Hill–Chao numbers allow decomposing gamma multifunctionality into alpha and beta components
Anne Chao, Chun‐Huo Chiu, Kai‐Hsiang Hu, Fons van der Plas, Marc W. Cadotte, Oliver Mitesser, Simon Thorn, Akira Mori, Michael Scherer‐Lorenzen, Nico Eisenhauer, Claus Bässler, Benjamin M. Delory, Heike Feldhaar, Andreas Fichtner, Torsten Hothorn, Marcell K. Peters, Kerstin Pierick, Goddert von Oheimb, Jörg Müller
Abstract
Biodiversity-ecosystem functioning (BEF) research has provided strong evidence and mechanistic underpinnings to support positive effects of biodiversity on ecosystem functioning, from single to multiple functions. This research has provided knowledge gained mainly at the local alpha scale (i.e. within ecosystems), but the increasing homogenization of landscapes in the Anthropocene has raised the potential that declining biodiversity at the beta (across ecosystems) and gamma scales is likely to also impact ecosystem functioning. Drawing on biodiversity theory, we propose a new statistical framework based on Hill-Chao numbers. The framework allows decomposition of multifunctionality at gamma scales into alpha and beta components, a critical but hitherto missing tool in BEF research; it also allows weighting of individual ecosystem functions. Through the proposed decomposition, new BEF results for beta and gamma scales are discovered. Our novel approach is applicable across ecosystems and connects local- and landscape-scale BEF assessments from experiments to natural settings.