Taking stock of and advancing knowledge on interaction archetypes at the nexus between land, biodiversity, food and climate

Global challenges related to land, biodiversity, food and climate interact in diverse ways depending on local conditions and the broader context in which they are embedded. This diversity challenges learning and integrated decision-making to sustainably transform the nexus, that is to say the interactions between these land-based challenges. Providing aggregated insights, archetype analysis has revealed recurrent patterns within the multitude of interactions, i.e. interaction archetypes that are essential to enhance the understanding of nexus relations. This paper synthesises the state of knowledge on interaction or nexus archetypes related to land, biodiversity, food and climate based on a systematic literature review. It focusses on the coverage of thematic aspects, regional distribution, social dimensions and methodologies. The results show that consideration of comprehensive land–biodiversity–food–climate interactions is rare. Furthermore, there are pronounced regional knowledge gaps, social dimensions are inadequately captured, and methodological shortcomings are evident. To enhance the investigation of interaction archetypes, we have framed a future research agenda providing directions to fully capture interactions across space and time, better use the potential of scenario archetypes and up-scale transformative actions. These advances will constructively contribute insights that help to achieve the ambitious objective to sustainably transform the nexus between land, biodiversity, food and climate.


Introduction
The post-2020 sustainability framework urgently demands that the challenges of land degradation, biodiversity decline, food insecurity and climate change must be addressed (United Nations, 2014, European Commission 2020, UNCBD 2021. Clearly, it is impossible to solve these land-based challenges separately through siloed, sectoral management approaches. Instead, the scope of action needs to be radically extended to specifically focus on the nexus, i.e. interactions between all relevant thematic aspects (Biggs et al 2015, Lal 2016, O'Connor et al 2021. For example, enhancing biodiversity and associated ecosystem services, such as water purification, pollination and biological pest control, are fundamental for re-configuring agricultural systems so that production can be sustained while ensuring climate adaptation and mitigation (Chappell andLavalle 2011, IPBES 2019). However, despite empirical evidence, integrated actions at large scale remain the exception and policies are misaligned (Schmidt-Traub et al 2019). Therefore, a central question is: what can we learn from specific local ways in which land use, biodiversity change, food production and climate dynamics co-evolve to overcome fragmentation and scale up integrative actions?
In response to this question, archetype analysis  has revealed recurrent, i.e. archetypical patterns of factors and processes that repeatedly determine land-based interactions within the multitude of local conditions (Brzezina et al 2017, Hartel et al 2018, Dasgupta et al 2019, Bahri et al, 2020. We define interaction or nexus archetypes as recurrent patterns of co-evolving land, biodiversity, food and climate dynamics. Interaction archetypes provide insights into functionally similar interactions focusing on an intermediate level of abstraction  in between the particularities of single cases and panacea perspectives (Schellnhuber et al 2002, Basurto andOstrom 2009). Through cumulative learning, they can enhance understanding and inform action to sustainably transform, i.e. reconfigure landbiodiversity-food-climate nexus relations. Yet, archetype research has so far often focussed on particular phenomena separately (Eisenack et al 2021), thereby leaving valuable potential to realise the full benefits the approach offers for tailoring policies and actions to particular contexts untapped. Highlighting this potential, archetype analysis has been proposed to advance future research on biodiversity, ecosystem services and related feedbacks within land systems, particularly in the context of scenario development (IPBES 2016). Future studies seeking to realise the benefits of archetype analysis should pay in-depth attention to validating their findings, a currently under-utilised opportunity to demonstrate their credibility and hence usefulness for informing decision-making (Piemontese et al 2022). Clearly defined application requirements, including intended users, spatial scale and temporal aspects of application, are prerequisites for determining the degree to which archetypes suitably respond to knowledge needs and sustainability challenges.
Sustainably transforming land-based interactions requires a sound understanding of socialecological system dynamics (Ostrom 2009, Mcginnis and Ostrom 2014, Díaz et al 2019. Social-ecological systems have been framed as complex adaptive systems highlighting that human land use is intrinsically tied to ecological dynamics (Allen andGarmestani 2015, Folke et al 2016). This reflects the close interdependence of all human and non-human beings and their environment that lies at the core of most Indigenous Peoples' notion of a good life (Acosta Espinosa 2011, Gregor Barié 2014. Hence, the capacity of all knowledge systems needs to be embraced to inform the transformation of complex adaptive systems. In complex systems, critical thresholds, cross-scale linkages and feedback loops imply nonlinear behaviour and associated patterns of system behaviour (Holling and Gunderson 2002, Scheffer and Carpenter 2003, Walker et al 2006, Sietz et al 2017a, Van Den Elsen et al 2020. Especially the social dimensions, including governance, human behaviour and human decision-making that shape complexity in land use (Ostrom 2009) deserve greater attention. Understanding their current influence and mechanisms is crucial for sustainability transformations. Lack of integration of complexity and the role of social dimensions in knowledge and action frameworks increases uncertainty in scenarios about future interaction trajectories (O'Connor et al 2021) undermining chances to reverse the persistent failure to achieve global sustainability goals (UN 2021).
This paper aims to take stock of and enhance knowledge about interaction archetypes to support learning and decision-making on the sustainable (re)configuration of land-based nexus relations. Based on a systematic literature review, we synthesise existing knowledge on interaction archetypes related to land, biodiversity, food and climate interlinkages in order to provide a state-of-the-art knowledge source. In particular, we capture the thematic aspects addressed, regional coverage, social dimensions and methodologies used to identify and apply interaction archetypes. Based on this synthesis, we frame an agenda for future research on interaction archetypes structured around three major frontiers. These frontiers provide directions to comprehensively investigate archetypical land-biodiversity-food-climate interactions, advance analysis of nexus scenario archetypes and support up-scaling and transfer of successful transformative action.

