Plant Association and Management Guide Siuslaw National Forest
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I United States Department of I Agriculture Plant Associationand Forest Setvice I Pacific Management Guide Northwest Region I 1986 Siuslaw I National Forest I I 'I I 1 I I 1 I I I I I I United States Department of PLANT ASSOCiATION AND MANAGEMENT GUIDE Agriculture SIUSLAW NATIONAL FOREST Forest Service By MUes A. Hemstrom, Area Eco'ogist Pacific Sheila E. Logan, Assistant Eco'ogist Northwest Region R6-Eco 220.1986a May 1986 .1 I I I II I I I I I CONTENTS I Page I INTRODUCTION 1 Objectives I Classification Concepts 1 I Methods 2 THE STUDY AREA 3 Climate 3 I Geology and Topography 15 Soils 15 Vegetation Overview 19 I Natural Disturbance and Succession 2k MANAGEMENT CHARACTERISTICS 26 Wildlife Habitat 26 I Stand Growth and Productivity 32 Early Seral Development 112 Plant Association Mapping 53 I KEY TO PLANT ASSOCIATIONS 511 ASSOCIATION DESCRIPTIONS 60 Sitka spruce/devil's club CSS6-21 61 I Sitka spruce/fool's huckleberry-red huckleberry CSS2-21 63 Sitka spruce/Oregon oxalis CSF3-21 65 Sitka spruce/salal CSS3-21 67 Sitka spruce/salinonberry CSS5-21 69 Sitka spruce/salmonberry-salal CSS5-22 71 Sitka spruce/swordfern CSF1-21 73 Western hemlock/devils club CHS5-21 75 Western hemlock/dwarf Oregon grape CHSI-21 77 Western hemlock/dwarf Oregon grape-salal CRS1-22 79 Western hemlock/evergreen huckleberry CHS6-1O 81 Western hemlock/Oregon oxalis CHFI-21 83 Western hemlock/rhododendron-dwarf Oregon grape CHS3-21 85 I Western hemlock/rhododendron-evergreen huckleberry CHS3-211 87 Western hemlock/rhododendron-salal CIfS3-22 89 Western hemlock/rhododendron/swordfern CHS3-23 91 Western hemlock/salal CHSI-23 93 Western hemlock/salmonberry CHS11-21 95 Western hemlock/salmonberry-salal CHS11-23 97 Western hemlock/salmonberry-vine maple CHS11-22 99 Western hemlock/swordfern CHF1-22 101 Western hemlock/vine maple-salal CHS2-21 103 I Western hemlock/vine maple/swordfern CHS2-22 105 Noble fir community 107 REFERENCES CITED 109 APPENDIXVegetative and Environmental Tables by Association 113 I I LIST OF FIGURES page Figure 1. Intensive ecology plot design. Adapted from USFS Region6Resources Inventory methods (1985) 2 Figure 2. Precipitation andpotential evapotranspiration, Cloverdale, Oregon (Johnsgard,1963) 14 Figure3. Precipitation andpotential evapotranspiration, Reedsport, Oregon (Johnsgard,1961) 5 Figure 14. Precipitation andpotential evapotranspiration, Tideater, Oregon (Johnsgard,1963) 6 Figure5. Precipitation andpotential evapotranspiration, Valsetz, Oregon (Johnsgard,1963) 7 Figure6. Mean maximum and mean minimum air temperatures for Cloverdale, Reedsport, Tidewater, and Valseta, Oregon (Johnsgard1963, US Department of Commerce1965) 8 Figure 7. Total annual rainfall, North half, Siuslaw National Forest (US Department of Commerce,1965) 9 Figure 7 (continued). Total annual rainfall, South half, Siuslaw National Forest (US Department of Commerce,1965) 10 Figure8. August,1983rainfall, north half, Siuslaw National Forest (courtesy J. Reim, hydrologist, Siuslaw National Forest) 11 Figure 8 (continued). August,1983rainfall, South half, Siuslaw National Forest (courtesy J. Rein, hydrologist, Siuslaw National Forest) 12 Figure9. November,1983rainfall, North half, Siuslaw National Forest (courtesy J. Rein, hydrologist, Siuslaw National Forest) 13 Figure9(continued). November, 1983 rainfall, South half, Siuslaw National Forest (courtesy J. Rein, hydrologist, Siuslaw National Forest) 114 Figure 10. Typical pattern of community development on North and South slopes, Sitka spruce zone 21 Figure 11. Typical pattern of community development on North and South slopes, western hemlock zone 22 Figure 12. Typical pattern of community development on North and South slopes, western hemlock zone, South end of the Siuslaw National Forest 23 Figure13. Successional paths in the western hemlock/salmonberry association 25 Figure 11k. Deviations of actual height from predicted height (King, 1966) in a sample of Douglas-fir from Alsea District, Siuslaw National Forest 41 Figure 15. Early seral height growth of salmonberry and conifers in the western hemlock/salmonberry plant association, Mapleton Ranger District, Siuslaw National Forest Figure 16. Early seral height growth of salmonberry and conifers in the western hemlock/salmonberry plant association, Waldport Rarer District, Siuslaw National Forest Figure 17. Early seral height growth of salmonberry and conifers in the western hemlock/swordfern plant association, Mapleton Ranger District, Siuslaw National Forest 116 Figure 18. Early seral height growth of salmonberry and conifers in the western hemlock/swordtern plant association, Waldport Rarer District, Siuslaw National Forest 117 Figure 19. Early seral height growth of salmoaberryand conifers