UNIT 3  URBAN ECOLOGY                                                                                Urban Ecology 
           Structure 
           3.0 Introduction 
           3.1 Objectives 
           3.2   Concept of Urban Ecology 
                   3.2.2  Sociological Understanding of Urban Ecology 
           3.3   Urban Ecosystems 
           3.4   Resource Ecology and Life - Supporting Resources 
           3.5   Economic Resources of the City 
           3.6   Integration of Human and Natural Environment 
           3.7   Challenges for Urban Ecology 
           3.8   Let Us Sum Up 
           3.9   Key Words 
           3.10  References and Suggested Readings 
           3.11  Answers to Check Your Progress 
           3.0  INTRODUCTION  
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           Urbanization has become aunstopable global phenomena in 21  century 
           leading to a number of changes in natural and social systems. As a result, 
           urban ecosystems are expanding around the world as people migrate to cities 
           and the human population continues to move from rural to urban setting.  
           Now what happens to other species as these urban ecosystems expand, and 
           how species live and interact in established urban ecosystems, is the central 
           focus of urban ecology. Over the past two decades, urban ecology has rapidly 
           expanded from simple studies evaluating what types of species are present in 
           urban ecosystems to complex investigations of the characteristics that allow 
           species to thrive in urban environments. 
           According to the United Nations, the anticipated population growth between 
           2000 and 2030, approximately 2 billion people, will be concentrated in urban 
           areas (UN 2004).  By the year 2030 more than 60 per cent (4.9 billion) of the 
           estimated world population (8.1 billion) will live in urban settlements, 
           compared to 29 per cent in 1950. In 2025, more than a dozen urban 
           agglomerations will have over 20 million inhabitants, and some will have 
           over 30 million. 23 of the 25 biggest urban agglomerations on the planet will 
           be in Africa, Asia, and Latin America, rather than in Europe or North 
           America (Kraas 2003). These megacities are considered ‘hotspots’ of global 
           change (Kraas 2007). Urbanised areas cover between approximately one and 
           six per cent of Earth’s surface, yet they have extraordinarily large ecological 
           ‘footprints’ and complex, powerful, and often indirect effects on ecosystems 
           (Rees & Wackernagel, 1994 in Endlicher et al. 2007). 
            
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           Introduction to Urban             3.1  OBJECTIVES  
           Environment 
                                             After reading this unit, you will be able to 
                                                  Define urban ecology 
                                             •
                                             •    Describe urban ecosystems and their importance 
                                             •    Elucidate the challenges of managing life support resources in urban 
                                                  environment 
                                             3.2  CONCEPT OF URBAN ECOLOGY 
                                             The term ecology is basically from natural sciences which addresses the 
                                             issues relating to biological patterns and environmental processes in any 
                                             natural setting, whether be forests, agricultural system, rural human 
                                             settlement or be urban. There are two ways in which scientific research and 
                                             studies have been conducted on the issues of urban ecology. The first one 
                                             focuses more on the biological and ecological processes and is led by the 
                                             natural sciences group, where more emphasis is laid on the relationships 
                                             between plant kingdom and animal kingdom and their relationships to 
                                             environmental factors. The second way of defining urban ecology is more 
                                             human centric or anthropocentric perspective, which is based on 
                                             multidisciplinary approach keeping human being first in improving quality of 
                                             life and living conditions for humans in urban areas.  Broadly, focusing on 
                                             urban development issues and habitats and challenges arising in urban 
                                             ecosystems. 
                                             As both `ecology' and `urban' have several meanings, `urban ecology' is a 
                                             diverse and complex concept with dierent dimensions. For instance, the 
                                             North American and European use of `urban ecology' dier. In Europe, urban 
                                             ecological research has traditionally focused on the biota, especially fora, of 
                                             urban areas, while North American research has been oriented towards social 
                                             sciences (Wittig and Sukopp 1993). On the other hand, the North American 
                                             urban ecological research has also included ecosystem fuxes and processes 
                                             (Pickett et al. 1997). These di  erent approaches to urban ecological research 
                                             indicate that urban ecology is a broad discipline, and it can be de®ned as 
                                             ecological research in the urban setting (Rebele, 1994). In addition to a 
                                             scienti®c component, urban ecological studies usually aim at explicit 
                                             applications of research in the planning and management of urban green areas 
                                             (Wittig and Sukopp 1993). Thus, urban ecology is by nature an applied 
                                             science. 
                                             In other words, urban ecology is more seen and understood as application of 
                                             methods and concepts of the biological science of ecology to urban areas, 
                                             which also requires and integrates the concerns, concepts, and approaches of 
                                             social sciences to produce a hybrid discipline. Urban ecological systems 
                                             include individual organisms, populations, communities, and landscapes, as 
            40                               well as buildings and infrastructure. Urban ecology further recognizes 
                                              
