scholarly journals How Do Disturbance-Generated Patterns Influence the Spatial Dynamics of Ecosystem Processes

2004 ◽  
Vol 28 ◽  
pp. 103-104
Author(s):  
Monica Turner ◽  
William Romme ◽  
Daniel Tinker
Keyword(s):  
Spatial Variability ◽  
Spatial Variation ◽  
National Parks ◽  
Spatial Patterns ◽  
Ecosystem Function ◽  
Spatial Dynamics ◽  
Ecosystem Processes ◽  
Current Theory ◽  
Spatial And Temporal Patterns ◽  
Magnitude Variation

Our studies following the 1988 Yellowstone flres demonstrated that succession was surprisingly more variable in space and time than even current theory would have suggested, and that initial spatial patterns of disturbance may persist to produce long­ lasting changes in vegetation. Our focus now is on explaining the spatial and temporal patterns of succession and understanding how these patterns influence ecosystem function. The most interesting new questions revolve around the degree to which the spatial variation in postfue vegetation in particular, the six orders of magnitude variation in pine sapling density, ranging from 0 to greater than 500,000 saplings/ha controls the spatial variability in ecosystem processes across the landscape. In our current research, we are conducting studies in both Grand Teton and Yellowstone National Parks to answer four major questions:

scholarly journals How Do Disturbance-Generated Patterns Influence the Spatial Dynamics of Ecosystem Processes?

2003 ◽  
Vol 27 ◽  
pp. 100-103
Author(s):  
Monica Turner ◽  
William Romme ◽  
Daniel Tinker
Keyword(s):  
Spatial Variability ◽  
Spatial Variation ◽  
National Parks ◽  
Spatial Patterns ◽  
Ecosystem Function ◽  
Spatial Dynamics ◽  
Ecosystem Processes ◽  
Current Theory ◽  
Spatial And Temporal Patterns ◽  
Magnitude Variation

Our studies following the 1988 Yellowstone fires demonstrated that succession was surprisingly more variable in space and time than even current theory would have suggested, and that initial spatial patterns of disturbance may persist to produce long­lasting changes in vegetation. Our focus now is on explaining the spatial and temporal patterns of succession and understanding how these patterns influence ecosystem function. The most interesting new questions revolve around the degree to which the spatial variation in postfire vegetation in particular, the six orders of magnitude variation in pine sapling density, ranging from 0 to greater than 500,000 saplings/ha controls the spatial variability in ecosystem processes across the landscape. In our current research, we are conducting studies in both Grand Teton and Yellowstone National Parks to answer four major questions:

scholarly journals How Do Disturbance-Generated Patterns Influence the Spatial Dynamics of Ecoystem Processes

2002 ◽  
Vol 26 ◽  
pp. 123-125
Author(s):  
Monica Turner ◽  
William Romme ◽  
Daniel Tinker
Keyword(s):  
Spatial Variability ◽  
Spatial Variation ◽  
National Parks ◽  
Spatial Patterns ◽  
Ecosystem Function ◽  
Spatial Dynamics ◽  
Ecosystem Processes ◽  
Current Theory ◽  
Spatial And Temporal Patterns ◽  
Magnitude Variation

Our studies following the 1988 Yellowstone fires demonstrated that succession was surprisingly more variable in space and time than even current theory would have suggested, and that initial spatial patterns of disturbance may persist to produce long­lasting changes in vegetation. Our focus now is on explaining the spatial and temporal patterns of succession and understanding how these patterns influence ecosystem function. The most interesting new questions revolve around the degree to which the spatial variation in postfire vegetation in particular, the six orders of magnitude variation in pine sapling density, ranging from 0 to greater than 500,000 saplings/ha controls the spatial variability in ecosystem processes across the landscape. In our current research, we are conducting studies in both Grand Teton and Yellowstone National Parks to answer four major questions:

scholarly journals How Do Disturbance Generated Patterns Influence the Spatial Dynamics of Ecosystem Processes?

