Pulse hypothesis in the establishment of Artemisia seedlings at Pahute Mesa, Nevada

Journal Article · Tue Jan 01 04:00:00 EST 1980 · Great Basin Nat.; (United States)

OSTI ID:6645393

Romney, E M; Wallace, A; Hunter, R B

New Artemisia seedlings are not established each year. Many that are established fail to survive because of unfavorable rainfall in succeeding years. A total of 184 young plants was examined for the number of annual growth rings to ascertain the year of establishment after all vegetation had been killed near the time of a nuclear test event in 1965. The three most important recent years for establishment and survival of new seedlings (as of 1976 and based on a sample of 184 plants) were 1966 (9 percent), 1969 (29%), and 1973 (36%). A total of 27% was established in the other years from 1965 to 1976. These three years were also the years with high rainfall input during preceding winter and spring months. If old plants are killed, seeds germinate with much lower inputs of precipitation. Many seedlings germinated in 1968 at a site where old ones had been burned off even though the rainfall was not favorable. Plants of a given age varied greatly in size according to their competition. Seedlings germinating in old stands grew little in comparison with those germinating in areas where old plants had been killed. One exception was an area where intense competition occurred due to large numbers of new plants, resulting in growth restriction on all plants.

• Research Organization: Univ. of California, Los Angeles
• OSTI ID: 6645393
• Journal Information: Great Basin Nat.; (United States), Journal Name: Great Basin Nat.; (United States) Vol. 4; ISSN GRBNA
• Country of Publication: United States
• Language: English

Related Subjects

510100* -- Environment
Terrestrial-- Basic Studies-- (-1989)
54 ENVIRONMENTAL SCIENCES
ARID LANDS
ATMOSPHERIC PRECIPITATIONS
COMPETITION
DATA
DESERTS
EXPERIMENTAL DATA
GROWTH
INFORMATION
NEVADA TEST SITE
NUMERICAL DATA
PLANT GROWTH
PLANTS
RAIN
REPRODUCTION
REVEGETATION
SHRUBS