Methodology
As the basis for our synthesis, we conducted a systematic literature review (Petticrew andRoberts 2006, Booth et al 2012). We searched peer-reviewed studies listed in the Web of Science and Scopus databases (last access 1 April 2021) using the following combined terms applied to titles, abstracts and keywords: archetyp * AND ((land OR farm * OR agric * ) AND (biodiv * OR 'ecosyst * service * ' OR food OR climat * )). These searches yielded 280 unique references. We limited this set to only those studies that met the following inclusion criteria: focus on at least one type of interaction between land and biodiversity, food and climate, identification or application of archetypes and related interactions, sound methodological description, interdisciplinary approach and comprehensive interpretation of results. We excluded the subject areas of medicine, biotechnology, atmospheric science, sanitation and architecture as these subject areas are beyond our focus on land-based interactions. Since archetype analysis is an emerging field of scientific research , Eisenack et al 2021, we focused our analysis on scientific literature. Using this selection procedure, we identified 50 thematic studies and two synthesis studies on archetype analysis. Although the selected thematic studies included research on syndromes, the predecessor of archetypes, capturing unsustainable patterns of human-nature interactions (Lüdeke et al 2004, Sietz et al 2006, Manuel-Navarrete et al 2007, we did not comprehensively cover syndrome studies. We were specifically interested in revealing the state of knowledge on archetype analysis as a rapidly advancing field of research capturing both sustainable and unsustainable patterns  that supports decision-making on sustainability with evidence-based and contextualised generalisations. We coded the 50 thematic studies according to the assessed types of interactions, their regional coverage, the main land systems addressed, social dimensions, archetype definitions, methods used to investigate archetypical interactions, data sources used, units of analysis and publication year. These categories emerged inductively during coding and subsequent analysis and provide important insights for advancing the knowledge on interaction archetypes. Investigating the type of interactions and regional coverage (section 3.1) yields insights into thematic and regional knowledge gaps. The social dimensions (section 3.2) critically shape current land use and provide insights into the potential for sustainability transformations. Archetype definitions (section 3.3) reveal variants and gaps in the conceptual foundations of archetype analysis. Investigating methods (section 3.4) provides insights into different methodologies yielding diverse types and qualities of insights. Lastly, we give a short overview of the temporal development of the research field (section 3.5). The two synthesis studies were dealt with separately providing the basis for evaluating archetype definitions and methodological portfolios. These studies were not a part of the quantitative synthesis. We drew lessons from a structured discussion of the synthesised findings to elaborate the future research agenda as a basis to enable better understanding and the sustainable management of land interactions with biodiversity, food and climate.

