Investigating the relationship between biodiversity and ecosystem multifunctionality: challenges and solutions

Abstract

Summary1. Extensive research shows that more species-rich assemblages are generally more productive and efficient in resource use than comparable assemblages with fewer species. But the question of how diversity simultaneously affects the wide variety of ecological functions that ecosystems perform remains relatively understudied. It presents several analytical and empirical challenges that remain unresolved. In particular, researchers have developed several disparate metrics to quantify multifunctionality, each characterizing different aspects of the concept and each with pros and cons. 2. We compare four approaches to characterizing multifunctionality and its dependence on biodiversity, quantifying (i) magnitudes of multiple individual functions separately, (ii) the extent to which different species promote different functions, (iii) the average level of a suite of functions and (iv) the number of functions that simultaneously exceeds a critical threshold. 3. We illustrate each approach using data from the pan-European BIODEPTH experiment and the R multifunc package developed for this purpose, evaluate the strengths and weaknesses of each approach and implement several methodological improvements. 4. We conclude that an extension of the fourth approach that systematically explores all possible threshold values provides the most comprehensive description of multifunctionality to date. We outline this method and recommend its use in future research.

Biotic homogenization can decrease landscape-scale forest multifunctionality

“…This result contrasts with the results of other studies focusing on more diverse and/or experimental grassland, aquatic, or soil communities. In these studies, higher α-diversity enhances α-multifunctionality even at very high thresholds (8,24), possibly due to strong complementarity effects. However, the diversity-ecosystem functioning literature has tended to concentrate on particular ecosystems and study designs.…”

“…Multifunctionality can be measured by a variety of methods, and the most appropriate means of doing so remains unresolved (24)(25)(26)(27), particularly at larger scales, where the desired distribution of ecosystem function across the landscape has not been quantified. At local scales, one can quantify ecosystem multifunctionality as the number of ecosystem functions that exceed a given threshold value, where the threshold equals a certain percentage of the maximum observed value of each function (10, 24) (hereafter "threshold-based multifunctionality"; Fig.…”

Microbial regulation of the soil carbon cycle: evidence from gene–enzyme relationships

“…In support of our argument, Reeve et al (2010) have stated that correlations between Microbial regulation of the C cycle P Trivedi et al traditional techniques and soil DNA might be stronger than with soil mRNA because DNA may better represent the potential functional capability of the microbial biomass rather than its current and presumably transient state represented by mRNA. Our results emphasize that to make valid assumptions on the biodiversity-functional relationships in future, parameters selected to measure ecosystem multifunctionality (multiple functions and services as in Byrnes et al, 2014) need to carefully consider their component parts, what drives these processes, how they relate to one another and also how the individual functions that they comprise should be weighted and measured. The extremely strong correlation between all enzyme activities with functional genes further suggests that soil microbes are a good proxy for soil functionality.…”

Multiple stressors and multifunctionality: limited effects on an illuminated benthic system

“…One approach to this question is to measure multifunctionality, i.e. the simultaneous performance of multiple functions [3] in response to either one or multiple stressors. Here, we do just that, using marine shallow-water sediment as a model system.…”