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Lakes, far from being the homogeneous environments we might expect, offer a rich and dynamic heterogeneity at multiple spatial and temporal scales that we are just beginning to understand. At the within-lake scale, a complex set of phenomena such as internal waves and stream intrusions leads to both horizontal and vertical heterogeneity. Developing an understanding of whether and how this heterogeneity affects ecosystem processes is in its early stages, but nutrient movement both horizontally and vertically may be more structured than previously conceptualized and will depend on interactions among nutrient loading, stratification, surface meteorology, and basin morphometry. Within a landscape, lakes often differ from each other both in their average characteristics and in their among-year dynamics. Much of this heterogeneity has been linked to how water flows across the landscape. In landscapes dominated by groundwater flow, there is often more heterogeneity in lake characteristics and response to climatic events than in landscapes where exposed bedrock leads to rapid horizontal transport of water. Humans can affect heterogeneity across lakes by causing changes in land use and cover and within lakes by simplifying the physical structure of the littoral zone. [ABSTRACT FROM AUTHOR]

The consideration of spatial heterogeneity in ecosystem science is a challenging problem both empirically and conceptually. Although conceptual frameworks have been developed for some aspects of the problem, there is as yet no overarching framework that links them together. In this paper, we review many of the conceptual frameworks used in the chapters of this book. We discuss how the ecosystem concept can be extended to the "landscape system." Like the ecosystem, the landscape system must have defined boundaries so that inputs and outputs can be distinguished from internal circulation. Given the delineation of the landscape system and its component ecosystems, a series of questions is posed that allow the investigator to determine what aspects of heterogeneity are likely to be important and what kind of model (homogeneous, mosaic, or interactive) most appropriately captures the behavior of the system. [ABSTRACT FROM AUTHOR]

Four themes emerging from papers presented at the Tenth Cary Conference are discussed in this synthesis. First, conditions are considered in which both landscape composition and configuration influence ecosystem function. Where there is some vector of flow (e.g., water, wind, animal) between landscape components that differ in type or rate of ecosystem processes, configuration will influence ecosystem function. The second theme is that a network perspective offers opportunities to advance both theoretical and applied analyses of landscape heterogeneity. Analyses of the interaction of human and natural networks and of networks and patches are fruitful areas for future research. A third theme is the need to reflect more fully the diversity of human activities and their history and institutions when assessing landscape heterogeneity and ecosystem function. Finally, an enhanced understanding of landscape heterogeneity and ecosystem function will improve four aspects of human interactions with nature: the framework of environmental regulations, management of land and water resources, environmental design, and ecosystem restoration. Realizing these improvements requires that we find a vocabulary to express to the public the influence of landscape heterogeneity on ecosystem function and hence the ecosystem services that society values. [ABSTRACT FROM AUTHOR]

Explanation and interpretation of spatial heterogeneity in nature have been central concerns in ecology since long before the word ecosystem was first defined. As ecological knowledge has developed during the past century, it has become clear that the problems of heterogeneity are diverse and can be studied as a number of component issues; together, the chapters of this book represent a state-of-the-art summary of current understanding. Simplifying assumptions of spatial homogeneity and temporal stability are still used widely in ecological research and will continue to be used for the foreseeable future, but long-term, global understanding requires a multiscale approach in which homogeneity and heterogeneity are parts of one continuum and change never stops. Future priorities for research include dynamic approaches to heterogeneity in complex spatial networks, the search for broad patterns in heterogeneity across spatial scales, and reconciling the goal of environmental sustainability with the fact that we live in a patchy, constantly changing world. [ABSTRACT FROM AUTHOR]

Relationships between spatial patterns and ecosystem function are briefly reviewed with regard to the current state of the science and its application and some important challenges. Ecosystem functions that are affected by heterogeneity include maintenance of species diversity (habitat) as well as material and energy cycles. Structural diversity and spatial heterogeneity play an important role in all of these functions and require increased attention. Spatial pattern or heterogeneity is important to ecosystem function at all spatial scales from centimeters to kilometers, not just the larger scales. The relevance of spatial patterns to ecosystem function, including the statistical patterns and significance of the relationships, depend on the function or parameters chosen and the spatial and temporal scales of interest. As a consequence, few, if any, general principles exist for interpreting the effects of landscape heterogeneity on ecosystem function. For example, heterogeneity does tend to increase the number of niches available and, hence, the diversity of environmental conditions that are present. Whether the effects of this increased diversity are positive or negative depends on the processes or organisms of interest. One important conceptual challenge in studying landscape heterogeneity is to move beyond the classic patch-corridor-matrix model to approaches that incorporate networks and gradients. [ABSTRACT FROM AUTHOR]

