The Beauty of Graph Theory

Interaction network structure explains species’ temporal persistence in empirical plant–pollinator communities

Domínguez-Garcia et al., 2024.

Despite clear evidence that some pollinator populations are declining, our ability to predict pollinator communities prone to collapse or species at risk of local extinction is remarkably poor. Here, we develop a model grounded in the structuralist approach that allows us to draw sound predictions regarding the temporal persistence of species in mutualistic networks. Using high-resolution data from a six-year study following 12 independent plant–pollinator communities, we confirm that pollinator species with more persistent populations in the field are theoretically predicted to tolerate a larger range of environmental changes. Persistent communities are not necessarily more diverse, but are generally located in larger habitat patches, and present a distinctive combination of generalist and specialist species resulting in a more nested structure, as predicted by previous theoretical work. Hence, pollinator interactions directly inform about their ability to persist, opening the door to use theoretically informed models to predict species’ fate within the ongoing global change.

https://n9.cl/070uj

Despite clear evidence that some pollinator populations are declining, our

ability to predict pollinator communities prone to collapse or species at risk

of local extinction is remarkably poor. Here, we develop a model grounded

in the structuralist approach that allows us to draw sound predictions

regarding the temporal persistence of species in mutualistic networks.

Using high-resolution data from a six-year study following 12 independent

plant–pollinator communities, we confirm that pollinator species with more

persistent populations in the field are theoretically predicted to tolerate

a larger range of environmental changes. Persistent communities are not

necessarily more diverse, but are generally located in larger habitat patches,

and present a distinctive combination of generalist and specialist species

resulting in a more nested structure, as predicted by previous theoretical

work. Hence, pollinator interactions directly inform about their ability to

persist, opening the door to use theoretically informed models to predict

species’ fate within the ongoing global change.

Despite clear evidence that some pollinator populations are declining, our

ability to predict pollinator communities prone to collapse or species at risk

of local extinction is remarkably poor. Here, we develop a model grounded

in the structuralist approach that allows us to draw sound predictions

regarding the temporal persistence of species in mutualistic networks.

Using high-resolution data from a six-year study following 12 independent

plant–pollinator communities, we confirm that pollinator species with more

persistent populations in the field are theoretically predicted to tolerate

a larger range of environmental changes. Persistent communities are not

necessarily more diverse, but are generally located in larger habitat patches,

and present a distinctive combination of generalist and specialist species

resulting in a more nested structure, as predicted by previous theoretical

work. Hence, pollinator interactions directly inform about their ability to

persist, opening the door to use theoretically informed models to predict

species’ fate within the ongoing global change.

Lynn Margulis presents the Gaia Hypothesis at NASA (1984)

Disruption of an ant-plant mutualism shapes interactions between lions and their primary prey

Kamaru et al., 2024

Mutualisms often define ecosystems, but they are susceptible to human activities. Combining experiments, animal tracking, and mortality investigations, we show that the invasive big-headed ant (Pheidole megacephala) makes lions (Panthera leo) less effective at killing their primary prey, plains zebra (Equus quagga). Big-headed ants disrupted the mutualism between native ants (Crematogaster spp.) and the dominant whistling-thorn tree (Vachellia drepanolobium), rendering trees vulnerable to elephant (Loxodonta africana) browsing and resulting in landscapes with higher visibility. Although zebra kills were significantly less likely to occur in higher-visibility, invaded areas, lion numbers did not decline since the onset of the invasion, likely because of prey-switching to African buffalo (Syncerus caffer). We show that by controlling biophysical structure across landscapes, a tiny invader reconfigured predator-prey dynamics among iconic species.

https://www.science.org/doi/10.1126/science.adg1464