The role of structured stirring and mixing on gamete dispersal and aggregation in broadcast spawning

SummaryUnderstanding how species and environments respond to global anthropogenic disturbances is one of the greatest challenges for contemporary ecology. The ability to integrate modeling, correlative and experimental approaches within individual research programs will be key to address large-scale, long-term environmental problems. Scale-transition theory (STT) enables this level of integration, providing a powerful framework to link ecological patterns and processes across spatial and temporal scales. STT predicts the large-scale (e.g. regional) behavior of a system on the basis of nonlinear population models describing local (e.g. patch-scale) dynamics and the interaction between these nonlinearities and spatial variation in population abundance or environmental conditions. Here we use STT to predict the dynamics of turf-forming algae on rocky shores at Capraia Island, in the northwest Mediterranean. We developed a model of algal turf dynamics based on density-dependent growth that included the effects of local interactions with canopy algae. The model was parameterized with field data and used to scale up the dynamics of algal turfs from the plot scale (20ϫ20cm) to the island scale (tens of km). The interaction between nonlinear growth and spatial variance in cover of turfing algae emerged as a key term to translate the local dynamics up to the island scale. The model successfully predicted short-term and long-term mean values of turf cover estimated independently from a separate experiment. These results illustrate how STT can be used to identify the relevant mechanisms that drive large-scale changes in ecological communities. We argue that STT can contribute significantly to the connection between biomechanics and ecology, a synthesis that is at the core of the emerging field of ecomechanics.

Section: Discussionmentioning

confidence: 99%

Linking patterns and processes across scales: the application of scale-transition theory to algal dynamics on rocky shores

Benedetti‐Cecchi

Tamburello

Bulleri

et al. 2012

“…there is more gamete-free water (white) than there is water containing gametes. Redrawn from Crimaldi (2012). (C) The intermediate disturbance hypothesis.…”

Section: External Fertilizationmentioning

confidence: 99%

The fallacy of the average: on the ubiquity, utility and continuing novelty of Jensen's inequality

Denny

2017

169

153

Biologists often cope with variation in physiological, environmental and ecological processes by measuring how living systems perform under average conditions. However, performance at average conditions is seldom equal to average performance across a range of conditions. This basic property of nonlinear averaging -known as 'Jensen's inequality' or 'the fallacy of the average' -has important implications for all of biology. For instance, a burgeoning awareness of Jensen's inequality has improved our ability to predict how plants and animals will respond to a warmer and more variable future climate. But for many biologists, the fallacy of the average is still a novel concept. Here, I highlight the importance of Jensen's inequality, provide a simple graphical approach to understanding its effects, and explore its consequences at atomic, molecular, organismal and ecological levels.

“…The comparative analysis of the SG and the PC shows that this is indeed possible and fruitful. Moreover, as in many cases of applications of methods from mechanical engineering to biomechanics, the benefit might also be substantial in the field of mechanical engineering itself, in terms of the generality of the methods (Crimaldi, 2012). (Stanford et al, 2008) Drag reduction in leaves (Vogel,1989) Corresponding numerical and experimental methods not commonly used in plant biomechanics…”

Section: Discussionmentioning

confidence: 99%

Methodological advances in predicting flow-induced dynamics of plants using mechanical-engineering theory

Langre

2012

SummaryThe modeling of fluid-structure interactions, such as flow-induced vibrations, is a well -developed field of mechanical engineering. Many methods exist, and it seems natural to apply them to model the behavior of plants, and potentially other cantilever-like biological structures, under flow. Overcoming this disciplinary divide, and the application of such models to biological systems, will significantly advance our understanding of ecological patterns and processes and improve our predictive capabilities. Nonetheless, several methodological issues must first be addressed, which I describe here using two practical examples that have strong similarities: one from agricultural sciences and the other from nuclear engineering. Very similar issues arise in both: individual and collective behavior, small and large space and time scales, porous modeling, standard and extreme events, tradeoff between the surface of exchange and individual or collective risk of damage, variability, hostile environments and, in some aspects, evolution. The conclusion is that, although similar issues do exist, which need to be exploited in some detail, there is a significant gap that requires new developments. It is obvious that living plants grow in and adapt to their environment, which certainly makes plant biomechanics fundamentally distinct from classical mechanical engineering. Moreover, the selection processes in biology and in human engineering are truly different, making the issue of safety different as well. A thorough understanding of these similarities and differences is needed to work efficiently in the application of a mechanistic approach to ecology.