Microsatellite primers in Parietaria judaica (Urticaceae) to assess genetic diversity and structure in urban landscapes.

PREMISE OF THE STUDY: Urbanization is one of the main factors contributing to loss of genetic diversity, as the resulting landscape fragmentation and habitat loss induce species isolation. However, studies of genetic structure and diversity in urbanized landscapes are still rare. We characterized microsatellite primers for Parietaria judaica to study this environment. • METHODS AND RESULTS: Eleven microsatellite loci from P. judaica, an urban plant, were isolated using shotgun pyrosequencing, and the simple sequence repeat (SSR) markers were screened in 20 individuals of P. judaica. The loci were tested on 166 individuals from three populations in different cities. The number of alleles ranged from two to 19, and expected and observed heterozygosity values ranged from 0.019 to 0.912 and 0.019 to 0.448, respectively. • CONCLUSIONS: The markers amplified well in the species and will be useful for examining genetic diversity and population genetic structure in this urban plant.

Relative importance of habitat and landscape scales on butterfly communities of urbanizing areas.

Agricultural decline and urbanization entail rapid alterations of the patterns of organization of rural landscapes in Europe. The spread of the urban footprint to the adjacent countryside contributes to the development of new anthropogenic ecosystems in formerly rural hinterlands. In this study, butterflies are considered as biological indicators of these rapid environmental changes. Our purpose is to better understand changes in biodiversity related to the evolution of available habitats in a mutating landscape. In this study, we investigate butterfly communities of four land-use types (fallow lands, gardens, vineyards, woodlands) within different landscape contexts. Our results reveal that variations in structure and functional composition of these communities are related to different levels of human disturbance at both landscape scale and habitat scale.

Gardens in urbanizing rural areas reveal an unexpected floral diversity related to housing density.

The increasing urbanization of rural areas leads to a strong development of horticultural flora, which is the main source of alien and invasive plants. In order to assess the pool of cultivated species under different urbanization pressures, the diversity and distribution of horticultural flora were studied in 120 Mediterranean gardens belonging to three housing density types. The results showed a great richness and heterogeneity of this flora, and similarities in species composition between gardens of the same housing density types. Twenty-four percent of the cultivated species are well adapted to the Mediterranean climate, and 21 species known to be invasive on the French territory have emanated from gardens. Inventorying areas adjoining gardens would be useful in identifying escaped garden plants and to assess the associated risks for biological diversity. The results also suggested a detailed analysis of the influence of social, economic and regional factors on planting practices, in order to identify the drivers of these original floral patterns.