University of California

Germinable seeds and periodicity of germination in annual grasslands


J. A. Young
R. A. Evans
C. A. Raguse
J. R. Larson

Authors Affiliations

J. A. Young was range scientists, Science and Education Administration/Agricultural Research, United States Department of Agriculture, Reno, Nevada; R. A. Evans was range scientists, Science and Education Administration/Agricultural Research, United States Department of Agriculture, Reno, Nevada; C. A. Raguse was Professor, Department of Agronomy and Range Science, and Agronomist in the Experiment Station, Davis; J. R. Larson was range conservationist, Pacific Southwest Forest and Range Experiment Station, Forest Service, United States Department of Agriculture, Fresno, California.

Publication Information

Hilgardia 49(2):1-37. DOI:10.3733/hilg.v49n02p037. February 1981.

PDF of full article, Cite this article


Germinable seed reserves and periodicity of germination of the plant species in annual communities were periodically and intensively sampled from 1974 through 1977 at the Sierra Foothill Range Field Station (SFRFS) and the U.S. Forest Service’s San Joaquin Experimental Range (SJER). One hundred samples of surface soil with accompanying litter were taken every 8 weeks, except when they were taken 1, 3, and 5 weeks after annual initial rains.

Few germinable seeds (mostly exotic annual legumes at SFRFS) were carried over from year to year. Dominant annual grasses had virtually no annual carryover. Litterborne and soilborne seed reserves gradually increased as the current year’s crop was dispersed. Through the fall, each species exhibited its own pattern of increased germ inability, which was highly dependent on its inherent afterripening requirements. In years when the initial fall rains resulted in simultaneous germination, the flush of germination began within a week, and by 5 weeks the reserve of germinable seeds was largely exhausted. The seedlings that established in these years accounted for only 20 to 30% of the germinable seeds present in the litter and surface soil before the initial rain. When the communities were subjected to 2 years of extreme drought (1975-76 and 1976-77), established seedling density and subsequent seed reserves dropped dramatically; species composition, however, remained relatively stable. Near-normal moisture conditions in 1977-78 resulted in near-normal communities except that a higher percentage of the seed reserve became established plants than before the drought.

Literature Cited

Allard R. W., Baker H. G., Stebbins G. L. Genetic systems associated with colonizing ability in predominately self-pollinated species. The genetics of colonizing species. 1965. New York: Academic Press. p. 49-76.

Bartolome J. W. Germination and establishment of plants in California annual grassland 1976. p.187. Ph.D. dissertation. Univ. of Calif. Berkeley

Bartolome J. W. Germination and seedling establishment in California annual grassland. J. Ecol. 1979. 67:273-81. DOI: 10.2307/2259350 [CrossRef]

Batzli G. O., Pitelka G. A. Influence of meadow mouse populations on California grasslands. Ecology. 1970. 51:1027-39. DOI: 10.2307/1933629 [CrossRef]

Biswell H. H., Graham C. A. Plant counts and seed production on California annual-type ranges. J. Range Manage. 1956. 9:116-18. DOI: 10.2307/3894229 [CrossRef]

Brenchley W. E. Buried weed seeds. J. Agric. Sci. 1918. 9:1-31. DOI: 10.1017/S0021859600004676 [CrossRef]

Brenchley W. E., Warington K. The weed seed population of arable soil. I. Numerical estimation of viable seeds and observations on their natural dormancy. J. Ecol. 1930. 18:235-72. DOI: 10.2307/2256005 [CrossRef]

Burcham L. T. California Rangeland. 1956. Sacramento: Calif. Division Forestry. 261p.

Buttery R. F., Green L. R. A checklist of plants of the San Joaquin Experimental Range. U.S. Forest Serv., Calif. Forest and Range Exp. Sta., Misc. Paper. 1958. 23:32 Berkeley, CA

Chang K. K. Detailed soil survey of the San Joaquin Experimental Range. O’Neal’s California. 1965. USDA Soil Conservation Service and Pac. Southwest Forest and Range Exp. Sta. Forest Service. 26p.

Draper N. R., Smith H. Applied regression analysis. 1966. New York: John Wiley &; Sons, Inc. 407p. DOI: 10.1081/STA-120015017 [CrossRef]

Duncan D. A., Woodmansee R. G. Forecasting forage yield from precipitation in California’s annual rangeland. J. Range Manage. 1975. 28:327-29.

