Chapter 17
Diversity–Function Relationships
and the Underlying Ecological Mechanisms
in Host-Associated Microbial Communities
Catalina Cuellar-Gempeler
Abstract Microbes have colonized, exploited, and inhabited animal and plant
tissues since these macroorganisms first appeared on Earth. The resulting host–
microbe interactions have far reaching consequences for animal and plant ecology
and evolution. However, how ecological mechanisms maintain microbial functions
beneficial for the host is still an open question. While some hosts keep diverse
communities, others limit membership to very few, functionally efficient, taxa. Here,
I outline the broad range of diversity–function relationships in host-associated
microbial communities and propose two approaches based on ecological theory to
better understand how and when to expect diversity to result in function. Specifically, I combine models from the Biodiversity-Ecosystem Function (BEF) literature
and assembly processes with evidence from host-associated microbial communities.
If we expand our perspective of diversity–function relationships, we will improve
our ability to predict the effect of environmental change on microbiomes and to
manage microbes for the benefit of human health and agriculture. Importantly, we
may get closer to answering whether microbes or their hosts are in control of the
biosphere.
17.1 Introduction
Since the origin of life, microorganisms have altered the environment by regulating
the availability of oxygen, nitrogen, and other resources (Gruber and Galloway
2008; Van Der Heijden et al. 2008; Falkowski et al. 2008), influencing the evolutionary trajectories of most metazoan groups (Yeoman et al. 2011; Fitzpatrick et al.
2018). In fact, Earth had been ecologically dominated by bacteria for over 3 billion
years before the first animals and plants (Knoll 2003). Moreover, bacteria have
colonized, exploited, and inhabited animal and plant tissues since the inception of
Kingdoms Animalia and Plantae (Dethlefsen et al. 2007; Krings et al. 2007;
C. Cuellar-Gempeler (*)
Department of Biological Sciences, Humboldt State University, Arcata, CA, USA
e-mail: cc349@humboldt.edu
© Springer Nature Switzerland AG 2021
C. J. Hurst (ed.), Microbes: The Foundation Stone of the Biosphere, Advances in
Environmental Microbiology 8, https://doi.org/10.1007/978-3-030-63512-1_17
297
Diversity–Function Relationships
and the Underlying Ecological Mechanisms
in Host-Associated Microbial Communities
Catalina Cuellar-Gempeler
Abstract Microbes have colonized, exploited, and inhabited animal and plant
tissues since these macroorganisms first appeared on Earth. The resulting host–
microbe interactions have far reaching consequences for animal and plant ecology
and evolution. However, how ecological mechanisms maintain microbial functions
beneficial for the host is still an open question. While some hosts keep diverse
communities, others limit membership to very few, functionally efficient, taxa. Here,
I outline the broad range of diversity–function relationships in host-associated
microbial communities and propose two approaches based on ecological theory to
better understand how and when to expect diversity to result in function. Specifically, I combine models from the Biodiversity-Ecosystem Function (BEF) literature
and assembly processes with evidence from host-associated microbial communities.
If we expand our perspective of diversity–function relationships, we will improve
our ability to predict the effect of environmental change on microbiomes and to
manage microbes for the benefit of human health and agriculture. Importantly, we
may get closer to answering whether microbes or their hosts are in control of the
biosphere.
17.1 Introduction
Since the origin of life, microorganisms have altered the environment by regulating
the availability of oxygen, nitrogen, and other resources (Gruber and Galloway
2008; Van Der Heijden et al. 2008; Falkowski et al. 2008), influencing the evolutionary trajectories of most metazoan groups (Yeoman et al. 2011; Fitzpatrick et al.
2018). In fact, Earth had been ecologically dominated by bacteria for over 3 billion
years before the first animals and plants (Knoll 2003). Moreover, bacteria have
colonized, exploited, and inhabited animal and plant tissues since the inception of
Kingdoms Animalia and Plantae (Dethlefsen et al. 2007; Krings et al. 2007;
C. Cuellar-Gempeler (*)
Department of Biological Sciences, Humboldt State University, Arcata, CA, USA
e-mail: cc349@humboldt.edu
© Springer Nature Switzerland AG 2021
C. J. Hurst (ed.), Microbes: The Foundation Stone of the Biosphere, Advances in
Environmental Microbiology 8, https://doi.org/10.1007/978-3-030-63512-1_17
297