Mapping habitats in support of biodiversity research

By Martin Jung, postdoctoral research scholar in the IIASA Ecosystems Services and Management Program.

IIASA postdoc Martin Jung discusses how a newly developed map can help provide a detailed view of important species habitats, contribute to ongoing ecosystem threat assessments, and assist in biodiversity modeling efforts.

Biodiversity is not evenly distributed across our planet. To determine which areas potentially harbor the greatest number of species, we need to understand how habitats valuable to species are distributed globally. In our new study, published in Nature Scientific Data, we mapped the distribution of habitats globally. The habitats we used are based on the International Union for Conservation of Nature (IUCN) Red List habitat classification scheme, one of the most widely used systems to assign species to habitats and assess their extinction risk. The latest map (2015) is openly available for download here. We also built an online viewer using the Google Earth Engine platform where the map can be visually explored and interacted with by simply clicking on the map to find out which class of habitat has been mapped in a particular location.

Figure 1: View on the habitat map with focus on Europe and Africa. For a global view and description of the current classes mapped, please read Jung et al. 2020 or have a look at the online interactive interface.

The habitat map was created as an intersection of various, best-available layers on land cover, climate, and land use (Figure 1). Specifically, we created a decision tree that determines for each area on the globe the likely presence of one of currently 47 mapped habitats. For example, by combining data on tropical climate zones, mountain regions and forest cover, we were able to estimate the distribution of subtropical/tropical moist mountainous rain forests, one of the most biodiverse ecosystems. The habitat map also considers best available land use data to map human modified or artificial habitats such as rural gardens or urban sites. Notably, and as a first, our map also integrates upcoming new data on the global distribution of plantation forests.

What makes this map so useful for biodiversity assessments? It can provide a detailed view on the remaining coverage of important species habitats, contribute to ongoing ecosystem threat assessments, and assist in global and national biodiversity modeling efforts. Since the thematic legend of the map – in other words the colors, symbols, and styles used in the map – follows the same system as that used by the IUCN for assessing species extinction risk, we can easily refine known distributions of species (Figure 2). Up to now, such refinements were based on crosswalks between land cover products (Figure 2b), but with the additional data integrated into the habitat map, such refinements can be much more precise (Figure 2c). We have for instance conducted such range refinements as part of the Nature Map project, which ultimately helped to identify global priority areas of importance for biodiversity and ecosystem services.

Figure 2: The range of the endangered Siamang (Symphalangus syndactylus) in Indonesia and Malaysia according to the IUCN Red List. Up to now refinements of its range were conducted based on land cover crosswalks (b), while the habitat map allows a more complete refinement (c).

Similar as with other global maps, this new map is certainly not without errors. Even though a validation has proved good accuracy at high resolution for many classes, we stress that – given the global extent and uncertainty – there are likely fine-scale errors that propagate from some of the input data. Some, such as the global distribution of pastures, are currently clearly insufficient, with existing global products being either outdated or not highly resolved enough to be useful. Luckily, with the decision tree being implemented on Google Earth Engine, a new version of the map can be created within just two hours.

In the future, we plan to further update the habitat map and ruleset as improved or newer data becomes available. For instance, the underlying land cover data from the European Copernicus Program is currently only available for 2015, however, new annual versions up to 2018 are already being produced. Incorporating these new data would allow us to create time series of the distribution of habitats. There are also already plans to map currently missing classes such as the IUCN marine habitats – think for example of the distribution of coral reefs or deep-sea volcanoes – as well as improving the mapped wetland classes.

Lastly, if you, dear reader, want to update the ruleset or create your own habitat type map, then this is also possible. All input data, the ruleset and code to fully reproduce the map in Google Earth Engine is publicly available. Currently the map is at version 003, but we have no doubt that the ruleset and map can continue to be improved in the future and form a truly living map.


Jung M, Raj Dahal P, Butchart SHM, Donald PF, De Lamo X, Lesiv M, Kapos V,Rondinini C, & Visconti P (2020). A global map of terrestrial habitat types. Nature Scientific Data DOI: 10.1038/s41597-020-00599-8 

Note: This article gives the views of the author, and not the position of the Nexus blog, nor of the International Institute for Applied Systems Analysis.