Ecological systems usually are heterogeneous, and this heterogeneity has important functional consequences. Nevertheless, it is not always necessary for ecologists to explicitly include this heterogeneity in their studies and models of ecological systems. Heterogeneity may be safely ignored if its grain size is much smaller than the spatial extent over which measurements are integrated or much larger than the spatial extent of the study area. Heterogeneity may be functionally unimportant if the vectors connecting patches are small or slow relative to the time span of the study or if the system is governed by processes with linear dynamics. Further, the heterogeneity expressed by some ecological systems may be amenable to analysis using simplified models. Finally, it may not be efficient to include heterogeneity in study designs or models, even if including heterogeneity would improve the study performance. Despite these considerations, ecologists will need to address heterogeneity explicitly in many cases to achieve a satisfactory understanding of ecosystem functioning, particularly for regional to global scales. Several other general issues concerning the functional consequences of heterogeneity arose at the Tenth Cary Conference. Human-caused heterogeneity probably has different characteristics and functional consequences than heterogeneity arising from other sources and therefore needs special attention. Models of heterogeneity developed in other disciplines that deal with heterogeneous, reactive systems (e.g., economics) may have application in ecology. At least some heterogeneous ecological systems appear to evolve in predictable ways because the functional consequences of heterogeneity feed back onto the structure of the system; these feedbacks need further study. [ABSTRACT FROM AUTHOR]

Streams are heterogeneous in both space and time. Hydrologic flowpaths along which biogeochemical processing occurs integrate different patches of the stream. Disturbance events (flood and drying) change these patches, alter connectivity, and reinforce spatial heterogeneity. Heterogeneity within patches (surface stream, hyporheic zone, sand bars, and riparian zone) is generated by the interaction of nitrogen (the limiting nutrient) in transport and organisms such as algae and bacteria. These organisms store nitrogen as they grow, alter N forms and concentrations in transport, and in some cases (e.g., denitrification) export it to the atmosphere. Changes in nitrogen in transport can be large, as are community responses to nitrogen availability, thus reinforcing spatial heterogeneity in successional time. Flowpaths connect patches as well and generate changes in recipient patches as a function of nitrogen delivery rate. This is especially evident at patch boundaries. In streams, flow is markedly linear and inexorably downstream in orientation; however, landscapes are drained by coalescing, dendritic networks that intimately connect stream channels with terrestrial flowpaths over and beneath soils. We propose that a unified theory of landscapes will require a focus on spatial linkage, a consideration of both spatial and temporal heterogeneity, and a blurring of distinctions between terrestrial and aquatic elements. [ABSTRACT FROM AUTHOR]

In this chapter we ask the question: To what extent does an understanding of landscape spatial heterogeneity inform conservation decisions? We answer this question in the context of two central decision-making fields within conservation biology: systematic conservation planning and population viability analysis. The conservation planning principles of comprehensiveness and representativeness are fundamentally reliant on data and concepts of compositional landscape heterogeneity. The principle of adequacy is not accommodated in conservation planning very well and it relies on an understanding of the configurational heterogeneity of the landscape. A major challenge for conservation planning scientists is to develop theory and decision support tools that incorporate ideas of population viability and spatially explicit ecological processes. Population viability analysis invariably includes spatial population processes, and as a field has largely focused on the importance of the configurational heterogeneity of landscapes. We argue that this focus might only be justified when the scale of planning coincides with either the scale of habitat heterogeneity or the scale at which small populations operate. Integrating population viability analysis into conservation planning, and showing a balanced interest in compositional and configurational heterogeneity, are important future challenges. [ABSTRACT FROM AUTHOR]

