scholarly journals Partitioning the variation in stream fish assemblages within a spatio-temporal hierarchy

2007 ◽  
Vol 58 (7) ◽  
pp. 675 ◽  
Author(s):  
Ben Stewart-Koster ◽  
Mark J. Kennard ◽  
Bronwyn D. Harch ◽  
Fran Sheldon ◽  
Angela H. Arthington ◽  
...  
Keyword(s):  
Temporal Variation ◽  
Total Variation ◽  
Fish Assemblages ◽  
Environmental Variation ◽  
Spatial And Temporal Variation ◽  
Spatial Effects ◽  
Explanatory Variables ◽  
Spatio Temporal ◽  
Variation Explained ◽  
Stream Fish Assemblages

This paper describes the relative influence of (i) landscape scale environmental and hydrological factors, (ii) local scale environmental conditions including recent flow history, and (iii) spatial effects (proximity of sites to one another), on the spatial and temporal variation in local freshwater fish assemblages in the Mary River, south-eastern Queensland, Australia. Using canonical correspondence analysis, each of the three sets of variables explained similar amounts of variation in fish assemblages (ranging from 44 to 52%). Variation in fish assemblages was partitioned into eight unique components: pure environmental, pure spatial, pure temporal, spatially structured environmental variation, temporally structured environmental variation, spatially structured temporal variation, the combined spatial/temporal component of environmental variation and unexplained variation. The total variation explained by these components was 65%. The combined spatial/temporal/environmental component explained the largest component (30%) of the total variation in fish assemblages, whereas pure environmental (6%), temporal (9%) and spatial (2%) effects were relatively unimportant. The high degree of intercorrelation between the three different groups of explanatory variables indicates that our understanding of the importance to fish assemblages of hydrological variation (often highlighted as the major structuring force in river systems) is dependent on the environmental context in which this role is examined.

Spatial and temporal variation in assemblages of Lutjanidae, Lethrinidae and associated fish species among mid-continental shelf reefs in the central Great Barrier Reef

2001 ◽  
Vol 52 (6) ◽  
pp. 843 ◽  
Author(s):  
Stephen J. Newman ◽  
David McB. Williams
Keyword(s):  
Continental Shelf ◽  
Temporal Variation ◽  
Fish Assemblages ◽  
Spatial And Temporal Variation ◽  
Shallow Trap ◽  
Fish Traps ◽  
Lutjanus Carponotatus ◽  
Plectropomus Leopardus ◽  
Trap Catches ◽  
Over Time

Visual censuses were used to survey shallow-water assemblages of the Lutjanidae and Lethrinidae among three mid-continental shelf reefs, and fish traps were used to survey deeper water assemblages below diveable depths. Significant differences were found in visual censuses of the Lutjanidae and Lethrinidae among reefs. Trap catches of the Lutjanidae and Lethrinidae varied more between depths and diel sampling periods than among reefs or over time. Lutjanus carponotatus, L. fulviflamma and Lethrinus miniatus were more abundant in shallow trap sets, whereas Lutjanus adetii, L. russelli, L. sebae, L. vitta, Gymnocranius audleyi, Lethrinus sp.2 and Abalistes stellaris were more abundant in deeper sets. Additionally, Lutjanus adetii, L. fulviflamma, L. quinquelineatus, L. russelli, L. sebae, L. vitta and Lethrinus miniatus were more abundant at night, whereas Lethrinus sp. 2, Abalistes stellarisand Plectropomus leopardus were more abundant during the day. The absence of significant temporal variation in the observed spatial patterns both among reefs and between depths indicates that these patterns may persist through time. The use of both visual censuses and fish traps to assess reef fish assemblages may provide an objective way of repeatedly censusing reefs for monitoring purposes, especially where differences among reefs and regions are important.

Spatial and temporal variation in morphology in Australian whistlers and shrike-thrushes: is climate change causing larger appendages?

