Rangeland Ecology & Management

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Detecting fragmentation of cover in desert grasslands using line intercept
Author
Kuehl, R. O.
McClaran, M. P.
Va, J.
Publisher
Society for Range Management
Publication Year
2001-01-01
Body

Changes in the amount or spatial distribution of grass plants are thought to be indicative of the stability of desert grasslands. This study assessed, through simulation, the sensitivity of statistical properties for distance between plants (fetch length), measured with a line intercept transect, to changes in the spatial distribution and amount of plant cover. Monitoring plots, 30 X 30 m, were simulated for 1, 2.5, 5, 10 and 15% grass cover with random and fragmented spatial distribution. Fetch lengths were measured on 2 randomly placed 30 m transects. In addition to the median and interquartile range, the asymmetry of the sampling distributions was measured with a ratio [(maximum-median)/(median-minimum)] that would identify the presence of at least 1 large open space. The accuracy of the fetch length method was confirmed by the similarity of its sampling distribution to that for the well known random point-to-plant sampling procedure. In both the fetch length and the point-to-plant measures, the median and interquartile range increased with decreasing cover for random and fragmented distribution. The asymmetry estimate increased sharply with increasing cover for the fragmented distribution but asymmetry was nearly constant with increasing cover for the random distribution. The results suggest that the evaluation of changes over time at a monitoring site could use fetch lengths measured along a line intercept transect to detect changes in both absolute and spatial arrangement of cover. The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact lbry-journals@email.arizona.edu for further information. Migrated from OJS platform August 2020

Language
en
Resource Type
Text
Document Type
Journal Issue/Article
Digital Object Identifier (DOI)
10.2307/4003529
Additional Information
Kuehl, R. O., McClaran, M. P., & Va, J. (2001). Detecting fragmentation of cover in desert grasslands using line intercept. Journal of Range Management, 54(1), 61-66.
IISN
0022-409X
OAI Identifier
oai:repository.arizona.edu:10150/643836
Journal Volume
54
Journal Number
1
Journal Pages
61-66
Journal Name
Journal of Range Management
Keywords
fetch length
simulation models
arid grasslands
deserts
canopy gaps
range condition
length
sampling
spatial distribution
grasses
New Mexico
fetch length
monitoring
simulation