Spatial and temporal variation in the diet of double-crested cormorants (Phalacrocorax auritus) breeding on the lower Great Lakes in the early 1990s

1997 ◽  
Vol 54 (7) ◽  
pp. 1569-1584 ◽  
Author(s):  
J Neuman ◽  
D L Pearl ◽  
P J Ewins ◽  
R Black ◽  
D V Weseloh ◽  
...  
Keyword(s):  
Great Lakes ◽  
Breeding Season ◽  
Prey Species ◽  
Extensive Study ◽  
Spatial And Temporal Variation ◽  
Phalacrocorax Auritus ◽  
Temporal And Spatial Variation ◽  
Preferred Habitat ◽  
Spatial And Temporal Heterogeneity ◽  
Temporal And Spatial

We sampled 1573 pellets and 560 boli regurgitated at double-crested cormorant (Phalacrocorax auritus) colonies on the three lower Laurentian Great Lakes (Lake Ontario, Lake Huron, and Lake Erie) during the breeding season in 1992 and 1994. This constitutes the first extensive study of cormorant diet in this region. We found significant spatial and temporal heterogeneity in diet among colonies within a lake. Differences in diet among colonies were usually consistent with knowledge of changes in fish behaviour during the cormorant breeding season, differences in the surrounding bathymetry among breeding colonies, and the proximity of colonies to the preferred habitat of prey species. Our results indicate that temporal and spatial variation, as well as the technique for diet determination, are very important factors that must be considered when assessing the effects of double-crested cormorant predation on fisheries.

Temporal and spatial variation in the energy intake of a brook trout (Salvelinus fontinalis) population in an Appalachian watershed

2006 ◽  
Vol 63 (12) ◽  
pp. 2675-2686 ◽  
Author(s):  
Ryan M Utz ◽  
Kyle J Hartman
Keyword(s):  
Energy Intake ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Stomach Contents ◽  
Spatial And Temporal Variation ◽  
Feeding Rates ◽  
Temporal And Spatial Variation ◽  
The Mean ◽  
Temporal And Spatial ◽  
Very High

Stream-dwelling salmonids in eastern North America are often restricted to headwater watersheds, where productivity is low and thus feeding conditions are poor. We sought to quantify how energy intake varies with spatial and temporal variation by monitoring feeding rates in multiple sites over the course of two years. Daily rations were calculated for 939 fish by examining stomach contents. Maintenance rations were compared with daily rations using a bioenergetics model. Consumption peaked in spring, dropped substantially in summer, and remained low until the following spring. A minority of fish fed at very high levels during all seasons, elevating the mean consumption of the population. Fish occupying large sites with low trout densities consistently consumed more energy than fish in smaller streams with high trout densities. A direct relationship between trout density and mean consumption was observed during summer, when feeding conditions were poorest. Our findings suggest that within a headwater watershed, larger reaches of streams where fewer trout are found act as important feeding areas and thus may be important habitat for brook trout (Salvelinus fontinalis).

Defining Recovery and Detecting when IT Occurs

2003 ◽  
Vol 2003 (1) ◽  
pp. 559-564 ◽  
Author(s):  
Keith R. Parker ◽  
Alan W. Maki
Keyword(s):  
Time Series Data ◽  
Recovery Process ◽  
Statistical Analyses ◽  
Series Data ◽  
Spatial And Temporal Variation ◽  
Anthropogenic Influences ◽  
Temporal And Spatial Variation ◽  
Temporal And Spatial ◽  
Corroborative Evidence ◽  
The Impact

ABSTRACT We define recovery of a biological resource as occurring when the injured resource reaches the state it would have been, had the impact not occurred. The recovery process, and natural spatial and temporal variation affect the abundance of an injured resource and will confound to either delay or accelerate detection of recovery. The effects of natural variation can be reduced by sampling design and statistical analyses, both of which remove potentially confounding influences of temporal and spatial variation. Reference areas are useful when they respond in the same way as the impacted areas to changes in climate and anthropogenic influences. Historical data and time series data collected after the impact event are useful for detecting recovery and for assessing ecological assumptions implied in statistical analyses. Corroborative evidence from co-occurring studies of toxicity and chemistry, and supplementary data on regional changes in climate and abundance can be useful for assessing recovery. Examples from the 1989 Exxon Valdez oil spill show that full recovery of oiled shorelines and seabirds occurred in the early 1990s.

Temporal and Spatial Variation of Vegetation Coverage in Beijing-Tianjin-Hebei Metropolis Circle with MODIS Vegetation Indices Data Product

2012 ◽  
Vol 500 ◽  
pp. 123-129
Author(s):  
Ya Qing Li ◽  
Xiao Juan Li ◽  
Jian Lian ◽  
Rong Hua Wang
Keyword(s):  
Spatial Variation ◽  
Vegetation Indices ◽  
Vegetation Coverage ◽  
Spatial And Temporal Variation ◽  
Distribution Data ◽  
Temporal And Spatial Variation ◽  
Mean Values ◽  
Modis Ndvi ◽  
Data Product ◽  
Temporal And Spatial

This paper describes the temporal and spatial variation of vegetation coverage in Beijing-Tianjin-Hebei Metropolis circle using 1km MODIS vegetation indices data product (MOD13A3), and the main satellite data used in this study were MODIS NDVI and EVI data, city borderline data and DEM. After processing data with ENVI software, the time-series maps of the NDVI and EVI were drawn by ArcMap software, and the curve charts were formed by Excel. By using the temperature, rainfall data and vegetation distribution data, the spatial and temporal variation of the VI was analyzed. The results shows that the MODIS VIs varies with season, and the curves of their monthly mean values are downwards opening quadratic parabolas, with the maximum appeared in June and July. The spatial distribution of MODIS vegetation indices is positively correlated with vegetation coverage, and appeared regional characteristics. The vegetation coverage of Beijing-Tianjin-Hebei Metropolis circle has obviously increased during the past years, due to the ecological project operated in the research region.

scholarly journals Phylogenetic paleoecology: macroecology within an evolutionary framework

Paleobiology ◽  
2021 ◽  
Vol 47 (2) ◽  
pp. 171-177
Author(s):  
James C. Lamsdell ◽  
Curtis R. Congreve
Keyword(s):  
Species Diversity ◽  
Spatial Variation ◽  
Geographic Distribution ◽  
Evolutionary Biology ◽  
Phylogenetic Signal ◽  
Evolutionary Rates ◽  
The Other ◽  
Ecological Data ◽  
Temporal And Spatial Variation ◽  
Temporal And Spatial

The burgeoning field of phylogenetic paleoecology (Lamsdell et al. 2017) represents a synthesis of the related but differently focused fields of macroecology (Brown 1995) and macroevolution (Stanley 1975). Through a combination of the data and methods of both disciplines, phylogenetic paleoecology leverages phylogenetic theory and quantitative paleoecology to explain the temporal and spatial variation in species diversity, distribution, and disparity. Phylogenetic paleoecology is ideally situated to elucidate many fundamental issues in evolutionary biology, including the generation of new phenotypes and occupation of previously unexploited environments; the nature of relationships among character change, ecology, and evolutionary rates; determinants of the geographic distribution of species and clades; and the underlying phylogenetic signal of ecological selectivity in extinctions and radiations. This is because phylogenetic paleoecology explicitly recognizes and incorporates the quasi-independent nature of evolutionary and ecological data as expressed in the dual biological hierarchies (Eldredge and Salthe 1984; Congreve et al. 2018; Fig. 1), incorporating both as covarying factors rather than focusing on one and treating the other as error within the dataset.

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