain common tree species, such as the American Chestnut( Castanea dentata), American Elm( Ulmus americana), Butternut( Juglans cinerea), Eastern White Pine( Pinus strobus), and others.
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