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

MINOLI, I.; CACCIALI, P.; MORANDO, M.; AVILA, L.J.

Quito

Congreso; XI Congreso Latinoamericano de Herpetologia; 2017

PUCE

The analysis of ecological nichecomprises both geographic and environmental spaces, and the subset of abioticand non-interactive variables is mainly defined as grinnellian niche. Analysisof this niche in an ectotherm taxa over different temporal scenarios, allowsevaluating and quantifying the effect of climate change, and contributes tounderstand biogeographic and ecological perturbation states. This work aims toanalyze both geographic and environmental spaces throughenvironmental niche modeling (ENM) in the present for the lizard genus Teius,and to project them to Mid-Holocene and to 2050 RCP 85 scenarios. We randomlytook 5000 points from an area considered accessible for each species, weselected a subset of the 19 current WorldClim 1.4 variables (based on aprotocol that minimizes correlation), we included altitude, and used layerswith a resolution ~1 km2 (30 arc-seconds). We performed nichemodeling, spatial and environmental space analysis (PCA and hypervolumemetrics) with Maxent 3.3.3k, R 3.3.3, and R packages: raster, rgdal, geosphere,rgeos, factoextra, and hypervolume. The Mid-Holocenepotentially suitable area decreased for T. oculatus (-29.55%) and for T.teyou (-6.82%), but T. suquiensis would have a larger suitable area(+26%). For the future scenario and with different magnitudes, all speciesshowed 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 environmentalspace of each species. The first 3 axes explained more than 86% of thevariation for each temporal scenario. The variables with higher contributionfor PC1 in Mid-Holocene and Present were BIO6, BIO7, BIO 4; for PC2 BIO17,BIO1, BIO15, BIO5; and BIO3, BIO5 and altitude for PC3. For the 2050 scenariothe variables with higher contribution for PC1 were BIO7, BIO9, BIO4, BIO6; forPC2 BIO, BIO17, BIO15; and altitude and BIO5 for PC3. The hypervolumen distancefor T. oculatus from the Present to the Mid-Holocene was 67.80 and to2050 was 309.10; for T. teyou to Mid-Holocene = 95.67 and to 2050 =442.67; and for T. suquiensis to Mid-Holocene = 275.57 and to 2050 =248.07. Teius oculatus and T. teyou had smaller suitable areas inthe Mid-Holocene and future scenarios than the present models, while T.suquiensis from the Mid-Holocene to the future showed a steady decrease ofthe potentially suitable area. The results of the changes over the geographicspace are congruent with the environmental space results, which provides notonly biogeographic but also ecological information about Teius.