|1. A view of landscapes as functioning systems|
|2. Spatial heterogeneity as an organizing principle in landscape dynamics|
|3. Function and dysfunction in landscape dynamics|
|4. The role of feedback loops|
|5. Assessing landscape dynamics: Thresholds and climate change|
|6. Concluding remarks|
A terrestrial landscape can be viewed as a system of biological elements (organisms, populations, communities) forming a pattern across a topographic geomorphic unit. The dynamics of these landscape systems are driven by topography and climate and by interacting geochemical and biophysical processes. Although we recognize that important conceptual advances in landscape dynamics have been developed, such as how landscapes behave as complex adaptive and self-organizing systems, in this chapter we particularly focus on the development of the notion of landscape function, that is, how a landscape works as a geochemical-biophysical system to regulate vital resources over space and time. In highly functional landscapes, a major rainfall event will trigger runoff, but, overall, little loss of water, topsoil, and organic matter occurs from the system because these resources are dynamically captured by patterned structures within the landscape such as vegetation patches, which function as reserves or resource “banks.” Vegetation patches then utilize retained resources (water, nutrients) in growth pulses to produce biomass such as seeds, most of which are cycled back into the system (soil seed banks). Biomass can also function to maintain the retentive capacity (structure) of the patch and can provide shelter and food for fauna or for consumption by livestock, which when harvested represent offtake from the system. Damaged landscapes become dysfunctional by losing their capacity to effectively regulate resources.
landscape dynamics. How a landscape, as a system of interacting components, structures, and processes, varies in space and time
landscape function. How a landscape works as a tightly coupled geochemical-biophysical system to regulate the spatial availability and dynamics of resources
landscape heterogeneity. The mix of different components, structures, and processes occurring in a landscape, such as how different organisms disperse among different vegetation patches
landscape restoration/rehabilitation. The actions and processes taken to help damaged landscapes recover toward a specified goal (landform, land use)
landscapes as self-organizing systems. How components, structures, and processes in a landscape dynamically organize to form complex, adaptive, and stable systems
landscape system threshold. A point in the dynamics of a landscape where the system changes to a different state, as, for example, a damaged landscape becomes dysfunctional to the point where available resources no longer support a species
We view landscapes and marvel at the patterning of their interconnected ecosystems and wonder about what dynamic processes have caused these patterns. What have we learned about the dynamics of landscape patterns and processes in recent times? In this chapter we explore new developments in landscape dynamics by building on the work of Turner, Gardner, and O’Neill (2001) and others and by adding our Australian perspective. Disturbance-induced effects on landscapes are described in later chapters in part IV.