TY - JOUR A1 - Emary, Clive A1 - Malchow, Anne-Kathleen T1 - Stability-instability transition in tripartite merged ecological networks JF - Journal of mathematical biology N2 - Although ecological networks are typically constructed based on a single type of interaction, e.g. trophic interactions in a food web, a more complete picture of ecosystem composition and functioning arises from merging networks of multiple interaction types. In this work, we consider tripartite networks constructed by merging two bipartite networks, one mutualistic and one antagonistic. Taking the interactions within each sub-network to be distributed randomly, we consider the stability of the dynamics of the network based on the spectrum of its community matrix. In the asymptotic limit of a large number of species, we show that the spectrum undergoes an eigenvalue phase transition, which leads to an abrupt destabilisation of the network as the ratio of mutualists to antagonists is increased. We also derive results that show how this transition is manifest in networks of finite size, as well as when disorder is introduced in the segregation of the two interaction types. Our random-matrix results will serve as a baseline for understanding the behaviour of merged networks with more realistic structures and/or more detailed dynamics. KW - Random matrices KW - Phase transition KW - Random eigenvalues KW - Population dynamics KW - Community matrix KW - Ecological network Y1 - 2022 U6 - https://doi.org/10.1007/s00285-022-01783-7 SN - 0303-6812 SN - 1432-1416 VL - 85 IS - 3 PB - Springer CY - Heidelberg ER -