Representing IIASA at the 2019 Centennial AGU Fall Meeting

By: Florian Hofhansl, postdoc in the IIASA Ecosystems Services and Management and Evolution and Ecology Programs

Florian Hofhansl shares his experience on presenting the wildfire climate impacts and adaptation model (FLAM) at the Google Exhibition Booth at the 2019 American Geosciences Union meeting held in San Francisco 9-13 December.

© Florian Hofhansl | Florian presenting the wildfire climate impacts and adaptation model (FLAM) at the Google Exhibit Booth.

The American Geosciences Union (AGU) Fall Meeting is the largest international Earth and space science meeting in the world. AGU is a great place to reconnect with colleagues as well as to build-up new professional relationships. The 2019 conference marked its Centennial in San Francisco, the home of the AGU Fall Meeting for more than 40 years, and thus I gladly took the offer to give a presentation about FLAM at the Google Exhibit Booth.

It was an honor to represent IIASA by presenting FLAM and discussing its implementation on the Google Earth Engine platform with experts face-to-face on-site. Right after the presentation I ran into a former YSSPer Sarath Guttikunda, who indicated that his experience in the IIASA Young Scientists Summer Program (YSSP) had a profound influence on his professional and personal life.

Another highlight of this year’s centennial conference edition was a presentation by Cesar Terrer, winner of the Peccei Award with Honors from the 2016 YSSP, who was invited to present a young scientists view of the future. His talk entitled “The future of earth vegetation under rising CO2” was featured in a special lighting talk session.

I have been attending the Fall Meeting since 2012 and will continue to attend this meeting for the foreseeable future as it is a great place to network with colleagues and embrace the joy of science with the community. Over the years, I keep on being inspired by other researchers filled with new perspectives, and have participated in scientific discussions that we hope will make our planet more sustainable.

© Florian Hofhansl | Florian presenting a poster about tropical plant functional traits at AGU19.

More about Florian Hofhansl’s research can be found here:

Note: This article gives the views of the author, and not the position of the Nexus blog, nor of the International Institute for Applied Systems Analysis.

Advocating for a new ecology grounded in systems science

By Brian Fath, Young Scientists Summer Program (YSSP) scientific coordinator, researcher in the Advanced Systems Analysis Program, and professor in the Department of Biological Sciences at Towson University (Maryland, USA) and Soeren Nors Nielsen, Associate professor in the Section for Sustainable Biotechnology, Aalborg University, Denmark

IIASA Young Scientists Summer Program (YSSP) scientific coordinator, Brian Fath and colleagues take an extended look at the application of the ecosystem principles to environmental management in their book, A New Ecology, of which the second edition was just released.

IIASA is known for some of the earliest studies of ecosystem dynamics and resilience, such as work done at the institute under the leadership of Buzz Holling. The authors of the book, A New Ecology, of which the second edition was just released, are all systems ecologists, and we chose to use IIASA as the location for one of the brainstorming meetings to advance the ideas outlined in the book. At this meeting, we crystallized the idea that ecosystem ontology and phenomenology can be summarized in nine key principles. We continue to work with researchers at the institute to look for novel applications of the approach to socioeconomic systems – such as under the current EU project, RECREATE – in which the Advanced Systems Analysis Program is participating. The project uses ecological principles to study urban metabolism – a multi-disciplinary and integrated platform that examines material and energy flows in cities as complex systems.

Our book argues the need for a new ecology grounded in the first principles of good science and is also applicable for environmental management. Advances such as the United Nations Rio Declaration on Sustainable Development in 1992 and the more recent adoption of the Sustainable Development Goals (2015) have put on notice the need to understand and protect the health and integrity of the Earth’s ecosystems to ensure our future existence. Drawing on decades of work from systems ecology that includes inspiration from a variety of adjacent research areas such as thermodynamics, self-organization, complexity, networks, and dynamics, we present nine core principles for ecosystem function and development.

