Wyniki wyszukiwania - BazTech

1

Effect of Mowing Height on Dominance of Annual Poaceae Plants

Inagaki Hidehiro, Saiki Chieko, Ichihara Minoru, Matsuno Kazuo, Tanno Yuuki, Yamashita Masayuki, Sawada Hitoshi

Journal of Ecological Engineering

|

2020

|

Vol. 21, nr 1

8--13

EN

Mowing weeds in rice paddy field ridges is essential for weed management. However, excessive mowing causes the dominance of the Poaceae weeds, which are host plants for rice stink bugs. In this study, the authors hypothesized that high mowing is more effective than low mowing in decreasing the dominance of Poaceae weeds. The dominance of the Poaceae weeds between high mowing (cut at a height of 5–10 cm) and low mowing (cut at ground level) was compared across 5 sites. As a result, the cover-abundance ratings of the Poaceae weeds were lower in the high mowing plots than that in the low mowing plots in all sites. In addition, the biodiversity index was higher in the high mowing plots than in the low mowing plots in each site. It was concluded that the increased mowing height effectively decreased the dominance of Poaceae weeds and this can be used as a strategy for controlling rice stink bugs.

2

Community Structure of Lumbricidae in Permanent Grassland and Arable Land

Mazur-Pączka Anna, Pączka Grzegorz, Kostecka Joanna, Garczyńska Mariola, Podolak Agnieszka, Szura Renata

Journal of Ecological Engineering

|

2019

|

Vol. 20, nr 5

1--6

EN

Lumbricidae play a key role in the soil environment as “the ecosystem engineers”. They participate in all the categories of services provided by ecosystems. In agricultural areas, the conventional intensive farming practices have led to a significant decline in the biological diversity of soils including earthworms. In this study, we attempted to characterize the community structure of earthworms in permanent grassland and arable land of the Didactic & Experimental Station of Rzeszów University in Krasne near Rzeszów. Similar densities of earthworms were observed in the grassland and in the arable land (101.01 ± 18.03 ind. ∙ m-2 and 82.12 ± 18.26 ind. ∙ m-2, respectively) (p > 0.05) as well as a similar biomass of Lumbricidae (77.72 ± 15.30 g ∙ m-2 and 54.34 ± 11.72 g ∙ m-2) (p > 0.05). In the research, 7 species of earthworms were found in the permanent grassland and 6 representatives of Lumbricidae were identified in the arable land. The identified earthworms represented all three main morpho-ecological groups. The density and biomass of epi-endogeic earthworm L. rubellus and the anecic species of L. terrestris were shown to be higher (p < 0.05) in the grassland as compared to the arable land. In order to protect Lumbricidae and to sustain the beneficial role of earthworms in an ecosystem, it is necessary to monitor the negative changes in populations of earthworm species attributed to various farming practices.

3

Guess the Larger Number

Gnedin A.

Mathematica Applicanda

|

2016

|

Vol. 44, No. 1

183–-207

EN

We discuss variations of the zero-sum game where Bob selects two distinct numbers, and Alice learns one of them to make a guess which of the numbers is the larger.

PL

Przedmiotem rozważań są odmiany gry o sumie zerowej, gdy Bob wybiera dwa różne numery, a Alice dowiaduje się jedną z nich, by zgadnąć, która z liczb jest większa.

4

Environmental influence on maturation and dominance relationships in the three-spined stickleback (Gasterosteus aculeatus L.) : temperature competes with photoperiod for primacy

Sokołowska E., Kulczykowska E.