Spatial heterogeneity of ecosystem structure and function is rarely taken into consideration in the management of our planet's freshwater resources. Incorporation of spatial heterogeneity provides a new way to view freshwater resources and leads to potentially useful management strategies. In this chapter, we address the relationship between the management of freshwater resources and spatial heterogeneity by introducing landscape concepts as they apply to water management, developing a conceptual framework, describing how this relationship applies to ecosystem services provided by fresh water, and using a case study that explains the potential relevance of spatial heterogeneity to water management. Landscape connectivity can be viewed as the overarching feature linking aquatic systems, with six types of landscape connections: two types of longitudinal (upstream-downstream and hydrogeomorphic), lateral (floodplain-river), lateral-vertical (hillslope-river), vertical (surface water-groundwater), and within-ecosystem linkages. Hypothesized relationships between landscape linkages and ecosystem services provided by fresh water are explored that address the role of spatial heterogeneity. The south Florida ecosystem is used as a case study to show how spatial heterogeneity in this system affects a variety of ecosystem services. Spatial heterogeneity of nutrient sources will influence the location of restoration efforts in the Everglades. In addition, ecosystem services of water supply, water quality, and navigation are influenced by the configuration of the highly interconnected and heavily managed Greater Everglades Ecosystem in south Florida. The socioeconomic and environmental consequences of this connectivity are explored under high and low flow conditions. [ABSTRACT FROM AUTHOR]

The occurrence and effects of fire vary greatly over multiple spatial and temporal scales. At a regional scale, variation in synoptic climate and associated vegetation characteristics results in diverse fire regimes, ranging from systems having frequent, low-severity fires (e.g., pine forests of the southwestern and southeastern United States) to systems characterized by infrequent but stand-replacing fires (e.g., subalpine and boreal forests of North America). At a finer scale, spatial variability in fuel mass and structure may influence fire ignition and severity under a middle range of weather conditions, but effects of fuels may be overwhelmed by effects of extreme weather—either extremely wet (no fire) or extremely dry and windy (large, severe fires). Almost all fire events exhibit a heterogeneous pattern of burning and create a mosaic of fire severity within the burned area, resulting in spatially variable changes in plant community structure, soil characteristics, and ecosystem processes of energy and biogeochemistry. We have a pressing need to better incorporate our understanding of spatial heterogeneity into wildland fire policy and management and to address urgent research questions about spatial patterns in fire history, fire effects, and responses of organisms and ecosystems to the spatial variability of fire. [ABSTRACT FROM AUTHOR]

Heterogeneity in urban ecosystems derives from a combination of natural and engineered landscape features, as well as behavior of human individuals and institutions. Modern urban regions in North America and elsewhere are no longer uniformly compact and densely populated but have extended into surrounding regions and include intricate mixes of residential, commercial, and residual agricultural, forest, and other managed and unmanaged vegetated areas. Compared to less developed ecosystems, heterogeneity in water, carbon, nutrient, and energy cycling may be enhanced, specifically over the short distances associated with urban development patterns. We review conceptual approaches to characterizing and representing heterogeneity in urban ecosystems and illustrate some of the main sources of heterogeneity resulting from interactions within and between urban patch networks, with special reference to examples drawn from the Baltimore Ecosystem Study. [ABSTRACT FROM AUTHOR]

Historically, population ecologists have equated environmental spatial heterogeneity with habitat spatial structure. Early models represented habitat spatial structure simply as population subdivision into habitat patches. Later models included at first partially and then fully explicit representation of the spatial relationships among habitat patches. More recently, landscape population ecologists have broadened the view of spatial heterogeneity to include the composition and configuration of the whole landscape. A change in landscape composition refers to a change in the cover types in the landscape, the proportions of each, or both. A change in landscape configuration refers to a change in the spatial pattern of cover types, independent of any change in landscape composition. We hypothesize that changes in landscape composition generally have much larger effects on population persistence than changes in landscape configuration. Landscape configuration should have a large effect on population persistence when both (i) configuration has a large effect on among-patch movement of the organism and (ii) among-patch movement has a large effect on population persistence. The first condition should hold for species whose movement direction is constrained, and the second condition should hold either (i) when colonization of empty habitat is important for persistence or (ii) for species that require more than one type of habitat. We discuss extensions of these ideas to the effects of landscape configuration on ecosystem processes. [ABSTRACT FROM AUTHOR]

