Intertidal cultivation of Gracilaria chilensis (Rhodophyta) in southern Chile: long term invertebrate abundance patterns

Aquaculture ◽  
1997 ◽  
Vol 156 (3-4) ◽  
pp. 269-278 ◽  
Author(s):  
Alejandro H Buschmann ◽  
Felipe Briganti ◽  
Claudia A Retamales
Keyword(s):  
Southern Chile ◽  
Gracilaria Chilensis ◽  
Abundance Patterns ◽  
Invertebrate Abundance

scholarly journals Chemically tagging the Galactic disk: abundance patterns of old open clusters

2008 ◽  
Vol 4 (S254) ◽  
pp. 133-138
Author(s):  
G. M. De Silva ◽  
K. C. Freeman ◽  
J. Bland-Hawthorn
Keyword(s):  
Large Scale ◽  
Galactic Disk ◽  
Chemical Properties ◽  
Open Clusters ◽  
Star Forming ◽  
Abundance Patterns ◽  
Chemical Tagging ◽  
Formation And Evolution ◽  
Moving Groups

AbstractThe long term goal of large-scale chemical tagging is to use stellar elemental abundances as a tracer of dispersed substructures of the Galactic disk. The identification of such lost stellar aggregates and exploring their chemical properties will be key in understanding the formation and evolution of the disk. Present day stellar structures such as open clusters and moving groups are the ideal testing grounds for the viability of chemical tagging, as they are believed to be the remnants of the original larger star-forming aggregates. We examine recent high resolution abundance studies of open clusters to explore the various abundance trends and reassess the prospects of large-scale chemical tagging.

scholarly journals Paradoxes of Poweshiek Skipperling (Oarisma poweshiek) (Lepidoptera: Hesperiidae): Abundance Patterns and Management of a Highly Imperiled Prairie Species

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Ann B. Swengel ◽  
Scott R. Swengel
Keyword(s):  
Tallgrass Prairie ◽  
Fire Management ◽  
First Year ◽  
Case Scenario ◽  
Worst Case ◽  
Abundance Patterns ◽  
In Fire ◽  
Percent Unit ◽  
Oarisma Poweshiek

Although Oarisma poweshiek sometimes occurred in localized abundance, its known range is centered on the highly decimated northern tallgrass prairie of North America. To aid its conservation, we analyze surveys from 1988 to 1997 of populations no longer being found. While we recorded 2403 individuals at 20 sites, five sites had 87% of individuals, while 12 sites had only 2% of individuals. Most surveys during O. poweshiek flight had zero individuals recorded. In peak vegetative characteristics for O. poweshiek, fire management had the highest mean abundance but the lowest median abundance and lowest percent occurrence compared to idling and haying. Mean abundance was by far the lowest in the first year postfire compared to longer since fire. Median abundance and percent unit surveys where O. poweshiek was found indicated higher abundances the longer since fire. Although this skipper occasionally exhibited super-recoveries after fire, the median result in fire-managed occupied sites was zero. In a few years, abundance appeared synchronized across many sites, either low (1993, 1997) or high (1994-1995). It is only through a constant focus on avoiding the worst-case scenario that the rare best-case scenario of long-term population persistence appears possible for O. poweshiek.

Functional approaches for assessing plant and invertebrate abundance patterns in arable systems

2009 ◽  
Vol 10 (1) ◽  
pp. 34-42 ◽  
Author(s):  
C. Hawes ◽  
A.J. Haughton ◽  
D.A. Bohan ◽  
G.R. Squire
Keyword(s):  
Abundance Patterns ◽  
Invertebrate Abundance

scholarly journals Anthropogenic drying in central-southern Chile evidenced by long-term observations and climate model simulations

Elem Sci Anth ◽  
2018 ◽  
Vol 6 ◽  
Author(s):  
Juan P. Boisier ◽  
Camila Alvarez-Garreton ◽  
Raúl R. Cordero ◽  
Alessandro Damiani ◽  
Laura Gallardo ◽  
...  
Keyword(s):  
Large Scale ◽  
Climate Model ◽  
Stratospheric Ozone ◽  
Emission Rates ◽  
Southern Chile ◽  
Adaptation Measures ◽  
Model Simulations ◽  
Drying Trend ◽  
Climate Model Simulations

The socio-ecological sensitivity to water deficits makes Chile highly vulnerable to global change. New evidence of a multi-decadal drying trend and the impacts of a persistent drought that since 2010 has affected several regions of the country, reinforce the need for clear diagnoses of the hydro-climate changes in Chile. Based on the analysis of long-term records (50+ years) of precipitation and streamflow, we confirm a tendency toward a dryer condition in central-southern Chile (30–48°S). We describe the geographical and seasonal character of this trend, as well as the associated large-scale circulation patterns. When a large ensemble of climate model simulations is contrasted to observations, anthropogenic forcing appears as the leading factor of precipitation change. In addition to a drying trend driven by greenhouse gas forcing in all seasons, our results indicate that the Antarctic stratospheric ozone depletion has played a major role in the summer rainfall decline. Although average model results agree well with the drying trend’s seasonal character, the observed change magnitude is two to three times larger than that simulated, indicating a potential underestimation of future projections for this region. Under present-day carbon emission rates, the drying pathway in Chile will likely prevail during the next decades, although the summer signal should weaken as a result of the gradual ozone layer recovery. The trends and scenarios shown here pose substantial stress on Chilean society and its institutions, and call for urgent action regarding adaptation measures.

scholarly journals A nitrogen-enhanced metal-poor star discovered in the globular cluster ESO280−SC06

