Ecosystem Multifunctionality

by

Peter K. Manning

• LAST REVIEWED: 02 March 2021
• LAST MODIFIED: 24 April 2019
• DOI: 10.1093/obo/9780199830060-0170

Introduction

Ecosystem multifunctionality can be defined as the ability of an ecosystem to provide multiple functions and services. While this definition appears intuitively simple, ecosystem multifunctionality can be difficult to define and measure in practice. While multifunctionality measures allow the overall performance of an ecosystem to be reduced to simple metrics, the overall merit and relevance of simplifying the wide range of functions provided by an ecosystem in this way has been debated. To date, the majority of work that explicitly refers to ecosystem multifunctionality has been from the field of ecology known as biodiversity and ecosystem function research. This has shown that the effects of biodiversity on the functioning of ecosystems are stronger for multiple functions than for single functions due to the fact that different species control different functions. Most of this work has focused on the plot scale (less than 1 hectare), but an earlier emerging and still highly active body of literature refers to the creation and maintenance of multifunctional landscapes. This work, which is typically conducted within the disciplines of ecosystem services, agronomy, and land management, focuses on the delivery of multiple ecosystem services at larger spatial scales. Ecosystem multifunctionality is a relatively new concept, therefore, the literature presented here is primarily drawn from the most-influential papers within the field, along with early-21st-century papers that have broken new ground within the topic. Interest in multifunctionality has sharply increased in the early 21st century (particularly since 2007), in part due to an increase in large collaborative research projects that make its quantification possible. Ecosystem multifunctionality is a very active and rapidly advancing area in ecological research. It is therefore recommended that papers citing those presented here are also investigated.

Definition, Measurement, and Debate

Ecosystem multifunctionality is a relatively new area of ecological research, and there is currently much debate regarding the merit of producing aggregated measures of ecosystem function, and the best way of measuring multifunctionality. Byrnes, et al. 2014a provide useful review and discussion of the most widely used measures, in particular the averaging approach (e.g., Maestre, et al. 2012), which takes the mean value of multiple standardized function measures, and the threshold approach, which counts the number of standardized functions exceeding a certain percentage of their maximum (e.g., Gamfeldt, et al. 2008) or a range of threshold values (e.g., Zavaleta, et al. 2010 and Wood, et al. 2015). The sensitivity of multifunctionality measures to the identity of their component functions is highlighted in Allan, et al. 2015, which generates a range of measures representing different stakeholder priorities. The overall merit of the multifunctionality approach has also been questioned. Multifunctionality measures can contain very different functions that can respond in opposing directions to a driver or are controlled by different underlying drivers; aggregating them therefore obscures information about these components, and inferences can be drawn about the drivers of multifunctionality that do not apply to all the component functions. These topics are covered in Bradford, et al. 2014a and in the correspondence that this paper stimulated (Byrnes, et al. 2014b; Bradford, et al. 2014b). Issues with information loss can be partially overcome by the method in Dooley, et al. 2015, although this requires large amounts of data and information. Manning et al. 2018 reviewed the benefits and risks of the multifunctionality concept. The study suggested that multifunctionality should be viewed as a property that exists at two levels. The first, ecosystem function multifunctionality, is defined as the array of biological, geochemical, and physical processes that occur within an ecosystem. The second, “ecosystem service multifunctionality”, is defined as the co-supply of multiple ecosystem services relative to their human demand. Measurement and definition of ecosystem multifunctionality at large scales (e.g., greater than 1 hectare) are complex and are covered in another section: Multifunctional Landscapes.

• Allan, E., P. Manning, F. Alt, et al. 2015. Land use intensification alters ecosystem multifunctionality via loss of biodiversity and changes to functional composition. Ecology Letters 18.8: 834–843.

  DOI: 10.1111/ele.12469

  Multifunctionality here is defined according a range of stakeholder priorities, ranging from agricultural production to the delivery of cultural ecosystem services. Doing this shows that the relationships among land use intensity, biodiversity, and multifunctionality are strongly dependent on how multifunctionality is defined.

• Bradford, M. A., S. A. Wood, R. D. Bardgett, et al. 2014a. Discontinuity in the responses of ecosystem processes and multifunctionality to altered soil community composition. Proceedings of the National Academy of Sciences of the United States of America 111.40: 14478–14483.

