Loren B. Byrne

Habitat structure: A fundamental concept and framework for urban soil ecology

Habitat structure is defined as the composition and arrangement of physical matter at a location. Although habitat structure is the physical template underlying ecological patterns and processes, the concept is relatively unappreciated and underdeveloped in ecology. However, it provides a fundamental concept for urban ecology because human activities in urban ecosystems are often targeted toward management of habitat structure. In addition, the concept emphasizes the fine-scale, on-the-ground perspective needed in the study of urban soil ecology. To illustrate this, urban soil ecology research is summarized from the perspective of habitat structure effects. Among the key conclusions emerging from the literature review are: (1) habitat structure provides a unifying theme for multivariate research about urban soil ecology; (2) heterogeneous urban habitat structures influence soil ecological variables in different ways; (3) more research is needed to understand relationships among sociological variables, habitat structure patterns and urban soil ecology. To stimulate urban soil ecology research, a conceptual framework is presented to show the direct and indirect relationships among habitat structure and ecological variables. Because habitat structure serves as a physical link between sociocultural and ecological systems, it can be used as a focus for interdisciplinary and applied research (e.g., pest management) about the multiple, interactive effects of urbanization on the ecology of soils.

Urban and agricultural soils: conflicts and trade-offs in the optimization of ecosystem services

On-going human population growth and changing patterns of resource consumption are increasing global demand for ecosystem services, many of which are provided by soils. Some of these ecosystem services are linearly related to the surface area of pervious soil, whereas others show non-linear relationships, making ecosystem service optimization a complex task. As limited land availability creates conflicting demands among various types of land use, a central challenge is how to weigh these conflicting interests and how to achieve the best solutions possible from a perspective of sustainable societal development. These conflicting interests become most apparent in soils that are the most heavily used by humans for specific purposes: urban soils used for green spaces, housing, and other infrastructure and agricultural soils for producing food, fibres and biofuels. We argue that, despite their seemingly divergent uses of land, agricultural and urban soils share common features with regards to interactions between ecosystem services, and that the trade-offs associated with decision-making, while scale- and context-dependent, can be surprisingly similar between the two systems. We propose that the trade-offs within land use types and their soil-related ecosystems services are often disproportional, and quantifying these will enable ecologists and soil scientists to help policy makers optimizing management decisions when confronted with demands for multiple services under limited land availability.

Scratching the surface and digging deeper: exploring ecological theories in urban soils

Humans have altered the Earth more extensively during the past 50 years than at any other time in history (Millennium Assessment 2003). A significant part of this global change is the conversion of land covers from native ecosystems to those dominated by human activities (Kareiva et al. 2007; Ellis and Ramankutty 2008). Although agricultural needs have historically been the dominant driver of land cover change (Millennium Assessment 2003), urbanization is now emerging as a primary process of land cover transformations around the world. As a result, urban ecology has emerged as an important research focus because of the increasing spatial extent of, and human population sizes in, urbanized ecosystems (Grimm et al. 2008a). Similarly to urbanized ecosystems, over the past several decades soils have been receiving increasing research attention due, in part, to growing appreciation of their linkages with aboveground ecosystems (Wardle et al. 2004; Wall et al. 2005) and global biogeochemical cycles (Schlesinger and Andrews 2000), and their roles in providing and regulating essential ecosystem services (Wall 2004). Yaalon (2007) recently pointed out that, although often underappreciated, soils are greatly impacted by human-mediated land cover changes and that greater understanding and mitigation of the impacts is needed to ensure the future sustainability of societies. Anthropogenic impacts on soils are perhaps most dramatic in urbanized ecosystems where humans remove, reconfigure, and pollute them to a greater degree than in other contexts (DeKimpe and Morel 2000). In this special issue of Urban Ecosystems, the two topics of urbanized ecosystems and soils are integrated Urban Ecosyst (2009) 12:9–20 DOI 10.1007/s11252-008-0078-3

Learner-Centered Teaching for Environmental and Sustainability Studies

This volume merges two aspects of education that have rapidly changed in recent years: environmental and sustainability education, and knowledge about effective pedagogy. Its central purpose is to disseminate engaging teaching activities that instructors can use to help increase students’ environmental literacy. The included activities are that require minimal instructor preparation, do not require elaborate setups or specialized materials, and can be used in many course contexts but especially in traditional (i.e., non-laboratory, indoor) classroom spaces; most can be completed in one or two class sessions. The target audience is primarily higher-education instructors (including graduate level), but high school teachers may find the resources appropriate for and adaptable to their courses, especially advanced ones. This introductory chapter frames the collection of teaching activities by discussing pedagogical challenges of environmental and sustainability education and the nature and implications of adopting learner-centered pedagogy. To foster critical, honest reflection about the approach, some of its inherent challenges and trade-offs are reviewed to help readers more thoughtfully reflect about how to implement it. The concluding section includes comments about learner-centered lecturing, the chapters’ structure and content, peer review of teaching activities, and the joy and necessity of learner-centered teaching for environmental and sustainability studies.

Conservation Triage: Debating Which Species to Save and Why

Because of human impacts on the biosphere, so many species are now threatened with extinction that it may not be possible to save them all. Akin to triage in a medical emergency situation, this challenge has brought forth the idea of conservation triage: having to make difficult choices and justifications about which species should be saved and which might not be savable. The goal of the learning activity described in this chapter is to engage students in this debate so they can gain insights into real-world conservation challenges and practice critical thinking and decision making skills in an authentic context. Students conduct preparatory research about endangered species, present their findings in class presentations and debate which species should receive conservation priority through instructor-guided decision-making. After completing the activity, students should be able to (1) describe various factors that affect species endangerment and conservation status; (2) define triage and apply the concept to examining sets of endangered species; (3) discuss the information needed and factors to consider when making conservation triage decisions; (4) articulate personal views about the value of different endangered species; and (5) explain how ethics and personal values relate to the study and practice of conservation biology.

An Introductory Examination of Worldviews and Why They Matter for Environmental and Sustainability Studies

A worldview is a complex cognitive and affective lens through which a person sees and interprets the world, including human-environment relationships. Examining worldviews is relevant to environmental and sustainability studies, in part, because they influence a person’s environmentally related decisions and divergent worldviews create conflict about environmental problems and solutions. Using physical glasses that make an abstract concept more concrete, the activity described in this chapter introduces students to worldviews and their links to environmental and sustainability issues through informal, open-ended, exploratory dialogue, catalyzed by the examination of four individuals’ hypothetical worldviews as playful case studies. The activity’s goal is to help students realize that everyone has a unique worldview that emerges from personal experiences, such that we should resist temptations to make assumptions about them or judge them too quickly. After completing this activity, students should be able to (1) describe what a worldview is and its many dimensions, (2) ask questions that help reveal dimensions of a person’s worldview, (3) discuss how worldviews influence people’s environmental and sustainability perspectives, (4) explain why examining worldviews is a valuable part of environmental and sustainability studies, and (5) reflect on one’s own worldview and the factors that have shaped it.