           
          specific urban ecosystems as a part of the global biogeochemical, economic,                Urban Ecology 
          and human demographic..... (Pickett and Cadenasso, 2012). From an even 
          broader view, urban ecology is the study of ecosystems that includes humans 
          living in cities and urbanising landscapes. It investigates ecosystem services 
          which are closely linked to patterns of urban development (Alberti 2005). 
          Thus, Urban ecology is an interdisciplinary field that supports societies’ 
          attempts to become more sustainable. It has deep roots in many disciplines 
          including geography, sociology, urban planning, landscape architecture, 
          engineering, economics, anthropology, climatology, public health, and 
          ecology. Because of its interdisciplinary nature and unique focus on humans 
          and natural systems within urbanised areas, ‘urban ecology’ has been used 
          variously to describe the study of humans in cities, nature in cities, and the 
          coupled relationships of humans and nature (Endlicher.,et al. 2007). 
          3.2.2. Sociological Understanding of Urban Ecology 
          Human Ecology has evolved an important area of study, where human being 
          and society is the focal point of concern, and central theme where all 
          enquirys are made keeping society as the actor  and factor in interaction with 
          other components of ecology. It is also regarded as a  social science paradigm 
          that seeks to understand the relationship between human organization and its 
          environment, both in terms of physical setting and sustenance.  The study of 
          urban ecology is an interdisciplinary approach which is based on components 
          from some of the established disciplines of sociology, anthropology, political 
          science, demography, geography and economics.  And at various times, 
          human urban ecology has been more or less connected to biological ecology. 
          Among its major topics, urban ecology is concerned with the patterns of 
          urban community sorting and change by socioeconomic status, life cycle, and 
          ethnicity, and with patterns of relations across systems of cities. 
          3.3  URBAN ECOSYSTEMS 
          Urban ecosystems can be understood as an ecosystems located in an urban 
          settings, it is in noway different from any other ecosystems except for its 
          location. Urban ecosystems are composed of biological components like 
          plants, animals, and other forms of life and physical components like soil, 
          water, air, climate and topography. In all ecosystems these components 
          interact with one another within a specified area. In the case of urban 
          ecosystems, however, the biological complex also includes human 
          populations, their demographic characteristics, their institutional structures, 
          and the social and economic tools they employ. But, unlike natural 
          ecosystems, urban ecosystems are a hybrid of natural and man-made 
          elements whose interactions are affected not only by the natural environment, 
          but also culture, personal behaviour, politics, economics and social 
          organisation. Urban ecosystems can no longer be considered as a separate 
          entity to the environment as they have direct and indirect impacts on the 
          immediate and wider environments. Many of the environmental problems                               41 
           
                                              
           Introduction to Urban             faced today (eg global warming, water and air pollution and inadequate 
           Environment                       access to safe drinking water) can be traced back to cities and lifestyle 
                                             choices. 
                                             According to Encyclopedia Britanica (2020), urban ecosystems also include 
                                             physical complex like buildings, transportation networks, modified surfaces 
                                             (e.g., parking lots, roofs, and landscaping), and the environmental alterations 
                                             resulting from human decision making. The physical components of urban 
                                             ecosystems also include energy use and the import, transformation, and 
                                             export of materials. Such energy and material transformations involve not 
                                             only beneficial products (such as transportation and housing) but also 
                                             pollution, wastes, and excess heat. Urban ecosystems are often warmer than 
                                             other ecosystems that surround them, have less infiltration of rainwater into 
                                             the local soil, and show higher rates and amounts of surface runoff after rain 
                                             and storms. 
                                             Urban areas can not exist in isolation. They require inputs from, and waste 
                                             assimilation functions of, other ecosystems. Ecological footprint analysis has 
                                             shown that many cities require a productive land and sea area several times 
                                             the city's size in order to support the population. The urban ecosystem 
                                             contains both individual and layered (nested) systems from three spheres: (a) 
                                             the natural environment, (b) the built environment and (c) the socio-
                                             economic environment. In order to develop policies and programs that 
                                             advance sustainable development and the equitable allocation of resources, 
                                             each system within the urban ecosystem needs to be recognized as a living 
                                             entity that constantly changes with time, location interventions. This 
                                             differentiates urban ecosystem from the typical segregated and static 
                                             management approach of ecosystems in its natural condition. Each 
                                             components of urban ecosystems require a dynamic balancing and 
                                             integration. In addition, the interdependencies and interactions between each 
                                             system and between the urban ecosystem as a whole and other ecosystems 
                                             need to be understood. Unhealthy urban ecosystems can lead to local and 
                                             wider environmental degradation, social problems, economic decline, human 
                                             health      problems         and      further       disconnection         from       nature.      
                                             (https://www.gdrc.org/sustdevHYPERLINK 
                                             "https://www.gdrc.org/sustdev/concepts/23-u-eco.html"/concepts/23-u-
                                             eco.html). 
                                             It is well known that there are many differences between urban ecosystems 
                                             and other ecosystems less dominated by humans. Urban ecosystems are 
                                             generally highly disturbed systems, subject to rapid changes in soil and plant 
                                             cover, as well as temperature and water availability. Buildings, roads, parking 
                                             lots, shopping and residential constructions  have covered the open land 
                                             space with concrete to form a largely impenetrable covering of the soil that 
                                             affects the flow of water and soil permeability for water getting into the land. 
                                             The plant life in urban ecosystems is also very different from plants in any 
                                             natural ecosystem, characterized by many alien species introduction and non-
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