Studies of gametophytes of Matteuccia struthiopteris (ostrich fern) in nature and in culture

1983 ◽  
Vol 61 (12) ◽  
pp. 3267-3270 ◽  
Author(s):  
P. von Aderkas
Keyword(s):  
Population Density ◽  
Field Data ◽  
Sex Expression ◽  
Density Effect

The sex expression of gametophytes of Matteuccia struthiopteris (L.) Todaro was compared in nature and in culture. Plants raised from multispore cultures (100 spores/cm2) exhibited the most variety in sexual–morphological types. Individually raised plants were slower to develop and showed less variety of sexual types than was found in the multispore cultures. There appeared to be a density effect on development. Field-collected gametophytes showed the least diversity, the populations being largely composed of poorly developed male and neuter plants. The experimental and field data are considered in relation to antheridiogen and population density studies.

Population density effect on radio frequencies interference (RFI) in radio astronomy

2012 ◽  
Author(s):  
Roslan Umar ◽  
Zamri Zainal Abidin ◽  
Zainol Abidin Ibrahim ◽  
Mohd Saiful Rizal Hassan ◽  
Zulfazli Rosli ◽  
...  
Keyword(s):  
Population Density ◽  
Radio Astronomy ◽  
Density Effect ◽  
Radio Frequencies

A critique of the «increasing population density effect»

1989 ◽  
Vol 4 (6) ◽  
pp. 515-523 ◽  
Author(s):  
K. R. Gibson ◽  
J. M. Calcagno
Keyword(s):  
Population Density ◽  
Density Effect

On the pelagic occurrence and dispersal of the benthic amphipod Corophium volutator

1989 ◽  
Vol 69 (1) ◽  
pp. 11-15 ◽  
Author(s):  
Karel Essink ◽  
Hans L. Kleef ◽  
Wim Visser
Keyword(s):  
Population Density ◽  
Field Data ◽  
Half Cycle ◽  
Corophium Volutator ◽  
Ems Estuary ◽  
Benthic Population

Field data on the pelagic occurrence of Corophium volutator were obtained in 1981–82 in the Dollard (Ems estuary). The pelagic population density averaged over a tidal half cycle was in the range 0–15 m-3. The pelagic population represents about 0.06% of the benthic population. On most sampling days pelagic occurrence resulted in a net flood surplus transport.

scholarly journals Comparison of three models of population density estimation for Central American red brocket deer (Mazama temama)

2018 ◽  
Vol 10 (1) ◽  
Author(s):  
Giovana Lizet Apan-Araujo ◽  
Susana Aurora González ◽  
Arcángel Molina- Martínez ◽  
Daniel Jiménez G ◽  
Oscar Agustín Villarreal E.B
Keyword(s):  
Population Density ◽  
Density Estimation ◽  
Field Data ◽  
Central American ◽  
Estimation Model ◽  
Wet Season ◽  
Wide Range ◽  
Data Deficient ◽  
Management And Conservation ◽  
Brocket Deer

The deer Mazama temama has a wide range in the tropical rain forest of Mexico, but the IUCN classifies it as Data Deficient, and information is urgently need for management and conservation. Here we assess which population density estimation model is more appropriate among those by Tyson (1959), Mandujano and Jones (2005) and Crego and Macri (2009). We compare them with field data from Tepetla (Puebla, Mexico), from 2015 to 2017, with three replicates in the wet season and three in dry season. An ANOVA indicated that the three methods produce equivalent results.

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