Riparian systems epitomize heterogeneity. As transitional semiterrestrial areas influenced by water, they usually extend from the edges of water bodies to the edges of upland terraces. Riparian systems often exhibit strong biophysical gradients, which control energy and elemental fluxes, and are highly variable in time and space.These attributes contribute to substantial biodiversity, elevated biomass and productivity, and an array of habitats and refugia. Focusing on riparian systems of medium-sized floodplain rivers, we describe heterogeneity at multiple space and time scales, illustrate interactions among scales, and propose a conceptual model integrating major system components. We show how climatic and geologic processes shape an array of physical templates, describe how disturbances redistribute materials, and illustrate how soils and subsurface processes form and are sustained. Collectively, these processes strongly influence plant productivity and fluxes of channel-shaping large woody debris (LWD). Ultimately, riparian ecosystem function integrates climate (past and present), geologic materials and processes, soil development and attendant microbial transformations, subsurface characteristics, plant productivity, animal activities, and LWD—and the active, continuous and variable feedbacks between the individual components. [ABSTRACT FROM AUTHOR]

The boreal forest covers 14% of the earth's vegetated surface but contains about 27% of the world's vegetation carbon and between 25% and 30% of the world's soil carbon. Unique features of this biome include cold climates, large areas of relatively flat topography, discontinuous permafrost, large and severe fire events, and the accumulation of peat. These characteristics are important in controlling energy and carbon cycling and either influence or are influenced by regional climate and hydrological regimes. Net ecosystem production (NEP) is the total carbon accumulation within an ecosystem and reflects the balance between net primary production (NPP), decomposition, and nonrespiratory losses (dissolved carbon export, fire, and land-use changes). In this chapter, we use soil carbon storage as a long-term estimate of NEP that integrates annual variability in the ecosystem processes contributing to carbon balance. Our overall hypothesis is that a combination of regional and local physiography creates spatial heterogeneity in hydrology and soil temperatures. Hydrology and thermal regimes, in turn, influence distributions of fire, permafrost, peatlands, and vegetation and ultimately control long-term carbon storage in many boreal climatic zones. Soil carbon storage varies tremendously between boreal stand types or features and is particularly large in poorly drained peatland and permafrost ecosystems. Landscape composition, then, is important for scaling carbon storage in boreal regions. However, whether the configuration of upland and lowland ecosystems influences carbon processes has not been adequately explored but likely is important to variations in carbon emissions during fire. Biological controls such as herbivory and insect outbreaks are important to the distribution of plant species and nitrogen availability in forest ecosystems, but their influence on wetland systems or long-term carbon dynamics is not well understood. [ABSTRACT FROM AUTHOR]

Vegetation patterns often resemble the pattern of the geological substratum. In some cases, however, correlations between soils and vegetation in patterned distributions appear to have developed in an initial homogeneous landscape. Here, soil-vegetation feedback processes appear to be responsible for the development of such patterns. In this paper, we discuss various systems and their feedbacks that may lead to formation of patterns. In semiarid systems, soil-water-vegetation feedbacks might lead to Turing-like self-organized pattern formation, as indicated by previously published models. In other cases of patterned soil-vegetation systems, feedback mechanisms may be involved that locally enhance growth of one species and inhibit that of other species. These interactions do not fulfill the criteria of Turing for pattern formation. However, such strong competitive interactions may lead to patterned vegetation as is shown by a study of a competitive model including spreading of the species. This pattern is not due to self-organization but depends on the initial boundary conditions. [ABSTRACT FROM AUTHOR]

In the ocean, the spatial distribution of biogeochemical tracers is affected by their physical transport in the fluid medium. Many tracer distributions such as sea surface chlorophyll and temperature are highly correlated at length scales of 1-100 km on account of a commonality in the transport processes that affect them. We characterize and differentiate between the spatial heterogeneity of the tracers by using a variance-based measure for "patchiness." When we analyze the satellite-derived fields of surface chlorophyll and temperature, we find that chlorophyll is more patchy than temperature (i.e., a greater proportion of its variance occurs at small scales). We explain such differences in heterogeneity by taking the approach that the observed spatial heterogeneity of a tracer results from a balance between processes that generate variance and those that shift the variance from one length scale to another. The longevity of the tracer determines the extent to which the variance can be shifted to another scale. In the surface ocean, variance introduced at large scales due to geographic variations can be driven to smaller scales by the horizontal stirring and stretching of fluid filaments. On the other hand, small-scale vertical motion associated with fronts introduces small-scale variance that spreads to larger scales if the tracer anomalies are long lasting. For the latter case, we derive a quantitative relationship between a tracer's patchiness and the timescales of processes that modify its concentration in the upper ocean. This relationship links the observed spatial heterogeneity in the system to the processes that contribute to its generation. It lends hope to our being able to use quantitative measures of spatial heterogeneity, like the patchiness parameter defined here, to gain information about processes or vice versa, to predict how the spatial heterogeneity might be modified as a result of a change in processes. [ABSTRACT FROM AUTHOR]