Oceanological and Hydrobiological Studies

|

2009

|

Vol. 38, No.4

31-48

EN

In this study, the influence of a combination of different photoperiods and temperatures on the final maturation and social interactions in three-spined sticklebacks was investigated. Water temperature appears to be the principal signal affecting gonadal development and breeding activity of sticklebacks in pre-spawning and spawning periods. Males can mature independently of photoperiod and a stimulatory effect of high temperature is not diminished by light deprivation. On the other hand, low temperature can inhibit the development of secondary sexual characters in males exposed to long day or constant light. In females, lighting seems to be more decisive for complete maturation and the lack of light delays the maturation rate, even in high temperature. While kept under the same conditions, males mature quicker than females. The presence of light and visual information are crucial to establish the social position of individuals in the group. In light, a rigid social hierarchy with one dominant, sexually active male is observed. In constant darkness, however, several males in the group demonstrate every sign of sexual activity.

5

Social relationship in a bank vole Clethrionomys glareolus (Schreber, 1780) population : video monitoring under field conditions

Łopucki R.

Polish Journal of Ecology

|

2007

|

Vol. 55, nr 3

543-558

EN

Social behaviour of the bank vole was video recorded during direct encounters between individuals under natural conditions. The apparatus consisted of miniature video cameras, a system of image processing and recording, and infrared emitters. This device enabled continuous 24-h observations at several sites simultaneously. The study was conducted in an alder swamp Ribonigri-Alnetum located in the Kampinos National Park, central Poland (52 [degrees] 20'N, 20 [degrees] 25'E). Observations were made in the late summers of 2002 and 2003 at six independent baited sites for 10 days and nights per each site. Rodents visiting the sites were individually marked by fur clipping. In sum, 13 053 visits to the sites and 1868 encounters between two marked individuals of C. glareolus were video recorded during 1440 hours of observation. It has been found that under natural conditions, bank voles most often avoided each other (55% of the encounters). In the case of close contacts they were aggressive (30%), rarely tolerant (7%), and during the remaining encounters they showed a mixed behaviour. The voles met mainly in the night (94% of the encounters) despite of 25% of their daily activity ran during the day. The frequency and character of encounters depended on the sex, age, and the origin of individuals. Encounters between males were more aggressive than between females (P <0.01). In encounters between opposite sexes, males were dominants (P <0.001). Individuals with a larger body mass were dominant in access to food (P <0.000). Cases of the dominance of juveniles over adults were interpreted as a result of the site of their origin. Social relations between individuals were characterised by persistence and repeatability in time. The results are compared with the literature describing experiments with animals kept in the laboratory or in enclosures, and field observations based on trapping techniques and telemetry.

6

Diversity and abundance of Gastrotricha in the psammon of mesotrophic lake

Nesteruk T.

Polish Journal of Ecology

|

2007

|

Vol. 55, nr 4

833-839

EN

Composition and abundance of Gastrotricha in lake psammon were studied and compared with those compared with those from other lake habitats. Samples were taken from April till October 2004 from 3 sites at the edge of zone frequently wetted by waves (hygropsammon) in a deep (38 m) mesotrophic lake situated in Łęczyńsko-Włodawskie Lakeland (south-eastern Poland). A total of 11 gastrotrich species belonging to Chaetonotidae family were found. Three species: Lepidodermella squamata Dujardin, Chaetonotus macrochaetus Zelnika i Ch. heideri Brehm dominated (52%) in total abundance. According to the previous studies the number of species occurring in bottom sediments of the same lake was higher by 11 - 14 species. Species diversity index H., amounted 2.19 being lower than that calculated for the gastrotrichs of inshore bottom and littoral sediments (2.88 and 2.58, respectively) and similar to the value given for epiphytic fauna (2.01) of that lake. The fauna of psammic Gastrotricha showed the greatest similarity (38%) to epiphytic fauna of that lake as measured by the index of homogeneity. Peak densities of psammic Gastrotricha were found in May (37.5 10[^3] ind. m[^-2]) and in September (32.8 10[^3] ind. m[^-2]) and marked decrease of density was observed in August and October (18.1 10[^3] m[^-2] and 13.6 10[^3] ind. m[^-2], respectively). Mean density and biomass were 25.35 10[^3] ind. m[^-2] and 3.8 mg m[^-2] respectively. Density and biomass of Gastrotricha were by two orders of magnitude lower in psammon than in bottom sediments of the lake.