Herds of wildebeest, schools of herring and various other groups of organisms that live together are not only visually stunning, but capable of supporting complex ecosystems for life, according to a new study by researchers at Oregon State University. maintain diversity and stability.
The study explains that when individuals come together to consume resources as a collective group, the surrounding ecosystem gains resilience and can support a greater variety of species. The study was published in the journal Nature ecology and evolution.
The results could be key advances in learning the process by which living systems exist in balance, where collective behavior is pervasive on the planet, which has a key role in everything from bacterial biofilms to human cities.
These collectives exhibit highly organized large-scale behavioral patterns that emerge spontaneously from localized interactions between nearby individuals. Our question was: what is the meaning of collective behavior in ecosystems?
Ben Dalziel, College of Science, Oregon State University
Dalziel and the team observed the presence of an emergent socio-ecological feedback between the structure and size of collective groups and the level of resources in an ecosystem. This feedback defended the system against crashes. The feedback reduced fluctuations in resource abundance and allowed other consuming species to thrive using the same resource, rather than stronger competitors pushing weaker ones to extinction.
Dalziel, a population biologist, led a collaboration that assessed the ecological significance of collective behavior from the perspective of two enduring ecological puzzles – the plankton paradox and the enrichment paradox.
The enrichment paradox is observed when there is an increase in the availability of food for prey due to enormous and unsustainable growth and destabilization of the predator population. This is observed in a predator-prey model.
The plankton paradox refers to various ecological communities, such as various types of phytoplankton, that thrive even when many other similar species compete for limited resources.
It is not certain that complex ecosystems will be stable – if you simply put a group of species together in an environment, the theory tells us that the result will probably be the collapse of the ecosystem. This means that real ecosystems must have some sort of special sauce that allows them to persist with a wide range of species..
Ben Dalziel, College of Science, Oregon State University
According to the researchers, the collective behavior observed in plants, animals, microorganisms and humans could be a strong ingredient of the sauce.
Dalziel and Mark Novak of the College of Science, James Watson of the Oregon State College of Earth, Ocean, and Atmospheric Sciences, and Stephen Ellner of Cornell University started with a standard model of a simple food web – two “consumers ” generics that feed on a shared resource.
A series of equations demonstrate the multiple variables in the model, such as per capita resource consumption and consumer mortality rate. However, in the current model, consumers vary only in the efficiency with which resources are captured.
Dalziel said:We built simulations in such a way that we could toggle collective behavior on and off without changing anything else in the system. What we found was that adding collective behavior was a game-changer in the simulations – it stabilized ecosystems that, according to ecological and evolutionary theory, should not be stable otherwise..”
The researcher explained that this was a missing piece of the knowledge puzzle. Much work has gone into learning how local individual behavior increases to impact behavior at the group level. The team also studied how these groups process information, but couldn’t find much about why the collective behavior is happening in the first place.
Dalziel describes the results as “good news” which contradicts the negative role played by collective dynamics.
Amid the challenges we face with the spread of misinformation online, which also involves collective dynamics, here is an example where collective behavior plays a fundamental role in sustaining life. And I also think it’s good that an aesthetically striking aspect of ecosystems – flocks of birds, etc. – can also play an important role in their stability and diversity..
Ben Dalziel, College of Science, Oregon State University
The research was supported by the National Science Foundation, DARPA, National Institutes of Health and NASA.
Journal reference:
Dalziel, comics, et al. (2021) Collective behavior can stabilize ecosystems. Nature ecology and evolution. doi.org/10.1038/s41559-021-01517-w.
Source: https://oregonstate.edu/
