Deliberate and less intentional urban forests

Abstract

The term ‘urban forest’ is an oxymoron and continues to provoke a staggering set of questions. The default practice of transplanting cloned saplings from nurseries into the city holds little promise of adding up to more than the sum of its destressed trees. In contrast, there is growing recognition of the unsanctioned emergent forest vegetation of urban fallows. While the fields of cultural geography and urban ecology recognize such unintentional urban forests for their layered sociocultural, ecological and health benefits, city administrators, the general public and even landscape architects have been slower to embrace them. However, consequences of global warming and the subsequent rise of urban ecology mandates an update regarding current challenges and potentials in managing urban forests. Park projects can expand the normative canon by embracing recent urban ecology concepts concerning spontaneous vegetation on fallow urban land, such as ‘ruderal’ and ‘fourth nature’. This paper critically reviews traditional notions of urban forestry and refutes the single tree planting approach. It questions standardized connotations and nativist biases towards invasive species and argues that spontaneous vegetation is well equipped to provide and expand critical networks to more resilient and enduring urban forest patches. It explores cases in Germany, in general, and Berlin, in particular, to ground the relevance for emergent vegetation. It considers the acknowledgment and utilization of recent developments in forestry science regarding microbial ecology, including the mycorrhizal and symbiotic macro/micro networks, important for landscape architecture and necessary to propose more resilient and healthy forested urban environments.