scholarly journals Contrasting seasonal patterns of relative temperature and thermal heterogeneity and their influence on breeding and winter bird richness patterns across the conterminous United States

Ecography ◽  
2021 ◽  
Author(s):  
Paul R. Elsen ◽  
Laura S. Farwell ◽  
Anna M. Pidgeon ◽  
Volker C. Radeloff
Keyword(s):  
United States ◽  
Seasonal Patterns ◽  
Relative Temperature ◽  
Bird Richness ◽  
Thermal Heterogeneity ◽  
Richness Patterns

Concordance of taxonomic richness patterns across multiple assemblages in lakes of the northeastern United States

1999 ◽  
Vol 56 (5) ◽  
pp. 739-747 ◽  
Author(s):  
Andrew P. Allen ◽  
Thomas R. Whittier ◽  
Philip R. Kaufmann ◽  
David P. Larsen ◽  
Raymond J. O'Connor ◽  
...  
Keyword(s):  
United States ◽  
Taxonomic Richness ◽  
Northeastern United States ◽  
Richness Patterns

Thermal heterogeneity in the hyporheic zone of a glacial floodplain

2001 ◽  
Vol 58 (7) ◽  
pp. 1319-1335 ◽  
Author(s):  
Florian Malard ◽  
Alain Mangin ◽  
Urs Uehlinger ◽  
J V Ward
Keyword(s):  
Surface Waters ◽  
Hyporheic Zone ◽  
Ecosystem Processes ◽  
Seasonal Patterns ◽  
Time Lags ◽  
Channel Network ◽  
Alluvial Groundwater ◽  
Summer Temperatures ◽  
Thermal Heterogeneity ◽  
Different Sources

We examined the thermal regime of surface and hyporheic waters at three kryal sites and four krenal streams within the channel network of a glacial floodplain. Temperature was continuously measured for 1 year in the surface stream and at sediment depths of 30 and 80 cm. The vertical pattern of water temperature was strongly influenced by the direction and intensity of surface water – groundwater exchanges. At sites characterized by strong downwelling of surface waters, the thermal regimes of surface and hyporheic waters were virtually identical. In contrast, inputs of groundwater substantially increased mean summer temperatures in the hyporheic zone of the main kryal channel, decreased summer temperatures in the hyporheic zone of krenal streams, and elevated hyporheic temperatures of all stream types during winter. Groundwater from different sources had dramatically different effects on the seasonal regime of temperature in the hyporheic zone. Inflow of shallow alluvial groundwater had minimal effects on seasonal patterns of hyporheic temperature, whereas upwelling from deep alluvial and hillslope aquifers resulted in significant time lags and differences in seasonal amplitudes between surface and hyporheic temperatures. The unexpectedly high thermal heterogeneity of hyporheic waters presumably sustains biodiversity and stimulates ecosystem processes in this glacial floodplain.

Seasonal Patterns of Spontaneous Abortion

1992 ◽  
Vol 24 (1) ◽  
pp. 71-76 ◽  
Author(s):  
Jeffrey E. Kallan ◽  
Eugene A. Enneking
Keyword(s):  
United States ◽  
Spontaneous Abortion ◽  
National Survey ◽  
Seasonal Pattern ◽  
The United States ◽  
Seasonal Patterns ◽  
Family Growth ◽  
Using Data

SummaryThe presence of a seasonal pattern of spontaneous abortion in the United States was found using data from the two most recent cycles of the National Survey of Family Growth (USA). The pattern was bimodal with peaks in March and August.

scholarly journals The hummingbird and the hawk-moth: Species distribution, geographical partitioning, and macrocompetition across the United States

2017 ◽  
Author(s):  
Abdel Halloway ◽  
Christopher J. Whelan ◽  
Joel S. Brown
Keyword(s):  
United States ◽  
Species Richness ◽  
Atmospheric Pressure ◽  
Summer Precipitation ◽  
Niche Overlap ◽  
The United States ◽  
Hawk Moth ◽  
Moth Species ◽  
Richness Patterns ◽  
Summer Time

ABSTRACTWe introduce a new concept called macrocompetition – defined as the mutual suppression of diversity/species richness of competing clades – and investigate evidence for its existence. To this end, we analyzed the distribution of two convergent nectarivorous families, hawk-moths and hummingbirds, over the continental United States to determine whether there is geographic partitioning between the families and its potential causes. Using stepwise regression, we tested for latitudinal and longitudinal biases in the species richness of both taxa and the potential role of 10 environmental variables in their distribution pattern. Hawk-moth species richness increases with longitude (eastward-bias) while that of hummingbirds declines (westward-bias). Similar geographic patterns can be seen across Canada, Mexico and South America. Hawk-moth species richness is positively correlated with higher overall temperatures (especially summer minimums), atmospheric pressure, and summer precipitation; hummingbird species richness is negatively correlated with atmospheric pressure and positively correlated with winter daily maxima. The species richness patterns reflect each family’s respective anatomical differences and support the concept of macrocompetition between the two taxa. Hawk-moth species richness was highest in states with low elevation, summer-time flowering, and warm summer nights; hummingbird species richness is highest in the southwest with higher elevation, greater cool season flowering and high daytime winter temperatures. Hawk-moths and hummingbirds as distinct evolutionary technologies exhibit niche overlap and geographical partitioning. These are two of three indicators suggested by Brown and Davidson for inter-taxonomic competition. We intend the patterns revealed here to inspire further exploration into competition and community structuring between hawk-moths and hummingbirds.

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