2019 ◽  
Vol 490 (1) ◽  
pp. 741-751 ◽  
Author(s):  
Jeffrey D Simpson ◽  
Sarah L Martell
Keyword(s):  
Globular Cluster ◽  
Globular Clusters ◽  
Binary Systems ◽  
Asymptotic Giant Branch ◽  
Red Giants ◽  
Horizontal Branch ◽  
Term Survival ◽  
Abundance Patterns ◽  
Metal Poor Star

ABSTRACT We report the discovery of the only very nitrogen-enhanced metal-poor star known in a Galactic globular cluster. This star, in the very metal-poor cluster ESO280−SC06 , has $[\textrm{N}/\textrm{Fe}]\, \gt +2.5$, while the other stars in the cluster show no obvious enhancement in nitrogen. Around 80 NEMP stars are known in the field, and their abundance patterns are believed to reflect mass transfer from a binary companion in the asymptotic giant branch phase. The dense environment of globular clusters is detrimental to the long term survival of binary systems, resulting in a low observed binary fraction among red giants and the near absence of NEMP stars. We also identify the first known horizontal branch members of ESO280−SC06 , which allow for a much better constraint on its distance. We calculate an updated orbit for the cluster based on our revised distance of 20.6 ± 0.5 kpc, and find no significant change to its orbital properties.

Two new records of the family Lobariaceae (Lichenized Ascomycota: Peltigerales) from Argentina.

2018 ◽  
Vol 53 (1) ◽  
pp. 5-8
Author(s):  
Alfredo Passo ◽  
Romina Vidal-Russell ◽  
Jose Martín Scervino ◽  
María Inés Messuti
Keyword(s):  
New Records ◽  
Southern Chile ◽  
The Family ◽  
Distribution And Ecology ◽  
First Time ◽  
Long Term Studies

As part of long term studies focused in the lichenized mycobiota diversity from southern Argentina, two species of the family Lobariaceae (Peltigerales), Pseudocyphellaria pluvialis and Sticta longipes, are registered for the first time in Argentina. These species were previously reported as endemic from southern Chile. Brief descriptions, illustrations and information about the distribution and ecology of the species are provided.

Long-Term Development of Biological Communities

1990 ◽  
Vol 5 ◽  
pp. 1-12 ◽  
Author(s):  
Robert E. Ricklefs
Keyword(s):  
Community Structure ◽  
Food Web ◽  
Relative Abundance ◽  
Functional Unit ◽  
Level Structure ◽  
Biological Communities ◽  
Abundance Patterns ◽  
Community Theory ◽  
Coexisting Species

I shall define biological community as the species comprising a temporally and spatially localized assemblage. Although members of a community may interact, I do not wish to imply that the community behaves as a functional unit or that interactions among members determine its structure. When discussing community structure in this paper, I refer exclusively to the diversity of species because of the general availability of comparative data and because most of community theory makes predictions concerning number of coexisting species. Other important community attributes, such as relative abundance patterns, trophic level structure, food web organization, resistance to and recovery from perturbation, and physical architecture, will not be considered.

scholarly journals Abundance patterns (1984-1987 / 1994-1998) of polychaete worms (Annelida) from an estuarine tidal flat, Pacific, Costa Rica

2015 ◽  
Vol 7 (2) ◽  
pp. 233-248
Author(s):  
José A. Vargas-Zamora ◽  
Jeffrey A. Sobaja-Cordero ◽  
Harlan K. Dean ◽  
Sylvia Solano-Upate
Keyword(s):  
Costa Rica ◽  
Anthropogenic Activities ◽  
Enso Event ◽  
Additive Models ◽  
Intertidal Flat ◽  
Red Tides ◽  
Data Set ◽  
Abundance Patterns ◽  
The Impact

The objectives of this report are to provide an updated list of the annelid polychaete worm species found at a tropical estuarine intertidal flat, describe long term oscillations of 11 of the species, and the impact of red tides as evidenced by PCA. From 1984 to 1987 (49 dates) 14 sediment cores (17.7 cm2 – 15 cm deep) were collected per date at low tide from a 400 m2 muddy-sand plot in the Gulf of Nicoya estuary (10oN-85oW), Pacific, Costa Rica. All cores were fixed in Rose Bengal stained formalin and sieved thru a 500 micron mesh screen. A total of 43 species of polychaetes were found and distributed among 25 families and 6600 individuals, of which 80% were represented by: Mediomastus californiensis (32.4%), Caraziella calafia (20.3%), Paraprionospio alata (9.2%), Scolotema tetraura (5.9%), Gymnonereis crosslandi (4.9%), Spiophanex duplex (3.8%), and Glycinde armigera (3.5%). M. californiensis was numerically dominant during most of the sampling dates. The Spionidae (6), Phyllodocidae (4), and Nereididae (3) were the more speciose polychaete families. Populations of all species were patchy in space and time. The abundance patterns of 11 species are illustrated for the 1984-1987 data set. These patterns may reflect declining populations at the beginning of 1984 perhaps influenced by the strong 1982-1983 ENSO event. During 1985 red tides may have influenced the abundances of polychaetes as indicated by the results of a PCA. This is the first time that population patterns of nine species of intertidal polychaetes over a three year period, and the impact of red tides on these worms are reported for this region of the eastern Pacific. General Additive Models (GAM) were applied to the abundances of M. californiensis and P. alata found during 1984-1987 and to additional data from 1994 to 1996 (28 dates) The GAM approach confirmed ealier observations of seasonal oscillations of these species during 1984-1987, but these trends were not found during 1994-1998. Previously unnoticed underlying patterns of unknown origin were also detected by the application of GAM. The theoretical framework needed for the interpretation of results from tropical benthic surveys could improve significantly from more long term monitoring. Long term abundance data is essential to evaluate the impacts of anthropogenic activities in estuaries.

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