I

EFFECT OF 2,4-D AND 2,4,5-T ON BLUE OAK 19

of 2,4,5-T was superior to the LITERATURE CITIED MCCULLY, W. G. AND R. A. DAREOW. ester of 2,4-D. AREND, J. L. AND L. L. COULTER. 1953. 1952. Control of post and blackjack Chemical frill girdling for pine release oaks with growth-regulator herbicides. 6. Dilution of 2,4-D amine with jll lower Michigan. Down to Earth. Proc. Fifth South. Weed Conf. 137- water gave no advantage in 8 (4) : 2-4. 140. EMRICK, WALTER E. 1953. An easy way effectiveness. It increased the PEEVY, F. A. 1954. Woody plant con- to kill your bull (digger) pines. Univ. trol in Southern Forests. Proc. Seventh time necessary for making California Ext. Service Leaflet (Ma- South. Weed Conf. 261-264. effective application and dera County) : l-9. added to the bulk of material EMRICK, W. E. AND 0. A. LEONARD. 1954. ROBERTS, E. G. 1954. Frilling with and to be carried. Delayed kill of interior live oak by fall without the application of 2,4,5-T in treatment with 2,4-D and 2,4,5-T. Jour. hardwood control. Proc. Seventh South. ‘7. An abrupt increase in effec- Range Mangt. 7: 75-76. Weed Conf. 294-296. tivcncss tcck place between GODDARZ+RAY E. 1954. Killing small SWEZEY, A. W. 1953. A report of pre- undesirable hardwoods by use of the October 6 and November 4. liminary investigations of the treat- Cornell tool. Down to Earth 10 (2) : The increase in effectiveness K ment of riparian trees with 2,4-D and 2,4,5-T by basal techniques. Res. Rept. in November appears to have HARRIS, G. H. 1926. The activity of Western Weed Control Conf. 42-43. been associated with an in- apple and filbert roots especially dur- crease in soil moisture and a ing the winter months. Proc. Amer. WEINTRAUB, R. L., J. H. REINHART, R. A. decrease in air temperature. Sot. Hort. Sci. 23 : 414-422. SCHE~FF AND L. C. SCHISLER. 1954. LEONARD, 0. A. 1952. Result of a cut- Metabolism of 2,4-dichlorophenoxyace- The trees remained sensitive surface experiment on interior live tic Acid. 3. Metabolism and persist- throughout the winter and oak. Research Rept., 13th Western ence in dormant plant tissue. Plant spring months. Weed Control Conference : 53-54. Physiol. 29 : 303-304.

are the Coast Range Mountains and the Pacific Ocean, and on the Ecology of California Grasslands east are the Sierra Nevada Moun- tains. In a few places the grass H. H. BISWELL type adjoins the ocean.

Professor of Forestry, University of Catliforaia, Berkeley, Climate California The climate of this area is the Mediterranean type, characterized West of the Sierra Nevada Di- Grass and woodland-grass ranges by wet, mild winters and long, hot, vide in California are 17.5 million are used primarily for domestic dry summers (Fig. 3). It is di- livestock production, and problems acres which contribute 80 percent verse, being affected by the Coast in management center around this of the forage for domestic live- Range Mountains which influence activity. A majority of the other stock grazing on the State’s wild- the air and cloud movements, and wildlands, however, have other pri- lands. The area includes two vege- by the Pacific Ocean which has mary values, such as watershed, tational types-the grass of 10 mil- moderating effects in certain areas. lion acres and the woodland-grass wildlife and other recreation, or of 7.5 million acres (Fig. 1). An- timber production. The grass and Precipitation usually begins in other 25 million acres or so of wild- woodland-grass ranges usually can October or November and ends in lands in California are also grazed be managed to the maximum for April or early May, with about by livestock, but comprise only 20 livestock, but on the other lands two-thirds falling from December percent of the forage. These acres proper consideration must be given through March. It varies in include the chapparal type, coastal to the various uses, and problems amount from about 6 inches, in the sagebrush, woodland, timber and in grazing are often complex and foothills surrounding the southern meadow types of the mountains, difficult ( Tal hot and Sampson, tip of the San Joaquin Valley and portions of the desert, and the 1948). along its west side, to ab,out 40 Great Basin sagebrush type east The grass and woodland-grass inches in certain portions near the of the Sierra Nevada Divide. In ranges occur mainly in the plains Coast. From May through Sep- addition to the wildlands, Califor- and foothills of the San Joaquin tember there may be little or no nia has about l,OOO,OOOacres of ir- and Sacramento valleys (Fig. 2). precipitation, a desirable state of rigated pastures with high grazing The grass type adjoins the valleys affairs from the stockman’s view- capacity-up to three animal units and is surrounded by the wood- point. At that time the forage is per acre per mcmth for seven land-grass (Wieslander and Jen- dry and might be leached of its months of the year. sen, 1946). West of the grasslands soluble nutrients even by light 20 H. H. BISWELL

