11/21/2016 READING THE LAND. vegetative & other indicators must be interpreted in context with other available sitecharacterization.

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1 READING THE LAND INTRODUCTION TO LANDSCAPES ON THE EDGE design & implementation of projects on Puget Sound shorelines & urban ravines Nov site assessment & evaluation using vegetative indicators Elliott Menashe THE MORE YOU LEARN ABOUT THE WORK SITE THE BETTER YOU CAN DO YOUR JOB vegetative & other indicators must be interpreted in context with other available sitecharacterization information CONSIDER: micro topography aspect slope gradient soils hydrology micro climate how do these factors affect landscape design? VASHON ISLAND, KING COUNTY 1

2 NATIVE SPECIES AS INDICATORS OF SITE CONDITIONS madrone ASSESS AS A PLANT COMMUNITY oceanspray salal COUPEVILLE, WHIDBEY ISLAND Pacific Madrone (Arbutus menziesii) indicates a dry, sunny, well drained site with sandy or gravelly soils (probably south or west facing) HOOD CANAL PENN COVE, WHIDBEY ISLAND OCEANSPRAY (Holodiscus discolor) Full to partial sun Dry to moderately dry sites Nitrogen medium sites Soil ph of

3 SALAL (Gaultheria shallon) Nitrogen poor soils Undisturbed areas DOUGLAS FIR (Pseudotsuga menziesii) Drier sites Well drained soils Deep, loam soils GREENBANK, WHIDBEY ISLAND BIGLEAF MAPLE (Acer macrophyllum) Moist, well drained soils Nitrogen rich sites 3

4 WESTERN RED CEDAR (Thuja plicata) Wet to moist sites North/East aspects Nutrient rich soils RED ALDERS ON STEEP SLOPES Indicates past disturbance: maybe clearing maybe landslides and/or presence of seeps & springs CAMANO ISLAND FROM WHIDBEY ISLAND SALMONBERRY (Rubus spectabilis) disturbed sites springs & seeps wet soils nitrogen rich soils 4

5 SKUNK CABBAGE (Lysichitum americanum) wetland soils organic muck soils nutrient rich soils wetland indicator indicates critical area Sitka spruce Red cedar MOSSES Shade Low soil fertility Compacted soil Moist soil Low ph (usually in a combination of two or more of the above) OLYMPIC NATIONAL PARK WESTERN SWORDFERN (Polystichum munitum) Nitrogen rich soils Humus rich soils Moist areas 5

6 TREE GROWTH HABIT TELLS A STORY SINCLAIR INLET, KITSAP COUNTY GUARDIAN & SENTINEL TREES HIGH value for slope protection Exposed & adapted to harsh conditions Resistant to storm damage Resistant to salt laden wind Exceptionally well rooted DOUGLAS FIR PACIFIC MADRONE indicates strong prevailing winds DOUGLAS FIR, ADMIRALTY INLET, ISLAND COUNTY 6

7 Curved-trunked Douglas Fir suggests past landslide from below tree is adapting rooting is secure providing slope stabilization should not be cut indicates a recent deep seated landslide Jack Strawed Trees on Slope Curved Tree Trunks (Pistol Butt) could indicate Soil Creep could be something else.. 7

8 DENSE PATCHES of RED ALDER on SLOPE indicates past mass soil movement PORT SUSAN, PUGET SOUND old growth stumps on steep slopes indicate a fairly stable site DOUGLAS FIR OLD GROWTH CEDAR, URBAN RAVINE Windthrowed Trees Shallow soils? Changes in hydrology? Recent logging or clearing? Atypical winds? The presence of root rot? 8

9 PARKED OUT SITES & LAWN SMUGGLER S COVE, WHIDBEY IS soils may be compacted SURFACE ROOTS compacted soils high watertable poor drainage shallow irrigation trees growing on beach indicates minimal wave energy and shoreline erosion HOLMES HARBOR, WHIDBEY ISLAND 9

10 READING THE WEEDS TO LEARN ABOUT THE SOIL indicates: erosion hydrology soil chemistry CLINTON BEACH, WHIDBEY ISLAND Common Dandelion (Taraxacum officinale) Disturbed areas Compacted soil Clayey soil Acidic soil Common Horsetail (Equisetum arvense) Water receiving Very moist soils Disturbed areas 10

11 Creeping Buttercup (Ranunculus repens) heavy clay soils wet soils poor drainage nitrogen rich soils Stinging nettle (Urtica dioica) disturbed sites acidic soils highly fertile soils damp areas often associated with Red alder Palm trees indicate It s time for a break NAVITI ISLAND, FIJI 11

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