scholarly journals Impact of Grazing History on Pollinator Communities in Fescue Prairie

Blue Jay ◽  
2019 ◽  
Vol 77 (1) ◽  
pp. 10-15
Author(s):  
Diana B Robson
Keyword(s):  

Impact of Grazing History on Pollinator Communities in Fescue Prairie


PLoS ONE ◽  
2016 ◽  
Vol 11 (6) ◽  
pp. e0156875 ◽  
Author(s):  
Isabelle Jouffroy-Bapicot ◽  
Boris Vannière ◽  
Virginia Iglesias ◽  
Maxime Debret ◽  
Jean-François Delarras




2019 ◽  
Vol 11 (11) ◽  
pp. 1364 ◽  
Author(s):  
Bohua Ling ◽  
Edward J. Raynor ◽  
Douglas G. Goodin ◽  
Anthony Joern

This study analyzed the spatial heterogeneity of grassland canopy nitrogen in a tallgrass prairie with different treatments of fire and ungulate grazing (long-term bison grazing vs. recent cattle grazing). Variogram analysis was applied to continuous remotely sensed canopy nitrogen images to examine the spatial variability in grassland canopies. Heterogeneity metrics (e.g., the interspersion/juxtaposition index) were calculated from the categorical canopy nitrogen maps and compared among fire and grazing treatments. Results showed that watersheds burned within one year had higher canopy nitrogen content and lower interspersions of high-nitrogen content patches than watersheds with longer fire intervals, suggesting an immediate and transient fire effect on grassland vegetation. In watersheds burned within one year, high-intensity grazing reduced vegetation density, but promoted grassland heterogeneity, as indicated by lower canopy nitrogen concentrations and greater interspersions of high-nitrogen content patches at the grazed sites than at the ungrazed sites. Variogram analyses across watersheds with different grazing histories showed that long-term bison grazing created greater spatial variability of canopy nitrogen than recent grazing by cattle. This comparison between bison and cattle is novel, as few field experiments have evaluated the role of grazing history in driving grassland heterogeneity. Our analyses extend previous research of effects from pyric herbivory on grassland heterogeneity by highlighting the role of grazing history in modulating the spatial and temporal distribution of aboveground nitrogen content in tallgrass prairie vegetation using a remote sensing approach. The comparison of canopy nitrogen properties and the variogram analysis of canopy nitrogen distribution provided by our study are useful for further mapping grassland canopy features and modeling grassland dynamics involving interplays among fire, large grazers, and vegetation communities.



1989 ◽  
Vol 76 (9) ◽  
pp. 1368-1379 ◽  
Author(s):  
Elizabeth L. Painter ◽  
James K. Detling ◽  
David A. Steingraeber


2007 ◽  
Vol 81 (1) ◽  
pp. 37-49 ◽  
Author(s):  
David R. Clements ◽  
Pam G. Krannitz ◽  
Shauna M. Gillespie


1969 ◽  
Vol 11 (3) ◽  
pp. 369-378 ◽  
Author(s):  
J. P. Langlands

SUMMARYThe ability of two groups of six Merino wethers aged 6 and 66 months to digest a lucerne ration was examined in order to detect possible biases in the use of faecal nitrogen as a faecal index substance. Earlier work with this technique had indicated a difference in selectivity between young and older sheep. No difference in ability to digest the ration was observed and it was concluded that the earlier observation was not an artefact in the faecal nitrogen technique. Oesophageal fistulae were prepared in 120 sheep differing in breed, sex, age, strain and previous history. Determinations were made of the nitrogen content, and in one experiment of the in vitro digestibility of the diet selected by sheep grazing various pastures. Significant differences in the nitrogen content of the diet selected by sheep varying in breed, age and previous grazing history were recorded on some pastures on some occasions but not on others. No significant differences were observed between sheep varying in strain or sex. No reason could be suggested for the occasional differences between groups in the nitrogen content or digestibility of the diet selected, but it appeared unlikely that it would be a major source of variation in the productivity of the different groups at pasture.



2013 ◽  
Vol 374 (1-2) ◽  
pp. 579-591 ◽  
Author(s):  
Alan G. Haynes ◽  
Martin Schütz ◽  
Nina Buchmann ◽  
Deborah S. Page-Dumroese ◽  
Matt D. Busse ◽  
...  


2015 ◽  
Vol 112 (28) ◽  
pp. 8672-8677 ◽  
Author(s):  
Susan P. Harrison ◽  
Elise S. Gornish ◽  
Stella Copeland

Local ecological communities represent the scale at which species coexist and share resources, and at which diversity has been experimentally shown to underlie stability, productivity, invasion resistance, and other desirable community properties. Globally, community diversity shows a mixture of increases and decreases over recent decades, and these changes have relatively seldom been linked to climatic trends. In a heterogeneous California grassland, we documented declining plant diversity from 2000 to 2014 at both the local community (5 m2) and landscape (27 km2) scales, across multiple functional groups and soil environments. Communities became particularly poorer in native annual forbs, which are present as small seedlings in midwinter; within native annual forbs, community composition changed toward lower representation of species with a trait indicating drought intolerance (high specific leaf area). Time series models linked diversity decline to the significant decrease in midwinter precipitation. Livestock grazing history, fire, succession, N deposition, and increases in exotic species could be ruled out as contributing causes. This finding is among the first demonstrations to our knowledge of climate-driven directional loss of species diversity in ecological communities in a natural (nonexperimental) setting. Such diversity losses, which may also foreshadow larger-scale extinctions, may be especially likely in semiarid regions that are undergoing climatic trends toward higher aridity and lower productivity.



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