Climate change will increase naturalization risk from garden plants in Europe

Aim: Plant invasions often follow initial introduction with a considerable delay. The current non-native flora of a region may hence contain species that are not yet naturalized but may become so in the future, especially if climate change lifts limitations on species spread. In Europe, non-native garden plants represent a huge pool of potential future invaders. Here, we evaluate the naturalization risk from this species pool and how it may change under a warmer climate. Location Europe. Methods: We selected all species naturalized anywhere in the world but not yet in Europe from the set of non-native European garden plants. For this subset of 783 species, we used species distribution models to assess their potential European ranges under different scenarios of climate change. Moreover, we defined geographical hotspots of naturalization risk from those species by combining projections of climatic suitability with maps of the area available for ornamental plant cultivation. Results: Under current climate, 165 species would already find suitable conditions in > 5% of Europe. Although climate change substantially increases the potential range of many species, there are also some that are predicted to lose climatically suitable area under a changing climate, particularly species native to boreal and Mediterranean biomes. Overall, hotspots of naturalization risk defined by climatic suitability alone, or by a combination of climatic suitability and appropriate land cover, are projected to increase by up to 102% or 64%, respectively. Main conclusions: Our results suggest that the risk of naturalization of European garden plants will increase with warming climate, and thus it is very likely that the risk of negative impacts from invasion by these plants will also grow. It is therefore crucial to increase awareness of the possibility of biological invasions among horticulturalists, particularly in the face of a warming climate

Studying the Spatial Distribution of Volunteered Geographic Data Through a Non-parametric Approach

Nowadays, new knowledge on the immaterial characteristics of surrounding landscapes can easily be produced by relying on volunteer contributions. However, the spatial distribution of the collected data may be influenced by the contributor’s location. Using data sets derived from the administration of a map-based survey, aimed at collecting explicit spatial information on sites perceived as having positive and negative qualities in Friuli Venezia Giulia (Italy), a descriptive analysis and a non-parametric procedure are employed to study the relevance of a respondent’s municipality of reference on the mapping activity. The findings indicate that the volunteered geographic data collected in the survey are not uniformly distributed across the study area and that a different spatial relationship exists between mapped elements and a respondent’s residence when the two different attributes of interest are considered. The results underline the importance of considering volunteers’ characteristics when engaging local populations in participatory initiatives

ROSCAs in Urban Ethiopia: Are the Characteristics of the Institutions More Important than those of Members?

Using household data from urban Ethiopia, we provide an empirical test of the economic theory of Rotating Savings and Credit Associations (ROSCAs) and identify the impact of ROSCAs and member characteristics on participation and volume of saving. Unlike other studies, we account for the endogeneity of all ROSCA variables. Muslims, individuals who live in richer households, the self-employed, private sector employees and households with large numbers of women are more likely to join ROSCAs. A robust finding is that the savings are significantly affected by the characteristics of the members but not that of the informal saving institution. Some policy implications are discussed.