Ecosystem services in postsecondary and professional education: an overview of programs and courses

ABSTRACT Postsecondary and informal professional educational opportunities have increasingly become an important mode of supporting the understanding, dissemination, and application of ecosystem services (ES). The development of professional activities and group characteristics (e.g. a shared vocabulary, common objectives, dedication of time) together with teaching and education are instrumental for the institutionalization of new ideas, concepts, and disciplines in society. Integrating ES into postsecondary and professional education can help us to understand complex human-environment interactions and shape policy towards greater socio-ecological sustainability. This study analyzes the current status of ES-related programs and courses offered at the postsecondary and professional levels around the world. We collected data in English on these opportunities in mid-2020 using Internet searches, crowdsourcing techniques, and personal knowledge and discovered 20 degree-granting programs and 112 courses focused on or related to ES. Our analyses suggest that most ES education is uncoordinated and aimed at graduate students (master’s or doctorate level), but is also interdisciplinary with an emphasis on ES as a plural concept. We argue that the continued evolution and application of ES depends on the concept’s integration into postsecondary and professional education and that more attention should be paid to these modes of knowledge sharing and building. Our analysis adds to the current understanding of the available formal and informal opportunities for learning about ES and provides a lens by which we can envision new pathways for increasing the reach and effectiveness of ES education and training.


Introduction
The field of ecosystem services (ES) has evolved over the past several decades to become an increasingly influential paradigm in the understanding of humannature relationships (Díaz et al. 2015;Costanza et al. 2017).Serving initially as a bridge between the fields of economics and ecology, ES describe the material and nonmaterial benefits that ecosystems provide to human well-being.The ES concept has gained prominence within environmental sustainability research (Abson et al. 2014), with the potential to enhance environmental management (Khosravi Mashizi and Sharafatmandrad 2021;Felipe-Lucia et al. 2022), climate change adaptation (Lavorel et al. 2020), and sustainable development (Bennett and Chaplin-Kramer 2016;Wood et al. 2018).
Despite explosive growth in ES research, its expansion into public discourse and decisionmaking has been limited (Daily et al. 2009;Costanza et al. 2017;Bouwma et al. 2018).Arguments against ES often focus on the concept's anthropogenic and economic framing, which can conflict with other perspectives, such as intrinsic value, relational value, and biodiversity as a goal (Schröter et al. 2014).The concept's vagueness and 'need for greater methodological and terminological consistency' (Bull et al. 2016, p. 103) have also been identified as a potential weakness inhibiting the uptake of the framework.
While detailed analyses of ES in research, application, and policy exist (Costanza and Kubiszewski 2012;Posner et al. 2016;McDonough et al. 2017), little work has been done to examine the integration of ES -and the related vast body of knowledge resulting from more than 25 years of research -into education, especially at the postsecondary and professional levels.Understanding the state of ES education and training could provide insight into strategies for mainstreaming the concept and advancing uptake by different audiences, such as professionals in planning, law, and policy-making (Braat and de Groot 2012;Saarikoski et al. 2018).Below, we explore the history and institutionalization of ES as a discipline, the role of education and training in this process, and the importance of education and training in enhancing the interdisciplinarity of ES and the uptake of ES in environmental policy and practice discourse.

History of the institutionalization of ES
Like other scientific disciplines with a clear paradigm and the support of knowledgeable individuals, ES research is evolving into a major academic field and undergoing a process of institutionalization -the adoption of new ideas, concepts, and disciplines by society (Clark 1972;Yarime et al. 2012).Figure 1 shows the major milestones and initiatives in this process.These initiatives (e.g.seminal publications, global ecosystem service assessments), among others, created a demand for ES knowledge specialists that helped to catalyze the development of specialized education and training programs centered on the subject.In this spirit, several handbooks and textbooks were published in the 2010s, documenting the advancement of a shared language and contributing to the development of ES as a distinct disciplinary branch of knowledge taught and researched at higher-education institutions (Kareiva et al. 2011;Nunes et al. 2014;Geneletti 2016;Potschin et al. 2016;Burkhard and Maes 2017).Additionally, the publication of comprehensive reviews and the launch of an ES-dedicated, peer-reviewed journal (Ecosystem Services) helped to provide a common space for further knowledge production (Braat 2012).
In academia, the ES discourse has evolved across disciplines, geographies, and actors (Chaudhary et al. 2015).Professional networks, such as the Ecosystem Services Partnership (ESP), A Community on Ecosystem Services (ACES), and the global sciencepolicy interface on ES, Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), work to bring together often disparate conversations through conferences and meetings but also serve as a platform for developing and advancing ES research and practice including workshops, resource databases, and educational and training mate- opportunities specializing in or related to ES.We define 'postsecondary' as educational levels following the completion of secondary education, including higher and vocational education, and also known as tertiary education (UNESCO Institute for Statistics 2012)