  DOI: 10.1073/pnas.1413707111

  Experimental communities varying in soil community complexity are compared, with the finding that overall multifunctionality of soil-based functions increases with community complexity. It is argued that this conclusion may not be informative because the overall multifunctionality response masks strongly divergent responses of individual functions.

• Bradford, M. A., S. A. Wood, R. D. Bardgett, et al. 2014b. Reply to Byrnes et al.: Aggregation can obscure understanding of ecosystem multifunctionality. Proceedings of the National Academy of Sciences of the United States of America 111.51: E5491.

  DOI: 10.1073/pnas.1421203112

  This was the response of Bradford and colleagues to the criticisms of Byrnes and colleagues. Together, the three articles make for interesting reading and nicely cover some of the pros and cons of the multifunctionality concept, while highlighting important issues regarding its measurement and interpretation.

• Byrnes, J. E. K., L. Gamfeldt, F. Isbell, et al. 2014a. Investigating the relationship between biodiversity and ecosystem multifunctionality: Challenges and solutions. Methods in Ecology and Evolution 5.2: 111–124.

  DOI: 10.1111/2041-210X.12143

  Recommended for anyone who intends to measure ecosystem multifunctionality. The relative merits of the different measures available at the time of writing are discussed, and the multiple-threshold approach is recommended. Useful R software code for computing and visualizing multiple threshold-based multifunctionality is provided.

• Byrnes, J. E. K., J. S. Lefcheck, L. Gamfeldt, J. N. Griffin, F. Isbell, and A. Hector. 2014b. Multifunctionality does not imply that all functions are positively correlated. Proceedings of the National Academy of Sciences of the United States of America 111.51: E5490.

  DOI: 10.1073/pnas.1419515112

  This letter was written as a response to Bradford, et al. 2014a. As implied by the title, the authors argue that the critique of the multifunctionality is flawed and that multifunctionality measures represent the overall response of an ecosystem’s functioning to a driver and so are not misleading.

• Dooley, A., F. Isbell, L. Kirwan, J. Connolly, J. A. Finn, and C. Brophy. 2015. Testing the effects of diversity on ecosystem multifunctionality using a multivariate model. Ecology Letters 18.11: 1242–1251.

  DOI: 10.1111/ele.12504

  A method for testing biodiversity-multifunctionality relationships is presented. In most cases this will be best suited to biodiversity experiments, since a large amount of data are required. However, where such data are available, the method allows for very detailed inferences.

• Gamfeldt, L., H. Hillebrand, and P. R. Jonsson. 2008. Multiple functions increase the importance of biodiversity for overall ecosystem functioning. Ecology 89.5: 1223–1231.

  DOI: 10.1890/06-2091.1

  This study presents a theoretical framework for the investigation of the biodiversity-multifunctionality relationship and was the first to use the threshold approach to measuring multifunctionality.

• Maestre, F. T., J. L. Quero, N. J. Gotelli, et al. 2012. Plant species richness and ecosystem multifunctionality in global drylands. Science 335.6065: 214–218.

  DOI: 10.1126/science.1215442

  An example of the averaging approach to measuring ecosystem multifunctionality. In this approach, a range of ecosystem function measures are standardized and the average of these scores is taken.

• Manning, P., F. van der Plas, S. Soliveres, et al. 2018. Redefining ecosystem multifunctionality. Nature Ecology and Evolution 2:427–436.

  DOI: 10.1038/s41559-017-0461-7

  The first major review of the multifunctionality concept and its benefits and risks. The paper extends the multifunctionality concept to two levels, ecosystem function multifunctionality and ecosystem service multifunctionality. Provides examples and tutorials on how to quantify calculate these.

• Wood, S. A., M. A. Bradford, J. A. Gilbert, et al. 2015. Agricultural intensification and the functional capacity of soil microbes on smallholder African farms. Journal of Applied Ecology 52.3: 744–752.

  DOI: 10.1111/1365-2664.12416

  This study makes use of the multiple-threshold approach endorsed in Byrnes, et al. 2014a in a study of agricultural soil functions and so provides a good example of the application of multifunctionality measures to a wider range of questions.

• Zavaleta, E. S., J. R. Pasari, K. B. Hulvey, and G. D. Tilman. 2010. Sustaining multiple ecosystem functions in grassland communities requires higher biodiversity. Proceedings of the National Academy of Sciences of the United States of America 107.4: 1443–1446.

  DOI: 10.1073/pnas.0906829107

  This paper is probably the first to use a multiple-threshold-based approach to the measurement of multifunctionality.