Brush matting sometimes is used to stop sand blowing. A surface mulch on the sand serves as a temporary check against sand movement. Brush was used in Michigan and Vermont on small blowouts when beachgrass was not obtainable. Rows of brush are laid with the butts toward the prevailing wind. Tops are laid over the butts of adjoining rows, like shingles. Permanent plantings of trees are set into the brush mat.

Brush mats have been of little value on dunes on the Pacific coast because winds have velocities of 40 to 50 miles an hour or more. Scouring or deposition of sand takes place as soon as the mat begins to deteriorate.

Hay can be used as a temporary mulch on blowouts or small areas of dune sand at road cuts, around dwellings, and in other disturbed areas. Permanent seedings or plantings must be made as soon as the weather is suitable because the hay mulch deteriorates very rapidly. The hay provides some organic matter, which is critically needed for successful dune plantings. Fire is a hazard when mulches are used.

Artificial barriers are only temporary measures.

THE ESTABLISHMENT of permanent vegetation is the final objective in the stabilization of dunes. The climax species of plants or species in common use in the area are best for the purpose. If grasses are the climax vegetation, a mixture of the right grasses will do the best job. If woody plants are the climax, the adapted species of trees and shrubs, properly managed, will provide the best permanent cover. The best adapted native species are found near the area of use and should therefore be considered for plantings.

Successful establishment of permanent vegetation is begun after the sand has been stilled.

Trees can be planted safely on Cape Cod 2 or 3 years after beachgrass is established. Various species of pine 3 to 5 years old and spaced 3 x 3 feet apart have been successful. They are Scotch pine (Pinus sylvestris), Mugho pine (P. mugo), Austrian pine (P. nigra), and pitch pine (P. rigida). The two native shrubs that have been transplanted successfully are southern bayberry (Myrica cerfera) and beach plum (Prunus maritime).

At Cape Hatteras in North Carolina,after moving sand dunes were stopped by planting them to sea-oats, beach-grass, adapted shrubs, and trees were planted for permanent cover.

At Fort Macon, N. C., a fair to good cover of sea-oats, sea panicgrass, broom-sedge (Andropogon virginicus), hoary milkpea (Galactic mollis) and trailing wildbean (Strophostyles helvola) was reported 2 years after planting.

On the gulf coast of Texas, seacoast bluestem (Andropogon littoralis), weeping lovegrass (Ergrostis curvula), and Veldtgrass (Ehrharta calycina) gave good stands when seeded in mulched dunes.

Stilled sands in the Great Lakes region are planted to jack pine (Pinus banksiana), Scotch pine, or pitch pine, spaced 4 x 5 feet, or to common pasture grasses, such as smooth brome (Bromus inermis) and orchardgrass (Dactylis glomerate), depending on the choice of the farmer.

A permanent cover is established on the inland dunes of the Great Plains by seeding into sorghum stubble such native grasses common to the area as Indiangrass (Sorghastrum nutans), switchgrass (Panicum virgatum), Canada wildrye (Elymus canadensis), sand bluestem or "turkeyfoot" (Andropogon hallii), big bluestem (A. gerardi), little bluestem (A. scoparius) and side-oats grama (Bouteloua curtipendula).

The best seeding time is in spring when soil moisture and rainfall are favorable for germination and growth.

Mowing is necessary to eliminate competition with weeds.

Along the west coast at the mouth of the Columbia River in Oregon and southward, a combination of native and commercially available species was used for final control. Tall fescue (Festuca elatior var. arundinacea) and Clatsop fescue (F. rubra), a local strain developed from native stands of red fescue, provided the sod cover. Hairy vetch (Vicia villosa) aided in the establishment of grasses by protecting them from sand blast and drying winds. Purple beachpea (Lathyrus japonicus) provided the long-lived legume in the mixture needed for furnishing nitrogen to the grasses. Seedings were made in the early fall when moisture was favorable and the temperatures were moderate.

