Research on the simultaneous provision of multiple ecosystem functions and services (multifunctionality) is advancing rapidly. The use of different sets of functions by each study limits comparability between studies and the provision of general management recommendations. Here, we analyze a comprehensive set of ecosystem functions from 15 studies covering a wide range of habitats and environmental conditions, from deserts to boreal forests, to identify the number of independent axes of variation (i.e., dimensions) that jointly describe ecosystem´s simultaneous provision of multiple functions (multifunctionality). In order to do so, we performed correlations between all our different functions, to assess which ones correlate better with others and with multifunctionality metrics. Then, we performed principal component analyses to quantify the number of dimensions that could represent variation across the large number of functions measured, and simulations to identify “indicators” for each of these axes.
Results/Conclusions
For each of the five dimensions of multifunctionality identified, we provide indicator functions, those that best represent the variation within those multifunctionality dimensions. These indicator functions include stocks (soil carbon, aboveground plant biomass), nutrient fluxes (soil enzymatic activities, dung decomposition, nitrification), and stoichiometric changes (N/P and C/P ratios). Soil C and beta-glucosidase activity were the best indicator functions overall, with results consistent across grass- and woody plant-dominated habitats and independent of environmental conditions. Our study provides the first comprehensive set of functions to measure overall ecosystem functioning and will help developing standardized multifunctionality measures that improve comparisons among studies and ecosystem management recommendations.