Student information

MSc thesis topic: Comparing spaceborne LiDAR data with Holdrige’s forest plots

This MSc topic will inventory available LiDAR data over Costa Rica to identify if there are LiDAR footprints overlapping the 48 sample plots from the Centro Cientifico Tropical from 1969. Once overlapping (or adjacent) footprints have been established a forest comparison will be carried out spanning more than 50 years.

Costa Rica boast a very high natural diversity and nowadays close to 60% of the country is forested. However, between the 1940s and late 1980s, Costa Rica had one of worst deforestation rates in Central America. Since then deforestation has declined significantly with an increasing number of reforestation projects. At the height of the deforestation period, tropical rainforests covered as little as 40% of the country (1986). Forest structure in Costa Rica varies substantially by elevation in the area (Munoz Mazon, 2020). The complexity of forest structure coupled with the variation along elevational gradients contributes to the high biodiversity reported from the country (Kappelle, 2016).

GEDI is a full-waveform laser based instrument that flies on the international space station. Instead of providing wall-to-wall satellite imagery, GEDI samples footprints of 25m diameter. Based on these footprints, it is possible to identify the full waveform, and to identify vegetation height at different levels in the canopy. GEDI data also can provide elevation data. Other indicators are plant area index, foliage height diversity and aboveground biomass density.

Identifying the waveform over the selected sample plots will allow for a quantitative comparison of the waveform information with data collected more than 50 years ago.

Relevance to research/projects at GRS or other groups

  • This project will foster a collaboration between GRS and a biogeographer with extensive experience in the forests of Costa Rica.

Objectives and Research questions

  • Identify GEDI lidar footprints overlapping or in the surrounding of the 48 previous established sample plots in Costa Rica.
  • Identify the GEDI lidar waveform from the available sample plots and develop a methodology to compare these waveforms with available standard profile plots to identify change.
  • Use available optical remotely sensed data (e.g. Landat and Sentinel 2) to identify stability or change points for the available sample plots.

Requirements

  • At least Intro to Remote Sensing
  • Geoscripting
  • Affinity with the processing of satellite image time series
  • Affinity with spaceborn LiDAR data.

Literature and information

  • Mazón, Miguel Muñoz, et al. "How forest structure varies with elevation in old growth and secondary forest in Costa Rica." Forest ecology and management 469 (2020): 118191.
  • https://www.globalforestwatch.org/dashboards/country/CRI/
  • Holdridge, L. R., W. C. Grenke, W. H. Hatheway, T. Liang, J. A. Tosi, Oxford : Pergamon Press, c1971, xxxi, 747 p. : ill. (part col.), ISBN: 0080163408
  • Kappelle, M. “Costa Rica’s Ecosystems: Setting the Stage.” In M. Kappelle ed., Costa Rican Ecosystems. University of Chicago Press, 2016, 744 pp. ISBN 022627893X
  • https://gedi.umd.edu/

Expected reading list before starting the thesis research

  • See above.

Theme(s): Sensing & measuring, Integrated Land Monitoring