Functional diversity can facilitate the collapse of an undesirable ecosystem state

Biodiversity may increase ecosystem resilience. However, we have limited understanding if this holds true for ecosystems that respond to gradual environmental change with abrupt shifts to an alternative state. We used a mathematical model of anoxic-oxic regime shifts and explored how trait diversity in three groups of bacteria influences resilience. We found that trait diversity did not always increase resilience: greater diversity in two of the groups increased but in one group decreased resilience of their preferred ecosystem state. We also found that simultaneous trait diversity in multiple groups often led to reduced or erased diversity effects. Overall, our results suggest that higher diversity can increase resilience but can also promote collapse when diversity occurs in a functional group that negatively influences the state it occurs in. We propose this mechanism as a potential management approach to facilitate the recovery of a desired ecosystem state

How puzzles are shaping our understanding of biodiversity: A call for more research into biodiversity representation in educational games

Games as a didactic tool (e. g., puzzles) are gaining recognition in environmental education to promote skill development, but also to develop a specific understanding of the natural world. However, a children’s puzzle containing representations of nature may unwillingly lead to “misconceptions” of biodiversity themes and processes, and an over-simplification of the relationship between people and nature. To solve this problem, positive connotations of biodiversity may prompt a conceptual change to a more nuanced, multifaceted conception of biodiversity

Selection in monoculture vs. mixture alters plant metabolic fingerprints

Aims: In grassland biodiversity experiments, positive biodiversity effects on primary productivity increase over time. Recent research has shown that differential selection in monoculture and mixed-species communities leads to the rapid emergence of monoculture and mixture types, adapted to their own biotic community. We used eight plant species selected for 8 years in such a biodiversity experiment to test if monoculture and mixture types differed in metabolic profiles using infrared spectroscopy. Methods: Fourier transform infrared spectroscopy (FTIR) was used to assess metabolic fingerprints of leaf samples of 10 individuals of each species from either monocultures or mixtures. The FTIR spectra were analyzed using multivariate procedures to assess (i) whether individuals within species could be correctly assigned to monoculture or mixture history based on the spectra alone and (ii) which parts of the spectra drive the group assignment, i.e. which metabolic groups were subject to differential selection in monocultures vs. mixtures. Important Findings: Plant individuals within each of the eight species could be classified as either from monoculture or mixture selection history based on their FTIR spectra. Different metabolic groups were differentially selected in the different species; some of them may be related to defense of pathogens accumulating more strongly in monocultures than in mixtures. The rapid selection of the monoculture and mixture types within the eight study species could have been due to a sorting-out process based on large initial genetic or epigenetic variation within the species

Plant responses to diversity‐driven selection and associated rhizosphere microbial communities

Plant diversity loss can alter plant–plant and plant–rhizosphere microbiome interactions. These altered interactions, in turn, may exert diversity‐driven selection pressure to which plants respond with phenotypic changes. Diverse plant communities may favour the survival and fitness of individuals with traits that avoid competition. Conversely, monocultures may accumulate species‐specific pests favouring greater investment in defence traits. Yet, it is unknown how altered plant rhizosphere interactions influence the plant diversity‐driven selection for altered plant phenotypes. We tested for plant diversity‐driven selection on plant above‐ground traits and how these traits are modified by their rhizosphere microbial communities after 11 years in experimental plant monocultures and mixtures. Plants propagated from monocultures or mixtures were grown in combination with their ‘home’ versus ‘away’ arbuscular mycorrhizal fungi (AMF) or non‐AMF microbes in two separate experiments using five and eight plant species, respectively. We hypothesized that plants in monocultures may be selected for better defence and better performance in association with rhizosphere microbial communities compared with plants in mixtures. Monoculture and mixture plants significantly differed in their above‐ground phenotypes. As predicted, plant traits related to defence (greater leaf mass per area and leaf dry matter content, reduced leaf damage) were more pronounced in monoculture plants in both experiments. Effects of the rhizosphere microbial communities, which generally enhanced plant growth, tended to be species‐specific. Significant three‐way interactions between diversity‐driven selection, AMF treatment and plant species showed that home versus away effects could be positive or negative, depending on plant species. We conclude that long‐term differences in plant diversity lead to selection for altered plant phenotypes. Such differences may be further modified in association with the AMF microbial communities derived from the different plant diversity treatments, but often outcomes are species‐specific. This suggests that plant species differ in their capacity to respond to diversity loss and associated changes in rhizosphere microbial communities, making it complicated to predict community‐level responses to such loss

Ontology and Integrative Research on Global Environmental Change: Towards a Critical GEC Science

This paper addresses 'integration' at the level of ontology to reflect on the conception and conduct of integrative research in Global Environmental Change (GEC) science. First, it outlines how the Earth system has become the dominant conceptual framework within which to approach GEC, marginalizing other ways of understanding the world. The paper argues that in order to grasp GEC and develop more effective responses to it, it is necessary to move beyond the singular ontology offered by the Earth system and engage with plural ontologies. Second, the paper highlights that scientific knowledge is inherently situated within networks of social and institutional power and oriented towards various social ends, and that as a consequences GEC science needs to reflect more deeply on the politics of its own knowledge production and its relationship to the policy sphere. In conclusion the paper calls for a more critical GEC science that builds these reflections into its scientific practices, and provides some leading questions that integrative research initiatives can use to guide self-reflexive research practices

Community evolution increases plant productivity at low diversity

Species extinctions from local communities negatively affect ecosystem functioning. Ecological mechanisms underlying these impacts are well studied, but the role of evolutionary processes is rarely assessed. Using a long‐term field experiment, we tested whether natural selection in plant communities increased biodiversity effects on productivity. We re‐assembled communities with 8‐year co‐selection history adjacent to communities with identical species composition but no history of co‐selection (‘naïve communities’). Monocultures, and in particular mixtures of two to four co‐selected species, were more productive than their corresponding naïve communities over 4 years in soils with or without co‐selected microbial communities. At the highest diversity level of eight plant species, no such differences were observed. Our findings suggest that plant community evolution can lead to rapid increases in ecosystem functioning at low diversity but may take longer at high diversity. This effect was not modified by treatments simulating co‐evolutionary processes between plants and soil organisms