Role of education and training in institutionalization
The development of professional activities and group characteristics (e.g.shared vocabulary, common objectives) together with education training resources are instrumental for the institutionalization of a scientific field (Clark 1968).Education and training, in particular, contribute to the mid-and long-term maintenance of this process, as trained students maintain and further advance their knowledge of the subject and overall competencies, particularly as they leave educational institutions and solidify the institutionalization of the topic through the progression of their careers.Previous research on the establishment of new fields into curricula has identified numerous challenges to institutionalization, including students' exposure to the ideas, the affiliation of topics, and the self-understanding of the new academic field (Stelmack et al. 2005).One reason might be that the support of a new field by teaching institutions tends to develop along a gradient, starting from informal teaching activities that provide limited exposure to the field (e.g.workshops, summer schools, Massive Open Online Courses or ['MOOCs']) towards more formal teaching and educational activities associated with academic credentials (e.g. a degree in a certain field).Formal educational programs dedicated to a specific subject field allow students to gain a deeper understanding of a topic compared to individual courses (Clark 1972).Consideration and categorization of existing education and training opportunities (e.g.degree programs, courses) can shed light on the extent to which students are formally exposed to the ideas and the concepts central to the core of a specific field or discipline (e.g.Stelmack et al. 2005).

Value of education and training to enhancing interdisciplinarity of ES
To achieve its full promise as a sustainability science and decision-making framework, there have been many calls to broaden and integrate disciplinary perspectives and outputs of ES (Carpenter et al. 2009;Daily et al. 2009;Abson et al. 2014;McDonough et al. 2017;Guerrero et al. 2018;Ainscough et al. 2019).While some evidence shows the ES research community becoming more interdisciplinary (Droste et al. 2018), the community has constantly been questioned concerning the degree to which it truly is (Schröter et al. 2014;Chaudhary et al. 2015;McDonough et al. 2017).In practice, ES research is highly clustered and compartmentalized by discipline (e.g. economic valuations on one hand to natural science research on the other (Abson et al. 2014;Chan and Satterfield 2020;Kadykalo et al. 2021), host educational institutions (inflexible to interdisciplinarity (Yarime et al. 2012;Jarvis et al. 2020)), and geography (e.g. the United States and European Union substantially lead the number of scholarly publications on ES (Chaudhary et al. 2015;McDonough et al. 2017;Droste et al. 2018;Wang et al. 2021).
There is considerable value in ensuring a variety of disciplines, with their unique approaches and methods, are equally represented in ES teaching and research activities.Since the ES research field already integrates varying epistemological and ontological communities (Hermelingmeier and Nicholas 2017), formal education could help towards developing truly interdisciplinary, multi-perspective ES methodologies, research, and solutions.However, it must also be noted that emerging inter-or transdisciplinary disciplines can face additional challenges to institutionalization related to education and training, such as limited dedicated staff, funding, and resources (Trench 2012).

Value of education/training to enhancing policy uptake or application
Scientists across fields must respond to growing calls to engage with policy and practice to support the uptake of science in decision-making (Lubchenco 1998;Evans and Cvitanovic 2018).The sciencepolicy interface is no longer seen as optional but 'essential' for advancing ES research and addressing global environmental challenges (Balvanera et al. 2020).Many barriers to evidence-informed conservation policy exist, including a basic lack of knowledge, methods, and tools by decision-makers to implement ES in their work (Schleyer et al. 2015).
A key solution to this science-policy disconnect identified in a survey of 758 people in policy and research positions from 68 countries is the idea of 'mainstreaming conservation' by introducing key conservation principles into the consciousness of the general population (Rose et al. 2018).A proposed solution from this survey to increase understanding of conservation science is 'better science education in schools and universities to improve science literacy of the population' (Ibid.).The integration of ES into postsecondary and professional education could, in theory, increase public understanding of ES and help the field become a recognized sustainability science and decision-making framework regularly used in policy applications.
There is some evidence that supports the idea that mainstreaming ES into postsecondary and professional education would enhance ES uptake in policy and practice.Research at the primary school level found ES concepts enable Swedish (Goodwin et al. 2019) and Finnish (Raatikainen et al. 2020) students to display complex notions of value from nature (i.e.intrinsic, instrumental, relational) expressed from both doing and feeling -a valuable outcome that could be pursued at higher education levels.In the ES community, the Natural Capital Project's tool InVEST, which geospatially models ES, found an increase in model use after training workshops were delivered (Posner et al. 2016a), as well as an increase in local capacity for ES research and practice following training (Ruckelshaus et al. 2015).

Current study
In this study, we examined the integration of ES and resulting knowledge into education at the postsecondary and professional levels.We aimed to summarize the state of ES at these levels using data gathered through a combination of internet searches, crowdsourcing and professional network inquiries, and personal knowledge.Our main research questions were: We also aimed to create an initial database of opportunities that could be used as the basis for future research on this topic and as a resource for both those interested in furthering their ES education and those teaching the framework.

Methods
For this exploratory analysis, we chose to focus on readily available data that could provide a broad overview of ES integration into postsecondary and professional education.Before beginning data collection, we established a classification scheme to sort the retrieved data.First, we differentiated between programs or combinations of multiple courses (not necessarily all ES-related) that lead to a postsecondary diploma or degree, and courses or individual units of study, which may or may not be provided as part of a degree-granting program.Courses were grouped into three categories: traditional college/university courses offered for credit; short courses, training programs, or workshops; and massive open online courses (MOOCs).

