Methods Landsat imagery for years spanning 1990 to 2000 were downloaded from the USGS Global Visualization Viewer. For each Landsat 5 or Landsat 7 scene, bands 3, 4, and 6 were extracted (these bands correspond to the red, near-infrared and thermal infrared parts of the electromagnetic spectrum). Normalized Difference Vegetation Index (NDVI) calculations were performed for 1990 and 2000 using the R programming environment. The thermal infrared band (band 6) was used to identify cloud cover which was removed from all NDVI rasters by assigning no data values to the cloud locations in the scene. A thermal infrared digital number of 125 or less was used to identify clouds. Difference in NDVI values between the years was computed and gain/loss was assessed using the following classification: Loss (difference 0.2 ). Costa Rica’s national park and reserve boundaries were traced from a georectified image from the Anywhere Costa Rica website in order to create one shapefile of park and reserve polygons. A 1 km buffer strip was created around each of the park boundaries. Using tabulate area, the pixels within each of the park buffer strips were classified as NDVI loss, no change, and NDVI gain in order to quantify vegetation loss surrounding parks from 1990 to Data were projected using the WGS 1984 UTM Zone 17S coordinate system. Vegetation Change Surrounding Parks and Reserves in Costa Rica from 1990 – 2000 By Olivia Collins ‘14 Introduction The expansion of ecotourism in countries such as Costa Rica is a great source of environmental protection and revenue but also holds a major potential threat to biodiversity. Though Costa Rica is a model country with regard to conservation and environmentally responsible ecotourism, one major obstacle facing the country is a lack of enforcement within and bordering national parks. Without proper enforcement, parks and their buffers have been subjected to practices such as logging and poaching over the last few decades. The objective of this project was to analyze vegetation within the borders of national parks and reserves in Costa Rica over the time period from 1990 to 2000 in order to determine if there are any patterns of vegetation loss and encroachment surrounding these protected areas. Using Landsat imagery, gains and losses in Normalized Difference Vegetation Index (NDVI) were measured between 1990 and 2000 to quantify changes in biomass within park buffers. Results Analysis results of NDVI gain/loss within 1 km buffer strips surrounding Costa Rica’s parks and reserves range from losses of 0% to 57%, or 4,050 km 2 to 34,199,820 km 2. Data were not available for all park buffers as a result of cloud cover. The parks with the highest vegetation loss in buffers are those in Northwestern Costa Rica such as Rincon de la Vieja, Miravalles Volcano, and Caño Negro. Of all of the analyzed park buffer area, 156,379,410 km 2 show vegetation loss and 645,120,450 km 2 show no vegetation change. Therefore approximately 18% of the area within park buffers experienced vegetation loss, 72% experienced no change, and 10% experienced vegetation gain. Discussion In general, buffers surrounding national parks and reserves exhibit no change between 1990 and 2000, which was a time period of ecotourism development and expansion. While it is difficult to place confidence in all measured vegetation gains, buffers also experienced increases in vegetation. It is possible that some vegetation increases are from growth of pre- existing plant biomass but some of the 10% gain can be explained by land use change, such as conversion of farmland to forest. One major limiting factor with regard to analyzing Landsat images of Costa Rica was cloud cover. It is of high importance to compare images captured during similar months in order to minimize the possibility of differences in vegetation caused by seasonal changes, as Costa Rica has extremely pronounced dry and wet seasons. It was very rare to find Landsat images from the same months that had minimal cloud cover due to Costa Rica’s tropical, rainy climate. References Dasenbrock, J “The Pros and Cons of Ecotourism in Costa Rica.” The Trade and Environment Database. tourism.htm. Lopez, J. “New Law Enforcement Focus on Guanacaste, Costa Rica.” Costa Rica Star. Oct. 7, guanacaste-costa-rica/28380/ Yu, W.D., Hendrickson, T., Castillo, A Ecotourism and conservation in Amazonian Peru: Short-term and long-term challenges. Environmental Conservation: 24: Acknowledgements Thank you to Dr. Manny Gimond for his assistance and guidance throughout this project. Figure 1 Normalized Difference Vegetation Index (NDVI) change between 1990 and 2000 in Costa Rica. White areas within Costa Rica’s boundaries symbolize no data as a result of cloud cover in Landsat images. Development within the 1 km buffer of Los Quetzales National Park. Source: /12/quetzal.jpg Source: Parque_Nacional_Manuel_Antonio_1.JPG Lack of data as a result of Landsat image cloud cover. NDVI Change Loss Gain No Change 1 km Park Buffer Parks & Reserves NDVI loss within the 1 km buffer of Manuel Antonio National Park.