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Special Lecture Stand Structural Diversity
Forest Mensuration II Special Lecture Stand Structural Diversity Silvicultural practices in North America have dramatically changed over last two centuries. Since European settlement, forest management practices have evolved from exploitation during 17 to 19 centuries, timber management in the twentieth century, and today’s ecosystem management. Special lecture FORE 3128 Special lecture
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Biological Diversity Structure Genetic diversity
Stand level diversity () Local landscape diversity () Regional diversity () Species richness Evenness CCFM National Status -Criteria and indicators of sustainable forest management in Canada - show the report. Biodiversity refers to the variability among living organisms and the ecological complexes of which they are a part. They can be measured at ecosystem, species, and genetic levels. Ecosystem diversity describes the variety of ecosystems found in a landscape. This is often call beta diversity. Species diversity refers to the number and relative abundance of species found in an area. Genetic characteristics found within a species and among different species. Special lecture FORE 3128 Special lecture
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Objectives Concepts Classification of stand structure
Measures of stand structural diversity Special lecture FORE 3128 Special lecture
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Stand structure attributes
Living trees Snags, CWD Age Composition Special lecture FORE 3128 Special lecture
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Stand structure Arrangement of trees in space
Vertical horizontal Stand structural diversity-Variability among trees vertically and horizontally within a stand Special lecture FORE 3128 Special lecture
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Why stand structural diversity?
Ecological A measure of biodiversity Wildlife habitat Ecosystem process (e.g., productivity) Social Visual quality Management - structure based Special lecture FORE 3128
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Vertical structure Single-storied/ normal Multi-storied/ irregular
Frequency (stems/ha) Single-storied/ normal Multi-storied/ irregular Multi-storied/ inverse J Two-storied/ bimodal Special lecture FORE 3128 Smith et al. 1997 Special lecture
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Special lecture FORE 3128 Special lecture
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Special lecture FORE 3128 Special lecture
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Special lecture FORE 3128 Special lecture
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Special lecture FORE 3128 Special lecture
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Special lecture FORE 3128 Special lecture
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Measures of vertical structural diversity
Shannon-Weiner index (H´) Variance of tree size (S2) Special lecture FORE 3128 Special lecture
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Shannon-Weiner index (H´)
Stand A Stand B P1 P2 0.9 0.1 0.5 Example Stand C 0.33 0.34 P3 0.33 0.69 H’ 1.10 Special lecture FORE 3128 Special lecture
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Shannon-Weiner index (H´)
Frequency (stems/ha) Shannon-Weiner index (H´) DBH Proportion (Freq.) DBH Proportion (BA) Special lecture FORE 3128 Special lecture
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Variance of tree size Frequency DBH Frequency Special lecture
(stems/ha) Variance of tree size DBH Frequency Special lecture FORE 3128 Special lecture
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Horizontal structure Stand 1 Stand 2 Stand 3 Random Clumped
(aggregate) Uniform Special lecture FORE 3128 Special lecture
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Random Special lecture FORE 3128
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Clumped Special lecture FORE 3128
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Special lecture FORE 3128 Clumped
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Uniform Special lecture FORE 3128
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Measure of horizontal structure
Clark and Evans’ test (C) Special lecture FORE 3128
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Observed mean distance
= ( ,,,)/15 = m Special lecture FORE 3128 Special lecture
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Expected mean distance
Random (Poisson) distribution m Standard error m Special lecture FORE 3128
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Clark and Evans’ test C Clumped Random Regular -1.96 1.96
-1.96 1.96 C Special lecture FORE 3128
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Three-dimensional structure
Special lecture FORE 3128
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Structural complexity index (SCI)
z x y z Special lecture FORE 3128 Special lecture
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Problem with SCI Stand 1 Stand 2 Stand 3 Tree heights = 5 m
Special lecture FORE 3128 Special lecture
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Summary Concepts Classification of stand structure
Vertical Horizontal Measures of stand structural diversity Shannon-Weiner index Variance of tree size Horizontal: Clark and Evans test Three-dimensional: SCI Special lecture FORE 3128 Special lecture
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Possible research topics
Does increasing structural diversity affect Stand productivity? Silvicultural feasibility? Special lecture FORE 3128 Special lecture
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Special lecture FORE 3128
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Special lecture FORE 3128
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How do we measure landscape structural diversity?
Special lecture FORE 3128
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Criteria for Sustainable Forest Management
Conserving Biological Diversity Maintenance and enhancement of Forest Ecosystem Condition and Productivity Conservation of Soil and Water Resources Forest Ecosystem Contributions to Globe Ecological Cycles Multiple Benefits to Society Accepting Society’s Responsibility for Sustainable Development Special lecture FORE 3128 Special lecture
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