**Group 3** ====== From sea to land, from land to sea ====== Wiki site of the practical exercise of the [[http://www.ictp-saifr.org/mathbio5|V Southern-Summer School on Mathematical Biology]]. Here you will find the exercise assignment and the group's products. If you are a group member login to edit this page, create new pages from it, and upload files. ==== Introduction ==== Ecosystems are made of many interconnected biotic and abiotic components. A biotic component may be connected to another via an ecological interaction, such as predation, or it may be connected to an abiotic component, such as nitrogen soil content. Human activities that impact one of the components of an ecosystem can negatively affect a whole chain of interactions. McCauley //et al.// (2012) report on the breakdown of a long interaction chain linking diverse ecosystem components of a remote Pacific atoll. {{http://www.nature.com/article-assets/npg/srep/2012/120517/srep00409/images_hires/w926/srep00409-f1.jpg|Long interaction chain linking forests to manta rays}} Long interaction chain linking forests to manta rays (Fig. 1 from McCauley //et al.// 2012) ===== Assignment ===== Propose a mathematical model to describe the dynamics occurring in the Pacific atoll in simple but well-grounded way. Use this model to compare the dynamics of the undisturbed ecosystem with the dynamics that includes human-facilited coconut palm (//Cocos nucifera//) expansion. ===== Proposed Questions ===== *What are the minimal components of the Pacific atoll ecosystem needed to understand its dynamics? *Does human impact cause cascading effects through the interaction chain? Does it cause the loss of interactions? ==== References ===== *McCauley //et al.// (2012) //From wing to wing: the persistence of long ecological interaction chains in less-disturbed ecosystems// Scientific Reports 2:409 DOI: 10.1038/srep00409 [[http://www.nature.com/articles/srep00409|link]]