Polyrhythmic foraging and competitive coexistence

Stability of consumer-resource interactions in periodic environments

Periodic fluctuations in abiotic conditions are ubiquitous across a range of temporal scales and regulate the structure and function of ecosystems through dynamic biotic responses that are adapted to these external forces. Research has suggested that certain environmental signatures may play a crucial role in the maintenance of biodiversity and the stability of food webs, while others argue that coupled oscillators ought to promote chaos. As such, numerous uncertainties remain regarding the intersection of temporal environmental patterns and biological responses, and we lack a general understanding of the implications for food web stability. Alarmingly, global change is altering the nature of both environmental rhythms and biological rates. Here, we develop a general theory for how continuous periodic variation in productivity, across temporal scales, influences the stability of consumer-resource interactions: a fundamental building block of food webs. Our results suggest that consumer-resource dynamics under environmental forcing are highly complex and depend on asymmetries in both the speed of forcing relative to underlying dynamics and in local stability properties. These asymmetries allow for environmentally driven stabilization under fast forcing, relative to underlying dynamics, as well as extremely complex and unstable dynamics at slower periodicities. Our results also suggest that changes in naturally occurring periodicities from climate change may lead to precipitous shifts in dynamics and stability.

Microbial coexistence in the rhizosphere and the promotion of plant stress resistance: A review

Plants can recruit soil microorganisms into the rhizosphere when experiencing various environmental stresses, including biotic (e.g., insect pests) and abiotic (e.g., heavy metal pollution, droughts, floods, and salinity) stresses. However, species coexistence in plant resistance has not received sufficient attention. Current research on microbial coexistence is only at the community scale, and there is a limited understanding of the interaction patterns between species, especially microbe‒microbe interactions. The relevant interaction patterns are limited to a few model strains. The coexisting microbial communities form a stable system involving complex nutritional competition, metabolic exchange, and even interdependent interactions. This pattern of coexistence can ultimately enhance plant stress tolerance. Hence, a systematic understanding of the coexistence pattern of rhizosphere microorganisms under stress is essential for the precise development and utilization of synthetic microbial communities and the achievement of efficient ecological control. Here, we integrated current analytical methods and introduced several new experimental methods to elucidate rhizosphere microbial coexistence patterns. Some advancements (e.g., network analysis, coculture experiments, and synthetic communities) that can be applied to plant stress resistance are also updated. This review aims to summarize the key role and potential application prospects of microbial coexistence in the resistance of plants to environmental stresses. Our suggestions, enhancing plant resistance with coexisting microbes, would allow us to gain further knowledge on plant-microbial and microbial-microbial functions, and facilitate translation to more effective measures.

Phenological Coadaptation Can Stabilize Predator–Prey Dynamics

In recent years, phenology – the seasonal timing of biological life cycles – has received increasing attention as climate change threatens to shift phenology. Phenology is crucial to the life cycle of organisms and their interactions with intimate partner species; hence, phenology has important fitness consequences suggesting that phenology can change through adaptive processes caused by species interaction. However, to date, there is limited understanding of how phenological adaptation occurs among interacting species and consequently affects ecological population dynamics. In this study, a phenological predator–prey co-adaptation model was evaluated to determine how adaptive phenological changes occur in prey and predator and how phenological coadaptation affects their coexistence. Population fluctuations tend to decrease and become stabilized when adaptation occurs rapidly. Furthermore, when adaptation is slow, predator–prey dynamics can be stabilized or destabilized depending on the initial difference in phenological timing between species. These results suggest that phenology shaped by slow coevolution can shift with changes in activity timing caused by environmental changes and simultaneously alter the stability of predator–prey dynamics. In contrast, phenology caused by rapid adaptation, such as phenotypic plasticity, may be robust to environmental change and maintain the stability of predator–prey dynamics. Understanding the types of adaptative processes that shape species phenologies may be crucial for predicting the ecological effects of climate change.