The book takes an extended look at the application of the ecosystem principles to environmental management. This begins with a review of sustainability concepts and the confusion and inconsistencies of this is presented with the new insight that systems ecology can bring to the discussion. Some holistic indicators, which may be used in analyzing the sustainability states of environmental systems, are presented. We also recognize that ecosystems and society are physically open systems that are in a thermodynamic sense exchanging energy and matter to maintain levels of organization that would otherwise be unattainable, such as promoting growth, adaptation, patterns, structures, and renewal.

Another fundamental part of the evolution of the just mentioned systems are that they are capable of exhibiting variation. This property is maintained by the fact that the systems are also behaviorally open, in brief, capable of taking on an immense number of combinatorial possibilities. Such an openness would immediately lead to a totally indeterminate behavior of systems, which seemingly is not the case. This therefore draws our attention towards a better understanding of the constraints of the system.

One way of exploring the interconnectivity in ecosystems is taking place mainly through the lens of ecological network analysis. A primer for network environment analysis is provided to familiarize the reader with notation including worked examples. Inherent in energy flow networks, such as ecosystem food webs, the real transactional flows give rise to many hidden properties such as the rise in indirect pathways and indirect influence, an overall homogenization of flow, and a rise in mutualistic relations, while hierarchies represent conditions of both top-down and bottom-up tendencies. In ecosystems, there are many levels of hierarchies that emerge out of these cross-time and space scale interactions. Managing ecosystems requires knowledge at several of these multiple scales, from lower level population-community to upper level landscape/region.

Viewing the tenets of ecological succession through a lens of systems ecology lends our attention the agency that drives the directionality stemming from the interplay and interactions of the autocatalytic loops – that is, closed circular paths where each element in the loop depends on the previous one for its production – and their continuous development for increased efficiency and attraction of matter and energy into the loops. Ecosystems are found to show a healthy balance between efficiency and redundancy, which provides enough organization for effectiveness and enough buffer to deal with contingencies and inevitable perturbations.

Yet, the world around us is largely out of equilibrium – the atmosphere, the soils, the ocean carbonates, and clearly, the biosphere – selectively combine and confine certain elements at the expense of others. These stable/homoeostatic conditions are mediated by the actions of ecological systems. Ecosystems change over time displaying a particular and identifiable pattern and direction. Another “unpleasant” feature of the capability for change is to further evolve through collapses. Such collapse events open up creative spaces for colonization and the emergence of new species and new systems. This pattern includes growth and development stages followed by the collapse and subsequent reorganization and launching to a new cycle.

A good theory should be applicable to the concepts in the field it is trying to influence. While the mainstream ecologists are not regularly applying systems ecology concepts, the purpose of our book is to show the usefulness of the above ecosystem principles in explaining standard ecological concepts and tenets. Case studies from the general ecology literature are given relating to evolution, island bio-geography, biodiversity, keystone species, optimal foraging, and niche theory to name a few.

No theory is ever complete, so we invite readers to respond and comment on the ideas in the book and offer feedback to help improve the ideas, and in particular the application of these principles to environmental management. We see a dual goal to understand and steward ecological resources, both for their sake and our own, with the purpose of an ultimate sustainability.

Note: This article gives the views of the author, and not the position of the Nexus blog, nor of the International Institute for Applied Systems Analysis.

Introducing a framework for 21st century biological invasions

By Bernd Lenzner, post-doctoral researcher at the Department of Botany and Biodiversity at the University of Vienna, Austria and IIASA YSSP alumnus

To guide action towards a sustainable future for nature and people, it is crucial to understand the role of invasive species in shaping global biodiversity and ecosystem services, as well as how this depends on human actions.

Imagine arriving at the shores of a country you have never visited before. What kind of nature awaits you? Will you be stunned by the beauty of plants and animals you only know from documentaries and books? Will you be fascinated by the songs of birds you’ve never heard before? Or, will you find species you know from your backyard and the landscape surrounding your home?

