•Case study on a new greenway in Berlin as example of a growing city.•The Green Belt Berlin shows how fortified structures can be transformed to greenways.•Implementation succeeded by linking ...ecological, cultural, and social approaches.•Integrating Wall remains and wild urban nature led to attractive greenspaces.•Design interventions were vital for multi-functionality and meeting social demands.
Urban greenways benefit urban dwellers by providing multiple ecosystem services and by supporting biodiversity conservation in cities. Increasing competition for open space in growing cities, however, often hinders the establishment of greenways in those places where social demands for related services are highest. In the wake of the fall of the Berlin Wall in 1989, a new greenway, the “Green Belt Berlin,” is being established within the former border zone, which now links Berlin’s core with the rural hinterland. An analysis of the planning approaches and principles that directed the implementation of the greenway and the transformation of vacant urban land into new parks revealed ways to (i) extend urban green infrastructure in times and places of political transformation; (ii) justify new greenspace by combining multiple ecological, social, and cultural goals within overarching planning programs; (iii) conserve and stage remnants of the Berlin Wall, allowing the greenway to become part of a decentralized memorial landscape; (iv) work with novel ecosystems and wild urban nature by integrating ecology with urban planning and design; and (v) use design interventions to create “orderly frames.” Spatial analyses indicate that the new greenway may reduce environmental inequity in Berlin as it largely intersects neighborhoods where disadvantaged status coincides with poor access to urban greenspace. This case study thus demonstrates opportunities to strengthen the urban green infrastructure of growing cities through integrative planning approaches.
Urban ecology is a well-established integrative discipline with many historical roots. One of the eminent pioneers of urban ecology is the German ecologist Herbert Sukopp, who works in Berlin since ...the late 1950s and is often referred to as the founder of the "Berlin School of Urban Ecology". On the occasion of his 90th anniversary in 2020, this paper aims to recognize and commemorate the major contributions of Sukopp to the field of urban ecology, based on his scientific work and on results of an online survey on his perception in the international scientific community. Sukopp’s contributions were groundbreaking for the establishment of urban ecology. Specifically, his work furthered: (1) the performance of comprehensive biodiversity studies across all land-use types within the city, in relation to the specifics of urban environments; (2) the establishment of modern approaches of nature conservation in cities and their integration into all land-use types, and the city as a whole; (3) the formation of a multidisciplinary conceptual basis of urban ecology as a modern science, with combined scientific and applied perspectives, ultimately aiming at the preservation and further development of nature within cities for the benefit of urban residents. Herbert Sukopp is thus an important and inspiring pioneer in the field of urban ecology.
Understanding the historical roots of invasion science provides insights into early perceptions of invasive species, allows us to trace the evolution of the discipline over time, and helps ...contextualize modern research. This paper analyzes work by Christian Ludwig Krause, published 250 years ago, on the invasion of an 18
th
-century European landscape by
Erigeron
Conyza
canadensis
(Canadian horseweed), one of the most common invasive species today and a widespread agricultural weed. Here an analysis is conducted of the ecological consequences and underlying mechanisms Krause described, how he evaluated
E. canadensis
invasions in different land-use systems and how his insights align with existing knowledge. Krause identified copious seed production and long-distance dispersal by wind as key mechanisms for the formation of dominant stands on degraded sandy soils. He recognized various ecosystem services associated with population establishment, such as erosion control, increased soil fertility, and the facilitation of other species. While Krause highlighted the benefits of
E. canadensis
invasions for the recovery of degraded grasslands and fields, he also acknowledged this introduced species as a troublesome weed in gardens. Thus, Krause’s work is not only an early report on the invasion of a cultural landscape subject to wind erosion but also an early example of a context-dependent invasion assessment, illustrating both positive and negative impacts of the same species in different environments. Krause’s perspective may encourage current assessments of
E. canadensis
not solely based on its presence or frequency, but on documented ecological and socioeconomic effects and their associated benefits or harms. As Krause impressively demonstrated 250 years ago, these effects can differ starkly in different environments, necessitating multiple responses to the same species.
