Ecological systems theory and second language research

“Context” has been increasingly featured and acknowledged in second language (L2) research because L2 teaching is recognised to be shaped by the environments in which it is situated. Numerous theoretical perspectives were introduced to L2 research that aim to capture the contextual forces at work in teaching and learning, including but not limited to Activity Theory, Complexity Theory, and Sociocultural Theory. Activity Theory holds that a learner's motives (human needs directed towards an object) are highly malleable, subject to the influence of such contextual variables as institutional rules, community, tools and artefacts available (see Leont'ev, 1978, 1981 who popularised Activity Theory from Sergei Rubenstein's founding and also Engeström's more current work in 1999). Complexity Theory, which has been widely adopted in both physical and social sciences, originates from physics (Martin et al., 2019). Complexity Theory was later introduced into L2 research by Diane Larsen-Freeman who posits that language learning is not only a process but a volatile and emerging system that is shaped by components of the system (e.g., learners, teachers, schools) engaging in constant and vibrant interactions (Larsen-Freeman, 2014). Sociocultural Theory highlights the sociocultural contexts where learning takes place (Lantolf, 2000; Vygotsky, 1978). Informed by a social constructivist view of learning, key concepts such as scaffolding (e.g., teachers’ support for learners) are put forward. In particular, Vygotsky argues that communication plays an indispensable role in language learning. Extrapolating Vygotsky's work to L2 research, Swain (2006) claims that languaging, dialogues among learners to discuss issues in L2 learning, is an important process of learning a L2.

living organisms and the physical components of the habitats of living organisms, the ecosystem (van Lier, 2014*). In educational research, with the advent of the social constructivist view of learning and teaching, the notion of "ecology" or "ecosystem" has been borrowed by researchers to refer to the environments where learning takes place. An ecological perspective is theorised by Bronfenbrenner (1979*) when he puts forward his seminal nested Ecological Systems Theory framework, which comprises four layers of context: MICROSYSTEM, MESOSYSTEM, EXOSYSTEM, and MACROSYSTEM. Neal and Neal (2013*) further highlight the temporal aspect of context and bring to the fore an additional dimension of context: CHRONOSYSTEM, which was not explicitly mentioned in Bronfenbrenner's book. In the same paper, Neal and Neal put forward a networked version of Ecological Systems Theory. While retaining the five layers of ecosystem, they redefine the notion of "setting" in Bronfenbrenner's (1979*) model. Bronfenbrenner defines "setting" as a location or physical space where people interact. However, given the increasing use of technology in communications, Neal and Neal (2013*) argue that setting is more appropriately understood as face-to-face and virtual interactions among people, focusing on the people rather than places. When presented diagrammatically, a nested Ecological Systems Theory reveals that layers of context form a series of concentric circles, while ecosystems in a networked Ecological Systems Theory are represented by discrete circles, which are connected by the people engaged in interaction in those contexts. In Table 1, we attempt to unpack the meanings of the five ecosystems with an example relevant to L2 learning and teaching.
