Life table response experiment
For species with significant differences in population growth rates with and without neighbours (A. calendula and P. debilis ), we used life table response experiment (LTRE) analysis to decompose differences in population growth rates into contributions from each transition between life stages. We modelled a simple two-stage life cycle of seeds and adults with a one-year time step estimated in Spring, before seed rain (Figure S2). We also included seed dormancy probabilities to incorporate the potentially important role of the seed bank (Nguyen et al. 2019, see Supplementary Methods). Using the “exactLTRE” package (Hernández et al. 2023), we carried out directional fixed design LTRE using intrinsic lambda (in the absence of neighbours) as the reference matrix compared to lambda in the presence of neighbours as the treatment.