scholarly journals Long-term success of stump sprouts in high-graded baldcypress–water tupelo swamps in the Mississippi delta

2006 ◽  
Vol 234 (1-3) ◽  
pp. 24-33 ◽  
Author(s):  
Richard F. Keim ◽  
Jim L. Chambers ◽  
Melinda S. Hughes ◽  
Luben D. Dimov ◽  
William H. Conner ◽  
...  
2007 ◽  
Vol 86 (3) ◽  
pp. 307-315 ◽  
Author(s):  
T.E. Törnqvist

AbstractA combination of geological and anthropogenic processes have rendered the U.S. Gulf Coast in general – and the Mississippi Delta in particular – extremely sensitive to coastal hazard. Thus, the Katrina disaster was not a question of ‘if’ but of ‘when’. This contribution outlines the geo-environmental context of the Mississippi Delta that evolved during the 20th century and set the stage for Hurricane Katrina’s devastation. This includes a brief discussion of the processes responsible for coastal erosion and wetland loss, the proposed measures to combat these problems, and the policy decisions (or, rather, the lack thereof) made so far. A connection is made with the 1953 storm surge that devastated the southwestern Netherlands and had a profound impact on Dutch science and engineering by providing the impetus for the widely known and highly praised Delta Plan, as well as for unprecedented studies of Holocene sea-level change. Whether a similar route will be followed for the Gulf Coast is primarily dependent on the amount of political will. Results are presented of recent studies of crustal movements in the Mississippi Delta that show surprising long-term stability of the Pleistocene basement, evidence that could prove critical for decision makers with regard to the rebuilding process. Finally, the neglect of the precarious situation along the Gulf Coast by the federal government is viewed as a possible metaphor for current U.S. policies with respect to science in general, and to global warming in particular.“Land that sits below sea level. Levees and dams that stand against nature’s fury. Countryside that sinks more every year. New Orleans? No. Holland: a nation whose flood protections makes ours look primitive and slapdash”John McQuaid, The Times-Picayune, November 13, 2005


Author(s):  
Claudia Zoccarato ◽  
Torbjörn E. Törnqvist ◽  
Pietro Teatini ◽  
Jonathan G. Bridgeman

Abstract. The extensive loss of land elevation and the consequent exposure to flood hazards are seriously threatening the long-term survival of the Mississippi Delta. Shallow compaction of the top soil is one of the major components contributing to the relative sea level rise. In the last decades, more subsidence measurements have become available and recent studies demonstrate that compaction of Holocene strata is dominant. Here we propose a novel application aimed at modeling the present-day shallow compaction due to consolidation processes in the top soil. Soil compaction is properly computed and accounts for the large soil grain motion and the delayed dissipation of pore-water overpressure. The grain motion is described by means of a Lagrangian approach with an adaptive mesh where the grid nodes follows the accretion/compaction processes. Model calibration is obtained from stratigraphic and geochrology information collected at the Myrtle Grove Subsidence Superstation, where a nearly 40 m-deep sediment core that penetrates the entire Holocene succession allows testing model results over long (millennial) timescales. Model validation with available observations from rod surface-elevation table – marker horizon (RSET-MH) data enables the model to predict future scenarios.


1979 ◽  
Vol 3 (4) ◽  
pp. 149-151 ◽  
Author(s):  
David S. Priester

Abstract Stump sprouts of both swamp (Nyssa sylvatica var. biflora (Walt.) Sarg.) and water (N. aquatica L.) tupelo can produce seeds two years after sprouting. For both species, seeds of tree origin are heavier and shoots of resulting seedlings are initially taller than those of sprout origin, but after one year seedlings of the two origins are not significantly different in shoot length and total weight. Thus, if seed crops are poor or fail to germinate after harvesting, stump sprouts can provide a suitable seed source within two years.


2000 ◽  
Vol 24 (2) ◽  
pp. 65-69 ◽  
Author(s):  
Emile S. Gardiner ◽  
D. Ramsey Russell ◽  
John D. Hodges ◽  
T. Conner Fristoe

Abstract Two water tupelo (Nyssa aquatica L.) stands in the Mobile Delta of Alabama were selected to test the hypothesis that mechanized felling does not reduce establishment and growth of natural water tupelo regeneration relative to traditional tree felling with chainsaws. To test the hypothesis, we established six, 2 ac treatment plots in each of two blocks on each of two sites, and randomly assigned plots to either mechanical tree felling with a tracked, swing feller or chainsaw felling. Each site was clearcut in Fall, 1992, and merchantable boles were removed by helicopter. Establishment and growth of regeneration was assessed prior to harvest and annually for 3 yr after harvest in five, 0.01 ac measurement plots located in each treatment plot. Stand harvesting promoted establishment of water tupelo seedlings such that 3 yr after treatment we recorded over 270/ac on each site regardless of felling method. Seedling height increased at a steady rate and averaged about 39 in. tall after three growing seasons. Woody competition also responded to the harvest, outnumbering water tupelo seedlings 3 yr after treatment by as much as seven to one on Site 2. Water tupelo stump sprouts developing from chainsaw felling grew well and averaged about 13.5 ft tall after three growing seasons. However, mechanical felling reduced water tupelo stump sprouting by 50% leading to a lower density of sprout clumps in mechanically felled plots (P = 0.0253). Our results indicated that mechanical felling techniques used in this study may adversely impact regeneration of water tupelo swamps where coppice is a desirable form of reproduction. South. J. Appl. For. 24(2):65-69.


2017 ◽  
Vol 35 (4) ◽  
pp. 297-313 ◽  
Author(s):  
Joseph H. Massey ◽  
C. Mark Stiles ◽  
Josh W. Epting ◽  
R. Shane Powers ◽  
David B. Kelly ◽  
...  

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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