Nature-based solutions (NBS) represent a recent umbrella concept to tackle land degradation and other urgent challenges. The concept has deep, often-hidden historical roots. To shed light on these ...origins, this paper examines 18th-century approaches to combat land degradation in a central European landscape, as documented in a 1773 book by Christian Ludwig Krause. First, historical sources on overexploitation and degradation of forests and grasslands in 18th-century Brandenburg (now part of Germany) are examined to illustrate major challenges of that period. Then, an analysis of Krause's book identifies the problems he addressed and the solutions he proposed in response. Krause astutely diagnosed the interaction of different land uses that led to the loss or degradation of forests and grasslands and then to wind erosion that severely affected agricultural fields. He identified reduced flower availability due to overgrazing as a threat to bees and honey production. His main recommendations include restoration of oak woodlands, establishment of tree plantations, recovery of degraded sandy areas, planting of hedgerows as living fences, and bee gardens. He justified these solutions by highlighting negative socioeconomic consequences of land degradation, such as timber shortages and reduced agricultural yields. He addressed farmers and other stakeholders directly, illustrating expected economic benefits of proposed interventions, including for the well-being of future generations. Krause's ideas stand out for several reasons: (i) they are underpinned by a clear-sighted understanding of natural components and processes, combined with practical experience; (ii) he treated land degradation as a social-environmental phenomenon, highlighting the responsibility of various stakeholders for problems and their solutions, supported by economic reasoning; (iii) he linked different land-use systems and local to regional scales, even incorporating urban-rural coupling of nutrient cycles. Most of his suggestions meet present-day criteria of NBS. Two aspects of his work fall outside the NBS framework: (i) historical data on the efficiency of the proposals are missing and (ii) biodiversity gains are not explicitly included in his proposals - although many of them would result in improved biodiversity. Christian Ludwig Krause can be considered an 18th-century pioneer of NBS, with his systems-based thinking serving as a model even today, and he was also a pioneer of ecological restoration and sustainable land use.
Display omitted
With insect population declines, cities are important habitats for wild pollinators. Urban beekeeping is an increasingly popular activity, yet honeybees present important risks to wild insect ...pollinators in cities. We argue for new, scientifically evidenced urban pollinator strategies to simultaneously enhance the benefits of urban beekeeping while protecting wild pollinators.
1. In a rapidly urbanising world, the ability of plant species to survive and build selfsustaining populations in urban environments is increasingly important for biodiversity conservation. Yet, the ...contribution of cities to biodiversity conservation remains unclear because ecologists have studied biodiversity patterns, largely without considering the population establishment of plants and the ways in which different kinds of urban ecosystems harbour native and endangered plant species. These limitations can mislead conservation policies for cities. 2. To better understand how urban ecosystems can contribute to biodiversity conservation, we propose a framework that links the population status (casual or established) of plant species with ecosystem novelty and highlights barriers to population establishment in different types of urban ecosystems, from natural remnants to novel ecosystems. 3. To quantify the relative importance of natural remnants vs. human-shaped ecosystems for the conservation of self-sustaining urban plant populations, we reanalyse a unique dataset from a metropolitan region in Europe with information on the population status of 1,199 plant species. 4. Results demonstrate that urban ecosystems harbour many established native and endangered species although a considerable share (37%) of species of conservation concern are confined to natural remnants. In hybrid and immature novel ecosystems, high species numbers reflect many species with only casual populations. The role of novel ecosystems as habitats for native and endangered plant species increases as novel ecosystems mature. 5. Synthesis and applications. General information about plant species richness in urban environments may mislead conservation policies as different kinds of urban ecosystems can play different roles in harbouring species of conservation concern. Moreover, presence/absence data can mask establishment failures of species. This proposed framework helps to distinguish between casual and established populations of plant species, and highlights barriers to population persistence in urban ecosystems, reflecting different land uses and land use histories over time. Revealing the role of natural remnants vs. hybrid vs. novel ecosystems as habitats for species of conservation concern illustrates opportunities for biodiversity conservation in all urban ecosystems and can support setting priorities for conservation.
The term “indicator” is frequently used at the interface between science and policy. Although there is a great demand for clear definitions of technical terms in science and policy, the meaning of ...indicator is still ambiguous. In this contribution, we analyze different meanings of the term in ecology and environmental planning, suggest a general definition, and make recommendations for its appropriate use. We determined that the ways in which indicator is defined differ greatly, and some definitions are mutually exclusive. We arrived at the conclusion that a broad definition of the term is feasible. We recommend distinguishing between indicators as ecological components, i.e., ecological units, structures, or processes and as measures, i.e., properties of a phenomenon, body, or substance to which a magnitude can be assigned, and between descriptive and normative indicators. This clarification prevents the term “indicator” from becoming a meaningless buzzword, improves communication among stakeholders, and assures the testability of theories that include indicators. To avoid problems based on different understandings of the term and to maintain integrity in its use, we advise always providing a definition of the indicator term.