In social sciences, there has been budding interest in conducting ecologically valid research (Lewkowicz, 2001), for example, in the form of naturalistic classroom-based research. An ecological perspective was introduced to the language education community by van Lier in his 1997 article on adopting an ecological lens to language classroom observation research. van Lier draws on Bronfenbrenner's (1979*) and Gibson's (1979) seminal work to discuss two approaches to classroom observation: microanalytical (an emic approach to research) and macroanalytical, with the latter referring to Bronfenbrenner's (1979*) four layers of context. van Lier (1997*) also introduces the notion of AFFORDANCE that refers to the alignment between learners' needs and environmental design. Following van Lier (1997*), a series of conceptual works were published, discussing various aspects and notions of Ecological Systems Theory, namely, types of interactions between individuals and contexts (Tudor, 2003*), temporal aspect of context (Kramsch, 2008*), an emic approach to research (Lafford, 2009*). These publications laid the groundwork for establishing a firm theoretical and conceptual basis for introducing Ecological Systems Theory into L2 research. Since then, aspects of Ecological Systems Theory have featured in L2 research in various topics, most evidently in the areas of computer-assisted language learning, language policy, language teacher education, and L2 classroom instruction. In this timeline, we aim to include key and recent publications related to the following themes: A. Conceptualisation of an ecological perspective B. Ecological research/perspective on computer-assisted language learning C. Ecological research/perspective on language policy D. Ecological research/perspective on L2 teacher education E. Ecological research/perspective on L2 classroom instruction F. Ecological research/perspective on L2 assessment Given the transdisciplinary nature of Ecological Systems Theory, selected works vis-à-vis conceptualisation (Theme A) extend beyond L2 research. To make the timeline relevant to L2 researchers, only primary L2 research informed by Ecological Systems Theory is included (Themes B-F). The focus of this timeline is on Ecological Systems Theory and L2 learning and teaching in naturalistic instructional settings that considers sociocultural influences, which is not to be confused with the broader meaning of the term "ecological" in applied linguistics, second language acquisition (SLA), and instructed second language acquisition (ISLA) research. In applied linguistics (especially in sociolinguistics), the term "language ecology" is used synonymously with "linguistic landscape" (for example, see publications in the journal Language Ecology, published by John Benjamins). The notion of "ecology" is also featured in the work of Jay Lemke (2000) on discourse and social dynamics, Jan Blommaert (2010) on timescales in globalised contexts, Uryu et al. (2014) on the ecology of intercultural interaction, and the field of ecolinguistics (e.g., Bang et al., 2007;Fill & Mühlhäusler, 2001;Stibbe, 2015). In SLA research, the edited volume by Leather and van Dam (2003) focuses on ecology and language acquisition that extends to non-instructional contexts. Regarding the established line of SLA research on task-based language teaching, albeit its focus on instructional setting, it rarely considers the role of contexts outside of the language classroom (Long, 2016). In ISLA, the interpretation of "ecology" is restricted to only classroom settings (in lieu of broader sociocultural settings) and ISLA research focuses on efficacy of pedagogical interventions rather than how contextual forces influence language acquisition (Loewen, 2014). In short, although we are aware of the connotative meaning of "ecology", the inclusion of this body of important work is beyond the remit of our timeline.
When selecting the entries to be included in the timeline, we consider importance of the publications, that is, classic work frequently cited in L2 research that adopts an ecological perspective (e.g., Bronfenbrenner, 1979*;van Lier, 1997*). More recent publications are also included, including a number that were published in 2021, to demonstrate the growing use of the theory in various subfields of applied linguistics. It must be noted that despite the long history of development of Ecological Systems Theory since 1979, its application to L2 research has only been recently taken up, resulting in a prolific growth in the amount of L2 ecological research in post-2019, especially in 2021.
When selecting L2 primary studies that employ Ecological Systems Theory, we take into account depth and explicitness of discussions of Ecological Systems Theory in the publications. In other words, we do not automatically include a publication that claims to adopt an ecological approach; rather, we review publications and include those that dedicate specific sections of the manuscript to discussing Ecological Systems Theory or its components. Another criterion for including L2 primary research is its substantive focus: we would like to include publications from a variety of sub-fields in L2 research to illustrate applications of (aspects of) the theory.