Data collection
To find relevant programs and courses, we collected data using several different approaches with the goal of being comprehensive rather than strictly systematic.We started with keyword searches using the Google search engine (Finlayson et al. 2014).Acknowledging the use of synonyms and concepts that overlap with ES (Kadykalo et al. 2019), we conducted searches using five key terms for describing the relationship between people and nature: 'ecosystem services', 'nature's benefits to people', 'nature's contributions to people', 'nature-based solutions', and 'ecological services'.We used each key term in combination with a string of modifiers ('college OR university OR course OR degree OR program OR programme') to further narrow the search to postsecondary and professional programs or courses.
Each key term search was conducted by two team members (i.e.replicated once) during June -September 2020 using the Google Chrome Incognito mode.Team members examined the webpage search results and recorded data for all hits that represented actual programs and courses and that contained at least one of the key terms in their title or description.In addition to the Google searches, one researcher conducted searches on Twitter and Studyportals, a global platform for finding higher education courses, using each key term to identify additional programs and courses.To capture other, nonsearchable data, two team members put out calls for ES-related programs and courses on the ESP and Young Ecosystem Service Specialists (YESS) listservs, and on Twitter.Lastly, all team members used their professional knowledge to help fill in gaps and acknowledge we will not have captured every eligible course/program through our methods -see Limitations.
Our research was primarily conducted in English.We acknowledge this language bias as a limiting factor in our discovery of available opportunities (see Konno et al. 2020 for a related discussion of language bias and ecological meta-analyses).Our data did include some non-English language opportunities which led us to incorporate that characteristic into our analysis.
The database of programs and courses used in this study is openly available through Harvard Dataverse at https://doi.org/10.7910/DVN/MRV7YQ.

Analysis
To facilitate our analysis, we collected descriptions of each course and program as searchable PDF documents in NVivo 20, a qualitative analysis software program.We attempted to collect the most complete description available for each record.For courses, we prioritized syllabi if available.We were unable to find descriptions of five courses, which limited some of our analyses for these courses.We recorded characteristics for each course and program based on the available information and descriptions in NVivo (Table 1).We adopted Haider et al. (2018) definitions of different types of mixed-disciplinary research to evaluate the disciplinarity of courses and programs (Table 2).For the purposes of this analysis, and the resolution for which data were available, we could not differentiate between multidisciplinarity and interdisciplinarity, nor evaluate the level of transdisciplinarity.
Thus, we define each course or program that integrated or considered more than two disciplines as 'interdisciplinary'.'Transdisciplinarity' is considered in the discussion section in the context of our findings.We evaluated the involved disciplines and interdisciplinary character in two ways as a way to triangulate the data and increase the accuracy of our findings (Alexander et al. 2008).First, during the data collection phase, we completed a manual analysis based on our initial reading of the available description of the disciplines used in each program/course.Programs and courses could be marked as representing more than one discipline and those combining more than one discipline were marked as interdisciplinary.Then, we used NVivo to conduct a series of text search queries using the descriptions.We created a list of search terms for each discipline (Appendix A) and used the 'stemmed words' option (e.g.searching for 'ecology' would also flag 'ecological').A team member  A process of collaboration between scholars and non-scholars on a specific real-world problem quality controlled each result to make sure matches were valid and applicable to the specific field of study (i.e. a physical sciences search term result did indeed signify the opportunity included content from that discipline).We also used NVivo to search the descriptions for the term 'interdisciplinary'.We used both a manual and an NVivo analysis to understand the ES content focus of programs and courses.In the manual analysis, we classified ES content focus into four categories based on common methodologies: biophysical, economic, sociocultural, and plural (Jacobs et al. 2018).For the NVivo analysis, we developed a list of search terms for each content focus category based on a trio of recent papers analyzing ES methodologies (Arias-Arévalo et al. 2018;Harrison et al. 2018;Jacobs et al. 2018) (Appendix B).We labeled any program/course with keywords from the plural category or two of the other three categories as plural.Similar to the above analysis, a team member quality controlled the results to ensure matches were valid and applicable to the specific content category.

Results
From the research conducted, we identified 20 degree-granting programs and 112 courses focused on or related to ecosystem services.About half of the programs (55%) were identified through the Google search procedure; six programs were found using Studyportals and three were found using Twitter.More than half of the courses (60%) were identified first through the Google search process.Crowdsourcing and Twitter each produced an additional 16 courses, eight came from personal knowledge, and five from Studyportals.Only 107 of the 112 courses had descriptions that we could use in our disciplines analyses (3.3).
We identified 90% of the programs as in-person only, with the remaining 10% being hybrid (part in-person and part online).Most of the courses were in-person only (74%), with 22% online-only and 4% considered hybrid.We categorized 46% of the courses as traditional college courses and 44% were workshops, short courses, or training programs.Only 10% were MOOCs.At the time of our analysis, all twenty programs were still being offered.However, one-third of courses were identified as former or one-time offerings.About half (53%) of the courses were identified as ongoing and we were unable to determine the status of 14% of the courses.

