Lauren Van Heukalem
Section No. 1
December 1st, 2014
Wa’ahila Ridge: Percent Cover of Megathyrus maximus and Senna surattensis and its relation to Elevation Abstract
Percent cover of both Megathyrus maximus and Senna surattensis is estimated using quadrats on 11 separate plots along Wa’ahila Ridge. Percent cover of these two plant species were compared to the measured elevation using a GPS, in each plot. A p-value greater than .005 for each indicates a lack of significance between elevation and percent cover. A correlation analysis was used to determine that there is no significance between the elevation and percent cover as M. maximus had a p-value of .873 and S. surattensis had a p-value of .380. Sample size as well as many other environmental factors may have played a part in the values that were calculated and the lack of significance thereof.
Megathyrus maximus is an invasive species of grass introduced to Hawai’i in the early 1900’s (Ripperton, 1933). Today it has become a dominant species that grows abundantly throughout Hawai’i. Another invasive species, Senna surattensis, also known in Hawai’i as Kolomano, is a rather widespread in the islands as well. It is a tree with yellow flowers and was originally introduced in 1871. Wa’ahila ridge, near the University of Hawai’i campus, has been an area of interest and data has been collected on various biotic and abiotic factors for several years. After visiting the ridge several times, it is apparent that M. maximus is one of the most dominant species throughout the 11 plots that work up the ridge. Measurements and data were collected by all Biology Lab 265 classes to determine many factors on the ridge including percent cover of vegetation, density of vegetation, dispersion of vegetation, etc. Upon initial observations of the ridge and the ecosystem, it appeared that rainfall generally increased with elevation. With this in mind it seemed only reasonable...
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