Interaction types and their regional distribution
The synthesis of interaction types and regional coverage revealed insights into thematic and spatial knowledge and gaps in this knowledge. The reviewed studies primarily investigated archetypical interactions of land in combination with food (82%) and less so in combination with biodiversity (50%) and climate (48%; figure 1). These foci are a good reflection of the global debate on sustainable land and food systems (UN 2014, European Commission 2020, UNCBD 2021. Knowledge on archetypical interactions is offered for specific subregions defined by IPBES (2020). These subregions serve as a reference in our synthesis to directly feed insights into global assessments of the importance and trends of biodiversity and nature's contributions to people (e.g. Nexus Assessment and Transformative Change Assessment of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services IPBES). Some studies presented global insights either at least partly covering all IPBES (2020) subregions or providing a generic perspective with general applicability.
Few of the studies (20%) considered the full set of land-biodiversity-food-climate interactions (figure 1). These studies addressed agricultural land systems mainly in combination with various other land uses and sectors such as forestry, nature conservation, urban areas, tourism and energy (e.g. Jäger et al 2015, Dasgupta et al 2019. These interactions were mainly investigated in central and western Europe and in Asia, including multiregional coverage. Focussing on less comprehensive interrelations, 16% of the studies exclusively considered landbiodiversity-food interactions (figure 1), explored in agricultural land systems, often in conjunction with nature conservation, recreation and forestry (e.g. Levers et al 2018, Li et al 2018. These studies covered primarily Europe and the global scale. In a regional perspective, most insights are available for central and western Europe, the global scale and western Africa (figure 2). A global scale extent enables regional comparisons encompassing diverse social-ecological contexts in which  land-biodiversity-food-climate interactions evolve. However, it inevitably only captures regional specificities to some extent. This means that regional aspects of underlying processes, such as land use intensity, biodiversity management and food production, are only captured in a generalised way. In particular, spatially and temporally well-resolved quantitative data and qualitative information on underlying processes are often not available at global scale, thereby largely constraining efforts to gain a comprehensive understanding of archetypical interactions across the globe.
Beyond the insights derived at global scale, it is particularly disadvantageous that there is low coverage of specific regions such as central and eastern Africa, Mesoamerica, South America and southern Asia (e.g. Locatelli et al 2017, Vidal Merino et al 2019. These regions include areas that bear high . The Caribbean is least covered, revealing the most pronounced regional knowledge gaps. Questions remain, for example, about the social-ecological consequences of colonialism and their persistence until today, e.g. related to the depletion of native flora and fauna including wild food species caused by large-scale sugar cane plantations and the introduction of exotic taxa (Paravisini-Gebert 2016, Wallman 2018). These findings indicate the urgent requirement to advance our regional knowledge on nexus problems and potential solutions to address land degradation, biodiversity loss, food insecurity and aggravating impacts of climate change in synergistic ways.

Social dimensions of archetypical interlinkages
Insights into the social components (Ostrom 2009) of interaction archetypes help to recognise leverage points suited to trigger transformative change. Considering three social dimensions, firstly, we captured governance referring to organisations, institutions and processes that shape policies and policy-making. Secondly, we took into account the human behaviour related to the characteristics and decision-making logic of stakeholders who manage land and benefit from the products of natural resource use. Thirdly, we recorded land use decisions as the central connector between natural resources and stakeholders.
Overall, only about half of the reviewed studies (n = 26) investigated how governance shaped archetypical interactions ( (Oberlack et al 2016) investigated governance and human behaviour at the same time. In contrast, 14 studies did not investigate any of the social dimensions considered in our review.
The limited consideration of social dimensions, and above all combinations of these, greatly restricts our knowledge and capacity to (re)organise land use in a way that fosters synergies and minimises trade-offs between land, biodiversity, food and climate concerns. For example, this concerns the allocation of costs and benefits among stakeholders and also impedes balancing stakeholders' interests. This resembles the inadequate consideration of the ways in which governance affects other land-based interactions such as framed in the water-energy-food nexus (Urbinatti et al 2020). A better understanding of the ways in which governance, human behaviour and land use decisions typically co-evolve and influence land-biodiversity-food-climate interactions is clearly needed to develop response options that adequately address social-ecological dynamics. Consideration of sudden changes, feedbacks, historical trajectories and dynamics of the broader social context (Ostrom 2009, Cumming et al 2020) is important to effectively manage leverage points for transformative change.

