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Several safe boundaries of critical Earth system processes have already been crossed due to human perturbations; not accounting for their interactions may further narrow the safe operating space for humanity. Using expert knowledge elicitation, we explored interactions among seven variables representing Earth system processes relevant to food production, identifying many interactions little explored in Earth system literature. We found that green water and land system change affect other Earth system processes strongly, while land, freshwater and ocean components of biosphere integrity are the most impacted by other Earth system processes, most notably blue water and biogeochemical flows. We also mapped a complex network of mechanisms mediating these interactions and created a future research prioritization scheme based on interaction strengths and existing knowledge gaps. Our study improves the understanding of Earth system interactions, with sustainability implications including improved Earth system modelling and more explicit biophysical limits for future food production.

Herbivory is a key process on coral reefs, which, through grazing of algae, can help sustain coral‐dominated states on frequently disturbed reefs and reverse macroalgal regime shifts on degraded ones. Our understanding of herbivory on reefs is largely founded on feeding observations at small spatial scales, yet the biomass and structure of herbivore populations is more closely linked to processes which can be highly variable across large areas, such as benthic habitat turnover and fishing pressure. Though our understanding of spatiotemporal variation in grazer biomass is well developed, equivalent macroscale approaches to understanding bottom‐up and top‐down controls on herbivory are lacking. Here, we integrate underwater survey data of fish abundances from four Indo‐Pacific island regions with herbivore feeding observations to estimate grazing rates for two herbivore functions, cropping (which controls turf algae) and scraping (which promotes coral settlement by clearing benthic substrate), for 72 coral reefs. By including a range of reef states, from coral to algal dominance and heavily fished to remote wilderness areas, we evaluate the influences of benthic habitat and fishing on the grazing rates of fish assemblages. Cropping rates were primarily influenced by benthic condition, with cropping maximized on structurally complex reefs with high substratum availability and low macroalgal cover. Fishing was the primary driver of scraping function, with scraping rates depleted at most reefs relative to remote, unfished reefs, though scraping did increase with substratum availability and structural complexity. Ultimately, benthic and fishing conditions influenced herbivore functioning through their effect on grazer biomass, which was tightly correlated to grazing rates. For a given level of biomass, we show that grazing rates are higher on reefs dominated by small‐bodied fishes, suggesting that grazing pressure is greatest when grazer size structure is truncated. Stres

Without drastic efforts to reduce carbon emissions and mitigate globalized stressors, tropical coral reefs are in jeopardy. Strategic conservation and management requires identification of the environmental and socioeconomic factors driving the persistence of scleractinian coral assemblages—the foundation species of coral reef ecosystems. Here, we compiled coral abundance data from 2,584 Indo-Pacific reefs to evaluate the influence of 21 climate, social and environmental drivers on the ecology of reef coral assemblages. Higher abundances of framework-building corals were typically associated with: weaker thermal disturbances and longer intervals for potential recovery; slower human population growth; reduced access by human settlements and markets; and less nearby agriculture. We therefore propose a framework of three management strategies (protect, recover or transform) by considering: (1) if reefs were above or below a proposed threshold of >10% cover of the coral taxa important for structural complexity and carbonate production; and (2) reef exposure to severe thermal stress during the 2014–2017 global coral bleaching event. Our findings can guide urgent management efforts for coral reefs, by identifying key threats across multiple scales and strategic policy priorities that might sustain a network of functioning reefs in the Indo-Pacific to avoid ecosystem collapse.

Interdisciplinary research and collaborations are essential to disentangle complex and wicked global socio-ecological challenges. However, institutional structures and practices to support interdisciplinary research are still developing and a shared understanding on how best to develop effective interdisciplinary researchers (particularly at early career stages) is lacking. Barriers to interdisciplinary approaches, which include diverse disciplinary ‘languages’, research time constraints and limited guidance on how to achieve interdisciplinarity in practice, further challenge this understanding. To help overcome these barriers, this paper provides practical advice for early career researchers and their mentors, as well as senior researchers and lab leaders, in the form of 10 tips: ‘Develop an area of expertise’; ‘Learn new languages’; ‘Be open-minded’; ‘Be patient’; ‘Embrace complexity’; ‘Collaborate widely; ‘Push your boundaries’; ‘Consider if you will engage in interdisciplinary research’; ‘Foster interdisciplinary culture’; and ‘Champion interdisciplinary researchers’. They are presented here to empower present and future generations of interdisciplinary researchers in their endeavour to solve contemporary socio-ecological challenges worldwide.

