An evaluation of spatial and temporal patterns of lightning- and human-caused forest fires in Alberta, Canada, 1980 - 2007

2010 ◽  
Vol 19 (8) ◽  
pp. 1059 ◽  
Author(s):  
Yonghe Wang ◽  
Kerry R. Anderson
Keyword(s):  
Spatial Patterns ◽  
Forest Fires ◽  
Spatial Information ◽  
Fire Suppression ◽  
Kernel Estimation ◽  
Temporal Patterns ◽  
Estimation Methods ◽  
Spatial And Temporal Patterns ◽  
Kernel Analysis ◽  
Southern Alberta

We used the K-function and kernel estimation methods to evaluate the spatial and temporal patterns of ignition locations of lightning- and human-caused forest fires in Alberta, Canada. Although both of these fire types have spatial patterns of cluster distribution, quantitative measures for evaluating the patterns in the province are lacking. Our results revealed annual differences in the spatial patterns between the two fire types, whereby fires caused by humans tended to be more clustered and had more complex spatial patterns than those caused by lightning. Spatial interactions of cluster and inhibition existed between the two fire types. Human-caused fires in the period 2003–07 were highly concentrated in the southern parts of the province, indicating the existence of an interaction between space and time. Kernel analysis confirmed the observation that in northern Alberta, lightning-caused fires were more likely to occur than human-caused fires; the opposite was true in southern Alberta. This study provided useful spatial information that is not obvious or cannot be inferred from visual examination of raw data. Such quantitative knowledge could lead to the development of fire-response and fire-suppression strategies appropriate to specific regions within the province.

scholarly journals Spatial and temporal patterns of carbon emissions from forest fires in China from 1950 to 2000

2006 ◽  
Vol 111 (D5) ◽  
Author(s):  
Aifeng Lü ◽  
Hanqin Tian ◽  
Mingliang Liu ◽  
Jiyuan Liu ◽  
Jerry M. Melillo
Keyword(s):  
Carbon Emissions ◽  
Forest Fires ◽  
Temporal Patterns ◽  
Spatial And Temporal Patterns

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 distribution patterns of tick-borne diseases (Tick-borne Encephalitis and Lyme Borreliosis) in Germany

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12422
Author(s):  
Sarah Cunze ◽  
Gustav Glock ◽  
Sven Klimpel
Keyword(s):  
Spatial Patterns ◽  
Lyme Borreliosis ◽  
Temporal Distribution ◽  
Temporal Patterns ◽  
Weather Conditions ◽  
Driving Factors ◽  
Spatial And Temporal Patterns ◽  
Federal States ◽  
Reporting Practices ◽  
Tick Borne Encephalitis

Background In the face of ongoing climate warming, vector-borne diseases are expected to increase in Europe, including tick-borne diseases (TBD). The most abundant tick-borne diseases in Germany are Tick-Borne Encephalitis (TBE) and Lyme Borreliosis (LB), with Ixodes ricinus as the main vector. Methods In this study, we display and compare the spatial and temporal patterns of reported cases of human TBE and LB in relation to some associated factors. The comparison may help with the interpretation of observed spatial and temporal patterns. Results The spatial patterns of reported TBE cases show a clear and consistent pattern over the years, with many cases in the south and only few and isolated cases in the north of Germany. The identification of spatial patterns of LB disease cases is more difficult due to the different reporting practices in the individual federal states. Temporal patterns strongly fluctuate between years, and are relatively synchronized between both diseases, suggesting common driving factors. Based on our results we found no evidence that weather conditions affect the prevalence of both diseases. Both diseases show a gender bias with LB bing more commonly diagnosed in females, contrary to TBE being more commonly diagnosed in males. Conclusion For a further investigation of of the underlying driving factors and their interrelations, longer time series as well as standardised reporting and surveillance system would be required.

The macroinvertebrate fauna of an Australian dryland river: spatial and temporal patterns and environmental relationships

2006 ◽  
Vol 57 (1) ◽  
pp. 61 ◽  
Author(s):  
Jonathan C. Marshall ◽  
Fran Sheldon ◽  
Martin Thoms ◽  
Satish Choy
Keyword(s):  
Spatial Patterns ◽  
Spatial Scales ◽  
Temporal Patterns ◽  
Environmental Aspects ◽  
Spatial And Temporal Patterns ◽  
Channel Network ◽  
Spatial Changes ◽  
Dryland River ◽  
Macroinvertebrate Fauna

Waterholes within the dryland Cooper Creek, Lake Eyre Basin, Australia, are connected only during floods and are typically isolated for long periods. Spatial changes in the macroinvertebrate assemblages of 15 of these waterholes belonging to four regions were explored and these changes were related to environmental aspects of the waterholes measured at four spatial scales: floodplain, waterhole, within waterhole and sample habitat. To explore temporal patterns, one region was sampled on four occasions differing in time since connection. Spatial patterns were characterised by ‘differentiation by distance’ whereby samples collected closer to each other in the landscape were more similar in assemblage composition than those collected further apart. Thus, there were significant differences between the assemblages of the four regions. Although there was a correlation between macroinvertebrate spatial patterns and a combination of local habitat, geomorphology and water chemistry attributes, it appears unlikely that these variables were responsible for the faunal differentiation by distance. Temporal variability was larger than spatial variability and temporal assemblage patterns were best explained by the ‘connectivity potential’ of waterholes, reflecting the position of individual waterholes within the broader channel network and long-term connectivity relationships, rather than the actual time since hydrological connection.

