Species fluctuations sustained by a cyclic succession at the edge of chaos

Abstract

Although mathematical models and laboratory experiments have shown that species interactions can generate chaos, field evidence of chaos in natural ecosystems is rare. We report on a pristine rocky intertidal community located in one of the world's oldest marine reserves that has displayed a complex cyclic succession for more than 20 y. Bare rock was colonized by barnacles and crustose algae, they were overgrown by mussels, and the subsequent detachment of the mussels returned bare rock again. These processes generated irregular species fluctuations, such that the species coexisted over many generations without ever approaching a stable equilibrium state. Analysis of the species fluctuations revealed a dominant periodicity of about 2 y, a global Lyapunov exponent statistically indistinguishable from zero, and local Lyapunov exponents that alternated systematically between negative and positive values. This pattern indicates that the community moved back and forth between stabilizing and chaotic dynamics during the cyclic succession. The results are supported by a patch-occupancy model predicting similar patterns when the species interactions were exposed to seasonal variation. Our findings show that natural ecosystems can sustain continued changes in species abundances and that seasonal forcing may push these nonequilibrium dynamics to the edge of chaos.chaos | coexistence | cyclic succession | rock-paper-scissors dynamics | rocky intertidal community

Chance, Variation and the Nature of Causality in Ecological Communities

“…The cyclic fluctuations of the populations in this community become irregular through the seasonality of the system and the time needed for the establishment of each of the species. Interestingly, the cyclic replacement is reminiscent of rock-paper-scissor interactions (Benincà et al 2015) but the dynamics do not resemble those of the E. coli strains described above (Kerr et al 2002). The reason might be that with sessile stages but global dispersal of recruits the intertidal community is neither global (leading to the dominance of a single species in the well-mixed flasks), nor completely spatially structured (resulting in balanced chasing at patch edges and overall stability).…”

“…from competition and predation process (Huisman and Weissing 1999). Recently, Benincà et al (2015) demonstrated for the first time that near-chaotic dynamics may occur in the world outside. In an intertidal ecosystem in New Zealand, cyclic replacements occur of barnacles colonizing bare rock, brown alga overgrowing barnacles, mussels settling on barnacles and algae, giving rise to bare rock as the mussels eventually detach.…”

Colonial, more widely distributed and less abundant bird species undergo wider population fluctuations independent of their population trend

“…[11]), and factors affecting this variability, generally classified into environmental effects or endogenous density-dependent processes, are numerous (e.g. [12–19]) and interact in complex ways [20–21]. …”

On The Correlation between Properties of One-Dimensional Mappings of Control Functions and Chaos in a Special Type Delay Differential Equation

“…Анализ таких систем представляет особый интерес, поскольку факторы генерации хаоса заложены в саму основу жизненного цикла клетки. Однако, в отличие от других уровней организации живой природы, для которых существуют убедительные примеры явления хаоса (так функционируют природные экосистемы [12], такой может быть стратегия поиска пищи у моллюска [13], так формируется пигментация у некоторых видов моллюсков [14][15][16], возникают спорадические эпидемии [17] и происходят вспышки численности в популяциях хищников, грызунов, и насекомых [18][19][20][21], так проявляются различные заболевания [22][23][24][25][26][27] и др. ), на внутриклеточном уровне, in vivo, экспериментально доказанных примеров хаоса нет, хотя теоретически он предсказан в различных молекулярно-генетических и метаболических системах [1, 10,11,[28][29][30][31][32][33][34].…”