Spatial heterogeneity is a hallmark of vegetation patterns in arid and semiarid landscapes. First observed in terms of the spatial array of vegetation patches, spatial heterogeneity is now more broadly interpreted as the cumulative outcome of the processes affecting the spatial and temporal distribution of vital resources such as water, topsoil organic matter, and propagules individually and collectively. Spatial resource redistribution is shown to be important at a variety of scales varying from millimetres to hundreds of metres and beyond and can be conveniently studied as a nested spatial hierarchy. The processes by which heterogeneous resource distribution arises are a mixture of physical and biological and can be represented by an information-structuring conceptual framework, which is described. Heterogeneity is crucial to the functioning of arid and semiarid lands, and changes in the scale of heterogeneity can be used to study and understand the processes underlying desertification and rehabilitation. Models of heterogeneous landscapes in semiarid landscapes have had two broad themes: a pragmatic approach, describing ecosystem function in landscapes under management, and a curiosity-driven approach, speculating about the de novo development of landscape heterogeneity. [ABSTRACT FROM AUTHOR]

Infectious disease epidemics in populations are inherently spatial—infectious agents are spread by contact from an infectious host to a susceptible host nearby. Among-host differences can determine which hosts suffer disease and the population dynamics of infectious disease epidemics. From the perspective of the infectious agent, a host is a habitat patch; among-host differences that are epidemiologically important are related to the concepts of compositional and configurational heterogeneity in landscape ecology. Heterogeneous mixing in epidemiology encompasses factors that determine who comes into contact with whom; it is analogous to configurational heterogeneity in landscape ecology. Other sorts of heterogeneity are analogous to compositional heterogeneity, including among-host differences in the duration of an infection, susceptibility to infection, or the amount of an infectious agent that is dispersed from an infected host. In real epidemics, compositional heterogeneity and configurational heterogeneity can introduce an overwhelming amount of complexity. Mathematical modeling provides a method for understanding epidemic processes and for taming the complexity. The idea of epidemic distance is introduced as a way of comparing and contrasting two different epidemic processes, and it is used to compare and contrast some of the mathematical models used to understand the role of space and spatial heterogeneity in epidemiology. In understanding real epidemics, the notion of parsimony is a guiding principle—heterogeneity should be weighed and ignored whenever possible. Several case studies are presented in which compositional and configurational heterogeneity are shown to be important. [ABSTRACT FROM AUTHOR]

Heterogeneity of land surface and atmospheric processes contributes to all aspects of the hydrologic cycle. Understanding the types and sources of this heterogeneity is a fundamental component of both theoretical and applied hydrology. Observations of heterogeneity occur at multiple scales ranging from within-canopy variation in water-holding capacity of a single leaf to spatial variation in precipitation at continental to global scales. Consequently, strategies for addressing heterogeneity in hydrologic modeling depend on the scale and type of process being modeled. Further, hydrologic models must address heterogeneity in both inputs and parameters as well as the representation of underlying physical processes. This paper provides an overview of heterogeneity and its implications for hydrologic modeling. Crucial examples of heterogeneity in inputs, parameters, and underlying physical processes are described, and approaches used to deal with heterogeneity within hydrologic modeling are discussed. In particular, the use of effective parameters, probabilistic approaches, and landscape tessellation are described as strategies to address heterogeneity in parameters and inputs. Explicit consideration of process heterogeneity is also considered from the perspective of physically based hydrologic modeling, and the implications for the coupling between hydrologic and ecological process models is discussed. [ABSTRACT FROM AUTHOR]

