Long-Term Impacts of Controlled Burns on the Ant Community (Hymenoptera: Formicidae) of a Sandplain Forest in Vermont

2014 ◽  
Vol 21 (1) ◽  
pp. NENHC-1-NENHC-12 ◽  
Author(s):  
Valerie S. Banschbach ◽  
Emily Ogilvy
2016 ◽  
Vol 46 (1) ◽  
pp. 20-24 ◽  
Author(s):  
Kyle A. Funk ◽  
Walter D. Koenig ◽  
Johannes M.H. Knops

Highly variable patterns of seed production (“masting”) have been hypothesized to be driven by internal dynamics of resource storage and depletion. This hypothesis predicts that if seed production is artificially reduced, then the availability of unused stored resources should result in subsequent enhancement of the seed crop. We tested this prediction in two oak species with contrasting patterns of annual seed production (highly variable and relatively constant) by means of controlled burns at various frequencies over a 17-year period. We found that controlled burns reduced acorn production by both species in the year of the burn. In the species with relatively constant productivity, acorn production returned to baseline levels in the year following a burn; however, in the species with highly variable productivity, acorn production significantly increased the year following a burn. These results support a key prediction of the stored resource hypothesis by means of a long-term experimental test in wild tree populations.


2012 ◽  
Vol 6 (3) ◽  
pp. 328-338 ◽  
Author(s):  
Akhmad Rizali ◽  
Yann Clough ◽  
Damayanti Buchori ◽  
Meldy L.A. Hosang ◽  
Merijn M. Bos ◽  
...  

Author(s):  
Marion L Donald ◽  
Tom Miller

Pairwise mutualisms are embedded within rich communities of co-occurring species. Mutualism by definition benefits partner species and theory predicts these effects can spill over into broader communities, with consequences for abundance, diversity, and composition. Specifically, positive feedbacks between partner species may shift competitive hierarchies and drive reductions in non-partner species. We used long-term monitoring data spanning 16 years to determine the ant partner species of tree cholla cacti (Cylindriopuntia imbricata), which reward ants with extrafloral nectar in exchange for anti-herbivore defense. We coupled these long-term data with short-term characterization of the ant community via pitfall trapping, which sampled partner and non-partner species across ten plots that varied naturally in cactus density. The long-term data revealed one dominant ant partner (Liometopum apiculatum) and two other less common partners (Crematogaster opuntiae and Forelius pruinosus). In the short-term census, the dominant ant partner occupied more cacti in plots of higher cactus density, and was also found at higher occurrence within the pitfall traps in the high cactus density plots, suggesting strong positive feedbacks that promote ant occurrence where plant partners are available. Despite the consistency of L. apiculatum partnership with cacti through time and the dominance of this partnership in areas of high cactus density, spillover effects from this mutualism appear limited. Of the common ant species, a single non-partner ant species showed a modest reduction in occurrence at high cactus density, possibly in response to increased presence of L. apiculatum. Additionally, the composition and diversity of the ant community in our plots were insensitive to cactus density variation, indicating that positive effects on the dominant ant partner did not have cascading impacts on the ant community. This study provides novel evidence that pairwise mutualisms, even those with strong positive feedbacks, may be limited in the scope of their community-level effects.


2019 ◽  
Vol 42 ◽  
Author(s):  
John P. A. Ioannidis

AbstractNeurobiology-based interventions for mental diseases and searches for useful biomarkers of treatment response have largely failed. Clinical trials should assess interventions related to environmental and social stressors, with long-term follow-up; social rather than biological endpoints; personalized outcomes; and suitable cluster, adaptive, and n-of-1 designs. Labor, education, financial, and other social/political decisions should be evaluated for their impacts on mental disease.


2016 ◽  
Vol 39 ◽  
Author(s):  
Mary C. Potter

AbstractRapid serial visual presentation (RSVP) of words or pictured scenes provides evidence for a large-capacity conceptual short-term memory (CSTM) that momentarily provides rich associated material from long-term memory, permitting rapid chunking (Potter 1993; 2009; 2012). In perception of scenes as well as language comprehension, we make use of knowledge that briefly exceeds the supposed limits of working memory.


1999 ◽  
Vol 173 ◽  
pp. 189-192
Author(s):  
J. Tichá ◽  
M. Tichý ◽  
Z. Moravec

AbstractA long-term photographic search programme for minor planets was begun at the Kleť Observatory at the end of seventies using a 0.63-m Maksutov telescope, but with insufficient respect for long-arc follow-up astrometry. More than two thousand provisional designations were given to new Kleť discoveries. Since 1993 targeted follow-up astrometry of Kleť candidates has been performed with a 0.57-m reflector equipped with a CCD camera, and reliable orbits for many previous Kleť discoveries have been determined. The photographic programme results in more than 350 numbered minor planets credited to Kleť, one of the world's most prolific discovery sites. Nearly 50 per cent of them were numbered as a consequence of CCD follow-up observations since 1994.This brief summary describes the results of this Kleť photographic minor planet survey between 1977 and 1996. The majority of the Kleť photographic discoveries are main belt asteroids, but two Amor type asteroids and one Trojan have been found.


1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.


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