Archetype definitions
Variants of and gaps in archetype definitions yield information on the conceptual foundations of the studies reviewed. Archetypes were defined from the perspectives of diverse meanings, features and reference literature. The meanings used to describe and evaluate archetypes included case typologies, building blocks and scenario archetypes . These were further differentiated according to specific features underlying the archetype analysis encompassing recurrent patterns, system archetypes, syndromes and scenarios.
In terms of specific meanings, the majority of studies (58%, figure 4) used a case typology approach capturing similarities across a set of cases. In contrast, around a quarter (28%) applied a building blocks approach in which individual cases can be characterised by one or a combination of several archetypes. Taking yet another perspective, a small proportion of studies (14%) investigated scenario archetypes depicting common features of possible future interaction trajectories.
Studies that used a case typology approach most frequently identified recurrent patterns (figure 4) in factors and processes that shape the interactions between land, biodiversity, food and climate (e.g. Adenle and Speranza 2021). Reference was mainly made to archetype definitions used in sustainability research  and land system science (Vaclavik et al 2013). Some studies related to other schools of thought, e.g. regularities in economies (Sadoulet and Dejanvry 1992)  In contrast, the majority of studies applying a building blocks approach used system archetypes as diagnostic tools to establish or synthesise insights into characteristic structures and dynamics of socialecological systems (figure 4). These studies either diagnosed system dynamics or tested a hypothesised system change (e.g. Nyam et al 2020). Reference was specifically made to the field of system archetypes (e.g. Senge 2006) investigating typical causal interlinkages reappearing across many cases such as the 'limits to growth' system archetype (Gohari et al 2013). System archetypes offer particular potential for analysing interactions between land, biodiversity, food and climate due to their focus on reappearing systemic interlinkages.
Among the studies approaching archetypes as case typologies and building blocks, only two studies used syndromes, i.e. recurrent non-sustainable human-nature interactions, as specific features (figure 4). They described change processes as archetypical dynamic and co-evolutionary patterns of human-nature interactions (e.g. Weissteiner et al 2011), referring to Downing and Lüdeke (2002) and Müller et al (2014). These studies take integrative perspectives capturing complex sets of factors at multiple levels and in multiple sectors, aiming to overcome single-faceted sectoral approaches.
Most studies that investigated scenario archetypes expectedly referred to scenarios as specific features ( Overall, about one quarter of the reviewed studies (28%) neither provided an archetype definition nor reference literature. The proportion of studies without reference literature was found to be particularly high in those using a case typology approach (figure 4). This may impede the drawing of comprehensive lessons aimed at informing transformative action, hence necessitating improvement in future research.

Methodologies
The reviewed studies employed methodologies resting on various methods, data sources and units of analysis. Influencing the type of insights gained from a study, these methodological aspects serve to reflect on epistemological and normative underpinnings, data requirements and implications in view of specific purposes and research questions . The methods used to identify and apply interaction archetypes stem from a broad methodological portfolio which has grown and diversified since the synthesis of the archetype methods applied in sustainability research . Overall, the reviewed studies used mainly qualitative methods (44%) and to a lesser extent quantitative (30%) and mixed methods, i.e. combining qualitative and quantitative approaches (26%). 36% of the studies used more than one method.
Among the purely qualitative studies (figure 5), the most frequently used method was qualitative system modelling (e.g. Turner et al 2016, Bahri 2020), often used to identify system archetypes (see section 3.3). Moreover, expert and stakeholder assessments, theoretical conceptualisations (e.g. The mixed method studies most frequently combined qualitative system modelling with quantitative integrative modelling and meta-analysis with qualitative classification. Further studies combined machine-learning algorithms with an expert/stakeholder assessment and qualitative classification with quantitative integrative modelling. Spatial statistics and rule-based classifications used to identify socialecological system archetypes  were not found in this review. The reviewed studies used one or several types of data sources (figure 6). Firstly, existing data were used whereby available statistical, census and remote sensing data were drawn on. Secondly, literature information was extracted from scientific publications. Thirdly, participatory data collection took place. This involved processes in which stakeholders took part in the data collection. Fourthly, selfcollected data were gathered through interviews and surveys of experts and stakeholders.
The most frequently used data source was scientific literature, followed by existing data, participatory data collection and self-collected data (figure 6). Most studies (64%) used only one data source. In contrast, 24% of the studies involved two sources, e.g. drawing on existing data in combination with Taken together, qualitative methods, functional relationships and information provided in scientific literature mostly informed the investigations on archetypical interactions, in various combinations. The knowledge derived provides valuable insights into principal relationships between factors and processes that recurrently shape the interactions. However, limited use of quantitative methods as well as participatory and self-collected data on stakeholders and scenarios leaves considerable unexplored potential to better understand the complexity determining the interactions and adaptive management options.