The enthalpies of extraction of lanthanide ions by bis(2-ethylhexyl) phosphoric acid (HDEHP) from aqueous nitrate solutions were determined using isothermal titration microcalorimetry. The solvent extraction system was selected as a model for developing a direct method for the calorimetric investigation of the thermochemistry of liquid-liquid distribution reactions. In order to provide a quantitative validation for a two-phase calorimetric technique, the enthalpy of extraction of Eu(III) by HDEHP was also determined applying the more conventional method of van't Hoff analysis of temperature-dependent extraction equilibrium constants. There was good agreement between the thermodynamic parameters determined by the two techniques. The extraction enthalpies were correlated with reported free energies of extraction of the lanthanides to investigate the extraction entropy patterns across the lanthanide series. The observed trends were in agreement with previous investigations into the interaction between the representative ligands and the lanthanide ions across the series., The enthalpies of extraction of lanthanide ions by bis(2-ethylhexyl) phosphoric acid (HDEHP) from aqueous nitrate solutions were determined using isothermal titration microcalorimetry. The solvent extraction system was selected as a model for developing a direct method for the calorimetric investigation of the thermochemistry of liquid-liquid distribution reactions. In order to provide a quantitative validation for a two-phase calorimetric technique, the enthalpy of extraction of Eu(III) by HDEHP was also determined applying the more conventional method of van't Hoff analysis of temperature-dependent extraction equilibrium constants. There was good agreement between the thermodynamic parameters determined by the two techniques. The extraction enthalpies were correlated with reported free energies of extraction of the lanthanides to investigate the extraction entropy patterns across the lanthanide series. The observed trends were in agreement with previous investigations into the interaction between the representative ligands and the lanthanide ions across the series.

The simultaneous extraction and recovery is discussed of Cs(+) and Sr(2+) in nuclear applications using anionic cobalt bis(dicarbollide) with synergistic additives such as polyethylene glycol (PEG). The extraction of Cs from nitrate media was investigated using chlorinated cobalt dicarbollide (HCCD) dissolved in the polar phenyl trifluoromethyl sulphone diluent, alone or with PEG. The results confirmed that Cs(+) phase transfer is based solely on cation exchange of H(+) for Cs(+) and that a previously reported nitrate dependency arises from the non-ideal behaviour of solute species. The enthalpy and entropy of the system calculated using appropriate corrections to the van't Hoff analysis were in good agreement with calorimetry results. Synergistic extraction of Cs(+) by HCCD and PEG did not occur. Although there is interaction between HCCD and PEG, and it is known that the interaction is responsible for the extraction of Sr(2+), the association is detrimental for the extraction of Cs(+) since a complex is formed which makes the HCCD unavailable for Cs(+) complexation., The simultaneous extraction and recovery is discussed of Cs(+) and Sr(2+) in nuclear applications using anionic cobalt bis(dicarbollide) with synergistic additives such as polyethylene glycol (PEG). The extraction of Cs from nitrate media was investigated using chlorinated cobalt dicarbollide (HCCD) dissolved in the polar phenyl trifluoromethyl sulphone diluent, alone or with PEG. The results confirmed that Cs(+) phase transfer is based solely on cation exchange of H(+) for Cs(+) and that a previously reported nitrate dependency arises from the non-ideal behaviour of solute species. The enthalpy and entropy of the system calculated using appropriate corrections to the van't Hoff analysis were in good agreement with calorimetry results. Synergistic extraction of Cs(+) by HCCD and PEG did not occur. Although there is interaction between HCCD and PEG, and it is known that the interaction is responsible for the extraction of Sr(2+), the association is detrimental for the extraction of Cs(+) since a complex is formed which makes the HCCD unavailable for Cs(+) complexation.