Graduation Year

Fall 2010

Document Type

Open Access Senior Thesis

Degree Name

Bachelor of Arts



Reader 1

Donald A. McFarlane

Reader 2

Kathleen Purvis-Roberts

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Rights Information

© 2013 Gizelle M. Pera


Though Costa Rica has suffered numerous bouts of deforestation to its valuable tropical rainforest area, especially in the 1970s, it has become a leader in its efforts to regenerate and restore its rainforest. However, studies and protocols for the assessment of forest regeneration are urgently required. Research has shown that the percentage of light penetrating the canopy floor, or light fraction, is a good indicator of rainforest maturity. In this study, digital rectilinear photography and a global positioning system receiver were used to survey the Firestone Reserve inCosta Rica in order to measure the light fraction differences between primary/riparian forest, bamboo plantation, secondary hardwood plantation, and natural secondary regrowth. The images were used to calculate light fractions with the software program ImageJ. Using ArcGIS, a kernel density plot was created, along with a map organizing the light fractions in the vegetation types. Significant differences in light fraction were found between bamboo and all other vegetation types, between secondary natural regrowth and secondary hardwood plantation, and between secondary natural regrowth and primary/riparian forest. No significance was noted between primary/riparian and secondary hardwood plantation, or between primary/riparian and secondary forest. Inaccuracies of the study could be due to the high amount of variance, low sample size, or high levels of sunlight that distort the photographs. Nevertheless, the study provided useful information concerning the differences between vegetation types and has implications towards regrowth and recovery of the rainforest.