Publication year
The publication year provides information on the temporal development of research on archetypical interactions. The reviewed studies have been published since 1992, yet the majority (88%) have appeared since 2015 (figure 8). Until 2013, studies captured only archetypical land-food-climate

Future research agenda
Our synthesis demonstrates that knowledge on archetypical interactions is limited in terms of interlinked thematic aspects, regional coverage, social dimensions and methodologies. The future agenda highlights research directions to capture archetypical interactions more comprehensively, close regional knowledge gaps, make better use of the potential of scenario archetypes and inform the up-scaling of actions.

Comprehensively capturing archetypical interactions across regions and scales
The next generation of interaction archetypes needs to pay attention to the full set of interactions between land, biodiversity, food and climate (see sections 3.1 and 3.2; figure 9(a)) to enable a solid understanding of the ways in which all involved thematic aspects typically co-evolve. Moving from fragmented perspectives to interaction archetypes helps to better understand recurrent challenges and opportunities ( figure 9(a)). Investigation of system archetypes (see section 3.3) provides a particularly suitable way to synthesise feedback mechanisms and diagnose or test hypotheses about archetypical dynamics. However, greater efforts are needed to trace patterns over time. Particular consideration needs to be dedicated to integrated analytical approaches that capture complexity, i.e. interdependency and feedback mechanisms (Scheffer and Carpenter 2003, Suding 2011, Cumming et al 2020. Important characteristics to be addressed encompass non-linear dynamics including thresholds, resilience, time lags and reversibility ( figure 9(b) 9(b)) are useful depictions for exploring non-linear interaction dynamics as a basis for analysing future scenario archetypes and adaptive management options. In the absence of alternative stable states, an existing, less sustainable stable state (see stability landscape I in figure 9(b)) requires adaptive management that substantially reconfigures the current social-ecological conditions so that another, more sustainable stable state emerges and a shift can occur. Yet, if another, more sustainable stable state exists, then there is potential for transformative change. In this case, interactions can be tipped out of the basin of attraction of their current state to shift to the alternative stable state (see stability landscape II in figure 9(b)). In contrast, more sustainable archetypical interactions require efforts to maintain or further improve their current state (see stability landscape III in figure 9(b)).
Systematic collection of time series data on interactions is key to be able to explore and effectively manage nexus relations. Participatory and selfcollected data (see section 3.4) offer particular opportunities to capture relevant processes in necessary detail. Established long-term observation systems can provide important lessons for monitoring landbiodiversity-food-climate interactions. They highlight the importance of coordinated, comprehensive and sustained data collection to inform decision making and actions on interconnected challenges and opportunities (Bestelmeyer et al 2011, GEO 2015. Integration of diverse data sources, such as derived from remote sensing, in-situ experiments and citizen observatories, offers a powerful tool for filling functional and regional knowledge gaps (see sections 3.1 and 3.2). Predictable long-term funding is a prerequisite for ensuring that data collection, synthesis and monitoring can be continued at time scales that are sufficiently long.
In future research, attention needs to be paid to under-researched regions, above all the Caribbean, Mesoamerica, central Africa and Oceania (see section 3.1). This encompasses current hotspots of change at the interface between biodiversity As demonstrated by ecological research, synergies and trade-offs may occur repeatedly at specific spatial or temporal scales, e.g. driven by recurrent weather extremes (Gonzalez et al 2020).
Advancing validation in future studies of interaction archetypes is important to strengthen the credibility of findings. Framed as a multidimensional procedure, validation should address conceptual validity (i.e. salience of research framing), construct validity (i.e. attribute selection) and application validity (i.e. usefulness of results for application by users), among other dimensions (Piemontese et al 2022). This requires the systematic planning of validation and the collection of validation data, alongside data on drivers of change, responses and action levers, as well as multi-stakeholder engagement.