© Johan Larson |

Most of us probably hope to find new, untouched nature with many plants and animals we haven’t encountered yet. Isn’t that after all the purpose of exploring our planet? Unfortunately, nowadays we see that the biota in many regions of the world are becoming more and more similar as a consequence of the movement of species by humans across the globe. Recent studies have shown that approximately 4% of all plants [1], 10% of all birds [2], and 2% of all amphibians and reptiles [3] worldwide can be found in regions outside their native distribution, and these numbers are increasing with no sign of saturation [4]. Once introduced, these so-called alien species can emerge as a major threat to global biodiversity [5] and ecosystem services [6], and lead to global biotic homogenization [7].

We know that these trends are driven not only by the intentional and unintentional human introduction of species into new regions through increased trade and transport, but also by how climate and land use facilitate the establishment of species outside their native range. While these drivers are expected to largely evolve in the decades to come, researchers have so far been unable to build scenarios exploring the long-term dynamics of the distribution of alien species and their impacts.

I lead a joint study between researchers from Vienna University, IIASA, and other colleagues that was recently published in the journal BioScience [8]. In our paper, we introduced the necessary steps for building scenarios of future long-term dynamics of biological invasion at a global scale. We propose a general framework for global 21st century scenarios and models of biological invasions and review essential datasets and milestones. This is the first time that biological invasions are put into a global scenario context with the aim to develop qualitative storylines that can be linked to quantitative models.

I actually started working on this in 2017 when I was still a PhD student in the Division of Conservation Biology, Landscape, and Vegetation Ecology at the University of Vienna, and a participant in the IIASA Young Scientists Summer Program. The project helped to build bridges between research communities deeply involved in core activities from the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES).

IIASA was involved in IPBES’ methodological assessment on the use of models and scenarios for biodiversity and ecosystem services and in its efforts to apply biodiversity models in existing IPCC scenarios [9] to deliver insights into the IPBES’ global assessment report released earlier this year. Recently, the IIASA Bending the curve project [10] led by David Leclère, a researcher in the Ecosystems Services and Management Program, used models to elicit what type and ambition of actions are necessary to reverse biodiversity declines, to support on-going discussions at the Convention on Biological Diversity (CBD) on a global international agreement for people and nature to be negotiated in 2020. I am a member of the IPBES expert group involved in the writing of the upcoming thematic assessment on invasive alien species and their control, and also a contributor to a new research project called AlienScenarios funded by BiodivERsA and the Belmont Forum. Led by my supervisor Franz Essl at the University of Vienna, this project will assess global and regional mid- and long-term trends of alien species richness and impacts, as well as develop scenarios for biological invasions.

In the near future, we hope to integrate these on-going projects, to allow better modeling of global biodiversity trends and their drivers, as integrating biological invasions into the global picture are required to materialize the 2050 vision of the Convention on Biological Diversity (CBD).


[1] van Kleunen M et al. (2015) Global exchange and accumulation of non-native plants. Nature, 525, 100-103.

[2] Dyer EE, Redding DW, Blackburn TM (2017) The global avian invasions atlas, a database of alien bird distributions worldwide. Scientific Data, 4, 170041.

[3] Capinha C, Seebens H, Cassey P, García-Díaz P, Lenzner B, Mang T, Moser D, Pyšek P, Rödder D, Scalera R, Winter M, Dullinger S, Essl F (2017) Diversity, biogeography and the global flows of alien amphibians and reptiles. Diversity and Distributions, 23, 1313-1322.

[4] Seebens H et al. (2017) No saturation in the accumulation of alien species worldwide. Nature Communications, 8, 14435.

[5] Maxwell SL, Fuller RA, Brooks TM, Watson JEM (2016) Biodiversity: The ravages of guns, nets and bulldozers. Nature, 536, 143-145.

[6] Pejchar L & Mooney HA (2009) Invasive species, ecosystem services and human well-being. Trends in Ecology and Evolution, 9, 497-504.

[7] Capinha C, Essl F, Seebens H, Moser D, Pereira HM (2015) The dispersal of alien species redefines biogeography in the Anthropocene. Science, 348, 1248-1251.

[8] Lenzner B, Leclère D, Franklin O, Seebens H, Roura-Pascual N, Obersteiner M, Dullinger S, Essf F (2019) A framework for global twenty-first century scenarios and models of biological invasions. BioScience, 69, 697-710.

