Including processual thinking
From the perspective of urban landscapes, there is a related trajectory between the development of ecology and public parks/urban green leading to what is today framed as green infrastructure, tied together by the changing landscape practices of industrialisation and increasing urbanisation. The below is a brief outline of the thinking and conceptual-isation of ecology, spanning from classification and entities to processes (Spirn, 2012, p. 8), which occurred during the same period as the emer-gence and elevation of public parks.
The scientist Alexander von Humboldt (1769-1859) became highly influ-ential due to his writings in the early 19th Century, articulating an under-standing of the Earth as a whole system. His works inspired numerous other renowned scientists and writers of the 19th century, such as Henry Thoreau (Walden, Life in the Woods, 1854), Charles Darwin (The Origins of Species 1859), and the father of nature conservation George Perkins Marsh (Man and Nature, 1864): all of these influential thinkers engage with the interplay between humans and nature (Skage, 2016;
Wulf, 2017, 2015). In 1866, the German zoologist Ernst Haeckel coined the term ecology9 to denote the relationships between living things and their environment. The Danish botanist Eugen Warming was among the earliest ecologists, introducing the ecology of plant societies in the late 19th century10, leading to the founding of ecology as a discipline.
According to Martin Odgaard, landscape ecology in its current form of field and conceptualisation can be traced back to the German geogra-pher and botanist Carl Troll11, who coined the term in 1939 (Odgaard, 2014, p. 63). Ecology and ecological thinking connect to the concept of ecosystems. Inspired by E. Warming, the eco-system concept was introduced in biology by the British botanist Sir Arthur Tansley in 1935 (Spirn, 2012, p. 4). From Tansley´s first description of ecosystems as the
´transfer of material between organisms and their environment´, he refined the conceptualisation as a ´whole systems approach´ inclusive of humans, human-generated processes and structures. Pickett and Cade-nasso emphasise that what is important about the ecosystem concept as framed by Tansley is that it goes beyond the dualism of human and nature, being inclusive of humans, human processes, as well as their artefacts:”[…] in his seminal definition, [Tansley], was at pains to empha-size that ecologists should study ecosystems that incorporate humans and human-generated processes and structures.” (Pickett and Cadenasso, 2002, p. 2).
ϵപ As the word Pkologie, in Haeckels book ´Generelle Morphologie der Organismen´
1Ϭപ Warming, E. (1ϴϵ5) Plantesamfund - Grundtrčk af den Ɔkologiske Plantegeografi 11പ The Geographic landscape and its Investigation, 1ϵ5Ϭ
Pickett and Cadenasso´s Three Tides in Urban Ecology
To provide an overview of the development of ecological thinking with relevance to landscape architecture, I draw upon Pickett and Cade-nasso, who provide an overview of the development of urban ecological science as three ´tides´ during the 20th century (Pickett and Cadenasso, 2013). The 1st Tide was during the 1920s, when Tansley coined the term ecosystem, and a few years later, the urban sociologists Robert Park and Ernest W. Burgess applied the ecological concept to the urban area, with a focus on space and social differentiation in the city. This resonated with biological ecology. The 2nd Tide was in the 1960-70s. Here, the biologists Howard and Eugene Odum developed the ecosystem concept into an area of research, making it a paradigm in ecology, seeking ´to understand the reciprocal metabolic connections between biological and physical systems´ (Pickett and Cadenasso, 2013, pp. 35–37). This developed into the budgetary approach, now fundamental to ecosystem science, and gave rise to industrial ecology and urban metabolism. The 2nd Tide contributed to how the 3rd Tide conceptualises the city as an ecosystem, which is central to urban ecology. The 3rd Tide gathered pace during the 1980s and remains ongoing. The 3rd Tide attempts to bridge ´social and biological knowledge, and it acknowledges the spatial heterogeneity and fine-scale dynamics as a feature and cause of urban change´ (Pickett and Cadenasso, 2013, p. 39).
3.3.5 SUM UP
INCREASING URBANISATION AND THE RISE OF PUBLIC PARKS AND ECOLOGICAL THINKING
Green infrastructure is rooted in ecosystem thinking, meaning that dimensions beyond, e.g. recreation or conservation, are required in order to qualify as green infrastructure. Isolated efforts, short-term solutions or smart-growth do not in themselves qualify as green infra-structures either (Benedict and McMahon, 2006). Nevertheless, histor-ical Greenways can be exemplary green infrastructure that integrates ecological thinking (Hellmund and Smith, 2006).
During the 19th century, many Western cities provisioned public parks.
This was in response to rapidly growing urbanisation, new industrial practices in both rural and urban areas, together with deficit side effects to human living conditions in the western cities of the late 18th to early 20th century. Public parks aimed to create multiple benefits for urban inhabitants, particularly through recreation and opportunities for socialising in green, public areas, under the notion of ´nature´. In the same period, the understanding of nature and the relationship between humans and nature was changing too, and early ecological thinking was developing. Ecology was rising, firstly, as a conceptual understanding of the world as being connected at a larger systems scale, as opposed to, e.g. a taxonomy or classifying single organisms. With the concep-tualisation of ecosystems, the dichotomy between human and nature dissolved, at least in theory. The synchronisation between increasing urbanisation/Industrialisation, the development in ecological thinking, and the rising of public parks, leading to greenways and green infrastruc-ture has been formed through the continuous exchange of knowledge between, e.g. biology, psychology, geography, nature conservation and sociology. This also extends to landscape architects who, using theories from different fields and professions, have transported this conceptualis-ation and knowledge into landscape design and planning.
The development from public parks to formalised policies on the bene-fits of green infrastructure, e.g. in the European Landscape Convention, represents some fundamental aspects of what is considered of value.
Today, green infrastructure is a growing field, often deeply connected to ecosystem services and the attribution of value, referring back to the expectations of values provided by green, public spaces, as formulated in the late 18th century. For example, the emphasis on multi-function-ality and the attribution of values at different levels, e.g. physical health, mental health and stress, culture, morale, the need for ´nature´ and the promotion of tolerance and democracy together with water manage-ment and concerns for biodiversity
The acknowledgement of the influence of urbanised areas over much larger tracts of land than they actually cover, requires a systems-thinking
approach towards landscape practices, relating to that of ecological thinking. Taken together, the trajectory of public parks and green infra-structure represents landscape-based efforts for responding to the conditions produced by increased urbanisation and changing land-use practices. The spatial answer was the provisioning of public green spaces with an array of functions and sensory experiences via planning land use for the common good. With climate change and further urbanisation, this might be more important than ever.
Figur 4.3.6: From wetland grazing to private investment to public park: the ´Vennelyst Parken´ is the oldest park in Aarhus. Until 1824, it was a swampy area, serving local farmers as public grazing for cows. By 1824 the private entrepeneur Høegh Guldberg rented the land and established a private park with events. The park had an entrence fee. By 1957 th area became part of the Aarhus University Campus, renowned for its buildings, designed by architect C. F. Møller, and the park area by landscape architect C. Th. Sørensen.
Sources: HMB map: GST, map 1914: Aarhus Wiki, photos:
Gustaf Lohm Cathedral
Aarhus Stream Vennelyst Park