Spatial locations and size measurements of Ambrosia dumosa in Joshua Tree National Park.
NCEAS 2162: Liebhold: Integrating the statistical modeling of spatial data in ecology
National Center for Ecological Analysis and Synthesis
Maria
Miriti
Department of Evolution, Ecology, and Organismal Biology, Ohio State University
318 W. 12th Avenue
Room 270 Aronoff Laboratory
Columbus
OH
43210
USA
miriti.1@osu.edu
http://www.biosci.ohio-state.edu/~mmiriti/
Andrew
Liebhold
Working group co-leader
Jessica
Gurevitch
Working group co-leader
This data set contains spatial locations and size measurements of Ambrosia dumosa plants sampled in a 1-ha plot in Joshua Tree National Park in 1984.
Ambrosia dumosa
desert plants
Joshua Tree National Park
spatial analysis
1984-03-15
1984-04-08
Genus
Ambrosia
Species
dumosa
Joshua Tree National Park, California
-115.7833
-115.7833
33.7667
33.7667
1120680946687
Study site and species
The study site is located on a gently sloping alluvial formation (bajada) northwest of the Eagle Mountains in Joshua Tree National Park, 10 km from the transition of the Colorado Desert to the Mojave Desert (115°47' W, 33°46' N; elevation 1006 m; photo in Howe and Wright 1986). The bajada is almost free of topographic heterogeneity. The steepest slope parallels the bajada and is 4%. Soils averaged from nine sampling stations at a depth of 10 cm consist of sand (62.4%), gravel (29.8%), and clays (7.8%). Rainfall averaged 18.5 cm/yr at the Cottonwood Spring ranger station (2 km distance) from 1970-1984. The most conspicuous species within the study site are Ambrosia dumosa (60% of stems) and Larrea tridentata (3% of stems; Miriti et al. 1998).Ambrosia dumosa (Gray) Payne (Asteraceae), is a low, intricately branched, monoecious, drought-deciduous, perennial shrub, usually 20-60 cm high. This species is characteristic of well drained soils below 1061 m, but occasionally occurs up to 1667 m, and is associated with Creosote Bush Scrub (Munz 1974). Leaves are pinnatifid, mostly clustered, 5-20 mm long, ovate in shape, and have 1-3 short obtuse lobes. Flower and fruit production usually occur from March through May. The life span of A. dumosa has been described from 35-50 yr to >200 yr (Bowers et al. 1995). Most seedlings occur close to conspecific adults, but many also occur in open spaces (Wright and Howe 1987, McAuliffe 1988, Miriti et al. 1998). Plants were mapped between 15 March and 8 April 1984. Each individual was mapped to the nearest 0.25 m within a square hectare (100 x 100 m) which was divided into 5 x 5 m subplots. Each plant was marked with an aluminum tag, and was identified by its species, height, major and minor axes, reproductive status and its location on the 100 x 100 m grid. Individuals greater than or equal to 10 cm tall were mapped only in the first 750 m2, and individuals greater than or equal to 20 cm tall were mapped over the remainder of the hectare.
Literature cited in methods
Bowers, J. E., R. H. Webb, and R. J. Rondeau. 1995. Longevity, recruitment and mortality of desert plants in Grand Canyon, Arizona, USA. Journal of Vegetation Science 6: 551-564. Howe, H. F., and S. J. Wright. 1986. Spatial pattern and mortality in the desert mallow (Sphaeralcea ambigua). National Geographic Research 2: 491-499. McAuliffe, J. R. 1988. Markovian dynamics of simple and complex desert plant communities. American Naturalist 131: 459–490. Miriti, M. N., H. F. Howe, and S. J. Wright. 1998. Spatial patterns of mortality in a Colorado Desert plant community. Plant Ecology 136: 41–51. Munz, P. A. 1974. A flora of southern California. University of California Press, Berkeley, California, USA. Wright, S. J., and H. F. Howe. 1987. Pattern and mortality in Colorado Desert plants. Oecologia (Berlin) 73: 543-552.
public
read
Ambrosia dumosa data
Spatial locations and size measurements of Ambrosia dumosa plants sampled in a 1-ha plot in Joshua Tree National Park in 1984.
miriti1984.txt
143927
1
#x0A
column
#x09
ecogrid://knb/connolly.206.1
TAG1
Tag ID
ID number of individual plant.
ID number of individual plant.
X
X coordinate
X coordinate of location of plant within the 1-ha plot.
meter
0.25
real
Y
Y coordinate
Y coordinate of location of plant within the 1-ha plot.
meter
0.25
real
HGHT84
Height
Height of the plant canopy.
centimeter
1
real
AXIS184
Major axis length
Length of major axis of the plant canopy.
centimeter
1
real
AXIS284
Minor axis length
Length of minor axis of the plant canopy.
centimeter
1
real
L2VOL84
Canopy volume
Volume of the plant canopy
cubiccentimeter
1
real
4360
cubiccentimeter