Hosts, locations, and languages
Programs and courses (excluding the online-only courses and site-dependent, on-demand workshops) were found in 27 countries.Programs were primarily located in Europe (55%) and North America (40%), with only one located in Africa (Figure 2).A fourth of the programs were offered in the United States of America.Both Canada and the Netherlands offered 15% of the programs.Courses were similarly located, with most in Europe (41%) or North America (25%), though we recorded at least one course on every continent except Antarctica.Also, for courses, the United States of America had the most (22%), followed by the United Kingdom (12%), and the Netherlands (8%).Unsurprisingly given our Englishbased searches, most programs and courses were offered only in English, with one program and five courses offered in Spanish and a handful of courses available in other languages, including Chinese, French, Portuguese, Russian, and Swedish.
Among the programs and courses, we identified 130 different host organizations, which included universities, research centers, NGOs, and governmental agencies.Most programs were hosted by a single institution of higher education or, in one case, an educational charity.Three programs (15%) were described as collaborations between two or more organizations, highlighting educational partnerships between institutions of higher education, research institutes, nonprofits, and private companies.For example, the program 'Advanced Master Think Water' at the University of Antwerp (BE) was described as a collaboration of the university and Belgian companies and administration, without naming concrete company names.Most courses (79%) were hosted either by a single higher education institution, research center, or government agency.Around 19% of the courses were described as collaborations either between multiple institutions of higher education (5%) or a mixture of partners (16%).Two courses were described as collaborations between two or more units within a single institution of higher education.Many of these collaborative courses were the outcome of projects.For example, four courses were organized by ValuES, a German project bringing together the German development agency, an environmental research center, and the Conservation Strategy Fund.Other courses were related to the Natural Capital Project and European research projects like Eklipse and ReNature.
Of the total 132 programs and courses, 85% were hosted by higher education institutions.Most of the universities offered only one or two courses.Portland State University (US) had the largest offering of one program and four courses, followed by Stanford University (US) with four courses, and Lund University (SWE) and University of British Columbia (CAN) each with one program and three courses.

Level of study and length
Most programs were offered at the graduate level (master/doctorate), with 15% offered at the Diploma/Associate (2-year study) or bachelor's level.
Program length varied from one year (12 months) to three or more academic years, depending on the degree level.Most courses were also offered at the graduate or continuing-education levels (33% for each category), though courses are also available at the undergraduate level (19%) and multiple levels (15%).Most courses were either one term/semester (42%) or less than one week (37%) in length, with 20% lasting between one week and one term (length was unknown for two courses).

Interdisciplinarity
In our manual analysis, we categorized 85% of programs and 52% of courses as interdisciplinary (Table 3).We categorized 35% of programs and 44% of courses as disciplinary.Twenty percent of programs and just 4% of courses were categorized as unknown based on the available information.We also conducted a word search in NVivo for the term interdisciplinary.In this NVivo analysis, half of the programs and 20% of course descriptions contained the word 'interdisciplinary'.

What disciplines are represented?
In our manual analysis, we identified 15% of programs as anchored in one discipline: two in social & behavioral sciences, and one in biological & environmental sciences.The other 85% of programs were identified as incorporating at least two disciplines (Table 3).The single disciplines most represented were biological & environmental sciences (70%), social & behavioral sciences (65%), and physical sciences (40%).The most common combination was biological & environmental sciences and social & behavioral sciences (35%).
In our NVivo analysis, 20% of programs incorporated keywords from only one discipline, two in physical sciences, one in biological & environmental sciences, and one in mathematics & statistics (with one program containing no keywords from any disciplines) (Figure 3).Another 75% of programs incorporated keywords from at least two disciplines.The single disciplines most represented were very similar to our manual analysis results: biological & environmental sciences (70%), social & behavioral sciences (65%), and physical sciences (55%).One notable difference was mathematics & statistics, which we did not identify at all in the manual analysis but was found in 45% of courses through the NVivo analysis.The most common combinations in the NVivo analysis were biological & environmental sciences, social & behavioral sciences, and agriculture/forestry/fisheries (10%), and a combination of those three plus physical sciences, mathematics & statistics, and law (10%) (Figure 3).
In our manual analysis of courses, we identified 54% as anchored in one discipline: 26 in social & behavioral sciences, 17 in biological & environmental sciences, 12 in physical sciences, and 3 in agriculture/ forestry/fisheries.The other 46% incorporated two or more disciplines (Table 3).The most represented disciplines in courses were social & behavioral sciences (68%), biological & environmental sciences (52%), and physical sciences (19%).The most common combination of disciplines was biological & environmental sciences and social & behavioral sciences (28%)  In the NVivo analysis, 31% of courses had keywords from only one discipline: 13% agriculture/forestry/ fisheries, 8% social & behavioral sciences, 4% biological & environmental sciences, 2% engineering or physical sciences, and 1% humanities & arts or mathematics & sciences (Figure 4).Twenty-seven percent contained no keywords of any discipline and the other 42% contained keywords from two or more disciplines.The disciplines most represented in the course descriptions were agriculture/forestry/fisheries (39%), social & behavioral sciences (30%), and biological & environmental sciences (29%) (Figure 4).The most common combinations in this analysis were agriculture/forestry/fisheries with biological & environmental sciences (7%), with social & behavioral sciences (3%), with engineering (3%), and with social & behavioral and biological & environmental sciences (3%) (Figure 4).