Tapping the potential of scenario archetypes
Projecting possible future interaction pathways is key to identifying leverage points for adaptive management. Yet, the inherent complexity in interactions including uncertainty and surprise challenges stakeholders to make and adapt management decisions (Holling 1973(Holling , 1978. The basis of adaptive management, including governance and human behaviour (section 3.2), needs to be urgently addressed to provide insights into the conditions under which transformative change can most effectively be initiated or reinforced (Allen and Garmestani 2015). For example, analysis of scenario archetypes (see section 3.3) can help to explore the innovative potential of agroecological re-organisation of agriculture (Sietz et al 2022), a decoupling of resource use from habitat degradation and circular economic approaches. In particular, consideration of transformative future pathways tailored to the characteristics of agricultural land systems (Sietz et al 2022) can advance the analytical power of scenario archetype models. The baseline period needs to be carefully chosen (e.g. climate baseline, Liersch et al 2020) as a reference for analysing interaction scenarios. Analysis of archetypical system dynamics has substantial potential to inform scenario analysis and adaptive management, above all when advancing its use in quantitative approaches (see sections 3.3 and 3.4), as it focuses on non-linear behaviour of complex systems and systemic feedbacks ( figure 9(b)). It supports adaptive management in its objective to use emerging windows of opportunities (Sietz et al 2017a), create synergies and balance tradeoffs providing a vision and direction for action.
Future scenario research is urged to integrate indigenous and local knowledge and cultural practices that have been the basis for the implementation of adaptive governance and successful navigation of transformative change. Important questions relate to the role that unity between humans and nature (IPBES 2019) can play in sustainably governing social-ecological interactions. Moreover, what implications may the Rights of Nature as part of Sumak Kawsay (Buen Vivir, 'good living') codified in the Constitution of Ecuador (Acosta Espinosa 2011, Kauffman and Martin 2017) have? What insights does nature's entitlement with rights as a collective subject of interest as framed in the Bolivian Law of Mother Earth (Pachamama; Gregor Barié 2014) offer for adaptively governing interactions in the future? Addressing these questions is essential to (re)design inclusive socio-ecological policies.

Scaling up successful actions
Interaction archetypes support learning from the multitude of observations and can inform decisionmakers on the up-scaling potential of the insights derived. Up-scaling refers to the expansion and transfer of successful actions (Linn 2012) as an integral part of systematically fostering desired trends and synergies while balancing trade-offs. Up-scaling involves testing, transferring and refining actions in regions with similar interactions based on the assumption that similar drivers and outcomes could be addressed by comparable actions (Sietz et al 2011). In particular, future research needs to expand the systematic investigation of potential transfer regions (Vaclavik et al 2016, Piemontese et al 2020 and discussion of transferability of successful actions (Sietz et al 2017b) using spatially explicit interaction archetypes in order to inform scaling considerations.
Different stakeholders' roles in scaling, e.g. their decision making and behaviour (see section 3.2) including expectations and evaluation of interactions and outcomes, need to be better understood to ensure successful expansion and refinement of actions. Scenario archetypes (see section 4.2) need to be appropriately inclusive to support stakeholders in exploring processes that may be triggered by up-scaling activities but cannot be fully anticipated.
Although strategies may diffuse spontaneously, systematic use of leverage points is needed to support the scaling of actions and sustain their success. This requires the identification of archetypical changes in highly influential social-ecological system properties. There are clear opportunities for investigating archetypical levers emerging at the interface between global sustainability goals. For example, climate adaptation priorities outlined in National Adaptation Plans established under the United Nations Framework Convention on Climate Change can support the achievement of Sustainable Development Goals. The future research agenda framed in this paper supports advanced analysis of archetypical leverage points as an indispensable means to design and implement the large scale action needed to transform the landbiodiversity-food-climate nexus.

Data availability statement
All data that support the findings of this study are included within the article.