We will focus on general aspects of the coupling of community assembly to spatial pattern formation, expected to be found in a variety of distinct ecosystems that share the capability of responding to an environmental stress by spatial patterning. To this end, we will first develop conceptual models that lend themselves to numerical bifurcation analysis and singular perturbation analysis, besides direct numerical simulations. Predictions of these analyses will then be tested on more elaborate system-specific models and confronted with empirical studies. In developing the models, we will use a trait-based approach, focusing on functional groups of species that share similar values of selected functional traits. We will further focus on cases where the functional traits are in trade-off relations, e.g. a trade-off between investment of plants in growing taller and its investment in tolerating environmental stress. The subsequent models typically consist of a biomass equation in the composed physical-trait space, coupled to  resource equations in the physical space. Their solutions provide information about the time development and asymptotic behaviours of three community-level properties – composition, functional diversity and total biomass – and their dependence on environmental conditions (Bera et al. 2021). Using these models we will investigate the reciprocal relationships between pattern formation and community assembly. That is, how the different pathways of ecosystem response by spatial patterning (shifts to longer-wavelength patterns, morphology changes) affect community structure, and how community reassembly feeds back on patterns by changing the Busse balloon and thus the capacity to evade tipping. We will study coexistence states and their potential to increase functional diversity by niche differentiation, and traveling-wave patterns where the transient nature of the local dynamics involves community assembly and re-assembly processes.