Spatial modeling of the ecological niche of Pinus greggii Engelm (Pinaceae): A species conservation proposal in Mexico

Abstract

Background Studies in Mexico have shown that the genus Pine has always been under evolutionary changes, however currently they have accelerated as a result of human activities. Pinus greggii is a species restricted by particular environmental conditions of the Sierra Madre Occidental, which is of socio-economic importance in terms of wood production and provides environmental services to the ecosystem. Species distribution models are a relevant geospatial tool in decision making, and notable applications exist such as identifying areas of distribution and zones susceptible to climate change. The objectives of this study were: 1) model and quantify the current distribution, and possible future distribution under four scenarios of climate change; 2) identify the most relevant environmental variables that drive changes in distribution; and 3) to propose adequate zones for the species’ conservation in Mexico. Methods 438 records of Pinus greggii from several national and international databases were obtained, and were cleaned up to get rid of duplicates and overestimations in the models. Climatic, edaphic, and topographic variables were used and were generated 100 distribution models for current and future scenarios with Maxent software. Results The model one under replicated of crossvalidation had the best statistic, with an area under the curve of 0.88 and 0.93 for model training and validation, respectively, a partial ROC of 1.94, and a significant Z test (p < 0.01). The current estimated area of Pinus greggii in Mexico was 617,706.04 ha and the most important environmental variables for current distribution were the annual mean temperature, mean temperature of coldest quarter, and slope. For the 2041–2060 models, annual mean temperature, precipitation of coldest quarter, and slope were most important. The future models (2041–2060) predict a decrease in suitable habitat for the species from 48,403.85 (7.8%; HadGEM2-ES RCP 8.5 model) to 134,680.17 ha (21.8%; CNRM-CM5 RCP 4.5). Conclusions The spatial modeling of current and future conditions of the ecological niche of Pinus greggii in this study allows the proposal of two zones for conservation purpose and in situ restoration for the species in northeastern (Nuevo Leon) and central (Hidalgo) Mexico.