In the research timeline below, which contains 31 entries published between 1979 and 2021, in addition to summarising the original contributions of each piece of work, relationships among the works are highlighted through small capitals whenever possible to demonstrate developments in the conceptualisation, operationalisation, and/or evaluation of L2 learning ecologies. From the timeline, there has been a widespread uptake of Ecological Systems Theory in L2 research, especially in areas related to computer-assisted language learning, language policy, L2 teacher education, L2 classroom instruction, and L2 assessment. Earlier work is mostly conceptual, introducing components of Ecological Systems Theory and underscoring its relevance and usefulness as a theoretical lens to L2 research. More recent publications, mainly adopting a qualitative research design, apply Ecological Systems Theory to examine sources of influence of L2 learning and teaching. Having said that, the majority of the reviewed studies demonstrate a fragmented application of Ecological Systems Theory, referring to specific notions of the theory such as "affordance" and "mutuality" rather than the philosophical underpinning of the theory (e.g., its eco-sociocultural view towards social phenomena, and its relationship with other sociocultural theories). Moreover, the central tenets of Ecological Systems Theoryinterplay among (1) layers of contexts, and (2) contexts and peopleare not captured in some of the reviewed studies. For example, some (e.g., Song & Ma, 2021*) focus on specific levels of contexts mentioned in Ecological Systems Theory rather than adopting a holistic view towards contexts, forfeiting the opportunity to examine the relationships among various contextual dimensions. Some (e.g., Hofstadler et al., 2021*), on the other hand, focus solely on contexts, neglecting the fact that people within the contexts are agentic beings who are not only influenced by the environments they are in but actively reshape the environments. With this timeline, we aim to introduce Ecological Systems Theory to the broad field of L2 research, demonstrating its usefulness as a theoretical framework. At the same time, we call for a more holistic and fine-grained understanding of the theory.

Note
* Indicates the full reference is available in the timeline itself. In this seminal book, Bronfenbrenner sets out to discuss the usefulness of "an ecological orientation" to researching and understanding human development. He then presents a nested framework of Ecological Systems Theory, focusing on four types of contexts: MICROSYSTEM, MESOSYSTEM, EXOSYSTEM, and MACROSYSTEM. Since then, the theory has then been widely influential, informing the conceptualisation of an ecological perspective in many of the entries in this timeline. van Lier provides an overview of the history of ecological approaches in various disciplines such as biology and psychology. He was the first scholar to apply the notion to lesson observation in language classrooms, defining an ecological perspective as the interactions between learners and learning environments. Turning to methodologies of ecological research, van Lier discusses two approaches: MICROANALYTICAL and MACROANALYTICAL. The former focuses on language learning in classroom contexts. As for the latter, van Lier draws on BRONFENBRENNER'S (1979) 1 nested ecological systems theory to outline the layers of context, or "ecosystems", which extend beyond the classroom. In his commentary, Tudor underscores that language teaching and learning is an increasingly complex process due to the advent of computer-assisted language learning. Referring to VAN LIER (1997), Tudor argues that an ecological perspective enables researchers to capture learner-centredness and individual learners' interactions with their learning environments. The original contribution of this work lies in the conceptualisation of factors that affect such interactions: PSYCHOLOGICAL, COGNITIVE, EXPERIENTIAL, SOCIOCULTURAL, and IDEOLOGICAL. This resembles BRONFENBRENNER'S (1979) nested ecological systems theory but also considers individual learner differences. To address the complexity of the language learning process, Tudor appeals for the value of emic research that emphasises experiences of participants as insiders.

A (Continued )
Language Teaching van Lier continues his exploration of an ecological view towards issues pertaining to language education, following VAN LIER (1997) that focuses narrowly on the application of an ecological perspective to language classroom observation. In this book, van Lier discusses the applicability of an ecological worldview for researching language learner identity, language learning development, and critical language pedagogy. In addition, van Lier argues for a need to take into account both macro (e.g., language policy) and micro (e.g., learner psychology) aspects of language learning ecology. van Lier writes about the resemblance between an ecological approach to research and Sociocultural Theory, and how such an approach can further advance language education research informed by Sociocultural Theory. This