Spatial and temporal changes in the grinnellian niche: a case study in teiid lizards

IGNACIO MINOLI; LUCIANO JAVIER AVILA; MARIANA MORANDO; PIER CACCIALI

Quito

Congreso; XI Congreso Latinoamericano de Herpetologia; 2017

PUCE

The analysis of ecological niche over shifts in the geographic and environmental space of an ectothermic genus, allow to evaluate and quantify the effect of climatic changes in temporal scenarios to understand biogeographic and ecological perturbation states. This work aims to analyze both geographic and environmental spaces through environmental niche modeling (ENM) in the present for the Teius genus, and to project them to Mid-Holocene and to 2050 RCP 85 scenarios. We made a previous selection among the 19 current WorldClim 1.4 variables and altitude over 5000 random points in an area considered as accessible for each species (M). All layers used have a resolution ~1 km2 (30 arc-seconds). Niche modeling, spatial analysis and environmental space analysis (PCA and hypervolume metrics) were performed with Maxent 3.3.3k, R 3.3.3, and R packets: raster, rgdal, geosphere, rgeos, factoextra, and hypervolume. The Mid-Holocene  potentially suitable area decreased for T. oculatus (-29.55%) and for T. teyou (-6.82%), but  T. suquiensis a would have a larger suitable area (+26%). For the future scenario and with different magnitudes, all species showed a decrease in the potentially suitable area compared to the present (T. oculatus = -9.30%, T. teyou = -0.79%, T. suquiensis = -37.58%). We observed changes in the environmental space in each of the species. The first 3 axes explained more than 86% of the variation for each temporal scenario. The variables that most contribute for PC1 in Mid-Holocene and Present were BIO6, BIO7, BIO 4; BIO17, BIO1, BIO15, BIO5 for PC2; and BIO3, BIO5 and altitude for PC3. For 2050 scenario the variables with higher contribution for PC1 were BIO7, BIO9, BIO4, BIO6; for PC2 BIO, BIO17, BIO15; and altitude, BIO5 for PC3. The hypervolumen distance from Present scenario was for T. oculatus Mid-Holocene = 67.80 and 2050 = 309.10; T. teyou Mid-Holocene = 95.67 and 2050 = 442.67; and T. suquiensis Mid-Holocene = 275.57 and 2050 = 248.07. T. oculatus and T. teyou presented smaller suitable areas in the Mid-Holocene and future scenarios than the present models. On the other hand, T. suquiensis from the Mid-Holocene to future scenario showed a steady decrease of the potentially suitable area. The results of the geographic space changes can be seen as congruent with the environmental space results, which provides not only biogeographic but also ecological information about Teius genus.