The objective of this paper is to explore the relationships between environmental heterogeneities and the flows and movements that suffuse through all environments. Flows and movements are treated as propagations of ecological influence through environmental space. Propagations are composed of four elements: (1) initiating events or conditions, (2) transport vectors, (3) transported entities, and (4) deposition or impact processes. All four elements have multiple dimensions in type and scale, but vectors are the most convenient means of discussing these phenomena. At a medial level of causation, 10 major vectors are convenient descriptors. These vectors are molecular diffusion; transport by fluvial, colluvial, or glacial modes, gravitational sedimentation, currents (tidal and extratidal), wind (with fire as a special case) agencies; and by electromagnetic radiation, sound, and animal locomotion. Obviously, each of these vector types has different behavior. Propagations can be initiated, or modified by, environmental heterogeneities. But also, propagations can create, maintain, and destroy heterogeneities. Thus, reciprocal cause and effect relationships exist between propagations and environmental heterogeneities. Analysis and understanding of these reciprocal interactions between propagations and heterogeneities requires some understanding of the mechanics of propagations, whether they involve wind, waves, or wallabies. In the same sense, analysis and understanding of how environmental heterogeneities alter propagations requires an appreciation for the global range of heterogeneity types, whether they are ripples, runnels, or run-on patches. Spatially explicit two- and three-dimensional models of propagations in heterogeneous environments are useful ways to develop understanding and, with caveats, to predict how processes and patterns interact. Some of the representational issues of building such models are reviewed in this paper, and three model examples are described. [ABSTRACT FROM AUTHOR]

Ecosystem processes are inherently variable in space and time, in part because they occur on a spatially heterogeneous template or landscape. For many purposes, the patterns of heterogeneity can be characterized as gradients, patchworks, or networks—or some combination of these fundamental patterns. Each class of landscape pattern implies that it has been generated by certain kinds of abiotic or biotic mechanisms, which can be described by particular mathematical formulations. We illustrate these points with a few selected, ecologically relevant examples. Quantitatively characterizing the patterns of variation in the template and understanding their causes, correlates, and consequences are important steps in investigating the influence of spatial heterogeneity on the structure and function of ecological systems at all scales from molecular to global. [ABSTRACT FROM AUTHOR]

Landscapes are spatially dynamic because materials and energy spread over them and change the distribution of ecosystem properties. This heterogeneity of the distribution of ecosystem properties can either be random or patterned. The landscape becomes patterned when the spread of materials and energy correlates an ecosystem property in one local neighborhood with that at another. When the spread of materials and energy does not correlate properties of different neighborhoods, then the landscape can still be heterogeneous but random. Various processes that result in spatial heterogeneity include physical disturbances (e.g., fire, erosion, etc.) that spread across neighborhoods and remove materials but whose spread is partly determined by previous disturbances; directional gradients in the flow of materials, energy, or information; and different diffusion rates of coupled ecosystem components combined with positive feedbacks, otherwise known as diffusive instability. Examples of these processes will be given from other papers in this conference and elsewhere. [ABSTRACT FROM AUTHOR]

Understanding the causes and consequences of spatial heterogeneity in ecosystem function represents a frontier in both ecosystem and landscape ecology. Ecology lacks a theory of ecosystem function that is spatially explicit, and there are few empirical studies from which to infer general conclusions. We present an organizing framework that clarifies consideration of ecosystem processes in heterogeneous landscapes; consider when spatial heterogeneity is important; discuss methods for incorporating spatial heterogeneity in ecosystem function; and identify challenges and opportunities for progress. Two general classes of ecosystem processes are distinguished. Point processes represent rates measured at a particular location; lateral transfers are assumed to be small relative to the measured response and are ignored. Spatial heterogeneity is important for point processes when (1) the average rate must be determined over an area that is spatially heterogeneous or (2) understanding or predicting the spatial pattern of process rates is an objective, for example, to identify areas of high or low rates, or to quantify the spatial pattern or scale of variability in rates. Lateral transfers are flows of materials, energy, or information from one location to another represented in a two-dimensional space. Spatial heterogeneity may be important for understanding lateral transfers when (1) the pattern of heterogeneity influences net lateral transfer and potentially the behavior of the whole system, (2) the spatial heterogeneity itself produces lateral transfers, or (3) the lateral transfers produce or alter patterns of spatial heterogeneity. We discuss homogeneous, mosaic, and interacting element approaches for dealing with space and identify both challenges and opportunities. Embracing spatial heterogeneity in ecosystem ecology will enhance understanding of pools, fluxes, and regulating factors in ecosystems; produce a more complete understanding of landscape function; and improve the ability to scale up or down. [ABSTRACT FROM AUTHOR]