Roadside Revegetation

TABLE OF CONTENTS
Figure 5-33 | Determining total N threshold values from reference sites 90
Figure 5-34 | Raising nitrogen levels 93
Figure 5-35 | The 13 essential mineral nutrients 95
Figure 5-36 | Soil pH levels across the US 97
Figure 5-38 | Soils with high salts 98
Figure 5-37 | Soluble salt affects on plants 98
Figure 5-39 | pH meter 99
Figure 5-40 | Wind erosion 101
Figure 5-42 | Areas in US with high winds 102
Figure 5-41 | Rainfall intensities across the US 102
Figure 5-43 | Freeze-thaw effects on planted seedlings 104
Figure 5-44 | Freeze-thaw ice crystals 104
Figure 5-45 | Soil erosion affects seed germination 105
Figure 5-46 | Soils are protected by a soil cover 105
Figure 5-47 | Many sites take more than one year to fully revegetate 106
Figure 5-48 | Sandy soils have low surface strength 106
Figure 5-49 | Infiltration rates 107
Figure 5-50 | Portable rainfall simulator 107
Figure 5-51 | Dry ravel 108
Figure 5-52 | Revegetation methods and slope gradients 109
Figure 5-53 | Effects of steep and gentle gradient slopes on revegetation 109
Figure 5-54 | Surface roughness creates favorable environment for germination 110
Figure 5-55 | Surface erosion increase with distance downslope 111
Figure 5-56 | Structures that shorten slope length 112
Figure 5-57 | Slumps and slides 112
Figure 5-58 | Water pressure and slope stability 113
Figure 5-60 | Restrictive layers and ground water 115
Figure 5-59 | Restrictive layers can decrease slope stability 115
Figure 5-61 | Live pole drains 116
Figure 5-63 | Effects of roots on slope stability 119
Figure 5-62 | Plant roots and slope stability 119
Figure 5-64 | Invasive species 122
Figure 5-65 | Hay often contains weed seeds 123
Figure 5-66 | Quality topsoil is low in weed seeds 124
Figure 5-67 | Gopher mounds 128
Figure 5-68 | Deer browsed seedlings 128
Figure 5-69 | Plastic netting can protect seedlings from animal browsing 129
Figure 5-70 | Chemical control of roadside vegetation 132
Figure 5-71 | Road signs identify areas to protect 132
Figure 5-72 | Graveling road surfaces can lead to burying roadside vegetation 133
Figure 5-73 | Creating shredded wood for mulch 134
Figure 6-1 | Steep roadcuts require erosion a control working group 138
Figure 6-2 | Example of a specialist species 138
Figure 6-3 | The Target Plant Concept 140
Figure 6-4 | Provisional seed zones 143
Figure 6-5 | Early planning for plant material procurement 147
Figure 6-6 | Planting long-tube stocktypes with an expandable stinger 148
Figure 6-7 | Survivorship can vary between spring and fall plantings 148
Figure 6-8 | Case Study – Low elevation, Western Cascade site 149
Figure 6-9 | Case Study – Cool, arid site 150
Roadside Revegetation: An Integrated Approach to Establishing Native Plants and Pollinator Habitat
xii