We are developing a next-generation model of the terrestrial biosphere and its interactions with the carbon cycle, water cycle and climate. Our revolutionary approach will lead to ecosystem models that rest on firm theoretical and empirical foundations, and eventually, more reliable projections of future climates and a newfound ability to address issues in sustainability, including the potential to maintain the biosphere’s capacity to regulate the carbon cycle while benefiting human well-being and development.

At the heart of the LEMONTREE project is Eco-evolutionary optimality theory.

Eco-evolutionary optimality (EEO) draws on the power of natural selection to eliminate traits or behaviours that are uncompetitive in a given environment. The development of EEO hypotheses are based on identifying trade-offs that organisms are required to make, for example in land plants between CO2 uptake and water loss.

The core of modelling EEO is therefore the mechanistic links between plant functional traits, their implications for resource demand and acquisition and biogeochemical cycling, and their effect on the plant’s competitiveness.

EEO approaches have primarily been used to analyse and model plant processes at the leaf level, including photosynthesis and primary production, dark respiration, stomatal behaviour, and the leaf economic spectrum.

At the whole plant level, EEO approaches are providing a way to explain the coordination of photosynthetic and hydraulic traits, and this work will ultimately enable us to model the water and carbon cycles in a simple but integrated way.