Conclusion
By bridging the bottom-up energetic processes and top-down cascading effects, our study contributes to reconciling food web studies using different currencies, e.g., energy and population size. Our findings advocate an energetic perspective in ecosystem management based on trophic cascade theory, where strategies should be designed according to the energetic dynamics of the focal system (Barnes et al. 2018). Our study serves as a benchmark for future research on more complex ecosystems over larger scales. In particular, in diverse food webs, energy transfer efficiencies between trophic levels are jointly determined by herbivore diversity and composition (e.g., in our experiment), plant (Behl et al. 2012; Buzhdygan et al.2020) or predator diversity (Griffin et al. 2008), as well as abiotic factors (Barneche et al. 2021; Eddy et al. 2021). Disentangling the influences of these processes is challenging but key to understanding the feedback between energetic processes and trophic interactions in natural ecosystems. Moreover, over long timescales, eco-evolutionary dynamics may alter species properties, e.g., anti-predation trait (Vestheim & Kaartvedt 2006) and thus food web energetics. Empirical and theoretical studies with respect to these directions should further contribute to a mechanistic understanding of the responses of multitrophic communities to environmental changes.