A hierarchical framework for the analysis of scale

Abstract

Landscapes are complex ecological systems that operate over broad spatiotemporal scales. Hierarchy theory conceptualizes such systems as composed of relatively isolated levels, each operating at a distinct time and space scale. This paper explores some basic properties of scaled systems with a view toward taking advantage of the scaled structure in predicting system dynamics. Three basic properties are explored:(1) hierarchical structuring, (2) disequilibrium, and (3) metastability. These three properties lead to three conclusions about complex ecological systems. First, predictions about landscape dynamics can often be based on constraints that directly result from scaled structure. Biotic potential and environmental limits form a constraint envelope, analogous to a niche hypervolume, within which the landscape system must operate. Second, within the constraint envelope, thermodynamic and other limiting factors may produce attractors toward which individual landscapes will tend to move. Third, because of changes in biotic potential and environmental conditions, both the constraint envelope and the local attractors change through time. Changes in the constraint structure may involve critical thresholds that result in radical changes in the state of the system. An attempt is made to define measurements to predict whether a specific landscape is approaching a critical threshold.

Integrating ecology with hydromorphology: a priority for river science and management

“…Concepts such as meta-stability, where a system is considered to vary within certain boundaries } unless subjected to major perturbations } are valuable (O'Neill et al, 1989). Much emerging theory in ecohydromorphology places variability at its core, such as the concepts of flood pulses (Junk et al, 1989), flow pulses (Tockner et al, 2000) and the natural river regime (Poff et al, 1997).…”

Determining the relative importance of catchment- and site-scale factors in structuring fish assemblages in small coastal streams

“…Indeed, increases in riffle habitat associated with increases in discharge lead to increases in density of ayu (Isao and Nobuhiko, 2012). These observations suggest that discharge could impact fish assemblages via changing site-scale environments, corresponding to the hierarchy hypothesis of stream ecosystems (O'Neill et al, 1989). Additionally, the large joint effect observed in my variation partitioning analysis might also reflect the hierarchical impact of catchment-and site-scale factors.…”

A Vision of the Future of Science: Reintegrating of the Study of Humans and the Rest of Nature

“…In understanding and modeling ecological and economic systems exhibiting considerable biocomplexity, the issues of scale and hierarchy are central (Ehleringer and Field 1993;O'Neill et al 1989). The term "scale" in this context refers to both the resolution (spatial grain size, time step, or degree of complexity of the model) and extent (in time, space, and number of components modeled) of the analysis.…”

“…The most important aspect of hierarchy theory is that ecological systems' behavior is limited by both the potential behavior of its components (biotic potential) and environmental constraints imposed by higher levels (O'Neill et al 1989). The flock of birds that can fly only as fast as its slowest member, or a forested landscape that cannot fix atmospheric nitrogen if specific bacteria are not present are examples of biotic potential limitation.…”