Knapp Plant Biodiversity in Urbanized Areas

Plant Functional Traits in Space and Time, Plant Rarity and Phylogenetic Diversity
1. Auflage 2010
ISBN: 978-3-8348-9626-1
Verlag: Vieweg & Teubner
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, 172 Seiten, Web PDF

Reihe: Physics and Astronomy (R0)

Urbanization is one of the main drivers of global change. It often takes place in areas with high biodiversity, threatening species worldwide. To protect biodiversity not only outside but also right within urban areas, knowledge about the effects of urban land use on species assemblages is essential.

Sonja Knapp compares several aspects of plant biodiversity between urban and rural areas in Germany. Using extensive databases and modern statistical methods, she goes beyond species richness: Urban areas are rich in species but plant species in urban areas are closer related to each other than plant species in rural areas, respectively. The urban environment, characterized by high temperatures and frequent disturbances, changes the functional composition of the flora. It promotes e.g. short-lived species with leaves adapted to drought but threatens insect-pollinated or wind-dispersed species. The author claims that the protection of biodiversity should not only focus on species richness but also on functional and phylogenetic diversity, also right within urban areas, to preserve a flora with a high potential for adaptation to changing global conditions.

Zielgruppe

Research

Autoren/Hrsg.

Knapp, Sonja

Inhaltsverzeichnis

General Introduction.- Urbanization Causes Shifts of Species’ Trait State Frequencies – a Large Scale Analysis.- Does Urbanization Cause Shifts of Species’ Trait State Frequencies? – A Small Scale Analysis.- How Species Traits and Affinity to Urban Land Use Control Plant Species Frequency.- Changes in the Functional Composition of a Central European Urban Flora over Three Centuries.- Challenging Urban Species Diversity: Contrasting Phylogenetic Patterns across Plant Functional Groups in Germany.

Leseproben

Chapter V – Challenging Urban Species Diversity: Contrasting Phylogenetic Patterns across Plant Functional Groups in Germany (S. 89-90)

1. Introduction

The high vascular plant species richness of urbanized areas in Germany is biased towards species with specific functional traits or trait states, and towards common species, as shown in the preceding chapters. The last aspect of species diversity to be analyzed here is phylogenetic diversity: In terms of species richness, an assemblage of three Poaceae species seems as diverse as an assemblage of one Poaceae, one Asteraceae and one Fagaceae species, but the former assemblage appears much less diverse when considering their phylogenetic background: The three Poaceae species belong to one family and are thus closer related to each other than the species from the three families of Poaceae, Asteraceae and Fagaceae.

Phylogenetic diversity, which measures the diversity of evolutionary relationships between species, reveals these underlying patterns, and so provides valuable information for species conservation and about mechanisms of species assembly (Vane-Wright et al. 1991). Phylogenetically closely related species often share specific traits or trait states through their common origin and evolutionary history (evolutionary niche conservatism, Harvey & Pagel 1991, Prinzing et al. 2001).

Hence, phylogenetic diversity is usually interrelated with the frequency of species per functional trait. However, phylogenetically closely related species can also develop different trait states due to adaptive radiation (e.g. Schluter 2000, Ackerly & Nyffeler 2004, Prinzing et al. 2008). In both cases, the environment influences the functional and phylogenetic structure of a species assemblage. We therefore expect differences not only in the functional but also in the phylogenetic structure of floras from urbanized and non-urbanized areas. While influences of urbanization on functional traits have been confirmed for a range of plant traits (e.g. Kleyer 2002, Williams et al. 2005, Lososová et al. 2006, present study), little is known about the effects of urbanization on phylogenetic diversity (but see Ricotta et al. 2008a).

Here, we compare the phylogenetic diversity of German vascular plant assemblages between urbanized and two types of non-urbanized areas, i.e. agricultural and semi-natural including forests (both referred to as rural, as defined in Chapter I, see Fig. A2). Our approach is a macroecological one, suitable to reveal large-scale patterns and well suited to reflect the influence of urbanization on biodiversity that does not stop at city borders but acts on large areas. Moreover, the positive relation between urban land use and species richness is especially strong at coarse scales (Pautasso 2007).

Über Autor(innen)

Dr. Sonja Knapp completed her doctoral thesis at the Department of Community Ecology at the Helmholtz-Centre for Environmental Research – UFZ in Halle and at the Department of Ecology, Evolution & Diversity at Frankfurt University, Germany.