ES content focus
In the manual analysis, we categorized most programs (70%) as having a plural focus, with the rest either using a strictly biophysical (25%) or sociocultural (5%) lens (Table 3).In the NVivo analysis, 45% of programs contained no keywords associated with the four content focus categories and were labeled unknown.Forty percent were identified as having a biophysical focus, 5% as economic, and 10% as plural.One program combined biophysical, economic, and plural content, and one combined economic and sociocultural content.
Almost half of the courses in our manual analysis were categorized as having a plural focus (49%), followed by a strictly biophysical (21%), sociocultural (11%), or economic focus (5%).In our manual analysis, we categorized 14% of courses as having an unknown focus due to limited information.In the NVivo analysis, most courses (67%) were associated with none of the four content focus categories and were labeled unknown.Seventeen percent were identified as having an economic focus, 9% plural, and 7% biophysical.Of the plural courses, two courses each were identified as having a focus that combined biophysical and economic; biophysical, economic, and sociocultural; or economic, sociocultural, and plural content.

Discussion
The field of ecosystem services has and will continue to evolve as it strives to understand complex humanenvironment interactions and shape policy toward greater socio-ecological sustainability.We argue that this evolution and application of ES relies heavily on the concept's integration into postsecondary and professional education and that more attention should be paid to these modes of knowledge sharing and building.Our analysis adds to the current understanding of the available formal and informal opportunities for learning about ES and provides a lens by which we can envision new pathways for increasing the reach and effectiveness of ES education.

Lack of coordination impedes institutionalization
As evidenced by the large ratio of courses to programs, it appears most ES education at the postsecondary and professional levels is not integrated into a full degree or training program.Additionally, about one-third of the total courses were only offered once or are no longer offered, signifying ES-specific training often occurs impromptu; courses developed for an immediate problem or specific purpose without planning or organization as long-term offerings.This trend could be explained, in part, by the relatively recent development of ES compared to other scientific disciplines, which, along with the inherent interdisciplinarity of the topic, leaves the responsibility for developing education opportunities up to interested individual scholars and professionals (Clark 1972).In addition to potentially being the only expert qualified to teach ES at an institution, these individuals may face limited resources (e.g.finding time to develop new courses, funding) and institutional constraints (e.g.lack of support or inertia for adding interdisciplinary coursework) (Trench 2012;Singh et al. 2019;Turner et al. 2022).For example, multiple ES-related courses created as part of an integrative graduate training program appear to have ended when program funding finished (e.g.Portland State University's Ecosystem Services Supporting Urbanizing Regions program).Additionally, well-published ES scholars (see Costanza and Kubiszewski 2012) were rarely listed as the instructor-of-record for the opportunities that we reviewed (with a few exceptions), potentially indicating that there are greater incentives for research and publishing than for developing new teaching courses (Zimmerman 2020).
An uncoordinated approach to ES education and training could have negative impacts on the field's institutionalization and development.Leaving the development of educational opportunities largely to individuals could limit or skew the perspectives being taught as well as hinder the growth of shared perspectives (Turner et al. 2022).Without a shared, predetermined curriculum or set of learning objectives, the material that is taught about ES is largely left up to individuals to decide.The individualized approach, while flexible and useful for expanding basic knowledge of ES, could lead to less consistency in ES education across the globe.It could also further root the field in specific, siloed disciplinary understandings, as even interdisciplinary scholars may not possess the expertise required to communicate the full breadth of the ES concept (Chang et al. 2020).
An informal approach to ES education may also contribute to the lack of a shared language among those interested in human-nature relationships, evidenced by the current debate of ecosystems services vs. nature's contributions to people (Kadykalo et al. 2019), which leads to larger perceptions of the field as in flux rather than a mature discipline worthy of academic and professional attention.
Another consequence of this uncoordinated approach could be a failure to initially capture students who may be interested in ES but have no idea that this field exists or are unsure of how to go about initially interacting with the subject matter (Brownell et al. 2013).Furthermore, students with an interest in researching ES may face difficulties in acquiring the deep knowledge and skills needed to become a subject matter expert (Lyall and Meagher 2012).Rather than taking a suite of courses that build upon one another, students 'read to get up to speed' or find other strategies to increase their knowledge.The substantial amount of time devoted to this intensive basic knowledge development takes away time from students (and their mentors) that could instead be used to further develop and promote ES science and uptake.Additionally, by building their educational knowledge base using literature alone, students may unintentionally skew their focus to a specific sub-discipline and miss interdisciplinary theory, perspectives, discourse, or methodologies that constitute the basis of the ES field (Welch-Devine et al. 2014).Previous research supports this argument, showing challenges for students concerning their exposure to ideas, affiliation of topics, and self-understanding of new academic fields (Stelmack et al. 2005).

