Water and Soil - Project Planning and Management for Ecological Restoration - page 110

and brings the subsoil to the top. The nutrient levels of the subsoil will not impede sown native
species. In addition, moisture will penetrate more quickly down the soil column.
At times, there will be a need to excavate large holes or trenches that will later be filled and
planted. It is critical for successful plant establishment to maintain the soil horizons when refilling
excavations. To accomplish this, segregate soils during excavation and provide separate piles for
the soil horizons. Stockpiled soil should be clearly defined and identified were it occurs in the
soil profile. If the stockpile is to remain for a long time, it is good practice to record location of
collection (if not nearby the excavation), fence the stockpile, and provide for erosion control. Re-
application should be done in layers in reverse order (reverse backfilling) following the soil profile
(making a layer cake).
Erosion Control and Slope Stabilization
In most areas, it is necessary to install temporary erosion control measures wherever disturbed
areas will be exposed to wind, rain, or snowmelt erosion during the construction period (includ-
ing temporarily stockpiled soil). There are many sources of information on erosion control best
management practices. Many state and regional water quality control boards have published field
manuals for erosion and sediment control.
There are numerous biotechnical strategies and designs for using live and dead native plant
materials for simultaneously achieving slope stabilization (e.g., stream bank stabilization), erosion
control (e.g., gully control), and native plant community restoration. Useful information on soil
bioengineering is available on the Web as well as in many publications describing the design of
bioengineering measures along with photographs, diagrams, and drawings depicting their con-
struction (Gray and Sotir 1996; Hoag and Fripp 2002; Schiechtl and Stern 1996; Schiechtl and
Stern 1997).
Commonly used in erosion control strategies are straw bales, straw mats, straw rolls, and similar
products containing vegetative matter such as coconut fiber (coir). Seed from undesirable species
is commonly found in these products; thus, it is very important to specify that these types of materi-
als should be “weed-free.” It is not uncommon for invasive weeds to be introduced onto restoration
project sites because of a failure to specify “weed-free” erosion control materials.