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Harvard Forest Symposium Abstract 2018

  • Title: Galapagos Tortoises, NDVI, and Climate
  • Primary Author: Noah Charney (University of Arizona)
  • Abstract:

    Despite the long term, intensive study of the Galapagos Island Archipelago, we still have very limited understanding of how a changing climate may impact ecology of the system. Working with a large data set from over 40 years of Giant Tortoise observations, historic observations of tortoises from expeditions in the early 1900s, satellite data on vegetation cover and climate data, we are examining basic relationships and using these to project under future and past climate scenarios. Projecting to future climates in the island system using a space-for-time substitution approach is problematic, because mean future climates are expected to fall outside of the range of average conditions anywhere on the island. We instead take a non-parametric simulation approach to projecting future vegetation productivity under future El Nino and La Nina patterns, by pairing historic climates with historic NDVI. We find a strong positive correlation between tortoise size and vegetation productivity, and preliminary results suggest that an increase in overall productivity in the future.

  • Research Category: Conservation and Management; Ecological Informatics and Modelling; Historical and Retrospective Studies; International Research Projects