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First Time At Niche Modeling?

This is a blog on the power of numeracy. My first book — Niche Modeling — is now in print.

The first six chapters are tutorial topics in R programming and theoretical topics in niche modeling: functions, data, spatial, topology, environmental data collections, and examples. The last six chapters are about using niche modeling to detect errors: bias, autocorrelation, non-linearity, long term persistence, circularity and fraud - useful information for any biological modeler.

Simple geometric model of range-shift errors

Filed under: Uncategorized, Ecological Niche Models — admin @ 7:38 am

A free pdf of Chaper 7 of Niche Modelling can be downloaded. Entitled ‘Bias’, a simple geometric model of range-shift illustrates my take on the problems of range-shift models. The model can be used to estimate exaggeration of reduction in range area due to climate change. The model uses a small number of parameters: width, shift and proportions. Each of these parameters have error terms. The error terms in the geometric model represent sources of error such as:
  1. Width error: Model overfitting
  2. Shift error: Differential response of species to climate change
  3. Proportional error: Truncation of range due to map boundaries
Download Chapter 7 here.

This chapter demonstrates how range-shift models might exaggerate species extinction, a problem highlighted in the paper Forecasting Effects of Global Warming on Biodiversity.