scholarly journals Growth Rates, Survivorship, and Sex Ratios of Juniperus virginiana on the New Jersey Piedmont from 1963 to 2000

2004 ◽  
Vol 131 (3) ◽  
pp. 187 ◽  
Author(s):  
James A. Quinn ◽  
Scott J. Meiners
Keyword(s):  
New Jersey ◽  
Growth Rates ◽  
Sex Ratios ◽  
Juniperus Virginiana

SEX RATIOS OF TWO SPECIES OF SPIDER CRABS, LIBINIA DUBIA H. MILNE EDWARDS, 1834 AND L. EMARGINATA LEACH, 1815, IN THE AREA OF GREAT BAY, NEW JERSEY

Crustaceana ◽  
1999 ◽  
Vol 72 (2) ◽  
pp. 187-192 ◽  
Author(s):  
Kenneth Able ◽  
Matthew Landau ◽  
Susan Beth O'Brien
Keyword(s):  
New Jersey ◽  
Sex Ratios ◽  
Otter Trawl ◽  
Beam Trawl ◽  
Female Ratio ◽  
Great Bay ◽  
Great Bay Estuary ◽  
Male Female Ratio ◽  
Collection Sites

AbstractOver a 7 year period, Libinia emarginata and L. dubia were sampled in the Great Bay estuary (New Jersey) and the waters immediately adjacent to it, using a beam trawl and an otter trawl. At collection sites where L. emarginata was common, the average male: female ratio was 2.5 : 1. Males were also significantly larger than females. Pendant une periode de 7 ans, Libinia emarginata et L. dubia on ete echantillonnes dans l'estuaire de Great Bay (New Jersey) et dans les eaux adjacentes, en utilisant un chalut a perche et un chalut a panneaux. La ou L. emarginata etait commun, la ratio moyenne males: femelles etait 2.5 : 1. Les males etaient aussi, de facon significative, plus grands que les femelles.

scholarly journals Shade is the most important factor limiting growth of a woody range expander

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0242003
Author(s):  
David Ward
Keyword(s):  
Interspecific Competition ◽  
Nutrient Availability ◽  
Growth Rates ◽  
Woody Plants ◽  
Separate Experiment ◽  
Old Fields ◽  
Juniperus Virginiana ◽  
Eastern United States ◽  
Forest Species ◽  
Eastern Redcedar

The expansion of woody plants into grasslands and old fields is often ascribed to fire suppression and heavy grazing, especially by domestic livestock. However, it is also recognized that nutrient availability and interspecific competition with grasses and other woody plants play a role in certain habitats. I examined potential factors causing range- and niche expansion by the eastern redcedar Juniperus virginiana, the most widespread conifer in the eastern United States, in multifactorial experiments in a greenhouse. Historical records suggest that the eastern redcedar is a pioneer forest species, and may be replaced as the forest increases in tree density due to shading. Another possible factor that affects its distribution may be nutrient availability, which is higher in old fields and other disturbed lands than in undisturbed habitats. In its historic range, eastern redcedars are particularly abundant on limestone outcrops, often termed ‘cedar barrens’. However, the higher abundance on limestone could be due to reduced interspecific competition rather than a preference for high pH substrates. I manipulated shade, fertilization, lime, and interspecific competition with a common dominant tree, the post oak Quercus stellata. In a separate experiment, I manipulated fire and grass competition. I measured growth rates (height and diameter) and above- and belowground biomass at the end of both experiments. I also measured total non-structural carbohydrates and nitrogen in these plants. Shade was the most important factor limiting the growth rates and biomass of eastern redcedars. I also found that there were significant declines in nitrogen and non-structural carbohydrates when shaded. These results are consistent with the notion that the eastern redcedar is a pioneer forest species, and that shade is the reason that these redcedars are replaced by other tree species. In the second experiment, I found that a single fire had a negative effect on young trees. There was no significant effect of competition with grass, perhaps because the competitive effect was shading by grasses and not nutrient depletion. Overall, the effects of shade were far more apparent than the effects of fire.