2020 ◽  
Vol 130 (1) ◽  
pp. 101-113
Author(s):  
Isabelle R Onley ◽  
Janet L Gardner ◽  
Matthew R E Symonds
Keyword(s):  
Climate Change ◽  
Body Size ◽  
Temporal Variation ◽  
Relative Size ◽  
Bird Species ◽  
Spatial And Temporal Variation ◽  
Climatic Warming ◽  
Morphological Response ◽  
Allen’S Rule ◽  
Spatio Temporal

Abstract Allen’s rule is an ecogeographical pattern whereby the size of appendages of animals increases relative to body size in warmer climates in order to facilitate heat exchange and thermoregulation. Allen’s rule predicts that one consequence of a warming climate would be an increase in the relative size of appendages, and evidence from other bird species suggests that this might be occurring. Using measurements from museum specimens, we determined whether spatio-temporal variation in bills and legs of Australian Pachycephalidae species exhibits within-species trends consistent with Allen’s rule and increases in temperature attributable to climatic warming. We conducted regression model analyses relating appendage size to spatio-temporal variables, while controlling for body size. The relative bill size in four of the eight species was negatively associated with latitude. Tarsus length showed no significant trends consistent with Allen’s rule. No significant increases in appendage size were found over time. Although bill size in some species was positively correlated with warmer temperatures, the evidence was not substantial enough to suggest a morphological response to climatic warming. This study suggests that climate change is not currently driving adaptive change towards larger appendages in these species. We suggest that other adaptive mechanisms might be taking place.

scholarly journals What drives the spatial distribution and dynamics of local species richness in tropical forest?

2017 ◽  
Vol 284 (1863) ◽  
pp. 20171503 ◽  
Author(s):  
Thorsten Wiegand ◽  
Felix May ◽  
Martin Kazmierczak ◽  
Andreas Huth
Keyword(s):  
Species Richness ◽  
Tropical Forest ◽  
Temporal Variation ◽  
Tropical Forests ◽  
Temporal Variability ◽  
Dynamic Models ◽  
Neutral Theory ◽  
Spatial And Temporal Variation ◽  
Demographic Stochasticity ◽  
Spatio Temporal

Understanding the structure and dynamics of highly diverse tropical forests is challenging. Here we investigate the factors that drive the spatio-temporal variation of local tree numbers and species richness in a tropical forest (including 1250 plots of 20 × 20 m 2 ). To this end, we use a series of dynamic models that are built around the local spatial variation of mortality and recruitment rates, and ask which combination of processes can explain the observed spatial and temporal variation in tree and species numbers. We find that processes not included in classical neutral theory are needed to explain these fundamental patterns of the observed local forest dynamics. We identified a large spatio-temporal variability in the local number of recruits as the main missing mechanism, whereas variability of mortality rates contributed to a lesser extent. We also found that local tree numbers stabilize at typical values which can be explained by a simple analytical model. Our study emphasized the importance of spatio-temporal variability in recruitment beyond demographic stochasticity for explaining the local heterogeneity of tropical forests.

scholarly journals The Spatio-temporal Analysis of b-value in the Banda Arc, Indonesia

2021 ◽  
Vol 873 (1) ◽  
pp. 012010
Author(s):  
Muhammad Bani Al-Rasyid ◽  
Mira Nailufar Rusman ◽  
Daniel Hamonangan ◽  
Pepen Supendi ◽  
Kartika Hajar Kirana
Keyword(s):  
Temporal Variation ◽  
Temporal Analysis ◽  
B Value ◽  
Spatial And Temporal Variation ◽  
Tectonic Structure ◽  
Time Period ◽  
Banda Arc ◽  
Spatio Temporal ◽  
The Impact ◽  
Large Earthquakes

Abstract Banda arc is a complex tectonic structure manifests by high seismicity due to the collision of a continent and an intra-oceanic island arc. Using the relocated earthquakes data from ISC-EHB and BMKG catalogues from the time period of 1960 to 2018, we have conducted a spatial and temporal variation of b-value using the Guttenberg-Richter formula in the area. Our results show that the spatial distribution of low b-values located in the south of Ambon Island and southeast of Buru Island. On the other hand, the temporal variation of b-value shows a decrease in the northern part of the Banda sea probably high potential to produce large earthquakes in the future. Therefore, further mitigation is needed to minimize the impact of earthquakes in the area.

scholarly journals Hot spot detection and spatio-temporal dynamics of dengue in Queensland, Australia

2014 ◽  
Vol XL-8 ◽  
pp. 197-204 ◽  
Author(s):  
S. Naish ◽  
S. Tong
Keyword(s):  
Temporal Variation ◽  
Temporal Dynamics ◽  
Hot Spot ◽  
Seasonal Pattern ◽  
Temporal Distribution ◽  
Health Concern ◽  
Spatial And Temporal Variation ◽  
Dengue Case ◽  
Spatio Temporal ◽  
Over Time