Biodiversity and pedodiversity: a matter of coincidence? .

2014 ◽  
Vol 2 ◽  
Author(s):  
Juan José Ibáñez Martí ◽  
Asunción Saldaña ◽  
Dilier Olivera
Keyword(s):  
Comparative Study ◽  
Natural Resources ◽  
Spatial Patterns ◽  
Temporal Patterns ◽  
Digital Data ◽  
Ecological Studies ◽  
Spatial And Temporal Patterns ◽  
Theoretical Concepts

The concept of diversity has been widely used in ecological studies, although mainly for the biotic component (biodiversity). Regrettably, the effects of abiotic structures (e.g. soils) on the biotic components of ecosystems, landscapes and biomes are still a matter of discussion. We examined the similarity and differences in spatial and temporal patterns between biodiversity and pedodiversity. This comparative study was possible because of the increased availability of digital data on soils and other natural resources at various scales for pedodiversity analysis using the same theoretical concepts and tools applied by ecologists for biodiversity analyses. Remarkably, the spatial patterns of pedogeographic units detected by pedologists are similar to those reported by biologists for a plethora of ecosystems.

Spatial and temporal patterns in Australian wheat yield and their relationship with ENSO

2002 ◽  
Vol 53 (1) ◽  
pp. 77 ◽  
Author(s):  
A. B. Potgieter ◽  
G. L. Hammer ◽  
D. Butler
Keyword(s):  
Spatial Patterns ◽  
Southern Oscillation ◽  
Wheat Yield ◽  
Temporal Patterns ◽  
Stress Index ◽  
Wheat Crop ◽  
Spatial And Temporal Variability ◽  
Spatial And Temporal Patterns ◽  
Yield Data ◽  
Australian Wheat

Spatial and temporal variability in wheat production in Australia is dominated by rainfall occurrence. The length of historical production records is inadequate, however, to analyse spatial and temporal patterns conclusively. In this study we used modelling and simulation to identify key spatial patterns in Australian wheat yield, identify groups of years in the historical record in which spatial patterns were similar, and examine association of those wheat yield year groups with indicators of the El Niño Southern Oscillation (ENSO). A simple stress index model was trained on 19 years of Australian Bureau of Statistics shire yield data (1975–93). The model was then used to simulate shire yield from 1901 to 1999 for all wheat-producing shires. Principal components analysis was used to determine the dominating spatial relationships in wheat yield among shires. Six major components of spatial variability were found. Five of these represented near spatially independent zones across the Australian wheatbelt that demonstrated coherent temporal (annual) variability in wheat yield. A second orthogonal component was required to explain the temporal variation in New South Wales. The principal component scores were used to identify high- and low-yielding years in each zone. Year type groupings identified in this way were tested for association with indicators of ENSO. Significant associations were found for all zones in the Australian wheatbelt. Associations were as strong or stronger when ENSO indicators preceding the wheat season (April–May phases of the Southern Oscillation Index) were used rather than indicators based on classification during the wheat season. Although this association suggests an obvious role for seasonal climate forecasting in national wheat crop forecasting, the discriminatory power of the ENSO indicators, although significant, was not strong. By examining the historical years forming the wheat yield analog sets within each zone, it may be possible to identify novel climate system or ocean–atmosphere features that may be causal and, hence, most useful in improving seasonal forecasting schemes.

scholarly journals Direct Visualization of Spatial and Temporal Patterns of Antimicrobial Action within Model Oral Biofilms

2008 ◽  
Vol 74 (6) ◽  
pp. 1869-1875 ◽  
Author(s):  
Shoji Takenaka ◽  
Harsh M. Trivedi ◽  
Audrey Corbin ◽  
Betsey Pitts ◽  
Philip S. Stewart
Keyword(s):  
Spatial Information ◽  
Capillary Flow ◽  
Temporal Patterns ◽  
Laser Scanning Microscopy ◽  
Antimicrobial Action ◽  
Confocal Laser ◽  
Green Fluorescence ◽  
Spatial And Temporal Patterns ◽  
Bulk Fluid ◽  
Oral Biofilms

ABSTRACT A microscopic method for noninvasively visualizing the action of an antimicrobial agent inside a biofilm was developed and applied to describe spatial and temporal patterns of mouthrinse activity on model oral biofilms. Three species biofilms of Streptococcus oralis, Streptococcus gordonii, and Actinomyces naeslundii were grown in glass capillary flow cells. Bacterial cells were stained with the fluorogenic esterase substrate Calcien AM (CAM). Loss of green fluorescence upon exposure to an antimicrobial formulation was subsequently imaged by time-lapse confocal laser scanning microscopy. When an antimicrobial mouthrinse containing chlorhexidine digluconate was administered, a gradual loss of green fluorescence was observed that began at the periphery of cell clusters where they adjoined the flowing bulk fluid and progressed inward over a time period of several minutes. Image analysis was performed to quantify a penetration velocity of 4 μm/min. An enzyme-based antimicrobial formulation led to a gradual, continually slowing loss of fluorescence in a pattern that was qualitatively different from the behavior observed with chlorhexidine. Ethanol at 11.6% had little effect on the biofilm. None of these treatments resulted in the removal of biomass from the biofilm. Most methods to measure or visualize antimicrobial action in biofilms are destructive. Spatial information is important because biofilms are known for their structural and physiological heterogeneity. The CAM staining technique has the potential to provide information about the rate of antimicrobial penetration, the presence of tolerant subpopulations, and the extent of biomass removal effected by a treatment.

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