1973 ALASKA RE VEGETATION WORKSHOP,

Transcription

1 COOPERATIVE EXTENSION SERVICE University of Alaska 1973 ALASKA RE VEGETATION WORKSHOP, " «WBBT «. MWBHNCE ^ 12/73/157/ACE/500 RP-239

2 TABLE OF CONTENTS A VEGETATIVE GUIDE FOR ALASKA Mr. Ted G. Freeman Soil Conservation Service l NEEDS AND REASONS FOR STABILIZATION 4 Mr. George D, Bow en Department of Highways SOIL CONSIDERATIONS IN REVEGETATION PROGRAM... 7 Dr. Sam Rieger Soil Conservation Service GRASSES AND LEGUMES FOR REVEGETATION IN ALASKA Dr. Les J. Klebesadel Agricultural Research Service FERTILIZERS 24 Dr. Winston M. Laughlin Agricultural Research Service MULCHING IN ALASKA,, r 27 Mr. J. C, Stover Alyeska Pipeline SITE PREPARATION AND SEEDING METHODS FOR CRITICAL AREAS,,,..,.,.,,..,...,.,,. 34 Mr. John L. Schwendiman Soil Conservation Service MAINTENANCE OF REVEGETATIVE GRASS SEEDINGS Mr. Art Hawk Soil Conservation Service USES OF WOODY AND HERBACEOUS ORNAMENTAL GROUND COVER MATERIALS,,,. 45 Mr. Alan C. Epps Cooperative Extension Service ALASKAN CLIMATIC AND ECOLOGICAL PATTERNS AS RELATED TO REVEGETATION POSSIBILITIES Dr. Wm, W. Mitchell Institute of Agricultural Sciences NATURE OF WATER POLLUTION 59 Dr, Fred Lotspiech Environmental Protection Agency

3 L, J, Klebesadel Agricultural Research Service, USDA The 1972 publication, A Vegetative Guide for Alaska, lists preferred varieties of grasses and legumes for use in revegetation in various areas of the state, according to soil types, growing conditions and intended uses, These suggestions represent the present status of our knowledge of the best species and varieties to be used, based on numerous trials over many years by various agencies and individuals. Two points should be stressed at the beginning of this talk: (1) Unfortunately, until very recently, we have had no project devoted solely to revegetation work. The little work done in this area has been accomplished on a basis somewhat peripheral to the main course of our work with forage crops, (2) Fortunately, we have had a project that has offered us a unique opportunity to gain an appreciation of the natural reservoir of native grasses and legumes in the Alaskan flora. This project, initiated in the late 1950's, enabled us to generally assess potential utility of these native plant materials for use in various avenues of artificial application, including revegetation and soil conservation. Active plant exploration continued for approximately a decade in Alaska by resident agronomists on this project funded substantially by The Rockefeller Foundation, Under the general supervision of R. L. Taylor, numerous trips were made by charter aircraft and riverboats to remote areas of Alaska and by vehicles on all of the (then) territory's road system. Along with collections of herbarium specimens, seed and vegetative transplants gathered over several years were used to establish field nurseries at the Matanuska Research Farm to evaluate indigenous species under uniform growing conditions. There, collections were observed throughout the growing seasons of several years to note winterhardiness, disease susceptibility, vegetative spread, seed-producing potential, and other agronomic characteristics. From these screening nurseries, numerous accessions potentially useful for forage, turf or conservation uses have been selected, propagated and moved along in more intensive evaluations, A stranger to revegetation problems and processes logically might ask the following questions concerning grasses and/or legumes to be used: "Why complicate the issue by recommending a long list of species? Why not test all of the logical contenders and arrive at the one very best species for all purposes?" The answer to this obviously is that soils and growing conditions vary markedly throughout Alaska and no single species is suitable for all of the many different situations where revegetation is required. For example, one grass may be superior on a drouthy site while a different