Emphasis on graduate education
Additionally, most programs and courses in our sample target graduate-level students or professionals, again potentially limiting early exposure to ES and narrowing the field of interested students.This concentration on post-graduate training may not truly reflect current integration into undergraduate training because of the lack of coordination discussed above.Many times, ES are not the focus of a course or program but taught as a subtopic that could only be identified through the syllabus or personal knowledge or relationship with the instructor.It is logical to reason that the ES concept at the undergraduate level is addressed in introductory courses that study broader processes and theories (e.g.ecology, environmental economics, environmental policy).This suggests ES occupies a space in postsecondary education of a subtopic that has not yet developed enough to ascend to a top-level topic for a course, similar to, for example, topics like conservation physiology, citizen/ community science, and conservation genomics.Further, the concentration on graduate education could reflect the lack of professional ES-related job opportunities available at the baccalaureate level, which potentially relates to the lack of advanced training available to pre-graduate students, producing a negative feedback loop.
This emphasis on graduate-level education could affect the institutionalization and growth of ES by limiting student exposure.Getting students interested in ES as a research field and career should start before they are searching for graduate programs; undergraduate courses and programs serve as a pathway for future ES leaders (Hackenburg et al. 2019).Even for students pursuing other environmental fields, ES could serve as an important topic that might be encountered later in their professional life (Taylor and Bennett 2016).Additionally, integrating ES into more undergraduate education could increase public awareness of ES and thus its power as a policy and conservation tool (Stelmack et al. 2005).

Positive -and negative -signs of interdisciplinarity
Through both our manual and NVivo analyses, we identified a majority of programs and courses as interdisciplinary.We found courses to be less interdisciplinary than programs, a logical finding considering the greater opportunities for multi-course programs to pull on courses from different disciplines.Interestingly, the NVivo keyword searches revealed less interdisciplinarity than our initial manual analysis, with one program and more than a quarter of courses containing no keywords associated with any discipline.This discrepancy could be attributed to our methodology in that our keyword lists represented only a subset of the ideas related to each discipline or methodology (Finlayson et al. 2014).
In practice, however, we also suspect our data reveal low interdisciplinarity and that programs/ courses merely consider rather than integrate two or more disciplines.While touted as an interdisciplinary field, previous analyzes have found that ES research remains siloed (McDonough et al. 2017;Kadykalo et al. 2021;Winkler et al. 2021), a reality that would naturally be reflected in how the framework is taught.This lack of interdisciplinary training then feeds back into research.It could also reflect a more general lack of resources/opportunities or incentives for interdisciplinary faculty (Rhoten and Parker 2004).Additionally, in many of the cases we examined, the focus seems to be on combining biological & environmental sciences and social & behavioral sciences with some inclusion of physical sciences and agriculture/forestry/fisheries.This speaks to the fact that ES were originally conceptualized in social-ecological systems and created to bridge ecology and economics but belies the challenge of integrating more disciplines into the field.
The lack of interdisciplinarity in postsecondary and professional educational opportunities matters because the issues ES seek to address require interdisciplinary thinking.Interdisciplinary teaching introduces students (and professionals) to the wide breadth of theories, concepts, and methodologies that represent a key strength of the ES framework (Bull et al. 2016;Schlüter et al. 2022).It can facilitate a path away from siloed work towards approaches that transcend the capabilities of individual disciplines to provide more effective solutions to complex world problems.Additionally, as ES become more mainstreamed into decisionmaking processes, non-academic organizations seek to hire students with interdisciplinary training, as noted by David Runnalls, Distinguished Fellow of the Centre for Intergovernmental Governance Innovation, 'The demand for people who can bridge the gap among the social and biological sciences will continue to grow in the field of sustainability' (University of Ottawa Institute of the Environment 2016).

ES as a plural concept
Related to interdisciplinarity, we believe a majority of programs and courses focus on ES as a plural concept.This plural focus supports the calls among ES scholars for the recognition and use of multiple perspectives or valuation methods to more fully understand the diverse beneficial relationships between people and nature (Arias-Arévalo et al. 2018;Jacobs et al. 2018).When the focus is not plural, the emphasis seems to be on purely biophysical or economic ES content and methodologies, which echoes the original disciplines -ecology and economics -giving rise to the field.A sociocultural lens, as evidenced in our NVivo analysis, only occurs in conjunction with another focal area.Up until the 2010s, there was a concerning lack of consideration by ES researchers of the social and cultural (Chan et al. 2012).The solution was to bring in perspectives from the social sciences while retaining strong ties to economic and biophysical frameworks, a transformation which seems now to be reflected in education offerings (Chan et al. 2012).
In general, about half of the program and course descriptions lacked any keywords that were associated with our four content focus areas (biophysical, economic, sociocultural, plural).While this finding in part can be attributed to our methodology, which relied on readily available descriptions, it could also reflect a tendency to not be explicit about the approaches being used to explore ES.
Relatedly, we identified a strong bias towards programs and courses being situated or offered only in the Global North.While partly an artifact of our searches being conducted in English, we think this also reflects the dominance of the Global North in ES research (Chaudhary et al. 2015;McDonough et al. 2017;Droste et al. 2018;Wang et al. 2021) and posit that this might influence both the perspectives and content being taught in ES-related programs and courses.The Global South offers unique perspectives and lessons for understanding humannature relationships not captured in the literature that take a more integrative approach compared to the capitalistic, utilitarian approaches often favored by the Global North (Gould et al. 2020;Allen et al. 2021).Digging into the potential impacts of the uneven geographic distribution of ES research and education is an area ripe for future research.

