Modelling microbial and plant diversity in multi-species agroecosystems: the DIMIVEA project
Abstract
Biogeochemical modelling is used to assess the impact of agricultural activities and climate on ecosystem carbon (C) and nutrient cycles and associated services or disservices, such as biomass production, C emissions/storage and nutrient retention. From an agroecosystem perspective, DIMIVEA is interested in the characterization and dynamic simulation of: i) the physico-chemical and
biochemical properties of soils, ii) the functional diversity of plant and soil microbial communities, and iii) their role in the provision of ecosystem services. The simulation of multi-species systems (grasslands, forests, multi-species cropping systems) ensures a detailed representation of the coupled
C-N cycles, but the models used remain simplified insofar as biological diversity is reduced to simplistic patterns of interactions with the environment. The creation of simulators based on the information provided by diversity attempts to overcome the paradigm of condensing biological diversity into constant parameters. This opens up new avenues of research to be explored to explain the
synchronisation of nutrient demand and supply in multi-species systems by modelling some plant and microbial diversity. By focusing on the characteristics of plant and microbial communities in mixed vegetation canopies, the consortium aims to provide a conceptual framework for extending the potential of models towards a reliable estimation of the ecological processes that support the
ecosystem services provided by these vegetal communities. Moving towards the creation of explicit, dynamic and integrated simulators of microbial and plant diversity, DIMIVEA represents a new paradigm that implies that related aspects of biological diversity cannot be ignored in agroecosystem modelling studies.
DIMIVEA integrates different experiences and knowledge in an attempt to model the ecological organisations that enable natural ecosystems and certain agro-systems to be productive, multifunctional (ensuring C storage, purification of drainage water, improvement of soil quality) and158 low-input. The aim is also to identify the ecological organisations to be favoured according to local soil
and climate contexts, and to propose agricultural practices likely to favour them in agro-systems. For its reflections and conceptualisations, the consortium relies on the aggregate microbial modelling (i.e. stocking/de-stocking microbes) and the experimental devices of the AGROECOseqC project of the European Joint Programme Cofund on Agricultural Soil Management (EJP SOIL). The partnership is committed to organising and leading dedicated workshops within the framework of scientific events such as international conferences and study days, and to progressing towards the writing of a synthesis and positioning article, envisaged as the horizon of a collective reflection in addition to the
production of model prototypes.