4 species performs best in moist areas. Some species are more tolerant of acid soils than others. And so on. For revcgetation purposes, grasses and legumes to be considered for use in Alaska fall into three general categories: (a) (b) (c) Varieties developed elsewhere, seed of which is abundantly available in North American seed-trade channels. For utility in Alaska, these materials range from good to totally useless, with most falling in the marginal category. New varieties developed in Alaska and possessing ideal adaptation for use in many areas of Alaska. Seed supplies of many of these currently are inadequate but efforts are being made to expand supplies. Potentially useful native grasses and legumes that we currently are looking at, several of which undoubtedly will be utilized in the future. No seed supplies of these exist except very small experimental lots or as harvested from native stands. Propagation The simplest and easiest propagation of grasses and legumes is by seed. In order to facilitate seed productions of new Alaskan varieties and native Alaskan species, numerous experiments must be conducted to define optimum managerial practices for most efficient seed production of each, A few of the native grasses evaluated display very vigorous vegetative spread by underground stems (rhizomes) but produce very few seed heads, and often very little seed in the seed heads that are produced. If these grasses are to be utilized, it will necessarily be via vegetative propagation such as "sprigging." By this method, rhizomes are dug from the soil, chopped into small segments, spread on a prepared seedbed and disked into the soil. This technique involves a more perishable product than seed and must be handled accordingly; however, much bermudagrass is successfully propagated by this method in the southeastern U.S. Varieties or Cultivars These words can be considered synonymous for purposes of this discussion. Their effect in revegetation is extremely important. A variety or cultivar simply means an identifiable selection of a plant species that is chosen for its combination of superior characteristics, and is thereby given a "name" (examples: Polar bromegrass, Nugget Kentucky bluegrass). It is then the responsibility of the plant breeder to maintain the genetic purity of the variety,

5 Variety names, then, become a vitally important clue to the usefulness of a grass or legume in Alaska. For example, timothy is a grass species widely used in Europe and North America. From this species, numberous varieties have been selected for their adaptation and superiority in the area where they were selected, or in other areas of similar climate. For superior winterhardiness in Alaska, we must use grass varieties selected for use in northern areas: Engmo timothy, from northern Norway is far more winterhardy in Alaska than Glair timothy, released in Kentucky and possessing ideal adaptation to states of that area, far south of Alaska. A cheaper price is sometimes an inducement to purchase a more southern-adapted variety than is recommended for use in Alaska. This frequently is unmasked as a "false-economy" when the poorly adapted variety winterkills and must be reseeded one or more years later. Annuals Several annual and winter-annual grass species are useful for temporary soil stabilization. For example, perennial species usually establish best with early planting. If, however, an area to be revegetated is not prepared for planting until mid-july or later, it may be prudent to seed an annual grass to hold soil materials in place against the erosional forces of autumn rains and spring melt water, A perennial cover can then be planted early during the following growing season. Species suited for such use include annual or "common" ryegrass and winter rye. These should be planted prior to August 10 to 15 in southcentral and interior Alaska. Spring barley is less satisfactory than ryegrass or winter rye, but is superior to oats for late-season planting, No annual legumes are recommended for use in soil stabilization in Alaska. Perennials - Grasses Among perennial grasses, two general growth types are recognized. Bunch-type grasses are characterized by very little spread of individual plants; each plant remains as a separate clump (examples: timothy, slender wheatgrass). Sod-forming grasses spread by underground rhizomes; these grasses tend to bind the soil somewhat better than bunch types and therefore are more effective soil stabilizers for many situations (examples: bromegrass, Kentucky bluegrass). The following grasses have been evaluated in south-central Alaska and found to be adequately winterhardy; if named varieties differ in hardiness, the first-named is hardiest in Alaska, varieties not listed are not recommended for use in Alaska. If no named varieties exist, non are listed