Strategies for an integrated, holistic, and accessible approach to ES education
To further support the growth and development of ES as an academic discipline, we offer four main recommendations based on the above findings.
First, we recommend the creation of a core curriculum, aimed at beginning postsecondary students (e.g.first-year undergraduate) but available to higher levels (e.g.masters and doctorate), designed to provide different levels of knowledge, from a basic introduction to an advanced understanding of ES (Mercer-Mapstone and Kuchel 2017;Löw Beer 2018).A starting point for the content could be the Routledge Handbook of Ecosystem Services (Potschin et al. 2016) or Natural Capital: Theory and Practice of Mapping Ecosystem Services (Kareiva et al. 2011), older books like Nature's Services: Societal Dependence on Natural Ecosystems (Daily 1997), but also reports and assessments originating from the science-policy interface, such as the IPBES Global Assessment (IPBES 2019).In addition to just designing more courses and programs for undergraduates, current graduate-and professional-level opportunities could also accept and encourage participation by interested undergraduate students.Additionally, we encourage ES educators to work directly with ES professionals to identify jobs that can be paired with knowledge and skill levels achieved at the undergraduate level.
A core curriculum could be delivered on campuses, as well as through a series of online workshops or MOOCs supported by a professional group, such as ESP, ACES, or YESS.These groups could provide institutional memory so that, with time, the ability to offer recurring courses becomes less resource intensive.In instances in which proposing new courses or programs (e.g.certificates, degrees) is difficult, we encourage increased interdisciplinarity in current offerings as another mechanism for broadening the scope of ES education.To support these efforts, we also call on scholars in the ES field to value teaching as an important part of their work in furthering the field alongside research and application (Raby et al. 2020) and to consider building the development of educational materials into new funding applications.
Second, we suggest that all courses currently being offered should incorporate interdisciplinary perspectives, which can be done by inviting guest lecturers or co-teaching (Chang et al. 2020), introducing alternative methodologies, incorporating diverse geographic perspectives, and using inter/trans-disciplinary texts as educational resources/teaching tools (e.g.IPBES assessments, SDG reports).Expanding more, courses should embrace transdisciplinarity by engaging nonacademic actors in and out of the classroom, such as through service projects (Chang et al. 2020).Encouraging the hiring of more interdisciplinary faculty positions (e.g.Cornell SES position 18,546) also has the potential to spill over into more interdisciplinary educational opportunities.
Several programs already exist that could serve as models for showing how interdisciplinary teaching can be done and the value it adds to student training.One example is the United States National Science Foundation (NSF) Research Traineeship (NRT) Program.This multi-university program engages 'STEM graduate students in high priority interdisciplinary or convergent research areas, through a comprehensive traineeship model that is innovative, evidence-based, and aligned with changing workforce and research needs' (NSF 2022).Programs such as the NRT Program that emphasize and encourage interdisciplinary education, research, and collaboration could be used as an educational model for students across the wide breadth of ES subdisciplines.
Similarly, if understanding ES as a plural concept is indeed a learning objective, the field could benefit from making this explicit in program descriptions, course outlines, and syllabi.These tools can communicate to students, even before instruction begins, not just what they will learn but what they need to learn to understand a subject (Eberly et al. 2001).Being deliberate in developing these materials can also provide instructors with the opportunity to carefully consider if and how their content matches their teaching intentions.
Our third recommendation builds on the finding that most programs and courses identified through our analysis are offered only in person, with no virtual option.This proclivity towards in-person coursework, combined with the finding that most opportunities were concentrated in Europe and North America, limits access for students interested in learning more about ES.In addition to diversifying the locations of in-person opportunities, we should think about expanding virtual learning options, including those on advanced ES topics (Geith and Vignare 2008).Given that our sampling overlapped with the COVID-19 pandemic, we did observe that some courses were just canceled or rescheduled to a later date rather than transitioned online.This could signal that some ES topics are not suitable for virtual environments (e.g. the team-based experiential learning described by Welch-Devine et al. 2014) but also might connect to the elective status of many current opportunities that made them expendable during the pandemic.We also saw a shift in some of the learning opportunities from in-person only to fully or partially online and propose that educators designing virtual opportunities share their experiences with what worked (Govindarajan and Srivastava 2020).Alternatively, online courses that are eligible to give credits might be an attractive way forward to broaden the potential attendance of such courses.
Lastly, more resources should be made available to formalize ES-related learning opportunities and connect educators interested in teaching the concept.Inspired by Mulder et al. (2008) and their work on science communication in academic programs, we recommend a register of ES-related postsecondary courses and programs.The database used in this analysis is available as an example and a beginning attempt at creating such a register.We encourage the ESP Education & Training task force to consider taking over its maintenance, including advertising it widely as an important community resource.
Online ES-related education and training resource pages should also be kept up-to-date and should be more widely advertised throughout the community.Individual ES educators could consider contributing syllabi to the Open Syllabus Project, a free online database designed to provide instructors with information that can inform and improve course design.Additionally, we propose the creation of a Community of Practice (CoP) for those teaching ES at the university level as a forum for sharing knowledge (see Metzger et al. 2019).The CoP could have regular meetings, as well as ad hoc meetings on specific teaching topics and a discussion board for more in-depth conversations.

