The Role of Urban Structures in the Distribution of Wasteland Flora in the Greater Paris Area, France

Abstract

Wastelands are likely to host a significant part of urban floristic diversity but have received limited attention because they are not considered interesting green zones. Here, we explore the potential role of wastelands in maintaining urban biodiversity to help define effective urban management plans. We quantified floristic diversity in 98 wasteland sites of Hauts-de-Seine, one of the most densely populated areas in France, and characterized the environmental parameters and spatial distribution of sites to identify some of the factors that influence plant species composition and to explore the impact of urban environment on the floristic interest of wastelands. Their floristic richness represented 58% of the total richness observed in the whole study area. Site richness depended on site area (the largest sites were the richest) and site age, with a maximum in sites of intermediate age (4 to 13 years). In the largest sites only (> 2500 m 2), the floristic distance among sites was positively correlated with geographic distance, which suggests that migration of species among large sites partly controls local floristic composition. In contrast, the environmental distance among sites was not correlated with floristic distance. Finally, we showed that the presence of collective and individual dwellings within 200 m of a wasteland decreased its floristic rarity, whereas the presence of rivers or ponds increased it. We derive several recommendations to optimize the management of wastelands with respect to conservation of urban biodiversity.

Plant species composition in green spaces within the built-up areas of Beijing, China

“…The surveys covered the main types of urban green spaces defined in the classification of green spaces in the Urban Garden and Afforestation Survey Collection of Beijing (Gardening and Bureau 2000), including park green space, protection green space, institutional green space, residential green space, street green space, and vacant land space (Table 1). Vacant land space is also included in our study because urban vacant lands are considered as habitats of crucial importance in urban areas (Muratet et al 2007). The number of sites selected from each type of green spaces was proportional to the area of the green space.…”

Green Roofs and Green Walls for Biodiversity Conservation: A Contribution to Urban Connectivity?

“…Green walls areas may remain well below this size. Living walls (all) 65.9 ± 3.09 (n = 21) 6-200 [44] Modular systems 188 ± 264.6 (n = 9) 28-900 [46] Continuous systems 118.3 ± 87 (n = 6) 40-300 [46] Like in small urban green spaces (e.g., Reference [64]) and larger ones (e.g., Reference [60]), significant relationships exist between the sizes of green roofs and green walls and species diversity, but those relationships are highly variable among communities, habitats, and time. The relationship between stone wall areas and plant richness has not yet been explored, but it is now known that the size of extensive and semi-extensive roofs (i.e., the more interesting systems for wildlife because of reduced maintenance) acts as a minor determining factor in the species richness of colonizing plants [49,62].…”

“…In the advanced stages of succession, tall grass and meadow vegetation, or pre-forest stages, shelter generalist species that prefer more humid conditions, with perennial species gaining dominance. Unlike green roofs, wastelands change in space and over time according to construction, demolition and succession; they can contribute to species dispersal and biodiversity conservation, but only if they are not too isolated [64]. Extensive and semi-intensive roofs could act as refuges for many wasteland species, thereby reducing the isolation of those habitats in cities.…”

The spatial genetic structure of the yellow-necked mouse in an urban environment – a recent invader vs. a closely related permanent inhabitant

“…On the other hand, several studies have demonstrated that urban areas can harbour diverse habitats, simultaneously supporting high biodiversity (e.g. Muratet et al 2007;Kadlec et al 2008). Seeking a better understanding of how an urban environment can affect population processes in various species, molecular genetics methods have long been applied to analyse gene flow within urbanized landscapes and among urban landscapes and surrounding rural areas, as well as to estimate genetic variability in urban populations of wild species (e.g.…”