6 SOD-FORMERS Grass Latin Name Varieties Smooth bromcgrass Kentucky bluegrass Red fescue Streambank wheat grass Creeping foxtail Quackgrass (Dromus in er in is) (Poa pratcnsis) (Festuca rubra) (Agropyron riparium) (Alopecurus arundinaceus) (A g ropy ron rep ens) ** - considered a serious weed in farm fields (Bromus pumpellianus) Arctic bromegrass Beach wildrye Salt bluegrass Sweet holygrnss (Elymus mollis)** (Poa eminens)** (Hieroeliloe odorata)*** Polar*, Carlton, Manchar Nugget*, Merion, Park Aretared*, Boreal, Olds Sodar Garrison (no vars.) (no vars.) (no vars,) (no vars,) (no vars.) Seed supplies not always adequate at present Commercial seed supplies non-existent at present, seed must be collected from native stands Poor seed producer, may require vegetative propagation BUNCH-TYPE: Grass Latin Name Varieties Timothy Hard fescue Siberian wildrye Arctic wheat grass Slender wheatgrass ** Bluejoint Tall arcticgrass (Phleum pratense) Engmo* (Festuca ovina duriuscula) Durar (Elymus sibiricus)* * (no vars.) (Agropyron sericeum)** (no vars.) (Agropyron trachycaulum) Revenue (Calamagrostis canadensis)** (no vars,) (Arctagrostis arundinacea) ** (no vars.) The following perennial grasses are considered marginally winterhardy for use in Alaska. They may perform well where winter stress is moderate or they may fail where stress is severe (habitat differences can greatly influence exposure to winter stress and resultant survival of grasses; a marginally winterhardy grass may consistently winterkill in

7 an exposed farmer's field where winds remove the insulating mantle of snow, but persist successfully in an adjacent roadside where snow remains in place over winter). This list is necessarily incomplete, as a listing of nil grasses in this category would be quite lengthy, Only those most commonly considered for use in Alaska are included. SOD-FORMERS: Grass Latin Name Varieties Reed canary grass (Phalaris arundinacea) Frontier Redtop (Agrostis alba) (novars.) BUNCH-TYPE: Grass Latin Name Varieties Meadow foxtail (Alopecurus pratensis) (novars,) Crested wheatgrass (Agropyron desertorum) Summit Perennials - Legumes Legumes are valued for their capacity to incorporate atmospheric nitrogen from air in the soil into their plant tissues, Some legumes spread by underground rhizomes (birdvetch) or above-ground stolons (white clover); some do not spread. Some have deep penetrating taproots (sweetclover), some have fibrous root systems (alsike clover). Certain of the legumes possess colorful, attractive flowers. As a group, legumes are less used and currently less important than grasses in revegetation. However, it is believed that their importance will grow as seed of adequately winterhardy legumes becomes available in Alaska. INTRODUCED LEGUMES; Legume Spreading: Latin Name Varieties Birdvetch (Vicia cracca) (novars.)** White clover (Trifolium repens) Intermediate: Alfalfa (Medicago sativa) Denali* Siberian alfalfa Non-spreading: (M. faleata)** (novars,) White sweet clover (Melilotus alba)**** Yellow sweet clover (Melilotus officinalis)**** Alsike clover (Trifolium hybrid urn) Aurora Red clover (Trifolium prat ens e) Alaskland* - 20-