[9] Kim HJ et al. (2018) A protocol for an intercomparison of biodiversity and ecosystem services models using harmonized land-use and climate scenarios. Geoscientific Model Development, 11, 4537-4562.

[10] Leclere D et al. (2018) Towards pathways bending the curve of terrestrial biodiversity trends within the 21st century. IIASA DOI:10.22022/ESM/04-2018.15241.

Note: This article gives the views of the author, and not the position of the Nexus blog, nor of the International Institute for Applied Systems Analysis.

Perspectives on transforming food and land use systems for sustainable development

By Frank Sperling, Senior Project Manager (FABLE) in the IIASA Ecosystems Services and Management Program

Food and land use systems play a critical role in managing climate risks and bringing the world onto a sustainable development trajectory.

The UN Secretary General’s Climate Action Summit in New York on 23 September seeks to catalyze further momentum for climate change mitigation and adaptation. The transformation of the food and land use system will play a critical role in managing climate risks and bringing the world onto a sustainable development trajectory.

Today’s food and land use systems are confronted with a great variety of challenges. This includes delivering on universal food security and better diets by 2030. Over the last decades, great strides have been made towards achieving universal food security, but this progress recently grinded to a halt. The number of people suffering from chronic hunger has been rising again from below 800 million in 2015 to over 820 million people today [1]. Food security is however not only about a sufficient supply of calories per person. It is also about improving diets, addressing the worldwide increase in the prevalence of obesity, and how we use and value environmental goods and services.

© Paulus Rusyanto |

Agriculture, forestry and other land use currently account for around 24% of greenhouse gas emissions caused by human activities [2]. Land use changes are also a major driver behind the worldwide loss of biodiversity [3]. Clearly, in light of population growth and the increasingly visible fingerprints of a human-induced global climate crisis and other environmental changes, business as usual is not an option.

Systems thinking is key in shifting towards more sustainable practices. A new report released by the Food and Land-Use System (FOLU) Coalition showcases that there is much to be gained. There are massive hidden costs in our current food and land use systems. The report outlines ten critical transitions, which can substantially reduce these hidden costs, thereby generating an economic prize, while improving human and planetary health.

The International Institute for Applied Systems Analysis (IIASA) contributed to the analytics underpinning the report [4], applying the Global Biosphere Management Model (GLOBIOM) [5]. A “better futures” scenario, which seeks to collectively address development and environmental objectives, was compared to a “current trends” scenario, which is basically a continuation of a business-as-usual scenario. The assessment illustrates that an integrated approach that acknowledges the interactions in the food and land use space, can help identify synergies and manage trade-offs across sectors. For example, shifting towards healthy diets not only improves human health, but also reduces pressure on land, thereby helping to improve the solution space for addressing climate change and halting biodiversity loss.

While understanding that the global picture is important, practical solutions require engagement with national and subnational governments. The challenge is to identify development pathways that address the development needs and aspirations of countries within global sustainability contexts. As part of FOLU, the Food, Agriculture, Biodiversity, Land and Energy (FABLE) Consortium was initiated to do exactly this. The FABLE Secretariat, jointly hosted by the Sustainable Development Solutions Network (SDSN) and IIASA, is working with knowledge institutions from developed and developing countries, to explore the interactions between national and global level objectives and their implications for pathways towards sustainable food and land use systems. Preliminary results from inter-active scenario and development planning exercises, so-called Scenathons, were recently presented in the FABLE 2019 report.

These initiatives highlight that acknowledging and embracing complexity can help reconcile development and environmental interests. This also entails rethinking how we relate to and manage nature’s services and their role in providing the foundation for the welfare of current and future generations. This is underscored by the prominent role nature-based solutions are given at the UN Secretary General’s Climate Action Summit. We need to move from silo-based, sector specific, single objective approaches to a focus on multiple objective solutions. In the land use space, this means embedding agriculture in the broader land use context, which accounts for and values environmental services, and linking to the food system where dietary choices shape human health and the demand for land.

