The Twin Ecosystems Project

The Twin Ecosystems Project: A new capability for field and laboratory ecosystems coupled by sensor networks and autonomous controls Statement of purpose: This project will develop ‘twin’ lab and field ecosystems to create a new capability that scales-down field observations inside fabricated ecosystems to uncover plant- microbial system responses to drought. The ‘twins’ will be integrated using sensor networks and interrogated through the development and application of novel in situ sensors, imaging, Omics analysis, and autonomous controls. Background: Discovering the fundamental biology that regulates ecosystem responses to changing climate is vital for predicting and managing ecosystem outcomes. To accurately identify biological drivers of ecosystem responses, technical approaches are needed to scale-down field observations to determine causal mechanisms as highlighted in recent DOE reports [1,2,3]. For example, such studies are needed to understand how plants, microbes, and communities of organisms adapt and respond to changing conditions [2] and how microbial communities impact plant performance and biogeochemical cycles [2, 3]. Summary: The goal of the TWIN ecosystem project (‘TWINS’) is to pilot laboratory and field ‘twin’ ecosystems that use sensors and autonomous controls to test the hypothesis that compositional changes in root exudates during drought stress select for beneficial rhizosphere microbes. To do this, TWINS brings together unique resources in fabricated ecosystems at Berkeley Lab, field ecology expertise and resources at PNNL, sensor and omics expertise at EMSL, lab automation and omics expertise at JGI, and the mathematical and computational expertise of CAMERA. TWINS builds on existing resources for investigating molecular interactions in the rhizosphere to gain insights into whether tall wheatgrass exudates select rhizosphere communities in response to drought, enabling us to leverage an existing drought study at PNNL using tall wheatgrass (Thinopyrum ponticum). Tall wheatgrass is a widely distributed species adapted to dry northern latitudes that is being considered as a bioenergy feedstock on marginal lands. It is known to develop soil “resource islands” or “hot spots” that may impose heterogeneous spatial distribution of important plant exudates impacting the soil microbiome, especially in response to drought when plants may differentially allocate photosynthates to particular roots. The field ‘twin’ will define climate conditions and hyperspectral signatures of drought stress enabling the lab ‘twin’ to characterize the composition, localization, and dynamics of microbes and exudates—providing powerful environmental controls and measurements which are essentially not possible in the field. TWINS has three Aims: Aim 1 will develop novel biosensors and integrate sensor platforms that measure plant-microbe response to drought. Aim 2 will pioneer integrated plant-microbe experiments coupling sensing, imaging, analysis, sampling, and interventions in fabricated ecosystems, and use these to autonomously control and capture key plant and microbial activities in the rhizosphere. Aim 3 will use these new integrated capabilities in the lab and field twins to test novel biosensors and investigate plant-microbe responses to drought stress.