article begins with a presentation of an ecological view of language and communication. As one of the first publications to apply an ecological view to English for Academic Purposes (EAP), Garner & Borg contend that this perspective perceives language use in EAP as holistic, dynamic, and situated within various disciplinary communities where the language is used. Using an EAP course as an example, the authors identify the potential for adopting a content-based approach in EAP courses to create an environment for engaging in authentic use of academic language in different academic disciplines. Hu's study focuses on the exosystem and macrosystem elements of BRONFENBRENNER'S (1979) framework to apply an ecological lens to researching language policy. Focusing on English Language Teaching (ELT) policy in China, Hu compares ELT practices in Chinese secondary schools in different parts of China to identify contextual factors that affect teachers' implementation of official ELT policies. Findings from this survey-based study reveal great disparity between ELT practices in more and less affluent regions in China. Specifically, more developed areas tend to adopt some form of communicative language teaching while traditional ELT methodologies are more pervasive in less developed parts of the country. Hu concludes that ELT in classrooms is influenced by sociocultural and economic forces. He attributes the limited success of Chinese ELT reforms to their prescriptive orientation without taking into account regional differences. When discussing an ecological frame of mind about second language acquisition (SLA) in her plenary speech, Kramsch draws on Larsen-Freeman's Complexity Theory to identify five major tenets of an ecological theory of SLA: relationships between self and others, the chronological aspect of the ecology, language learning as an emergent process, problematisation of the notion of speech communities, and repeated patterns of events. Kramsch closes by providing an example of multilingual language ecology and discussing implications for foreign language teachers. The value of this piece lies in Kramsch's explicit comparison between Ecological Systems Theory and Complexity Theory. This study extends the application of Ecological Systems Theory to online language learning environments. Reviewing work by VAN LIER (1997) and others, Berglund postulates that an ecological approach to researching language learning in virtual environments should capitalise on language learners' perception of affordances of learning spaces. Berglund also draws a parallel between such an ecological perspective and Vygotsky's Sociocultural Theory, highlighting the situatedness of language learning. Focusing on learners' multimodal online interactions using a videoconferencing tool, findings suggest that learners' participation rates and conversational strategies were influenced by not only contextual factors, such as technological tools and communicative tasks, but also learners' individual differences, including learning experiences, and speaking styles. In this way, this study emphasises the interplay between context and learners. This introduction to a special issue on computer-assisted language learning (CALL) includes extensive discussions on an ecological approach to language use and language education. Referring to VAN LIER (1997) and KRAMSCH (2008), Lafford discusses the affordances of adopting an ecological framework as an analytical lens through which to examine issues and trends in CALL. In particular, the metaphorical use of the notion of ecology is useful in unravelling the seamless interrelatedness between the social, cognitive, and environmental dimensions of language learning using technology. Reiterating VAN LIER (1997) andTUDOR (2003), Lafford posits that the key tenets of an ecological approach to language study include such principles as the adoption of emic approach to research, the conception of language as context-specific, and language use as a dynamic, non-linear process. Lafford concludes the section on the ecological perspective by stressing that CALL research aiming to investigate efficacy of educational technologies should take into consideration contextual factors, and that there needs to be a stronger emphasis on CALL infrastructure, which refers to the environment where technology and pedagogy synthesise. This piece strengthens the relevance of Ecological Systems Theory to CALL research. van Lier continues his discussion on an ecological perspective to language learning by defining an ecology as interactions among the physical, social, and semiotic elements in an educational setting. He then outlines the core attributes of an ecology of language learning: relationships among the physical, social, and symbolic; quality of educational experiences; and learners' agency. In addition to conceptualisation, van Lier concludes by recommending useful research methodologies with which to conduct ecological research, namely case study and action research underpinned by theories that take into consideration complexity of the language learning process (e.g., complexity theory, activity theory).

