External validation of relative suitability for estimating the potential distribution of Pinus lagunae

Abstract

Pinus cembroides subsp. lagunae is a conifer endemic to the Sierra La Laguna, Baja California Sur, Mexico, whose range has been reduced to the degree of being considered vulnerable. Therefore, it is necessary to implement its restoration and promotion, which requires knowing its potential distribution, which can be determined with information of its ecological requirements. But little information is available on this, with the Maxent algorithm being presented as an alternative. Although Maxent derives parameters to evaluate the accuracy of results, these are only based on information from the sites used. Because of this, an external validation was performed comparing the defined distribution with Maxent (optimal, good, regular, low, and no potential), and the potential distribution determined based on the altitude and precipitation requirements of this species. Maxent mapping within the study area with greater precision (overall 85.9%) and concordance (60.6 Kappa index) was performed using untransformed values. While within the Sierra La Laguna Biosphere Reserve, the overall accuracy was 72.6% with a concordance of 52.9 (Kappa index). It was concluded that Maxent's potential distribution was comparable to that determined based on altitude and precipitation.