Additional study limitations
Our search likely did not capture all potential programs and courses incorporating ecosystem services.While 'ecosystem services' has come to define the benefits of ecosystems to people in international research and policy, the concept has not yet become common knowledge and remains for many 'technical jargon' (Thompson et al. 2016).Even among technical audiences, other terminology exists to describe the benefits and relationships between people and nature that may have escaped our search queries.Additionally, we primarily conducted our research in English, which only turned up a few programs or courses with sites written in other languages, indicating a potential language bias that could be countered in future research by employing multilingual searches.
Future qualitative research could more fully and further explore the depth and breadth of course and program content.To analyze these aspects more fully, including the degree of inter-, multi-, or transdisciplinarity of offerings and how courses and programs integrate perspectives across disciplines, additional data from interviews or questionnaires with program directors, as well as instructors, should be conducted to supplement this study.
We relied greatly on readily available information and recognize our data most likely represents a sample of the totality of ES-related postsecondary and professional opportunities.It is highly likely that information on many courses and programs ES are not publicly available and searchable.However, we believe our varied data collection methods, including attempts to capture programs/ courses from the broader ES community (i.e.Twitter, listserv), resulted in a representative sample, allowing us to abstract our findings to this larger population.Relying on readily available program and course descriptions also limited what we could find through both our automated and manual analyses.A more in-depth study of course/program content would benefit from having access to detailed syllabi or curricula.As with any qualitative study, researcher bias could also have influenced our results, especially considering the broad nature of some of our conceptual frameworks (e.g.ES content focus).However, we tried to reduce potential bias and human error by using multiple coders, reviewing the results as a group, and using computer-assisted searches to further verify our findings.

Conclusion
Ecosystem services have developed into one of the leading paradigms for understanding and valuing nature's contributions to human well-being.However, little attention has been paid to how this concept is disseminated and taught.Here, we examined trends in how ES is integrated into both postsecondary and professional education.We found the current approach to be largely uncoordinated and focused on graduate students with positive and negative signs of interdisciplinarity and a focus on ES as a plural concept.We hope this initial inventory serves as a springboard for future research and conversations around the integration of ES in postsecondary and professional education.For ES to truly become mainstream as a way of thinking that influences decision-making, we need to be training a diverse workforce that can contribute to its continued advancement as a body of knowledge and its application in policy.We must also not forget that in addition to preparing future ES leaders, education 'enable(s) learners to think and imagine concepts for alternative futures' (Holfelder 2019) providing a fertile, expansive ground for the consideration of alternative ways of thinking, which will be needed to transform to a more sustainable planet for people and nature.

Figure 1 .
Figure 1.Ecosystem services have evolved as a discipline through a process of institutionalization beginning in the late 1970s and continuing through today.

Figure 2 .
Figure 2. Countries with ecosystem services-related programs and courses.Countries with at least one program have a striped pattern.Colors indicate the number of courses in each country, with darker colors signifying more courses.

Figure 3 .
Figure 3.A summary of the most common disciplines and combinations of disciplines found in program descriptions using NVivo keyword searches.The bottom-left horizontal bar graph labeled 'Set size' indicates the total number of programs containing keywords related to the different disciplines.The connected circles indicate combinations of disciplines found in program descriptions and the vertical bars represent how many times that combination was found.For example, the combination of biological & environmental sciences and social & behavioral sciences was found in only one program while the combination of biological & environmental sciences, social & behavioral sciences, and agriculture/forestry/fisheries were found in two programs.

Figure 4 .
Figure 4.A summary of the most common disciplines and combinations of disciplines found in course descriptions using NVivo keyword searches.The bottom-left horizontal bar graph labeled 'Set Size' indicates the total number of courses containing keywords related to the different disciplines.The connected circles indicate combinations of disciplines found in course descriptions and the vertical bars represent how many times that combination was found.For example, the combination of agriculture/forestry/fisheries and social & behavioral sciences was found three times.

Table 1 .
Program and course characteristics determined from the available descriptions.Multiple answers allowed c Select one d Categories derived from (Chan and Satterfield 2020) e Only used in the NVivo text search.
a Non-academic organizations Institutions of Higher Education (e.g.colleges, universities) Type (courses only) b MOOCs (Massive Open Online Courses) (e.g.Coursera, EdX) Traditional college course (e.g. offered for credit as part of a degree-seeking program) Workshop, short course, or training program Mode of instruction b Hybrid (in-person and online) a Fill in b

Table 2 .
Definitions Haider et al. 2018)isciplinary research (adapted fromHaider et al. 2018).Mixed discipline research Definition Multidisciplinarity Multidisciplinarity is thematically organized rather than problem-oriented.Disciplinary boundaries are generally not crossed, but rather different disciplines are considered in parallel Interdisciplinarity Interdisciplinarity integrates perspectives, information, data, techniques, tools, concepts, and/or theories from two or more disciplines Transdisciplinarity

Table 3 .
Results of the manual and NVivo analyses for understanding disciplines within programs and courses.