2005 ◽  
Vol 29 ◽  
pp. 59-60
Author(s):  
Monica Turner ◽  
William Romme ◽  
Daniel Tinker
Keyword(s):  
Spatial Variability ◽  
Spatial Variation ◽  
Spatial Patterns ◽  
Ecosystem Function ◽  
Spatial Dynamics ◽  
Temporal Patterns ◽  
Ecosystem Processes ◽  
Current Theory ◽  
Spatial And Temporal Patterns ◽  
Magnitude Variation

Our studies following the 1988 Yellowstone fires demonstrated that succession was surprisingly more variable in space and time than even current theory would have suggested, and that initial spatial patterns of disturbance may persist to produce long­lasting changes in vegetation. Our focus now is on explaining the spatial and temporal patterns of succession and understanding how these patterns influence ecosystem function. The most interesting new questions revolve around the degree to which the spatial variation in postfire vegetation -- in particular, the six orders of magnitude variation in pine sapling density, ranging from 0 to greater than 500,000 saplings/ha --controls the spatial variability in ecosystem processes across the landscape.

scholarly journals Spatial and Temporal Patterns in Post-Fire Nitrogen Dynamics of Lodgepole Pine Forests in the Greater Yellowstone Ecosystem

2001 ◽  
Vol 25 ◽  
pp. 149-150
Author(s):  
Monica Turner ◽  
William Romme ◽  
Daniel Tinker
Keyword(s):  
National Parks ◽  
Ecosystem Processes ◽  
Landscape Patterns ◽  
Spatial And Temporal Variation ◽  
Limiting Factor ◽  
Greater Yellowstone Ecosystem ◽  
Spatial And Temporal Patterns ◽  
Research Attention ◽  
Greater Yellowstone

Our study addresses the effects of fire­generated landscape patterns, or variability in structure and composition of successional forest communities, on ecosystem processes such as biogeochemical cycling and productivity. Forest fire is a well-studied disturbance, yet little is known about the long-term implications of a fire-generated landscape mosaic for ecosystem processes. In particular, the dynamics of nitrogen turnover, availability, and sequestration following stand­replacing fire in conifer forests, has received surprisingly little research attention, even though nitrogen is thought to be a limiting factor in most coniferous forests (Smithwick et al. in press). Our current work in Grand Teton and Yellowstone National Parks builds on our previous and continuing long-term studies of the causes and consequences of fire in the Greater Yellowstone Ecosystem (Turner et al. 2003). The fires of 2000 provided new opportunities for studying spatial and temporal variation in ecosystem processes soon after severe disturbances and how these patterns develop and change through time.

scholarly journals Inter-community variability in total particle number concentrations in the eastern Los Angeles air basin

2010 ◽  
Vol 10 (23) ◽  
pp. 11385-11399 ◽  
Author(s):  
N. Hudda ◽  
K. Cheung ◽  
K. F. Moore ◽  
C. Sioutas
Keyword(s):  
Los Angeles ◽  
Spatial Variability ◽  
Spatial Variation ◽  
Urban Areas ◽  
Particle Number ◽  
Meteorological Conditions ◽  
Monitoring Station ◽  
Size Distributions ◽  
Central Monitoring ◽  
Seasonal And Diurnal Variations

