UVM Theses and Dissertations
Format:
Print
Author:
Copeland, Erin Marie
Dept./Program:
Forestry Program
Year:
2006
Degree:
M.S.
Abstract:
Riparian vegetation structures provide functionality and geomorphic controls to adjacent streams. The structural condition of aggregate patches (and their range of variability) at the reach scale influences the riverine system at the landscape scale. Yet, stream assessment approaches in the northeastern United States have focused on stream channel geomorphology as a primary indicator of stream condition, with a cursory examination of riparian vegetation. The physical components of riparian forests directly affect stream geomorphology and stream assessments would be more complete if they incorporated vegetative measurements. Creation of self similar classes of vegetative structure and examination of structures as related to stream assessment scores will facilitate understanding of forest structural influences on streams.
Our research: (1) investigated structural variability across a diversity of landforms within riverine corridors; (2) examined the disturbance regimes influencing differences among landforms and patch types; (3) classified riparian forest structural conditions based on this analysis; (4) looked at relationships between Rapid Geomorphic Assessment Scores (VTDEC) and riparian forest structure and; (5) determined the scale at which stream geomorphology and land cover are linked. We sampled 32 sites in the northwestern Champlain Valley, VT, USA. Sites were stratified by landform and were sampled using multiple forest inventory methods. Multiple statistical methods (GOF, Classification Analyses, and CART) were used to complete the analysis.
Structural condition varied within patches as a result of agricultural land use and flooding disturbance. The classification analysis designated groups based on land use, landform and stand development. Four forest metrics explained the greatest amount of variability in RGA scores; standard deviation of basal area was the greatest predictor of RGA. In addition, RGA was positively related to forest cover and negatively related to agricultural cover at the 2 finest scales. Riparian forest structures influence stream geomorphology and should be included in models examining stream condition using stream geomorphology as a surrogate.
Our research: (1) investigated structural variability across a diversity of landforms within riverine corridors; (2) examined the disturbance regimes influencing differences among landforms and patch types; (3) classified riparian forest structural conditions based on this analysis; (4) looked at relationships between Rapid Geomorphic Assessment Scores (VTDEC) and riparian forest structure and; (5) determined the scale at which stream geomorphology and land cover are linked. We sampled 32 sites in the northwestern Champlain Valley, VT, USA. Sites were stratified by landform and were sampled using multiple forest inventory methods. Multiple statistical methods (GOF, Classification Analyses, and CART) were used to complete the analysis.
Structural condition varied within patches as a result of agricultural land use and flooding disturbance. The classification analysis designated groups based on land use, landform and stand development. Four forest metrics explained the greatest amount of variability in RGA scores; standard deviation of basal area was the greatest predictor of RGA. In addition, RGA was positively related to forest cover and negatively related to agricultural cover at the 2 finest scales. Riparian forest structures influence stream geomorphology and should be included in models examining stream condition using stream geomorphology as a surrogate.