title: Spectral analysis unmasks synchronous and compensatory dynamics in plankton communities.
abstract: Community biomass is often less variable than the biomasses of populations within the community, yet attempts to implicate compensatory dynamics between populations as a cause of this relationship often fail. In part, this may be due to the lack of appropriate metrics for variability, but there is also great potential for large-scale processes such as seasonality or longer-term environmental change to obscure important dynamics at other temporal scales. In this study, we apply a scale-resolving method to long-term plankton data, to identify the specific temporal scales at which community-level variability is influenced by synchrony or compensatory dynamics at the population level. We show that variability at both the population and community level is influenced strongly by a few distinct temporal scales: in phytoplankton, ciliate, rotifer, and crustacean communities, synchronous dynamics are predominant at most temporal scales. However, in phytoplankton and crustacean communities, compensatory dynamics occur at a sub-annual scale (and at the annual scale in crustaceans) leading to substantial reductions in community-level variability. Aggregate measures of population and community variability do not detect compensatory dynamics in these communities; thus, resolving their scale dependence unmasks dynamics that are important for community stability in this system. The methods and results presented herein will ultimately lead to a better understanding of how stability is achieved in communities.
authors.affiliation: Department of Biology, McGill University, Montreal, Quebec, Canada. dvasseur@ucalgary.ca
authors.forename: David A
authors.initials: DA
authors.lastname: Vasseur
authors.forename: Ursula
authors.initials: U
authors.lastname: Gaedke
mesh_terms: D000818:Animals; D018533:Biomass; D017753:Ecosystem; D008386:Marine Biology / Q000379:methods; D009792:Oceans and Seas; D010839:Phytoplankton / Q000502:physiology; D010933:Plankton / Q000502:physiology*; D011156:Population Density; D011157:Population Dynamics; D012621:Seasons; D013057:Spectrum Analysis / Q000379:methods*; D013997:Time Factors