Display omitted
•All populations of 213 endangered plants related to different ecosystems in Berlin.•Most populations were found in forests, grasslands and ruderal sites.•Novel urban ecosystems ...harbored most populations of endangered plants.•Yet population density was highest in natural remnants.•Strong arguments for broad approaches in urban biodiversity conservation.
As urbanization accelerates globally, a better understanding of how cities contribute to biodiversity conservation is increasingly pressing. Previous studies reveal that cities can harbor a considerable biological richness, including endangered plant species. Yet, a key question on the urban contribution to plant conservation remains critically open, as little information is available on how populations of endangered plant species occur across different biotope types within cities and to what extent anthropogenically shaped vs. natural ecosystems provide habitats for endangered plants. We analyzed a unique dataset on the exact geographical position of 1742 populations of 213 endangered plant species in the city of Berlin. We first assessed the relative importance of Berlin’s nine major biotope classes as habitats of these species. Second, we applied the novel ecosystem concept to quantify endangered plant populations for natural remnants vs. hybrid vs. novel ecosystems within Berlin. Populations of endangered plant species were generally, although unevenly, associated with specific biotope classes, with forest, grassland, and ruderal biotopes as the most important habitats. Surprisingly, novel ecosystems harbored the highest numbers of total populations, of total species, and of species that were exclusively confined to one type of ecosystem novelty. Quantifying the relative importance of biotope classes and novel vs. (near-)natural ecosystems as habitats of endangered species demonstrates that the urban contribution to biodiversity conservation is best ensured by providing a range of ecosystems. Rather than prioritizing only natural remnants, we thus argue for broad approaches to urban biodiversity conservation that include novel ecosystems.
Assessing the impacts of alien plant species is a major task in invasion science and vitally important for supporting invasion-related policies. Since 1993, a range of assessment approaches have been ...developed to support decisions on the introduction or management of alien species. Here we review the extent to which assessments (27 approaches) appraised the following: (i) different types of environmental impacts, (ii) context dependence of environmental impacts, (iii) prospects for successful management, and (iv) transparency of assessment methods and criteria, underlying values and terminology. While nearly all approaches covered environmental effects, changes in genetic diversity and the incorporation of relevant impact parameters were less likely to be included. Many approaches considered context dependence by incorporating information about the actual or potential range of alien species. However, only a few went further and identified which resources of conservation concern might be affected by specific alien plant species. Only some approaches acknowledged underlying values by distinguishing negative from positive impacts or by considering the conservation value of affected resources. Several approaches directly addressed the feasibility of management, whereas relevant factors such as availability of suitable management methods were rarely considered. Finally, underlying values were rarely disclosed, and definitions of value-laden or controversial terms were often lacking. We conclude that despite important progress in assessing the manifold facets of invasion impacts, opportunities remain for further developing impact assessment approaches. These changes can improve assessment results and their acceptance in invasion-related environmental policies.
Display omitted
•First study on biodiversity interaction in relation to other activities in parks.•12% of all observed activities were interactions with individual plant species.•About 17% of wild or ...cultivated plants from local species pools were utilized.•Provisioning services and cultural services of park flora were quantified.•Gender and cultural diversity play a role in human-biodiversity interaction.
In a rapidly urbanizing world, people are increasingly at risk of being disconnected from nature. Previous studies demonstrate that urban parks support contact of urban dwellers with “nature”, urban foraging activities and contribute to human well-being. While the importance of biodiversity underlying ecosystem services is broadly acknowledged, the role of individual plant species in the interaction of park visitors with biodiversity has received less attention. By applying a mixed methods approach in two parks in Berlin (biodiversity analysis, observation, interviews), we aimed to (i) determine the importance of biodiversity interaction at the species level in relation to other park activities, (ii) identify the range of used and non-used plant species, (iii) determine purposes underlying the utilization of individual species, and (iv) analyze gender-related differences in these activities. Results indicated a considerable proportion of activities related to individual plant species (12%), compared to other activities in parks. In total, 26 cultivated or spontaneous species (ca 17% of the local species pools), were used for consumption (60%), decoration (21%) and biodiversity experience (17%). Native and non-native plants were utilized proportionally to local supply. More women (78%) than men interacted with plant species. Another 33 species were identified as being gathered in Berlin outside of gardens based on interviews of park visitors. Findings support approaches toward a biodiversity-friendly park design and management. Maintaining and facilitating biodiversity interactions for a broad range of park-users is a promising pathway to biodiversity conservation in cities and would help counteract the loss of experience in human-nature interactions.
PDF