Evans R. A., Kay B. L., Young J. A. The microenvironment of a dynamic annual community in relation to range improvement. Hilgardia. 1975. 43:79-102. DOI: 10.3733/hilg.v43n03p079 [CrossRef]

Evans R. A., Love R. M. The step-point method of sampling—A practical tool in range research. J. Range Manage. 1957. 10:208-12.

Evans R. A., Young J. A. Plant litter and establishment of alien annual species in rangeland communities. Weed Sci. 1970. 18:697-703.

Evans R. A., Young J. A. Microsite requirements for establishment of annual rangeland weeds. Weed Sci. 1972. 20:350-356.

Evans R. A., Young J. A. Enhancing germination of dormant caryopses of downy brome. Weed Sci. 1975. 23:354-357.

Evans R. A., Young J. A. Influence of abiotic factors in annual grasslands of California 1980. Abstracts, Soc. for Range Management 33rd Annual Meeting. p 12

Evans R. A., Young J. A., Kay B. L. Germination of winter annual species from a rangeland community treated with paraquat. Weed Sci. 1973. 22:85-187.

Harper J. L. Population biology of plants. 1977. New York: Academic Press. 892p.

Heady H. F. Changes in a California annual plant community induced by manipulation of natural mulch. Ecology. 1956. 37:798-812. DOI: 10.2307/1933071 [CrossRef]

Heady H. F. Vegetational changes in the California annual type. Ecology. 1958. 39:402-416. DOI: 10.2307/1931750 [CrossRef]

Heady H. F., Barbour M. G., Major J. Valley grassland. Terrestrial vegetation of California. 1977. New York: John Wiley &; Sons. 1002p.

Heady H. F., Torrell D. T. Forage preferences exhibited by sheep with esophageal fistulas. J. Range Manage. 1959. 12:28-34. DOI: 10.2307/3895214 [CrossRef]

Hedrick D. W. The mulch layer of California annual ranges. J. Range Manage. 1948. 1:22-25. DOI: 10.2307/3894375 [CrossRef]

James E.B. Botanical composition and productivity in the California annual grassland in relation to rainfall 1969. p.47. M.S. Thesis, Univ. Calif., Berkeley

Major J., McKell C. M., Berry L. J. Improvement of medusahead infested rangelands. Univ. Calif. Agric. Exp. Sta. Leafl. 1960. 123:3

Major J., Pyott W. T. Buried, viable seeds in two California bunchgrass sites and their bearing on the definition of a flora. Vegetation. 1966. 13:253-82. DOI: 10.1007/BF00643329 [CrossRef]

Murphy A. H. Predicting forage yield based on fall precipitation in California annual grasslands. J. Range Manage. 1970. 23:363-65. DOI: 10.2307/3896168 [CrossRef]

Raguse C. A., Young J. A., Evans R. A. Germination of California range plants in response to a summer rain. Agron. J. 1977. 69:327-29.

Stebbins G. L. Jr. Self-fertilization and population variability in the higher plants. Am. Naturalist. 1957. 91:337-54. DOI: 10.1086/281999 [CrossRef]

Sumner D. C., Love R. M. Resident range cover often cause of seeding failure. Calif. Agric. 1961. 15(2):6

Williams W. A., Love R. M., Berry L.J. Production of range clovers. Univ. Calif. Agric. Exp. Sta. Circ. 1957. 458:19 DOI: 10.5962/bhl.title.60945 [CrossRef]

Young J. A., Evans R. A. Germinability of seed reserves in a big sagebrush community. Weed Sci. 1975. 23:358-64.

Young J. A., Evans R. A., Kay B. L. Temperature requirements for seed germination in an annual-type range community. Agron. J. 1973. 65:656-59.

Young J. A., Evans R. A., Kay B. L. Dispersal and germination dynamics of broadleaf filaree, Erodium botrys (Cav.). Bertol. Agron. J. 1975. 67:54-57.

Young J. A., Evans R. A., Eckert R. E. Jr. Germination of medusahead in response to temperature and afterripening. Weed Sci. 1968. 16:92-95.

Young J, Evans R, Raguse C, Larson J. 1981. Germinable seeds and periodicity of germination in annual grasslands. Hilgardia 49(2):1-37. DOI:10.3733/hilg.v49n02p037
Webmaster Email: wsuckow@ucanr.edu