plants mature and dry in late April and early May, with some, but not all, of the perennials stay- ing green slightly longer. From then until the fall rains, the land- scape of dry forage is golden brown. Any green herbs are most- ly summer weeds and may indicate deteriorat#ed range conditions. In early March the evergreen shrubs and trees of the woodland- grass type resume growth, and the deciduous plants put out new leaves soon thereafter. The shrubs and trees are green throughout the summer except for certain species, such as poison oak and California buckeye, which drop their leaves in early August. The plants are all adapted in one way or another to the Mediter- ranean climate. The annual herbs grow and mature when moisture is plentiful, and are dry during the long, hot summer. The perennial grasses and forbs do likewise, being mainly dry and dormant during summer. Pine bluegrass, for ex- ample, dries equally as early as any annual and is completely dor- mant during the summer. This adaptation gives it an advantage over the annuals because it starts growth in the fall with less pre- cipitation, and makes more rapid initial growth, thus placing it in a better position to compete with surrounding v e g e t a t i o n. The shrubs and trees are deep rooted. FIGURE 1. Upper. Grass type range grading into woodland-grass in background, as Some have small, thick, heavily- indicated by scattered blue oa,ks. On west-facing slope of central Sierra Nevada cutinized, evergreen leaves ; others foothills at 500 ft. elevation. Lower. Woodland-grass range at the same location at 1,000 ft. elevation. drop their leaves before the end of the extremely dry summer period. The herbaceous vegetation is rainfall. During the dry summer To the casual observer, the land- composed mainly of annuals. These period the days are mostly clear scape of herbaceous vegetation ap- and the perennials vary in percent- with maximum temperatures f re- pears remarkably uniform, but it age from place to place. Because quently above 105” F. and the rel- is extremely diverse and composed of the great abundance of annuals, ative humidity often 10 to 15 per- of hundreds of species in varying the grasslands have become known cent and sometimes lower. amounts. It becomes green soon as the annual vegetation type of after the first rains, and the California (Talbot, et aE., 1939). Landscape and Vegetation amount of growth is considerable In the foothills east of the San The grass and woodland-grass in the fall months if conditions are Joaquin Valley, for example, an- types are similar in many respects, favorable. During December, Jan- nuals comprise about 98 percent of but the latter has a landscape of uary and February, growth is slow the plant cover; perennial, grass- scattered trees and shrubs while because the minimum temperatures like plants (sedges and rushes), the other does not. In the grass are near freezing. With the re- 1 to 4 percent ; and other perennial type, however, scattered areas of turn of warmer weather in March grasses and forbs, less than 1 per- chaparral may be found. the growth becomes rapid. The cent (Talbot and Biswell, 1942). ECOLOGY OF CALIFORNIA GRASSLANDS 21

Along the coast, some of the per- ennials are abundant locally. The annual plant cover fluctuates greatly from year to year, depend- VEGETATION TYPES ing on the weather and other growth factors, especially in the more arid portions where even nor- mal rainfall may produce little WOODLAND-CRASS growth (Talbot, et aZ., 1939). The more abundant plants on grass and woodland-grass ranges include the following (alien species indicated by ‘) :

Annual Grasses and Porbs *Soft chess, Bromus mollis *Rip@ grass, Bromus rigidus *Red brome, Bromus rubens *Slender oat, Aven’a baabata *Wild oat, Avena, fatua *Common foxtail, Hordeurn hystrix Foxtail fescue, Festuca megalura *Common ryegrass, Lo %tbrn mkltifEorum *Broadleaf filaree, Erodium botrys ‘Red-stem filaree, Erodiu’m c&utarium *Bu.r clover, Medicago hispida Annual clovers, Ttifolium spp. *Napa thistle, Cetitaurea melitensis Tarweed, Hemkotia spp. ’ Spanish clover, Lotus americanus Ground lupine, Lupinus bioolor

Perennial Grasses Purple needlegrass, Stipa pulchra Pine bluegrass, Poa sca,brella Creeping wildrye, Elymus triticoides Melic grass, Melieu’ califorkca FIGURE 2. Map of California showing distribution of grass and woodland-grass California oatgras, Danth#otia cali ranges which provide 80 percent of the forage for domestic livestock from the State’s f ornica wildlands. Squirrel grass, Sita8nion hystrix