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Sin Wang Chong et al. Cao draws on the line of work by VAN LIER (1997;2010)  This qualitative study examines environmental influences on a language teacher's use of technological tools in developing learners' agency. Pinpointing such ecological notions as affordance and interaction, the authors' investigation centres on connections among affordances of technological tools, the teacher's pedagogical knowledge, and her belief in cultivating L2 learners' agency. The theoretical underpinnings of this study draw on works by ecological researchers such as VAN LIER (1997, 2010, and Vygotsky's Sociocultural Theory. The uniqueness of this study lies in its single case study design, demonstrating further how Ecological Systems Theory can serve as a useful theoretical framework to inform in-depth qualitative research. Han applies VAN LIER'S (1997, 2010 ecological perspective to language learning to researching L2 learners' engagement with written corrective feedback. The study includes one teacher participant and two student participants in a Chinese university. Similar to LIU & CHAO (2018), this case study aims to identify the learner and contextual variables that affect learners' engagement with written corrective feedback. A secondary objective of the study is to capture how learner and contextual factors interact to shape feedback engagement. This study is one of the first to put forward the notion of "alignment," arguing that for engagement to take place, it is essential to establish alignment between learners' needs and contextual affordances. Taking a social justice stance, Stelma & Fay discuss the notion of applied linguistics ecology. Highlighting key notions in ecological perspective such as mutuality and affordances, the authors offer an alternative view that universities in non-English speaking contexts should respond to the dominance of English as an international academic language through acknowledging and encouraging the development of goals of various stakeholders (e.g., international students) in the ecology. This novelty of this work rests in its emphasis on a less frequently discussed notion in the ecological model, "mutuality" (referring to the indispensable nature of two elements in an ecosystem), which is a critical take on the ecological perspective. Mercer discusses how the wellbeing of eight ELT teachers in the private sector in Malta is positively and negatively affected by their work environments. Environments, or ecologies, identified through two rounds of interviews include the local ELT industry, the school, and the teacher participants' teaching experiences. This work is original owing to its application of an ecological perspective to language teacher psychology, marrying the psychological and ecological turns in L2 research (see also SAGHAFI ET AL., 2017). Niu employs VAN LIER's (1997, 2010  Mercer puts forward a case for making wellbeing a core business in ELT. She defines "wellbeing" as the outcome of one's capacity to identify affordances in their social and professional environments and grounds her arguments using an ecological lens. She posits that any interventions aiming to improve ELT teachers' wellbeing should consider both teachers' needs and changes in the educational system. This study is a fine example of applying an ecological frame to reconceptualise an emerging L2 notion. Focusing on six three-year-old L2 learners, Schwartz & Deeb's study examines favourable factors that lead to productive use of L2 in a bilingual speaking preschool classroom in Israel. This is one of the first studies that applies an ecological perspective to researching young L2 learners. The ecological component of this study is based on VAN LIER'S (1997, 2010 ecological perspective of language learning, focusing on micro-and macro-context where L2 learning takes place. The results suggest that children-led, play-based classroom activities are conducive to young learners' use of L2.  VAN LIER (1997, 2010, BRONFENBRENNER (1979), and others, Shiravn et al. present an ecological conceptual framework comprising five nested ecosystems: micro-, meso-, exo-, maco-, and chrono-. Grounded on an ecological viewpoint, interviews of six adult EFL learners reveal myriad contextual factors that cultivate the learners' mindset towards L2 writing. Findings unravel factors ranging from individual learners' traits to sociocultural ones, which shape the development of L2 writers' mindset. This study, together with MERCER (2021) that focuses on ELT teacher wellbeing, demonstrates the usefulness of employing an ecological perspective to reconceptualise new L2 notions. In this case, the focal concept, L2 mindset, is reconceptualised as an emergent, complex, and dynamic construct. Like some earlier entries in the timeline, Solmaz defines "affordances" as learners' perceived benefits of a pedagogical intervention. In the context of an online collaborative reading tool, the researcher discusses linguistic and social affordances of this technology-mediated reading practice for improving learners' writing skills and grammar. The study is an insightful reference to conducting ecologically-informed L2 research, underscoring the usefulness of collecting both perceptual and observational data when analysing ecologies of learning. B Focusing on Chinese as an additional language policy in Hong Kong, Tsang conducts interviews with ten Chinese-as-an-additional-language secondary school teachers to identify contextual features that promote and constrain teacher agency. The uniqueness of this study vis-à-vis an ecological perspective is its explicit focus on the temporal aspect of contexts, highlighting Chinese language policy changes before and after the 1997 handover of Hong Kong to China. Findings suggest that there is a constant interplay between language policy and Chinese-as-an-additional-language teachers who are "micro-level language planners" (p. 36).

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1 Author names are shown in small capitals where the study referred to appears elsewhere in this timeline.
Language Teaching