Ina Säumel

How healthy is urban horticulture in high traffic areas? Trace metal concentrations in vegetable crops from plantings within inner city neighbourhoods in Berlin, Germany

Food production by urban dwellers is of growing importance in developing and developed countries. Urban horticulture is associated with health risks as crops in urban settings are generally exposed to higher levels of pollutants than those in rural areas. We determined the concentration of trace metals in the biomass of different horticultural crops grown in the inner city of Berlin, Germany, and analysed how the local setting shaped the concentration patterns. We revealed significant differences in trace metal concentrations depending on local traffic, crop species, planting style and building structures, but not on vegetable type. Higher overall traffic burden increased trace metal content in the biomass. The presence of buildings and large masses of vegetation as barriers between crops and roads reduced trace metal content in the biomass. Based on this we discuss consequences for urban horticulture, risk assessment, and planting and monitoring guidelines for cultivation and consumption of crops.

Herbaceous plants as filters: Immobilization of particulates along urban street corridors

Among air pollutants, particulate matter (PM) is considered to be the most serious threat to human health. Plants provide ecosystem services in urban areas, including reducing levels of PM by providing a surface for deposition and immobilization. While previous studies have mostly addressed woody species, we focus on herbaceous roadside vegetation and assess the role of species traits such as leaf surface roughness or hairiness for the immobilization of PM. We found that PM deposition patterns on plant surfaces reflect site-specific traffic densities and that strong differences in particulate deposition are present among species. The amount of immobilized PM differed according to particle type and size and was related to specific plant species traits. Our study suggests that herbaceous vegetation immobilizes a significant amount of the air pollutants relevant to human health and that increasing biodiversity of roadside vegetation supports air filtration and thus healthier conditions along street corridors.

Orchards for edible cities: Cadmium and lead content in nuts, berries, pome and stone fruits harvested within the inner city neighbourhoods in Berlin, Germany

Todays urban gardening focuses mainly on vegetable production and rarely includes fruit trees. Health effects of consuming urban crops are questioned due to high local pollution loads. Here, we determined cadmium and lead content in the edible parts of nuts, berries, pome, and stone fruits harvested from fruit trees and shrubs within inner city neighbourhoods of Berlin, Germany. We analysed how local settings at sampling sites shaped the trace metal content. We revealed significant differences in trace metal content depending on species, fruit type, local traffic, and parameters related to barriers between the sampling site and neighbouring roads. Higher overall traffic burden and proximity to roads increased whereas buildings or vegetation as barriers reduced trace metal content in the edible biomass. We demonstrate, that the consumption of non-vegetable fruits growing in inner city sites in Berlin does not pose a risk on human health as long as the fruits are thoroughly washed and it is provided that site pollutions and impacts are considered in garden concepts and guidelines.

Wild growing mushrooms for the Edible City? Cadmium and lead content in edible mushrooms harvested within the urban agglomeration of Berlin, Germany.

Health effects by consuming urban garden products are discussed controversially due to high urban pollution loads. We sampled wild edible mushrooms of different habitats and commercial mushroom cultivars exposed to high traffic areas within Berlin, Germany. We determined the content of cadmium and lead in the fruiting bodies and analysed how the local setting shaped the concentration patterns. EU standards for cultivated mushrooms were exceeded by 86% of the wild mushroom samples for lead and by 54% for cadmium but not by mushroom cultures. We revealed significant differences in trace metal content depending on species, trophic status, habitat and local traffic burden. Higher overall traffic burden increased trace metal content in the biomass of wild mushrooms, whereas cultivated mushrooms exposed to inner city high traffic areas had significantly lower trace metal contents. Based on these we discuss the consequences for the consumption of mushrooms originating from urban areas.

Plants in Urban Settings: From Patterns to Mechanisms and Ecosystem Services

More than half of the global human population is living in urban areas, and the trend towards further urbanization is strongly increasing (MEA 2005; United Nations 2008). Hence, the majority of people globally will experience “nature” and related ecosystem services primarily within the urban fabric (Gilbert 1989; McKinney 2002; Miller and Hobbs 2002; Miller 2005; Goddard et al. 2010). There is increasing evidence that urban land uses affect profound changes in all environmental components and that humans are the main drivers of change (Sukopp et al. 1979; Pickett et al. 2001; Alberti et al. 2003; Grimm et al. 2008). Urban growth has been identified as a major threat to biodiversity (e.g. Hansen et al. 2005), but at the same time, urban regions can harbour an array of species (Sukopp and Werner 1983; Gilbert 1989; Pys?ek 1993; McKinney 2002) and contribute to the conservation of biodiversity. However, distinct urban ecosystems cannot replace totally the habitat function of (near-)natural systems (Kowarik 2011).

Water sensitive design potentials in Paris, Berlin, and Budapest revisited

Abstract Impacts of extreme weather events are increasing due to ongoing climate change. Floods in the urban areas not just damage properties but also threat human life. Coping with these challenges in metropolises of old Europe is difficult as the ex-istent building structures and combined rainwater and sewage systems originating from the 19th century. We compare three old European capital cities (Berlin, Budapest and Paris) regarding rainwater management concepts. We identify important spatial land use types of blue-green infrastructure and corresponding measures for the implementation towards a more water sensitive management by using the case study approach.

Between cultural and ecological processes: historical plant use in communal parks in Berlin, Germany

Communal urban parks originating from the 19th and early 20th centuries are key elements of the European heritage and provide numerous ecosystem services. Here, we examine five public parks in Berlin, Germany, to evaluate whether their historical plantings have left ecological footprints. In a brief presentation, we explore why and when these parks came into being. The park design and development, original plant assortment and plant use patterns within the parks revealed continuities and discontinuities over time that influenced the vegetation, particularly woody species. In four of five parks only a few historical patterns and materials were preserved, and the original species diversity decreased significantly over the centuries. Finally, we discuss the potential spread of exotic ornamentals from the parks to their surroundings and the ecological impacts of horticultural history within the urban matrix.