Abstract. Ultrafine Particles (UFP) can display sharp gradients in their number concentrations in urban environment due to their transient nature and rapid atmospheric processing. The ability of using air pollution data generated at a central monitoring station to assess exposure relies on our understanding of the spatial variability of a specific pollutant associated with a region. High spatial variation in the concentrations of air pollutants has been reported at scales of 10s of km for areas affected by primary emissions. Spatial variability in particle number concentrations (PNC) and size distributions needs to be investigated, as the representativeness of a monitoring station in a region is premised on the assumption of homogeneity in both of these metrics. This study was conducted at six sites, one in downtown Los Angeles and five located about 40–115 km downwind in the receptor areas of Los Angeles air basin. PNC and size distribution were measured using Condensation Particle Counters (CPC) and Scanning Mobility Particle Sizer (SMPS). The seasonal and diurnal variations of PNC implied that PNC might vary significantly with meteorological conditions, even though the general patterns at the sites may remain generally similar across the year due to consistency of sources around them. Regionally transported particulate matter (PM) from upwind urban areas of Los Angeles lowered spatial variation by acting as a "homogenizing" factor during favorable meteorological conditions. Spatial variability also increased during hours of the day during which the effects of local sources predominate. The spatial variability associated with PNC (quantified using Coefficients of Divergence, CODs), averaged about 0.3, which was generally lower than that based on specific size ranges. Results showed an inverse relationship of COD with particles size, with fairly uniform values in the particle range which is associated with regional transport. Our results suggest that spatial variability, even in the receptor regions of Los Angeles Basin, should be assessed for both PNC and size distributions, and should be interpreted in context of seasonal and diurnal influences, and suitably factored if values for exposure are ascertained using a central monitoring station.

Spatial dynamics of soil moisture and temperature in a black spruce boreal chronosequence

2006 ◽  
Vol 36 (11) ◽  
pp. 2794-2802 ◽  
Author(s):  
Ben Bond-Lamberty ◽  
Karen M Brown ◽  
Carol Goranson ◽  
Stith T Gower
Keyword(s):  
Soil Moisture ◽  
Spatial Variability ◽  
Sampling Design ◽  
Black Spruce ◽  
Structural Characteristics ◽  
Spatial Dynamics ◽  
Spherical Model ◽  
Local Scale ◽  
Spatial Dependencies ◽  
The Mean

This study analyzed the spatial dependencies of soil moisture and temperature in a six-stand chronosequence of boreal black spruce (Picea mariana (Mill.) BSP) stands. Spatial variability of soil temperature (TSOIL) was evaluated twice during the growing season using four transects in each stand, employing a cyclic sampling design with measurements spaced 2–92 m apart. Soil moisture (θg) was measured on one occasion. A spherical model was used to analyze the geostatistical correlation structure; θg and TSOIL at the 7- and 21-year-old stands did not exhibit stable ranges or sills. The fits with stable ranges and sills modeled the spatial patterns in the older stands reasonably well, although unexplained variability was high. Calculated ranges varied from 3 to 150 m for these stands, lengths probably related to structural characteristics influential in local-scale energy transfer. Transect-to-transect variability was significant and typically 5%–15% of the mean for TSOIL and 10%–70% for θg. TSOIL and θg were negatively correlated for most stands and depths, with TSOIL dropping 0.5–0.9 °C for every 1% rise in θg. The results reported here provide initial data to assess the spatial variability of TSOIL and θg in a variety of boreal forest stand ages.

scholarly journals Microbes as Engines of Ecosystem Function: When Does Community Structure Enhance Predictions of Ecosystem Processes?

2016 ◽  
Vol 7 ◽  
Author(s):  
Emily B. Graham ◽  
Joseph E. Knelman ◽  
Andreas Schindlbacher ◽  
Steven Siciliano ◽  
Marc Breulmann ◽  
...  
Keyword(s):  
Community Structure ◽  
Ecosystem Function ◽  
Ecosystem Processes

scholarly journals Spatial Pattern Oriented Multi-Criteria Sensitivity Analysis of a Distributed Hydrologic Model

2018 ◽  
Author(s):  
Mehmet Cüneyd Demirel ◽  
Julian Koch ◽  
Gorka Mendiguren ◽  
Simon Stisen
Keyword(s):  
Sensitivity Analysis ◽  
Spatial Variability ◽  
Spatial Pattern ◽  
Spatial Patterns ◽  
Performance Measures ◽  
Sampling Strategy ◽  
Behavioral Model ◽  
Hydrologic Model ◽  
Actual Evapotranspiration ◽  
Model Parameters

