A field study of the effects of water depth, order of emergence and flowering on the growth of Typha glauca shoots using the Richards model

In the Delta Marsh, Manitoba, the hybrid cattail Typha glauca Godr. forms large monodominant stands over a wide range of water depths (25–100 cm). Despite a considerable body of research concerning the origin and development of this important species, its ecology has received little attention. In field studies conducted in two freshwater wetland sites in the Delta Marsh, mean height and biomass of vegetative shoots of T. glauca increased significantly along a gradient of increasing water depth. Product–moment correlations between height and biomass were [Formula: see text]. Flowering shoots, in contrast, were less flexible in their response to depth. No significant differences associated with depth were found in reproductive biomass, height, spike width, spike length, or gap length of flowering spikes harvested in August. Differences in size of vegetative shoots were interpreted as a plastic response that may play a role in adaptation to a range of water depths. By adjusting the length of underwater shoot tissue, the ramet maintains relatively constant aerial shoot dimensions. Growth of shoots in deep water is enhanced by an intrinsic factor (juvenility) and an environmental factor (edge effect). Key words: Typha glauca, water depth, growth, plasticity, field study, morphometric response.

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Effect of water depth on population parameters of a Typha glauca stand

Canadian Journal of Botany ◽

10.1139/b92-046 ◽

1992 ◽

Vol 70 (2) ◽

pp. 349-351 ◽

Cited By ~ 37

Author(s):

I. Waters ◽

J. M. Shay

Keyword(s):

Water Depth ◽

Shoot Density ◽

Depth Range ◽

Population Parameters ◽

Shoot Height ◽

Frequency Distributions ◽

Shoot Size ◽

Shoot Mass ◽

Response To Water ◽

Typha Glauca

The response of a Typha glauca stand to a water depth gradient was studied in a small marsh pond in Delta Marsh, Manitoba. Weekly density counts and height measurements were made from May to October 1986 in permanent quadrats at five depths from 25 to 100 cm. Shoot mass was estimated from shoot height using a regression model based on destructive analyses. Shoot density declined significantly from 41 shoots/m2 at 25 cm to 12 shoots/m2 at 85 cm but increased at 100 cm to 38 shoots/m2. Shoot mass increased in shoots growing at water depths from 25 to 65 cm, resulting in relatively constant stand biomass over this depth range. Stand biomass declined at 85 cm and reached its maximum (1789.8 g/m2) at 100 cm. Frequency distributions of shoot size categories based on height deviated from normality and were negatively skewed at all depths, with the greatest skewness occurring at 100 cm. These population parameters were interpreted as evidence of a plastic population response to water depth. Key words: clonal macrophyte, frequency distributions, plasticity, shoot density, Typha glauca, water depth.

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Fish fauna of peatland waters in the middle Mahakam, Kutai Kartanegara, East Kalimantan, Indonesia

E3S Web of Conferences ◽

10.1051/e3sconf/202132201018 ◽

2021 ◽

Vol 322 ◽

pp. 01018

Author(s):

Iwan Suyatna ◽

Komsanah Sukarti ◽

Henny Pagoray ◽

Arif Data Kesuma ◽

Tunggul Butarbutar ◽

...

Keyword(s):

Field Study ◽

Water Depth ◽

Fish Fauna ◽

Cage Culture ◽

East Kalimantan ◽

Fish Samples ◽

Fishing Gears

A field study was carried out to collect fish from the lake and streams/rivers around the peatland from December 2020 to February 2021. Fishing gears such as gillnet, snakehead pole and line, lift net, trap net ("sawaran", "julu"), and fish pot ("tokong", "pangilar", "bubu" or "lukah" and "tempirai") were operated. Sampling sites, water velocities, and water depth were measured using GPS Garmin 60 CSX, current meter hydrologic velocity meter, and fishfinder Portable, respectively. Generally, water velocities of streams measured were much more rapid than the lakes ranging between 0.33 m/s (at water depth: 4.20 m) and 0,69 m/s (at water depth: 6.80 m); and "not detected" (at water depth: 2.40 m) and 0.34 m/s (at water depth: 1.20 m) respectively. Of 7,377 fish samples, there were 50 species discovered belonging to 19 families. Cyprinidae was the most populated in individuals and species as well (1,022 Ind.; 21 taxa). It was followed by Bagridae (63 Ind.; five taxa), Channidae (53 Ind.; three taxa), Clariidae (10 Ind.; three taxa), Siluridae (403 Ind.; three taxa), while other families had just one taxon. Diversity was observed higher in streams (35 species) than lakes (30 species). Local fishers are still performing unselective fishing for feeding fish cage culture.

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Seminar and Field Study

Kappa Delta Pi Record ◽

10.1080/00228958.1966.10516624 ◽

1966 ◽

Vol 2 (4) ◽

pp. 146-146

Keyword(s):

Field Study

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Investigating the Unified Motive Scales

European Journal of Psychological Assessment ◽

10.1027/1015-5759/a000571 ◽

2020 ◽

pp. 1-5

Author(s):

Martin Bettschart ◽

Marcel Herrmann ◽

Benjamin M. Wolf ◽

Veronika Brandstätter

Keyword(s):

Field Study ◽

Predictive Validity ◽

Selection Process ◽

Police Department ◽

Longitudinal Field ◽

Explicit Motives ◽

Achievement Motive

Abstract. Explicit motives are well-studied in the field of personality and motivation psychology. However, the statistical overlap of different explicit motive measures is only moderate. As a consequence, the Unified Motive Scales (UMS; Schönbrodt & Gerstenberg, 2012 ) were developed to improve the measurement of explicit motives. The present longitudinal field study examined the predictive validity of the UMS achievement motive subscale. Applicants of a police department ( n = 168, Mage = 25.11, 53 females and 115 males) completed the UMS and their performance in the selection process was assessed. As expected, UMS achievement predicted success in the selection process. The findings provide first evidence for the predictive validity of UMS achievement in an applied setting.

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Employees’ Critical Thinking, Leaders’ Inspirational Motivation, and Voice Behavior

Journal of Personnel Psychology ◽

10.1027/1866-5888/a000193 ◽

2018 ◽

Vol 17 (1) ◽

pp. 33-41 ◽

Cited By ~ 4

Author(s):

Jing Jiang ◽

Ang Gao ◽

Baiyin Yang

Keyword(s):

Critical Thinking ◽

Field Study ◽

Voice Behavior ◽

Research And Practice ◽

Inspirational Motivation ◽

Positive Effect

Abstract. This study uses implicit voice theory to examine the influence of employees’ critical thinking and leaders’ inspirational motivation on employees’ voice behavior via voice efficacy. The results of a pretest of 302 employees using critical thinking questionnaires and a field study of 273 dyads of supervisors and their subordinates revealed that both employees’ critical thinking and leaders’ inspirational motivation had a positive effect on employees’ voice and that voice efficacy mediates the relationships among employees’ critical thinking, leaders’ inspirational motivation, and employees’ voice. Implications for research and practice are discussed.

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