I beg all of you your excuses, because the stupid question. I am exploring niche conservatism in five species of Ericaceae. I created two backgrounds sets in order to explore niche similarity (using R package ecospat). In the first set, backgrounds were defined by the predicted (thresholded) distribution of each species, while in the second set backgrounds were defined through minimum convex polygons 50 Km radius from each occurence point. The fact is that I've got similar similarity (p) values using both backgrounds, except for two species (C and D in the following table), for which I got higher similarity values when using the smaller background (values in bold) and smaller values when using the widest background (values in italics below the values in bold).

enter image description here

Can anybody be so kind as explain in an idiot-proof style what is going on here? Your answer(s) will be very appreciated,

  • $\begingroup$ For those of us not familiar with that package or the context here, what exactly are you doing and why? What is your data? $\endgroup$ – user2974951 Jan 11 at 12:52
  • $\begingroup$ The package allows to compare ecological niches in environmental space (their breadth, position, similarity and overlap) defined through and PCA of the environmental variables. How much of those environmental variables you pick is defined by the extent of the background. $\endgroup$ – perep1972 Jan 11 at 18:48

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.