Breeding and Fecundity of the Glass Shrimp, (Pasiphaea multidentata (Decapoda, Caridea), in the Gulf of Maine

1969 ◽  
Vol 26 (8) ◽  
pp. 1969-1983 ◽  
Author(s):  
S. Apollonio
Keyword(s):  
Linear Function ◽  
Growth Rates ◽  
Carapace Length ◽  
Gulf Of Maine ◽  
Sex Ratios ◽  
Decapod Crustacean ◽  
Deep Waters ◽  
Age Of Maturity ◽  
Males And Females ◽  
Second Clutch

About 1450 specimens of the decapod crustacean Pasiphaea multidentata were collected in deep waters of the Gulf of Maine in 1966–69, and were examined for size, sex, weight, breeding, fecundity, and feeding. The sizes and sex ratios of the catches vary with the egg-bearing seasons, suggesting that ovigerous females are susceptible to greater predation. The data do not permit estimates of growth rates or age of maturity. The ratios of carapace length to total length differ in males and females. Two egg clutches per female per year were produced, the second clutch being smaller in numbers, probably because of "reproductive fatigue" in the female. In each clutch the number of eggs produced is a linear function of carapace length. About 50% of the stomachs were empty. Eighteen per cent contained crustacean remains of which about half could be identified as remains of the copepods Metridia longa, M. lucens, and Euchaeta norvegica. Epizoic suctorians were found on a few shrimps.

Demographic differences among populations of Northern Map Turtles (Graptemys geographica) in intact and fragmented sites

2009 ◽  
Vol 87 (12) ◽  
pp. 1147-1157 ◽  
Author(s):  
A. M. Bennett ◽  
M. Keevil ◽  
J. D. Litzgus
Keyword(s):  
Growth Rates ◽  
Sex Ratios ◽  
Habitat Alteration ◽  
Population Densities ◽  
Demographic Differences ◽  
Fragmented Habitats ◽  
Habitat Alterations ◽  
Map Turtles ◽  
Graptemys Geographica ◽  
Northern Map Turtle

Habitat fragmentation is a leading cause of reptile declines worldwide. We examined demographic differences between populations of Northern Map Turtles, Graptemys geographica (Le Sueur, 1817), inhabiting intact and fragmented sites along the Trent–Severn Waterway (TSW) in Ontario over two field seasons. We examined population densities, sex ratios, body size, and growth rates in two control sites and two fragmented sites (where the waterway is disrupted by dams). We predicted that population density would be higher in control sites, and that sex ratios would differ among sites. Abundance was greater than expected, but densities could not be compared owing to a lack of recaptures. Sex ratios in control sites were slightly male-biased and were significantly female-biased in fragmented sites. Turtles in fragmented habitats were significantly smaller than those in control habitats. Estimated growth rates of juveniles and males were significantly reduced in fragmented populations compared with controls. We hypothesize that habitat alterations in fragmented sites are differentially affecting demographic classes because of the intersexual niche divergence observed in Map Turtles. We emphasize the need for further research to examine the interactions between habitat alteration and invasive species and the effects they are having on Northern Map Turtle populations.

scholarly journals Notes on the Natural History of Cycas seemannii (Cycadaceae)

2001 ◽  
Vol 19 (1) ◽  
pp. 35 ◽  
Author(s):  
Gunnar Keppel
Keyword(s):  
Natural History ◽  
Seed Dispersal ◽  
Growth Rates ◽  
New Caledonia ◽  
Sex Ratios ◽  
History Of ◽  
Adverse Environments

Cycas seemannii occurs in several habitats in Vanuatu, New Caledonia, Fiji and Tonga, but is mostly coastal. Growth rates are about 5-15cm.yr-1 and sex ratios observed were almost neutral. Mechanisms to survive in adverse environments are discussed. Female plants were found to produce, on average, longer leaves with more leaflets than male plants. Larvae of an unidentified moth, which are parasitised by at least two species of wasps, mine the leaflets of C. seemannii. Reproduction occurs mainly by seeds and bulbils. Wind appears to be the major pollination agent. Seed dispersal, other than oceanic, appears to be inefficient.

Ecology of loggerhead marine turtles Caretta caretta in a neritic foraging habitat: movements, sex ratios and growth rates

2012 ◽  
Vol 160 (3) ◽  
pp. 519-529 ◽  
Author(s):  
ALan F. Rees ◽  
Dimitris Margaritoulis ◽  
Robert Newman ◽  
Thomas E. Riggall ◽  
Paul Tsaros ◽  
...  
Keyword(s):  
Growth Rates ◽  
Sex Ratios ◽  
Caretta Caretta ◽  
Foraging Habitat ◽  
Marine Turtles

Community-based dental programs: University of Medicine and Dentistry of New Jersey-New Jersey Dental School

1999 ◽  
Vol 63 (12) ◽  
pp. 969-975 ◽  
Author(s):  
WR Cinotti ◽  
RA Saporito ◽  
CA Feldman ◽  
G Mardirossian ◽  
J DeCastro
Keyword(s):  
New Jersey ◽  
Dental School ◽  
Community Based
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