Doing so will help bridge the international policy objectives of the UN Framework Convention on Climate Change (UNFCCC), the UN Convention on Combating Desertification (UNCCD), the Convention on Biological Diversity (CBD), and the Sustainable Development Goals (SDGs) enshrined in ‘The 2030 Agenda for Sustainable Development’. This represents an opportunity to create a new value proposition for agriculture and other land use activities where environmental stewardship is rewarded.


[1] Food and Agriculture Organization (FAO) et al. (2019). The State of Food Security and Nutrition in the World 2019. Safeguarding against economic slowdowns and downturns. Rome, FAO.

[2] Intergovernmental Panel on Climate Change (IPCC) (2019). Climate Change and Land. IPCC Special Report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems. Intergovernmental Panel on Climate Change (IPCC).

[3] Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) (2018). The IPBES assessment report on land degradation and restoration. Montanarella, L., Scholes, R., and Brainich, A. (eds.). Secretariat of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, Bonn, Germany. 744 pages.

[4] Deppermann, A. et al. 2019. Towards sustainable food and land-use systems: Insights from integrated scenarios of the Global Biosphere Management Model (GLOBIOM). Supplemental Paper to The 2019 Global Consultation Report of the Food and Land Use Coalition Growing Better: Ten Critical Transitions to Transform Food and Land Use. Laxenburg, IIASA.

[5] Havlik P, Valin H, Herrero M, Obersteiner M, Schmid E, Rufino MC, Mosnier A, Thornton PK, et al. (2014). Climate change mitigation through livestock system transitions. Proceedings of the National Academy of Sciences 111 (10): 3709-3714. DOI: 1073/pnas.1308044111 [].

Note: This article gives the views of the author, and not the position of the Nexus blog, nor of the International Institute for Applied Systems Analysis.

Shaping my scientific career

By Davit Stepanyan, PhD candidate and research associate at Humboldt University of Berlin, International Agricultural Trade and Development Group and 2019 IIASA Young Scientists Summer Program (YSSP) Award Finalist.

Participating in the YSSP at IIASA was the biggest boost to my scientific career and has shifted my research to a whole new level. IIASA provides a perfect research environment, especially for young researchers who are at the beginning of their career paths and helps to shape and integrate their scientific ideas and discoveries into the global research community. Being surrounded by leading scientists in the field of systems analysis who were open to discuss my ideas and who encouraged me to look at my own research from different angles was the most important push during my PhD studies. Having the work I did at IIASA recognized with an Honorable Mention in the 2019 YSSP Awards has motivated me to continue digging deeper into the world of systems analysis and to pursue new challenges.

© Davit Stepanyan

Although my background is in economics, mathematics has always been my passion. When I started my PhD studies, I decided to combine these two disciplines by taking on the challenge of developing an efficient method of quantifying uncertainties in large-scale economic simulation models, and so drastically reduce the need and cost of big data computers and data management.

The discourse on uncertainty has always been central to many fields of science from cosmology to economics. In our daily lives when making decisions we also consider uncertainty, even if subconsciously: We will often ask ourselves questions like “What if…?”, “What is the chance of…?” etc. These questions and their answers are also crucial to systems analysis since the final goal is to represent our objectives in models as close to reality as possible.

I applied for the YSSP during my third year of PhD research. I had reached the stage where I had developed the theoretical framework for my method, and it was the time to test it on well-established large-scale simulation models. The IIASA Global Biosphere Management Model (GLOBIOM), is a simulation model with global coverage: It is the perfect example of a large-scale simulation model that has faced difficulties applying burdensome uncertainty quantification techniques (e.g. Monte Carlo or quasi-Monte Carlo).

The results from GLOBIOM have been very successful; my proposed method was able to produce high-quality results using only about 4% of the computer and data storage capacities of the above-mentioned existing methods. Since my stay at IIASA, I have successfully applied my proposed method to two other large-scale simulation models. These results are in the process of becoming a scientific publication and hopefully will benefit many other users of large-scale simulation models.

Looking forward, despite computer capacities developing at high speed, in a time of ‘big data’ we can anticipate that simulation models will grow in size and scope to such an extent that more efficient methods will be required.

Note: This article gives the views of the author, and not the position of the Nexus blog, nor of the International Institute for Applied Systems Analysis.