Nebraskaland

NEBRASKAland May 2018

NEBRASKAland Magazine is dedicated to outstanding photography and informative writing with an engaging mix of articles and photos highlighting Nebraska’s outdoor activities, parklands, wildlife, history and people.

Issue link: http://mag.outdoornebraska.gov/i/977334

Contents of this Issue

Navigation

Page 13 of 63

14 NEBRASKAland • MAY 2018 Tree Diversity By Steve Brey, Horticulturalist With emerald ash borer about to ravage our state and eliminate one of our most widespread and common native trees, the green ash, tree diversity is imperative. Dutch elm disease took the American elm out of our pallet of plantable trees starting in the 1960s. Every village, town and city used this iconic tree as a street and park tree. Because of our love for this tree, we couldn't get enough of it, and that was a big mistake. Along came Dutch elm disease, which for the most part, wiped out the entire American elm population. We learned a valuable lesson: diversify, diversify, and diversify. The problem is we did not heed our own advice, and because of this we are now facing another monumental problem of removing ash trees. Entire neighborhoods, or in the case of our state parks, entire campgrounds were planted back to ash after we lost our elms. That was understandable, as ash is a native tree; this species is very tough and able to withstand harsh growing conditions. But there was no excuse for over-planting. A useful guideline for tree planting is the 10-20-30 rule, proposed by Dr. Frank Santamour at the U.S. National Arboretum. The 10-20-30 rule, also called the 10 percent rule, basically states that in any one area the tree population should not contain more than 10 percent of one species, 20 percent of one genus and 30 percent of one family. If we follow this guideline now and in the future, we may not be faced with catastrophic losses when another insect or disease problem occurs. As an example, if you have 100 trees growing in one of your campgrounds you should have no more than 20 different kinds of oaks or 20 maples. Reducing trees to 30 percent of any given family becomes a little more difficult. Some experts have proposed the idea of no more than 5 percent of one species planted in any given area. Many of our campgrounds have cottonwoods that pre-date the campgrounds themselves, and these old giants are coming to the ends of their lives. This turnover will give us a chance to diversify these areas so we do not repeat history. Therefore, no more than 20 percent of any one genus should be planted in a given area. This concept is far from perfect, but it is a start to diversifying our campgrounds. ■ Tree diversity throughout the state will be key in the coming years to prevent disease outbreaks. PHOTO BY ERIC FOWLER

Articles in this issue

Links on this page

view archives of Nebraskaland - NEBRASKAland May 2018