Effects of landscape structure and patch characteristics on the density of central populations of the eastern green lizard Lacerta viridis

Abstract

A better understanding of the impact of habitat loss on population density can be achieved by evaluating effects of both parameters within remnant habitat patches and parameters of the landscape surrounding those patches. The integration of predictors at the patch and landscape level is scarce in animal ecological studies, especially for reptiles. In this study, a patch–landscape approach was applied to evaluate the combined effects of within‐patch habitat quality, patch geometry and landscape configuration and composition on the density of remnant populations of the eastern green lizard, Lacerta viridis, in a highly modified landscape in Bulgaria. Landscape composition variables (proportion of different land covers) were measured at different spatial scales surrounding patches. Single‐scale models were built to evaluate combined effects of all predictors on density, when including all landscape composition variables at a specific spatial scale. Multi‐scale models were applied to analyze combined effects when including landscape composition variables at the scale of their strongest effect (scale of effect, SoE). Results showed that the SoE of proportion of cropland and urban areas was small (50 m), while for proportion of habitat was large (1.5 km). The overall effect of habitat loss was better explained by the multi‐scale model. Population density increased with patch area and decreased with patch shape irregularity and with the proportion of three land cover types surrounding patches—cropland, urban areas, and habitat. Combining patch and landscape parameters is important to identify ecological processes that occur simultaneously at different spatial levels and landscape scales, which would imply the application of multi‐scale approaches for the protection of wild animal populations. Results are contrasted with what is known about occupancy patterns of the species in the same region and approaches to integrate both occupancy and density, in the field design of animal ecological studies are suggested.

Urban oasis? Abundant dice snake (Natrix tessellata) populations along artificial lakeside habitats in urban landscapes

“…Contrary to our prediction and the results of some previous studies (Doherty et al 2020;Prieto-Ramírez 2023;Woolley et al 2023), we found that urban land use cover was positively correlated with the mean abundance of snakes (Fig. 2A; Table 5), implying that populations living in more urbanized habitats are more abundant.…”

Deterioro de ecosistemas y paisajes: Lo último al 2023

“…Importante acción de deterioro cumple los micro plásticos en los esquemas de agua dulce, aunque no es un indicador de la calidad ecológica tienen efectos nocivos que deben ser estudiados, se observaron altos niveles de nutrientes principalmente el fósforo, el intestino de oligoqueto presentó alto número de micro plásticos a la vez desnutrición y trastornos digestivos (Cheng et al, 2023;Prieto-Ramírez, 2023;Ribeiro et al, 2023).…”