Assessing sustainability in North America’s ecosystems using criticality and information theory

Abstract

Sustainability is a key concept in economic and policy debates. Nevertheless, it is usually treated only in a qualitative way and has eluded quantitative analysis. Here, we propose a sustainability index based on the premise that sustainable systems do not lose or gain Fisher Information over time. We test this approach using time series data from the AmeriFlux network that measures ecosystem respiration, water and energy fluxes in order to elucidate two key sustainability features: ecosystem health and stability. A novel definition of ecosystem health is developed based on the concept of criticality, which implies that if a system’s fluctuations are scale invariant then the system is in a balance between robustness and adaptability. We define ecosystem stability by taking an information theory approach that measures its entropy and Fisher information. Analysis of the Ameriflux consortium big data set of ecosystem respiration time series is contrasted with land condition data. In general we find a good agreement between the sustainability index and land condition data. However, we acknowledge that the results are a preliminary test of the approach and further verification will require a multi-signal analysis. For example, high values of the sustainability index for some croplands are counter-intuitive and we interpret these results as ecosystems maintained in artificial health due to continuous human-induced inflows of matter and energy in the form of soil nutrients and control of competition, pests and disease.

Human gut microbiota networks disturbance by parasites in indigenous communities: Effect on bacteria genera related to depression incidence subnetworks

“…Recent results show convincing evidence that criticality may be a key feature of a healthy state [43][44][45][46]65 . Our results show that due to the presence of parasites, there is a depart from criticality via a diminish of emergence (adaptability) and then a loss of health.…”

Disturbance in human gut microbiota networks by parasites and its implications in the incidence of depression

“…Recent results show convincing evidence that human health requires that systemic physiological signals, such as heart rate, be at criticality [29][30][31][32]51 . Our results show that due to the presence of parasites, there is a depart from criticality via a diminish of emergence (adaptability) and then a loss of health.…”

Ecosystem antifragility: beyond integrity and resilience

“…Summarizing, in the dynamic response of ecosystems under the criticality framework (Ramírez-Carrillo et al, 2018), a healthy ecosystem is found where a balance between robustness and adaptation is reached. In the case of network topology, the ecosystems need to develop a good balance between strong and weak interactions in order to be stable.…”

“…The universality of criticality is still under consideration and is known as the "criticality hypothesis" which states that systems in a dynamic system that shifts between order and disorder reach the greatest level of computing capacities when reaches a balance between robustness and flexibility (see Roli et al, 2018 and references therein). This idea of criticality was recently used in an information theory approach to defining ecosystem health and sustainability (Ramírez-Carrillo et al, 2018). In this article, Ramírez-Carrillo et al (2018) consider that an ecosystem is healthy if it is in criticality, as a mixture of scale invariance (as power laws in power spectra) and a balance between adaptability and robustness.…”

“…This idea of criticality was recently used in an information theory approach to defining ecosystem health and sustainability (Ramírez-Carrillo et al, 2018). In this article, Ramírez-Carrillo et al (2018) consider that an ecosystem is healthy if it is in criticality, as a mixture of scale invariance (as power laws in power spectra) and a balance between adaptability and robustness.…”