Agenda - Parks and Recreation Commission - 09/20/2001

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Minnesota Forests· The acreage of Minnesota's forests has greatly decreased since the firs~ European settlers arrived. Then, about 31.5 million acres of our state's 51.2 million acres were forested. Wi~ the development of a.=~'iculture, roads, and cities, forests now cover only about I6.7 million acres. Fortunately, tree planting ~md natural succession are restoring some of the previously ~'orested M. innesota's forests have immense economic a~d.environmenral importance. The production and processing of wood and wood fiber is the second larges~ manufacturing industr7 in Minne- sota. Millions of tourists and r~cmadonal users are attracted- to the beauty and solitude of our forests. Forests also provide habitat for wildlife, protect soils, and renew water resources. And they eniuance the appearance of communities and promote health by reducing noise, cutting energy costs, screening unsightly views, and attracting songbirds and other wildlife. Your interest in learning more about trees is a major step toward protecting and enhancing these values. Shade Tolerance, Growth Rate, and Life Span The tree descriptions in this book include remarks abou~ u'ee uses, habitat, landscape limita- tions, and unique characteristics. They also note shade tolerance, height growth rate prior to maturity, and typic'al tit'e span. Shade Tolerance Shade tolerance describes the species' ability to establish and survive in various de~ees of shade. Shade-intolerant species require full sunlight. Intermediate species can survive in partial shade. Shade-tolerant species can surviv, e in dense shade. These classes not only provide impor- aunt species selection information for ¢'ianang, they-also can help you differentm£e species growing in a shaded forest from those ~owing in full sunlight. Growth Rate Growth rates are based on the height increase of a tree growing under average conditions in the Upper ivlidwest prior to maturity. Slow-growing is defined as 12 inches or tess per year, moder- ate-growing, t3 to 0-4 inches per year; and fast-growing, 25 inches or more per year. Trees grow continuously, but growth usu.ally slows ~'ter maturity. Life Span Trees are described az shor~-lived (less than 76 years), intermediate (76 to 150 years), or tong- lived (longer than [50 yearz). A tree's li£e span is influenced by many factors (e.g., disease. damage). Downtown urban trees, for,~ample, on average live only l0 percent as long = trees in rural area~. Therefore, the classes pg0vided, should only be viewed as potential ages. ........ 6 Minnesota