Hydrologic models are conventionally constrained and evaluated using point measurements of streamflow, which represents an aggregated catchment measure. As a consequence of this single objective focus, model parametrization and model parameter sensitivity are typically not reflecting other aspects of catchment behavior. Specifically for distributed models, the spatial pattern aspect is often overlooked. Our paper examines the utility of multiple performance measures in a spatial sensitivity analysis framework to determine the key parameters governing the spatial variability of predicted actual evapotranspiration (AET). Latin hypercube one-at-a-time (LHS-OAT) sampling strategy with multiple initial parameter sets was applied using the mesoscale hydrologic model (mHM) and a total of 17 model parameters were identified as sensitive. The results indicate different parameter sensitivities for different performance measures focusing on temporal hydrograph dynamics and spatial variability of actual evapotranspiration. While spatial patterns were found to be sensitive to vegetation parameters, streamflow dynamics were sensitive to pedo-transfer function (PTF) parameters. Above all, our results show that behavioral model definition based only on streamflow metrics in the generalized likelihood uncertainty estimation (GLUE) type methods require reformulation by incorporating spatial patterns into the definition of threshold values to reveal robust hydrologic behavior in the analysis.

The effect of spatially variable overstory on the understory light environment of an open-canopied longleaf pine forest

2002 ◽  
Vol 32 (11) ◽  
pp. 1984-1991 ◽  
Author(s):  
Michael A Battaglia ◽  
Pu Mou ◽  
Brian Palik ◽  
Robert J Mitchell
Keyword(s):  
Spatial Variation ◽  
Spatial Patterns ◽  
Longleaf Pine ◽  
Light Availability ◽  
Canopy Structure ◽  
Basal Area ◽  
Pinus Palustris ◽  
Pine Forest ◽  
Large Group ◽  
The Relationship

Spatial aggregation of forest structure strongly regulates understory light and its spatial variation in longleaf pine (Pinus palustris Mill.) forest ecosystems. Previous studies have demonstrated that light availability strongly influences longleaf pine seedling growth. In this study, the relationship between spatial structure of a longleaf pine forest and spatial pattern of understory light availability were investigated by comparing three retention harvest treatments: single-tree, small-group, large-group, and an uncut control. The harvests retained similar residual basal area but the spatial patterns of the residual trees differed. Hemispherical photographs were taken at 300 stations to calculate gap light index (GLI), an estimate of understory light availability. Stand-level mean, variation, and spatial distribution of GLI were determined for each treatment. By aggregating residual trees, stand mean GLI increased by 20%, as well as its spatial variation. Spatial autocorrelation of GLI increased as the size of the canopy gaps increased and the gaps were better defined; thus, the predictability of GLI was enhanced. The ranges of detrended semivariograms were increased from the control to the large-group harvest indicating the spatial patterns of understory GLI became coarser textured. Our results demonstrated that aggregated canopy structure of longleaf pine forest will facilitate longleaf pine seedling regeneration.

Variability in organic matter lost by combustion in a boreal bog during the 2001 Chisholm fire

2003 ◽  
Vol 33 (12) ◽  
pp. 2509-2513 ◽  
Author(s):  
Brian W Benscoter ◽  
R Kelman Wieder
Keyword(s):  
Organic Matter ◽  
Species Composition ◽  
Spatial Variability ◽  
Spatial Variation ◽  
Fire Severity ◽  
Small Scale ◽  
Western Canada ◽  
Direct Combustion ◽  
Site Variation

Fire directly releases carbon (C) to the atmosphere through combustion of biomass. An estimated 1470 ± 59 km2 of peatland burns annually in boreal, western Canada, releasing 4.7 ± 0.6 Tg C to the atmosphere via direct combustion. We quantified within-site variation in organic matter lost via combustion in a bog peatland in association with the 116 000-ha Chisholm, Alberta, fire in 2001. We hypothesized that for peatlands with considerable small-scale microtopography (bogs and treed fens), hummocks will burn less than hollows. We found that hollows exhibit more combustion than hummocks, releasing nearly twice as much C to the atmosphere. Our results suggest that spatial variability in species composition and site hydrology within a landform and across a landscape could contribute to considerable spatial variation in the amounts of C released via combustion during peatland fire, although the magnitude of this variation may be dependent on fire severity.

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