Macroecology & biodiversity

An overarching theme of my research is  discovering general large-scale and cross-scale ecological patterns  and elucidating their causes and consequences, which is the field of macroecology.   A substantial portion of this research centers around understanding patterns of biodiversity, which I highlight below.

 The Equilibrium Theory of Biodiversity Dynamics

Over the last eight years , in collaboration with David Storch from the Center for Theoretical Studies in Prague, I have been developing a general theory of biodiversity patterns and dynamics called the Equilibrium Theory of Biodiversity Dynamics. This theoretical framework sheds light on the role of extinction, speciation, energy, and the biodiversity-ecosystem function relationship in driving variation in species richness across space and time. such as the latitudinal diversity gradient and patterns observed fossil time series. And it shows that the positive and non-linear effects of species richness on ecosystem functioning can lead to tipping points and alternative stables states in the dynamics of ecosystems.

Okie, J.G. and D. Storch. 2025. The Equilibrium Theory of Biodiversity Dynamics: A General Framework for Scaling Species Richness and Community Abundance along Environmental Gradients. American Naturalist 205(1). DOI: 10.1086/733103.

Storch, D., I. Simova,  J. Smyčka, E. Bohdalková, A. Toszogyova, J.G. Okie. 2022. Biodiversity dynamics in the Anthropocene: How human activities change equilibria of species richness. Ecography 44:1-19.

Storch, D., E. and J.G. Okie. 2019. The carrying capacity for species richness. Global Ecology and Biogeography 28:1519-1532.

Storch, D., E. Bohdalková, and J.G. Okie. 2018. The more-individuals hypothesis revisited: the role of community abundance in species richness regulation and the productivity-diversity relationship. Ecology Letters 21: 930-937. (Supporting Online Material). 

The metabolic-environmental filtering theory of biodiversity

I've also worked on developing and testing theory on patterns in local biodiversity that integrates environmental filtering processes (i.e., niche-based community assembly) with metabolic theory. This theory predicts how alpha and beta diversity should change along gradients of temperature, pH, and other environmental variables. I've evaluated the theory with data on the microbial diversity of soils along an elevational gradient of a mountainside in the McMurdo Dry Valleys of Antarctica, as well as soils spanning a 3000 km latitudinal gradient.

Bo Wu, F. Liu, M. D. Weiser, D. Ning, J. G. Okie, L. Shen, B. Chai, J. Li, Y. Deng, K. Feng, L. Wu, S. Chen, J. Zhou, and Z. He. Temperature determines the diversity and structure of N2O-reducing microbial assemblages. Functional Ecology 32: 1867-1878. 

Okie, J.G., D.J. Van Horn, D. Storch, J.E. Barrett, M.N. Gooseff, L. Kopsova, and C.D. Takacs-Vesbach. 2015. Niche and metabolic principles explain patterns of diversity and distribution: theory and a case study with soil bacterial communities. Proc. Roc. Soc. B 282:20142630.  

Scientific Figure  Examples

From Okie et al. (2015):