Trees and Shrubs while others are more limited. Usu- Napa thistle, are among the worst Blue oak, Quercus douglasii ally the alien species can be ex- of the weeds. Interior liveoak, Quercus wislixenti pected to comprise at least 50 per- The introduction of aliens prob- Buckeye, Aesculus calif ornica cent of the plant cover, but often ably began with the Spanish Mis- Digger pine, Pinus sabinia(na they account for 90 percent, or sions, and has continued to the Wedgeleaf ceanothus, Ceanothus even more. A majority of the curbeatus present day. During the Mission Poison oak, Rhus diversiloba aliens are annuals, although a few, period, 1769-1824, such important Hollyleaf buckthorn, Rhamnus crocea such as Klamath weed (Hype&urn aliens as wild oats, bur clover and Manzanita, ArctostaphyZos spp. perforafum), are perennial. Napa thistle were introduced (Rob- The aliens came from many areas bins, 1940). Examples of very re- Changes in the Native Grasslands -Europe, Eastern and Western cent introductions are halogeton Great changes in the vegetation Asia, South Africa, Australia, (Halogeton glomeratus) and goat- of California grasslands have oc- South America and other regions grass (Aegilops triuuzcialis) . The curred since the first Spanish Mis- of the United States. A majority dates of the earliest introductions sions were established nearly 200 were probably introduced uninten- were determined through studies years ago. These have been brought tionally, but others were brought of plant materials found in adobe about chiefly by an invasion of in purposely. Some of these are bricks from the walls of old build- alien species-nearly 400 of them valuable forage plants, such as bur ings, including Missions, whose on grassland ranges (Robbins, clover, red-stem filaree and soft construction dates were known 1940). Some of these are adapt- chess, but others, such as Medusa- (Hendry and Bellue, 1936). Dates able, aggressive, and widespread head (Elymus capu,t-medusa) and of later introductions were found 22 H. H. BISWELL by such means as studies of plant ante have been observed where ro- conclusions derived from studies collections and botanical literature. dents have dug out bulbs of this of these relict areas. On the oth- There is considerable speculation species. If rodents have increased er hand, Indians may have burned about that portion of the native with grazing, it is possible that the grasslands at fairly frequent vegetation which the alien plants they have played an important role intervals, thereby favoring purple displaced. Was it chiefly peren- in affecting plant composition. needlegrass. On the grass-covered nial grasses, or was it native an- A few early writings (such as slopes around Berkeley, vacant lots nual plants ? There is no final one by Davy in 1902)) in describ- are burned annually for fire haz- answer to this question because ing the stock ranges of northwest- ard reduction with the result that early records were not made. It is ern California, present evidence some now support large amounts possible that both types were dis- that native perennial grasses, par- of purple needlegrass. placed in varying degre*es in differ- ticularly California oatgrass, were Importance of Soils ent areas because there are hun- dominant and that, they were dis- dreds of native annuals in the placed by aliens. Clements (1934) Much of the variability in grass- California grasslands as well as arrived at somewhat similar con- land vegetation is related to dif- numerous perennial grasses. Peren- clusions through studies of relict ferences in soils. There are many nials grasses may have decreased areas. In a railroad right-of-way soil series ; even in a square mile there might be a dozen or more. The differences to be expected in plant cover as related to solils are 80 WEATHER RECORDS- BERKELEY illustrated in Table 1. These data 1 were obtained from a small, rec- tangular enclosure of less than one acre that crossed two distinct soil series. The centers of the sample plots on the two1 soils were not more than 100 feet apart. Such marked differences in com- position are not common to all soil series, but. may be expected in places where the soils are as dif- ferent as sandy loams and clays. Th,ere is indication, although nothing very definite, that many grassland soils are gradually los- ing their fertility under continued cropping. This results in a thin- ning of the vegetation and an in- crease in shorter lived and more weedy species. When such areas are fertilized, remarkable changes “SONDJFMAMJJA often take place in the vegetation. FIGURE 3. Graph of rainfall and temperatures for California grasslands. In the For example, in one area common drier areas there may be little or no rainfall for five months of the summer, and the ryegrass and weeds, were displaced temperatures are considera.bly higher. almost entirely by bur clover. In another area, broadleaved filaree’ decreased and true clovers in- greatly along the Coast where con- near Fresno, abundant purple nee- creased; in still another, tarweed ditions are most favorable for dlegrass was found, with the con- was largely replaced by bur clover them, while native annuals may clusion that this was the dominant and common ryegrass. have formed most of the “lost” por- grass over hundreds of miles of the Changes Under Grazing tion in such areas as the lolwer foot- San Joaquin Valley in the primi- Protection hills of the western slope of the tive