Dengue has been a major public health concern in Australia since it re-emerged in Queensland in 1992–1993. This study explored spatio-temporal distribution and clustering of locally-acquired dengue cases in Queensland State, Australia and identified target areas for effective interventions. A computerised locally-acquired dengue case dataset was collected from Queensland Health for Queensland from 1993 to 2012. Descriptive spatial and temporal analyses were conducted using geographic information system tools and geostatistical techniques. Dengue hot spots were detected using SatScan method. Descriptive spatial analysis showed that a total of 2,398 locally-acquired dengue cases were recorded in central and northern regions of tropical Queensland. A seasonal pattern was observed with most of the cases occurring in autumn. Spatial and temporal variation of dengue cases was observed in the geographic areas affected by dengue over time. Tropical areas are potential high-risk areas for mosquito-borne diseases such as dengue. This study demonstrated that the locally-acquired dengue cases have exhibited a spatial and temporal variation over the past twenty years in tropical Queensland, Australia. There is a clear evidence for the existence of statistically significant clusters of dengue and these clusters varied over time. These findings enabled us to detect and target dengue clusters suggesting that the use of geospatial information can assist the health authority in planning dengue control activities and it would allow for better design and implementation of dengue management programs.

scholarly journals INVESTIGATING THE POTENTIAL OF ACTIVITY TRACKING APP DATA TO ESTIMATE CYCLE FLOWS IN URBAN AREAS

2016 ◽  
Vol XLI-B2 ◽  
pp. 515-519
Author(s):  
J. Haworth
Keyword(s):  
Temporal Variation ◽  
Intelligent Transportation Systems ◽  
Urban Areas ◽  
Temporal Structure ◽  
Transportation Systems ◽  
Spatial And Temporal Variation ◽  
Linear Regression Models ◽  
Activity Tracking ◽  
Spatio Temporal ◽  
On The Road

Traffic congestion and its associated environmental effects pose a significant problem for large cities. Consequently, promoting and investing in green travel modes such as cycling is high on the agenda for many transport authorities. In order to target investment in cycling infrastructure and improve the experience of cyclists on the road, it is important to know where they are. Unfortunately, investment in intelligent transportation systems over the years has mainly focussed on monitoring vehicular traffic, and comparatively little is known about where cyclists are on a day to day basis. In London, for example, there are a limited number of automatic cycle counters installed on the network, which provide only part of the picture. These are supplemented by surveys that are carried out infrequently. Activity tracking apps on smart phones and GPS devices such as Strava have become very popular over recent years. Their intended use is to track physical activity and monitor training. However, many people routinely use such apps to record their daily commutes by bicycle. At the aggregate level, these data provide a potentially rich source of information about the movement and behaviour of cyclists. Before such data can be relied upon, however, it is necessary to examine their representativeness and understand their potential biases. In this study, the flows obtained from Strava Metro (SM) are compared with those obtained during the 2013 London Cycle Census (LCC). A set of linear regression models are constructed to predict LCC flows using SM flows along with a number of dummy variables including road type, hour of day, day of week and presence/absence of cycle lane. Cross-validation is used to test the fitted models on unseen LCC sites. SM flows are found to be a statistically significant (p<0.0001) predictor of total flows as measured by the LCC and the models yield R squared statistics of ~0.7 before considering spatio-temporal variation. The initial results indicate that data collected using fitness tracking apps such as Strava are a promising data source for traffic managers. Future work will incorporate the spatio-temporal structure in the data to better account for the spatial and temporal variation in the ratio of SM flows to LCC flows.

scholarly journals EXPLORING SPATIAL AND TEMPORAL VARIATION WITHIN RESERVOIR FOOD WEBS: PREDICTIONS FOR FISH ASSEMBLAGES

1998 ◽  
Vol 8 (1) ◽  
pp. 104-120 ◽  
Author(s):  
James E. Garvey ◽  
Natalie A. Dingledine ◽  
Nicholas S. Donovan ◽  
Roy A. Stein
Keyword(s):  
Temporal Variation ◽  
Food Webs ◽  
Fish Assemblages ◽  
Spatial And Temporal Variation

scholarly journals Spatial and temporal distribution of drainage and solute leaching in heterogeneous urban vegetation environments