8 **** Several varieties of these biennial legumes are available from Canada and the conterminous states. However, because those varieties are nonhardy to marginally so in Alaska, their use here is not recommended New experimental selections in plant breeding programs at the Institute of Agricultural Sciences are far superior to imported varieties in winterhardiness; however, seed supplies are not yet adequate for release to growers. Perennials - Native Alaskan Legumes Numerous native legumes occur throughout Alaska, Several species play a conspicuously effective role in natural revegetation processes. This is seen in areas of glacial retreat, roadbuilding and other areas left devoid of vegetation. Some of the native legumes are active "colonizers" or "pioneer" species that precede other vegetation and effectively stabilize soil materials, and build up soil fertility, thereby assisting to promote successful entry of other plants. It is logical that following artificial seed increase, several of these species can contribute materially to artificial revegetation efforts. The various species of native legumes differ considerably in habitat requirements; therefore, careful attention will have to be devoted to planting species on sites where they will thrive, Some of the species judged to possess potential for use in revegetation work are included in the following list. No named varieties or commercial seed supplies exist of these legumes: Lupines: Arctic lupine Nootka lupine Large-leaved lupine Milkvetehes: American milkvetch Williams milkvetch Alpine milkvetch Harringtons milkvetch Tanana milkvetch Yukon milkvetch Sweetv etches: Alpine sweetvetch Mackenzie sweetvetch Oxy tropes: Koyukuk Plains Wild peas: Beach pea (Lupinus arcticus) (L. nootkatensis) (L. polyphyllus) (Astragalus americanus) (A. williamsii) (A. alpinus) (A. harringtonii) (A. striatus) (A. yukonis) (Hedysarum alpinum americanum) (H. mackenzii) (Oxytropis koyukukensis) (Oxytropis campestris) (Lathyrus maritimus)

9 REFERENCES 1. Hodgson, H. J., R. L. Taylor, A. C. Wilton, and L. J. Klebcsadel Registration of Nugget Kentucky bluegrass. Crop Science. 11: Hodgson, H. J., R. L. Taylor, A, C. Wilton, and L, J, Klebesadel Registration of Polar bromegrass. Crop Science. 11: Irwin, D. L, Forty-seven years of experimental work with grasses and legumes in Alaska. Alaska Agr. Exp. Sta. Bui, p. 4. Klebesadel, L, J Response of native bluejoint grass (Calamagrostis can ad ens is) in subarctic Alaska to harvest schedules and fertilizers, Proc. IX International Grassland Congress, Sao Paulo, Brazil, 5. Klebesadel, L. J. 1969, Agronomic characteristics of the little-known northern grass Arctagrostis latifolia var. arundinacea (Trin.) Griseb., and a proposed common name, tall arcticgrass. Agronomy Journal, 61:45-49, 6. Klebesadel, L. J. 1969, Winter survival and spring forage yield of winter rye varieties in subarctic Alaska as influenced by date of planting. Agronomy Journal. 61: Klebesadel, L. J, Siberian wildrye (Elymus sibiricus L.); Agronomic characteristics of a potentially valuable forage and conservation grass for the North. Agronomy Journal. 61: , 8. Klebesadel, L, J, Agronomists evaluate native grasses, Agroborealis. 1:5. 9. Klebesadel, L. J Influence of planting date and latitudinal provenance on winter survival, heading, and seed production of bromegrass and timothy in the Subarctic, Crop Science. 10: , Klebesadel, L. J, 1970, Effects of nitrogen on heading and on other components of bromegrass seed yield in the Subarctic. Crop Science, 10: , 11, Klebesadel, L, J, Nyctoperiod modification during late summer and autumn affects winter survival and heading of grasses. Crop Science. 11: Klebesadel, L, J Native Alaskan legumes studied. Agroborealis. 3: Klebesadel, L. J, 1971, Time of planting critical for Alaska grass seed growers. Agroborealis. 3:14,

10 14. Klebesadel, L. J., C. 1. Branton and J.,J. Koranda, 1!)(>2. Seed characteristics of bluojoint and techniques for threshing. Journal of Range Management, 15: , 15. Klebesadel, L. J., A. C. Wilton, R. L. Taylor, and J. J. Koran da, Fall growth behavior and winter survival of Festuca rubra and Poa pratensis in Alaska as influenced by latitude of adaptation. Crop Science, 4: , 16. Klebesadel, L. J., and W. M. Laughlin Utilization of native blue joint grass (Calamagrostis canadensis) in Alaska. Alaska Agr, Exp. Sta, Forage Research Report No pp. 17. Klebesadel, L. J., and R. L. Taylor, New Alaskan grasses excel in winterhardiness. Agroborealis, 44: