Previous Research

Population and Regeneration Associated with Quercus Tomentella on       Santa Rosa Island’s Black Mountain – Channel Islands National Park 

July 2014

ABSTRACT:

Using descriptive statistics and geographic information system analysis, baseline data on population and regeneration of the endemic Island Oak, Quercus tomentella, was collected to discover the progress of regeneration on Santa Rosa Island’s Black Mountain. Many of the Q. tomentella strands in Channel Islands National Park are not currently recruiting to the seedling/sapling stage. Looking specifically at the population on Santa Rosa Island, I aim to determine whether the current oak population is increasing, and if it is, where regeneration is occurring. Using elevation analysis, samples of this population were given an elevation extent in relation to the elevation range of the main core of trees. Using this data it was found that regeneration for the majority of samples were located above the main core, which could lead to significant new factors leading to the regeneration process.

Photo from Soledad Road looking south at the population of Q. tomentella represented in this study

Photo from Soledad Road looking south at the population of Q. tomentella represented in this study

 

ArcMap showing main core of population (shaded blue) with a 20-meter buffer applied. Red and green points represent waypoints of the trees which make up the representative sample for this population. Blue points represent the waypoints of the core

ArcMap showing main core of population (shaded blue) with a 20-meter buffer applied. Red and green points represent waypoints of the trees which make up the representative sample for this population. Blue points represent the waypoints of the core

 

Statistical Analysis showing the differences between the three elevation extents used in this study

Statistical Analysis showing the differences between the three elevation extents
used in this study

Results:

Not including the core trees, a total of 125 trees made up the representative sample for this population. Of those 125 trees, 13 trees were found to be adjacent to, or in the same elevation range, as the core of this population; 4 were found to be below the core of this population; and 108 trees were found to be above the core of this population. These trees were located on the southern boundary (uphill) of the core. This finding was interesting and contradicts my original hypothesis. Contrary to my hypothesis, regeneration was to the south of the main core. This leads me to believe the easterly winds that blow across the island are not a significant factor in the process of regeneration. Animals could be a more likely factor in the regeneration process of this population of Q. tomentella.


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