2013 ◽  
Vol 10 (5) ◽  
pp. 6695-6721
Author(s):  
H. Nouri ◽  
S. Beecham ◽  
A. M. Hassanli ◽  
G. Ingleton
Keyword(s):  
Temporal Variation ◽  
Vegetation Cover ◽  
Temporal Distribution ◽  
Drainage Water ◽  
Spatial And Temporal Variation ◽  
Temporal Behaviour ◽  
Drainage Rate ◽  
Spatio Temporal ◽  
Trees And Shrubs ◽  
Solute Leaching

Abstract. Deep percolation enhancement from recycled wastewater irrigation may contribute to salt accumulation and water table elevation that can ultimately cause soil and ground water degradation. The spatial and temporal variation of drainage rate and solute leaching were investigated in an urban park containing heterogeneous landscape plants that were irrigated with recycled wastewater. Field monitoring was undertaken at Veale Gardens in the Adelaide Parklands, Australia. Based on the landscape variation in Veale Gardens, two landscape zones were defined: one being largely covered with turf grasses with few trees and shrubs (MG) with the second zone being mostly trees and shrubs with intermittent turf grasses (MT). Experiments were performed using two zero-tension lysimeters placed horizontally 100 cm below ground to monitor the spatio-temporal behaviour of drained water and nutrient loadings for four seasons. The outcomes showed a large spatial and temporal variation of drainage quantity and quality in the MT and MG zones. The low vegetation cover in the MG zone resulted in more drained water than in the high vegetation cover (MT zone). In both zones, more drainage water was collected in winter than in other seasons. This is in spite of the input water showing a maximum rate in summer. The seasonal salinities measured in the two lysimeters showed very similar trends with the lowest salinity rate in autumn with the levels increasing through winter and spring. Chemical analyses of the leachate solute indicated no detrimental impact from using recycled wastewater during the study period.

scholarly journals Time or Space? Relative Importance of Geographic Distribution and Interannual Variation in Three Lineages of the Ascidian Pyura chilensis in the Southeast Pacific Coast

2021 ◽  
Vol 8 ◽  
Author(s):  
Pilar A. Haye ◽  
Xavier Turon ◽  
Nicolás I. Segovia
Keyword(s):  
Genetic Structure ◽  
Temporal Variation ◽  
Pacific Coast ◽  
Mitochondrial Gene ◽  
Temporal Stability ◽  
Spatial And Temporal Variation ◽  
Human Consumption ◽  
Genetic Lineages ◽  
Southeast Pacific ◽  
Spatio Temporal

Spatial and temporal variation of environmental parameters can affect dispersal, recruitment and population persistence of marine benthic species. Studies including inter-annual comparisons of genetic structure often indicate high/moderate temporal heterogeneity in marine invertebrates, which may be a prevailing pattern. This suggests that temporal studies are necessary to understand the dynamics of marine metapopulations. In this study, we analyzed the spatio-temporal genetic structure of the ascidian Pyura chilensis, a low dispersal sessile marine species endemic from the Southeast Pacific coast and highly demanded for human consumption. We sequenced a fragment of the mitochondrial gene Cytochrome Oxidase I (COI) from 1,005 individuals of six locations (30–40 individuals per site and year) spanning a wide latitudinal range (24°–42°S) and sampled over 5 years (2012, 2014, 2015, 2016, and 2017). The genetic structure of COI indicates the presence of three monophyletic lineages (haplogroups 1–3) previously described for the species, being one of them highly divergent and geographically restricted (~39°S, Los Molinos). Considering the whole dataset, a picture of strong spatial differentiation but temporal stability emerged in Pyura chilensis. However, detailed studies of the two main lineages revealed important differences in the extent of spatio-temporal variation. Analyses using haplotype frequencies sorted by site and year showed that, for haplogroup 1, genetic variation was explained mainly by differences between sites, while for haplogroup 2 differences between years were prevailing. Haplogroup 3 was restricted to the most southern sites, and also showed inter-annual variability in its frequency. These results point to disparate patterns of genetic differentiation, which may reflect different adaptive scope or variation in reproductive and dispersal features and could be a response to extreme events such as El Niño (2015–2016). This work calls for caution when obtaining general trends in species clearly differentiated in lineages, and prompts instead for separate analyses of sub-specific genetic lineages whenever possible.

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