in the western hemlock/salal plant association,Mapleton Ranger District, Siuslaw National Forest Figure 20. Early seral height growth of salmonberryand conifers in the western heinlock/salal plant association,Waldport Rarger District, Siuslaw National Forest 119 Figure 21. Early seral cover development of selected shrub and herb species, western hemlock/salmonberry association, Mapleton Ranger District, Siuslaw National Forest 50 Figure 22. Early seral cover development of selected shrub and herb species, western heinlock/swordfern association, !lapleton Rarger District, Siuslaw National Forest 51 Figure 23. Early seral. cover development of selected shrub and herb species, western hemlock/salal association, Maplet.on Ranger District, Siuslaw National Forest 52 II LIST OF TABLES page Table 1. Soil series of Siuslaw National Forest plant associations 16 Table 2. Total rooting depth and effective rooting depth for soils of the Siuslaw National Forest 18 Table 3. Comparison of autecological characteristics of important Coastal tree species 20 Table IL. Wildlife habitat attributes for plant associations of the Siuslaw National Forest 27 Table5. Snags per acre by decay for plant associations of the Siuslaw National Forest 29 Table 6. Physical characteristics of Douglas-fir snags by detericration stage, Western Oregon 30 Table 7. Presence of cavities, decay class distribution, and diameter class distribution by snag species for Si.uslaw National Forest snags 30 Table 8. Snag species, cavity presence, diameter class distribution, and mean heitght by decay class for Siuslaw National Forest snags 31 Table 9. Snag species, cavity presence, decay class, and mean height by diameter class for Siuslaw National Forest snags 31 Table 10. Attributes of down woody debris by decay class for Siuslaw National Forest plant associations 33 Table 11. Physical characteristics of Douglas-fir logs by deterioration stage, Western Oregon 35 Table 12. Stand productivity by plant association for the Siuslaw National Forest 36 Table 13. Deviations of actual heights of stem sectioned Douglas-fir trees from predicted heights using King (1966) Table ilL. Height growth of crop trees by plant association group for the Siuslaw National Forest 43 Table 15. Height growth of salmonberry by plant association group for the Siuslaw National Forest 43 Table 16. List of TRI abbreviations, scientific and comn names of trees, shrubs, and herbs used in the key and association descriptions 58 INTRODUCTION Intensive management of National Forest lands addendum to this guide published in the near requires accurate evaluation of resource future. condition, capability and response to management. How can different forest types be distinguished? Classification of the Siuslaw National Forest How do they respond to manipulation?How lands is part of a larger project to classify all produotive.are they? Complete knowledge--acre by lands in Region 6. The ecology program has been acre--of species populations, growth rates, involved in this project for several years and the biomass, soils, and environment cannot be compiled Regional Forester has set a deadline of 1987 for at present. A reasonable alternative is to let finishing the classification work. the vegetation and soils of a site indicate potential species composition, productivity and response to management. CLASSIFICATION CONCEPTS Plant populations that have developed on a site Although climax stands have not developed on the over a long period have come into balance with, Siuslaw National Forest, a scheme based upon and are useful indicators of, their environment. potential natural vegetation was used for A classification of long-term, stable plant classification. Extensive, catastrophic fire communities (or assooiatjons)-.-combined with soils swept nearly all the landscape in the past 150 information--can be the basis of resources years. The few areas not burned support evaluation, project planning, and land management old-growth Douglas-fir and will not move into planning (USDA Forest Service Handbook 2090.11, climax condition for at least one or two 1986). centuries, even if left uncut. The use of potential natural vegetation (i.e., climax) to Classification of plant associations allows us to: describe plant associations does not mean that stands must be in climax status to be classified Plan management strategies--evaluate or even that we will ever see climax conditions. resource condition, productivity, and Instead, the concept relates to the environmental responses to manipulation. conditions that determine where a species could be climax and where it could not. Communicate--record successes or failures of' management actions, provide common Two major series are foun& on the Siuslaw National descriptions of resource conditions and Forest, the western hemlock series