Pickett(ing) a point in urban ecology where systems thinking can help to “close the loop”

In Pickett et al’s review, “Urban Ecological Systems: Linking Terrestrial, Ecological, Physical, and Socioeconomic Components of Metropolitan Areas,” the authors attempt to establish a matrix for assessing and fixing an urban system ecology, from the personal (household) on up to the greater community or region (city). First, the authors must establish the problems faced by cities and urban centers, be they biotic, abiotic, trophic, faunal or socioeconomic.

They review disparate literature that seeks to address the ecological issues in isolation, i.e. single views or lenses that do not give real or complete expectations and predictions. Drawing on specific examples of more complete holistic views, they attempt to adequately address environmental and budgetary city systems through a human ecosystems approach (where socioeconomic, biotic and abiotic processes are combined in and around cities) to give a realistic prediction and understanding of ecological systems.

They point out a great deal of descriptive knowledge has been gathered regarding the unique biota of cities; however, most of the information on the terrestrial components of urban ecological systems comes from views of ecology in cities not the ecology of cities. For instance, we know that deer populations, medium animals like skunks, raccoons, house cats, small animals like mice, rats and squirrels thrive in urban settings. We understand that this is because there are no large predators, but also because the structure of the ecology of a city (flora, fauna, microscopic biota) has all but eliminated the specialist creatures of the ecology. Cities have become foci’s of the best generalist creatures as compared to rural areas, where the sheer quantity of species/varieties of food tend to not allow any one species to become dominant. The soil is unique and varied in cities due to construction, and many areas are reduced to empty lots. The ground, soil and other elements are mixed in unique ways, the dirt in urban areas creates mineral and chemical sinks that would never occur in a rural location. The type of nutrients that are available in cities and the life that can readily feed on them is unique. In many cases, certain plants and organisms have become genetically specific to a harder climate.

The diversity of life (or lack thereof) in a city, however, is not completely uniform across all areas of the same urban center. Pickett et al cites many studies that show floral biota, whether native or non-native, can be greatly diversified in areas of economic wealth compared to that of low-income areas. In general, economically wealthy areas have a greater sink of food available for the local fauna.

However, the paper points out the flaws inherent with pursuing ecological research centered on budgetary studies. This is because such research, especially those that center on material and energy budgets, are often informed by biogeochemical-closed homeostatic (self-dependent, self-sustaining) systems. Pickett et al believes, sadly, that a budgetary approach cannot tell if a system is closed or open (open or closed ecology look the same through a budgetary lens). A solely budgetary view of economics is the equivalent of saying that “since you cannot see a difference there is none, and any social factors that affect a budgetary perspective of ecology are at most on the periphery”. The authors say this is faulty logic since you cannot tell ecological differences from budgetary lenses. This being the case, to adequately address environmental and budgetary city systems, a human ecosystems approach is suggested (where socioeconomic, biotic and abiotic processes are combined in and around cities) to give a realistic prediction and understanding of ecological systems.


This illustration shows the most general larger and nested components of an ecosystem that is affected by humans.

Patch dynamics can be used to address the areas of cities on a social and ecological level to gain predictive examples. The concept of Patch dynamics came into being in the 1940’s as ecologists began to take note of the fact that every ecosystem was made up of smaller ecosystems. So, the heterogeneity of any given system can be examined over a period of time and the causes and effects can be measured. Because of the nature of patch dynamics, a system can be examined from personal (household) to greater community or region (city) depending on how detailed you need to look. Any type of approach that integrates the whole (ecological, social, budgetary in a well analyzed patch dynamic) would be the best approach when trying to develop healthy, self-organizing, self-integrating systems in a metropolitan area.

Perhaps this is a simplified view but it seems to me that if any human/ecological/societal system is treated through the matrix of Patch dynamics, a method for assessing and fixing any given human ecosystem can be easily established.


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