The Hierarchical Structure of Ecosystems: Connections to Evolution

Abstract

Ecologic systems, which are involved mainly in the processing of energy and materials, are actually nested one inside another-they are simultaneously parts and wholes. This fundamental hierarchical organization is easy to detect in nature but has been undervalued by ecologists as a source of new insights about the structure and development of ecosystems and as a means of understanding the crucial connections between ecologic processes and large-scale evolutionary patterns. These ecologic systems include individual organisms bundled into local populations, populations as functional components of local communities or ecosystems, local systems making up the working parts of larger regional ecosystems, and so on, right up to the entire biosphere. Systems at any level of organization can be described and interpreted based on aspects of scale (size, duration, and "membership" in more inclusive entities), integration (all the vital connections both at a particular focal level and across levels of hierarchical organization), spatiotemporal continuity (the "life history" of each system), and boundaries (either membranes, skins, or some other kind of border criterion). Considering hierarchical organization as a general feature of ecologic systems could reinvigorate theoretical ecology, provide a realistic scaling framework for paleoecologic studies, and -most importantly -forge new and productive connections between ecology and evolutionary theory.

Distribution of species diversity values: A link between classical and quantum mechanics in ecology

“…In fact, the configuration of ecosystems is recognizable because they have a particular fractal structure (Nielsen, 2000;Ulanowicz, 2004;Miller, 2008) composed of different parts arranged in a definite pattern (Margalef, 1963). So, the analytical use of ED H should improve the consistency of our results since each one of these ED H s can be assumed as an alternative combination of macrostates (classes of H p values) with a variable degree of internal connectivity at a smaller scale (microstate).…”

Lessons from EEO: Toward a Universal Evolutionary Curriculum

“…& Ecosystems interconnect over the Earth's surface-as when mammals come to the river's edge to drink, or eagles come to catch the fish. Ultimately, the flow of energy (beginning with sunlight-trapped by the photosynthesis of plants and algae at the base of the food chain) links up life all over planet Earth (Miller 2008). & The role a local population of a species plays in an ecosystem is its "ecological niche."…”

Flux-based hierarchical organization of Escherichia coli’s metabolic network

“…Hierarchical organization has been recognized as a salient feature of biological networks, spanning from the molecular to the ecosystem scale [1,2,3,4,5].…”