Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: great cormorant

Sortuj według:

Ogranicz wyniki do:

Soil conditions under great cormorant and grey heron colonies in a wetland : Effect on soil nematode abundance and trophic structure

Kozacki Dawid, Ilieva-Makulec Krassimira, Hryniewicz Marek, Makulec Grzegorz

Journal of Water and Land Development

2023

no. 58

79--88

This study aimed to investigate how great cormorants and grey herons affect the density and trophic diversity of soil nematodes under breeding colonies located in Stawy Raszyńskie Nature Reserve (central Poland). Soil samples from the colonies were compared to control samples from adjacent areas unaffected by birds. Samples were taken at each site (two colonies and two relevant control sites) to a depth of 20 cm, and the soil cores were split into topsoil (0-10 cm) and subsoil (10-20 cm). A modified Baermann method was used to extract nematodes from the soil. The soil under nests supported more abundant nematode communities, but with a lower trophic diversity compared to the control sites. The cormorants had a greater impact on nematodes than the herons. We found that the external nitrogen input, the higher organic matter content and abundance of ammonifying bacteria, as well as the lower soil pH under the colonies than in the control sites, affected the nematode trophic groups in different ways. Compared to the control sites, there were significantly more bacterivorous nematodes but fewer herbivorous nematodes under the colonies. No predatory nematodes were found under the bird colonies and, in the case of the cormorant colony, no omnivorous nematodes. No significant differences in the abundance of fungivorous nematodes between the impact and the control plots were noticed. The results indicate that allochthonous input under bird colonies promotes microbial activity and the most opportunistic trophic group of nematodes, which may at least temporarily enhance decomposition and mineralisation processes and consequently affect nutrient cycling in the wetland soil.

Occurrence of Nematodes in the alimentary tract of great cormorants [Phalacrocorax carbo (Linnaeus, 1758)] in colonies located in the upper and lower Vistula River

Stocka I., Dziekońska-Rynko J., Mierzejewska K., Stańczak K., Wziątek B.

Oceanological and Hydrobiological Studies

2017

Vol. 46, No. 2

168--173

The occurrence of nematodes in the alimentary tract of great cormorant Phalacrocorax carbo (L., 1758) nestlings was studied in the Włocławek Reservoir located on the Vistula in central Poland and in adult birds wintering in the south of Poland, with the food base in the upper Vistula. Mixed (max 4 species) nematode infections were found in all birds. Apart from Contracaecum rudolphii Hartwich, 1964 found in all studied birds, the third- and fourth-stage larvae as well as adult individuals of the following species were also present: Eustrongylides excisus Jägerskiöld, 1909, Anisakis simplex (Rudolphi, 1809), Hysterothylacium aduncum (Rudolphi, 1802), Desmidocercella numidica Seurat, 1920, Synquaria squamata (Linstow, 1883), Cosmocephalus obvelatus (Creplin, 1825), Baruscapillaria carbonis (Dubinin et Dubinina, 1940). The overall mean intensity of infection with nematodes was 23.4 ± 11.6 in nestlings and 175.7 ± 110.9 in adult cormorants. The most common species was C. rudolphii with the mean infection intensity of 12.5 ± 5.9 in nestlings and 154.6 ± 111.4 in adults. The second most common species was E. excisus. S. squamata, C. obvelatus and D. numidica were less common in both age groups. A. simplex and H. aduncum were found only in nestlings, while B. carbonis only in adults.