More lasting protection can be provided along the west coast by planting stabilized dunes to adapted shrubs and trees. Mixed plantings are recommended in order to safeguard against the complete destruction of the tree cover from an epidemic of disease or insect pests. The one shrub that is most commonly used for this purpose is Scotch-broom (Cytisus scoparius). It provides good protection, adds beauty to the landscape, and, being a legume, supplies nitrogen to the soil. Two species of pine are planted for final control as 2-year seedlings spaced 8 x 8 feet alternating with the Scotch-broom. Monterey pine (Pinus radiate) is planted on the California coastal dunes. Shore pine (P. contorta) is planted on the coastal dunes of Washington and Oregon.

CAREFUL MANAGEMENT is necessary when stabilized sand-dune land is used. The erosion hazards are many, and the damages resulting from misuse come about quickly and usually are severe. Delays in making prompt repair of breaks in the protective vegetative cover, whether grass or trees, can be costly.

We list seven uses and cite the precautions for each.

Recreation: Trails and roads leading through loose sand should be covered with gravel, crushed rock, or blacktop in order to prevent a serious break in the sod or other ground cover that would subject the area to blowing. Provision should be made for adequate parking, camping, and bathing facilities to prevent undue wear and destruction of ground cover.

The entire area requires protection from fire by building fire trails and by restricting smoking and fires to camp areas. Containers should be provided for disposing of papers, trash, and other material that may otherwise increase the fire hazard. Promiscuous cutting of vegetation is not permitted. Wildlife: It is essential that an adequate cover of good food plants be maintained in order to attract wildlife. Such cover provides the needed shelter and food under which wildlife thrives. One should prevent fires and maintain trails and roads to provide access to all parts of the area for fire control.

Homes: Homes should not be built on unstable sands, such as foredunes where sand is being blown in.

When homes are being built in dune sand, proper precautions should be taken to prevent undue disturbance of existing ground cover. Access roads or trails should be surfaced promptly in order to avoid sand removal and deposition around buildings. Breaks in the sod should be repaired at once.

Woodlands: Woodlands on dunes provide fuel, posts, and pulpwood. Dunes with a good understory furnish Christmas greenery, such as salal, swordfern, cascara, huckleberry, and bearberry.

If seed trees of climax species do not occur nearby, they should be included in the composition to assure greater permanence by supplying the necessary seed for reproduction. One should give them proper protection by preventing fires, building trails, and regulating the cutting of trees.

Watershed cover and storage: The open texture of dune sand permits the ready intake of water without serious runoff. Stabilized dunes therefore act as reservoirs. Thus the Sandhills of Nebraska, for example, regulate stream flow by supplying water for domestic and irrigation use steadily throughout the growing season. The maintenance of a good cover prevents clogging stream channels with sand and debris and facilitates the infiltration of water.

Special crops: The growing of special crops can be considered only on azonal soils where the soil profile has begun to develop a condition that exists only in dune troughs or the more level low-lying flats between the stabilized dunes. This use is not recommended, but the pressure for land may be such that these lands are used for growing such crops as bulbs, cultivated blueberries, and cranberries.

Green manure crops help to maintain the organic matter and productivity of the soil. They also protect the soil during the time of year when the crop leaves the ground bare. To get high yields and enough cover to keep the surface from eroding, green manure crops should be fertilized. One should cultivate only as necessary to control weeds. Rotations for other than bog crops should include grasses and legumes in rotation. Windbreaks are necessary for adequate soil protection if such lands continue in cultivation.

Grazing: Pastures and ranges on dunes must be grazed carefully in order to keep the surface protected at all times. Every good pasture and range management practice is necessary to keep the range or pasture in good condition. Proper attention should be given to stocking rates, rotation and deferred grazing, and the placing of salt to avoid concentration of livestock at watering places and to aid in better distribution. Trailing to water and salt on the dune ranges should not be permitted.

The blow areas should be repaired promptly before they get larger and spread. The bottoms of haystacks or hay cut when the seed is ripe are used as mulch for stabilizing such danger spots; they should then be covered with brush to keep livestock out.

STABILIZED DUNES are managed primarily for recreation and for their esthetic value and for the protection of more valuable agricultural land, including forests, highways, harbors, military installations, resorts, towns, and cities.

Sand dunes must be stabilized and properly managed in order to control shifting sands permanently. Without proper management, there is grave danger of losing all the money and effort that has been invested in stabilization. For the most part, they should remain in ownership that provides for the enjoyment of the greatest number of people and without damage to the vegetation on them.