condition. Recently, however, Sierras. It is possible also that it has been observed that this par- During the past twenty years a perennial forbs, such as blue dicks ticular species may be favored by number of protected areas have (Brodiaea ca~phta), were more frequent burning. Since such been studied in order to record plentiful and have decreased. The rights-of -way were burned almost changes in vegetation when such blue dicks has a fleshy bulb some- annually at the time Clements areas are not grazed. The rapid- times sought after by rodents. made his observations in 1918, it ity of change depends on rate of Hillsides with a plowed appear- leaves doubt about the value of accumulation of mulch, weather ECOtLOGY OF CALIFORNIA GRASSLANDS 23 and other factors that affect gen- Table 2. Example of changes in annual vegetation of areas under protection eral distribution and growth of compared with those under grazing. (1933 was a dry year; the others were normal plants. An example of change and or above in precipitation.) succession is illustrated in Table Treatment 1933 1935 1937 1938 1939 2 from data reported by Talbot, Percentage in forage cower Biswell, and Hormay (1939). Closed to livestock and rodents: Grasses 2 96 99 80 99 On fertile soils which produce Forbs 98 4 1 20 1 large volumes of forage and mulch, the plant cover is, likely to change Open to livestock and rodents: 2 21 33 57 78 rapidly toward ripgut grass, a tall Grasses Forbs 98 79 67 43 22 and shade-tolerant species with - seeds well equipped with barbs that take them down to mineral sion for many years. In certain ripgut grass for best forage, and soil. When protection follotws coastal areas, the succession may heavy grazing may result in sum- heavy grazing, a common pattern go farther, and ripgut grass be dis- mer weeds, such as turkey mullein of change is from f orbs to soft placed by creeping wildrye, a per- (Eremocarpus setigerus) and tar- chess, to slender oat, to ripgut ennial grass with strong rhizomes, weeds. The latter change is ex- grass. It appears that much of or by black mustard (Brass& plained on the basis that the for- the change in species composition nigra), poison hemlock (Conium age crop heavily utilized is unable is caused by accumulation of wuzculatum), or other tall growing to use all the soil moisture, and mulch. If the mulch is removed weeds. the summer weeds thrive on that by hand, the plant cover may be The idea is frequently expressed which remains in the soil. Moder- set back to the stage of forbs. that perennial grasses will take ate grazing results in more growth Where mulch accumulates slowly over under grazing protection. during winter than does close the changes in plant cover are less This happens occasionally but not grazing (Bentley and Talbot, rapid, and the vegetation may stay always. In a protected area of fer- 1951). in a relatively low stage of succes- tile soil near Berkeley a stand of A system of grazing manage- 65 percent purple needlegrass de- ment that provides for fairly close Table 1. Example of differences in creased to about 10 percent after grazing in the early spring, fol- botanical composition of California several years of protection, being lowed by light grazing or complete grasslands as related to soils. crowded out chiefly by ripgut protection as the forage crop ma- Laughlin Montezuma grass which was growing three or tures, usually results in less rip- Plants sandy loam clay four feet tall (Sampson, 1955). gut grass and summer weeds and Percentage in forage cover. In the foothills east of the San a larger volume of the late grow- Perennial grasses Joaquin Valley, pine bluegrass ing species, such as soft chess, and forbs: gradually decreased under protec- common ryegrass, bur clover and California oat- tion. In another case, sods of sev- true clovers. - e-al species transplanted into a grass 1 The perennial grasses in the for- Sheep sorrel, fertile soil gradually decreased in age cover often increase, or can Burnem aceto- number. There is evidence that be maintained, under a system of sella 7 - certain of the perennial grasses, grazing management that retards English plantain, such as pine bluegrass and nod- the growth and reproduction of Plantago lanceo- ding needlegrass (Stipa lepida), - annuals but favors that of the per- lata 4 increase during periods of drought ennials. This happens where the Annual grasses and also on poor soils where com- annuals are grazed fairly close up and for&: petition from other plants may not tot the time of maturity, followed Ripgut grass 34 2 be so great as under more favor- by complete protection to permit Silver hairgrass, able conditions. the perennials to grow flower Aira curyophyl- stalks and mature seed. California lea 11 - Influences of Grazing Foxtail fescue 11 2 oatgrass, near the Coast, was Soft chess 9 2 Botanical composition of the shown to increase under this sys- Common ryegrass 4 20 vegetation is influenced both by in- tem of grazing from 3 percent of Slender oat 4 - tensity of grazing and the season the cover to 15 percent in three Bur clover 4 40 during which the range is utilized. years. A slight difference in time Tarweed, Moderate grazing usually gives the of maturity of the perennial and Hemizonia con- densest cover of forage as well as that of the annuals made it pos- gesta - 23 the more desirable species. Light sible for the perennial to increase Others 7 11 grazing may result in too much under this system of grazing. 28 H. H. BISWELL

