Pievų tvarkymo įtaka paukščių pasiskirstymui ir gausumui Rusnės saloje

Mindaugas Survila Influence of meadows management to birds distribution and abundance in Rusnė Island Summary Meadows of Rusnė Island are very fertile. 15 years ago these meadows were hayed three times per year. After collapse of kolkhoz system and because of economical and social reasons it was cea...

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Bibliographic Details
Main Author: Survila, Mindaugas
Other Authors: Mierauskas, Pranas
Format: Master Thesis
Language:Lithuanian
English
Published: Institutional Repository of Vilnius University 2007
Subjects:
Online Access:https://repository.vu.lt/VU:ELABAETD1929722&prefLang=en_US
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Summary:Mindaugas Survila Influence of meadows management to birds distribution and abundance in Rusnė Island Summary Meadows of Rusnė Island are very fertile. 15 years ago these meadows were hayed three times per year. After collapse of kolkhoz system and because of economical and social reasons it was ceased to hay in these meadows. The content of nutrients in meadows soils has increased, and conditions for nitrophilous plants has formed, so meadows has overgrown by high grasses and bushes. Transformed communities of meadows are not suitable for breeding of shorebirds that prefer open land. Shorebirds were almost extinct at 1993-2000 years because territory was covered by weeds and scrubs of 2 m height. Investigations were made in two points. First point (plots A) was a area of 73.1 ha that is hayed since 2000 year. The second point (plots B) was control area of 46.6 ha that is 3.2 km farther to east and has very similar abiotic conditions. This area is abandoned for 12 years now. Bird abundance, domination, diversity, species distribution were researched for 5 years (2002-2006). The tasks of research were: a)To measure change of absolute numbers of birds that nest in plots A (managed area), b) To measure change of absolute numbers of birds that nest in plots B (abandoned area), c) To compare results of observations in plots A and B. There were found these numbers of nesting shorebirds in area A (hayed area) at third year of haying: 5 pairs of Aquatic Warbler (Acrocephalus paludicola) (0.87 pairs/10 ha); 4 pairs of Black-tailed Godwit (Limosa limosa) (1.43 pairs / 10 ha), 9 pairs of Common Redshank (Tringa totanus) (2.47 pairs/10 ha).