In a class of the MSc Applied Geoinformatics at Salzburg University a group of students, supervised by Dr. Gudrun Wallentin, developed a model based on the topic of
the invasive species guava on Isabela Island. Running for three decades, the model covers the timespan from 1980 to
2010. Having the initial guava spread from 1980 the model refers to a real
start state and can be compared to the real spread of guava during the last
decades. Guava as such was introduced to the Galápagos for cultivation in 1858
into protected areas and human-use zones and today covers more than 40000 ha of
land on Isabela Island, mostly within the agricultural zone and the adjacent
protected area (Miller et. al. 2010). In 2004 Kerr et al. describe guava plants
as one of the greatest threats to the terrestrial ecosystem of the islands.
The goal of the model is to show how birds could be part
of the influence of the guava spread on Galápagos Islands. The concept and
therefore the model are based on more generic assumptions which make the
results highly discussable in the way of usability and reasonability.
Nevertheless the model shows the basic behavior of birds and an increase of
dispersal of guava seeds due to birds which was the intension.