Influermes of Fire to change from one type to an- on wildlands. These ranges are Grassland fires that consume other. Factors favoring brush in- green in winter and golden brown the dry vegetation and mulch have crease are : (1) single fires which in summer. The vegetation is much the same effect as removing usually increase germination of nearly all annual, and comprised this material by grazing or by brush seeds and prepare seedbeds; chiefly of alien species. It appears hand. Neither method destroys the (2) close grazing, late in the green remarkably uniform to the casual seed in the ground, nor completely forage period, which decreases the observer but is, in fact, extremely removes all the seed on the surface. capacity of the herbaceous vegeta- variable, being influenced by dif- The change in composition is usu- tion to deplete the soil of its mois- ferences in soils-of which there ally toward forbs and other s,pe- ture, which can be used by brush are many series and types-graz- ties, such as the filarees and bur seedlings in summer ; and (3) late ing use, and occasional fires. In clover, that do best with little rains that replenish soil moisture, the woodland-grass ranges there is mulch. If grazin g should be light thus favoring brush seedlings in a tendency for woody - vegetation preceding fire on areas with abun- summer. Retarding factors are : to increase. dant mulch and ripgut grass, a (1) a dense cover of herbaceous vegetation at maturity, which uses great change toward forbs may be LI’TERATURE CITED all soil moisture; (2) t,wo fires in expected. On the other hand, if BENTLEY, J. R. W. TALBOPP.1951. close succession, the second de- AND M. grazing has been close, with an Efficient use of annual plants on cattle abundance of forbs in the cover, stroying the brush seedlings that ranges in the California foothills. U. 8. the effects of fire will be slight follow the first fire ; (3) browsing Dept. Agr. Circ. 870. 52 pp. (Hervey, 1949). An example of by deer, sheep and cattle. Factors BISWELL, H. H. 1954. The brush con- responses of annual vegetation to important in causing changes in trol problem in C?alifornia. Jour. Range Mangt. 7: 57-62. fire is given in. Table 3. brush type are fires and differen- tial browsing. Fires are more det- CLEMENTS, F. E. 1934. The relict method in dynamic ecology. rimental to non-sprouting species Jour. Ecol. 22: 39-68. Table 3. Example of effect of fire in than to sprouting ; therefore the DAPP, J. B. 1902. Stock ranges of moderately grazed area near Berkeley, tendency is for the sprouting Northwestern California. U. S. Bur. California. plants to increase in proportion to Plant Indus. Bull. 12. 81 pp. Plant group Unburned Burned the non-sprouting species. Brows- HENDRY, G. W. AND M. K. BELLUE,. 1936. An approach to Southwestern agri- Percentage in forage ing, of course, is more detrimental to the palatable plants than to the cultural history through adobe brick cover analysis. Reprinted from Univ. of N. unpalatable. Grasses 89 47 Browsing may not Mexico Bull. The Univ. Press, Albu- Forbs 11 53 only kill some of the plants indi- querque, N. Mexico. vidually, but it also decreases com- HERVEY, D. F. 1949. Reaction of a petition, thereby favoring the un- California annual-plant community to Increase in Trees and Shrubs palatable species. Thus, combina- fire. Jour. Range Mangt. 2: 116-121. Throughout the woodland-grass tions of fire and browsing may re- KADISH, A&TRAM. 1955. Vegetation as related to soil type. Unpublished data. type, trees and shrubs have a tend- sult in stands of unpaIatabIe ROBBINS, W. W. 1940. Alien plants ency to increase in abundance. sprouting species of little value on range lands. growing without cultivation in Cali- This increase is greatest where the fornia. Calif. Agr. Expt. Sta. Bull. woodland-grass joins the woodland In recent years, deer popula- 637. 128 pp. and timber types. Here growth tions have increased throughout SAMPSON, A. W. 1955. Unpublished often becomes thick enough to most of the woodland-grass tvne. data. choke out the herbaceous vegeta- It can be expected thatUd,ringU