Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 3

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  patrolling intensity
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
1

Effects of forested strips on spider assemblages in adjacent cereal fields: dispersal activity of spiders

100%
Kajak A.
Polish Journal of Ecology
|
2007
|
tom 55
|
nr 4
Spiders are important components of agricultural ecosystems as far as they affect markedly the abundance of crop pests. The objective of the study was to determine whether the planting of forested strips (shelterbelts) in agricultural area enhances the biomass of spiders active on soil surface of cereal fields and if the exchange of individuals between these habitats depends on the age of trees. The investigations were carried on in 2000 and repeated in 2003/2004 along transects across young shelterbelts (2–11 years old) – ecotones – fields. In the second period the 150 years old forest strip was included into the study. So altogether in both periods the study was performed in the strip-managed area in forested strips 2, 6, 7, 11, and 150 years old, adjacent cereal fields and in the control field located in a deforested area. The intensity of patrolling (number of individuals captured per trap per day) the soil surface by spiders was investigated using pitfall traps forming lines parallel to the shelterbelt. The results of both investigation periods show, that forested strips increased the biomass of patrolling spiders (BP – biomass of spiders per trap per day) in the fields. It was higher in the fields located in the strip-managed area than in the deforested area by ca 70%. The BP decreased gradually with the increasing distance from the strips. Differences between the strip and the field at a distance of 50m were significant (two-way ANOVA, post hoc Tukey test). The reason for the higher BP in the fields adjacent to forested strips was mainly the dispersal of larger spiders from strips to adjacent fields. Dispersal is high between the very young strip and the field and low between the oldest strip and the field. The group of forestinhabiting species accounted for 0.3–0.5% of the total number of spiders in the field located in deforested area. In the fields adjacent to young shelterbelts this proportion increases with the strips age from 1 to 6%. But in the field bordering the oldest forest strip it is low again and accounted for 1.4%. In this field the proportion of agrobionts is almost as high (94%) as in the field located in deforested area (98%). Similarly the species diversity was very low there. The mean individual body mass of spiders from all the fields located in the strip-managed area was 2.7 times higher than in the control field (P <0.001). It can be concluded, that in the old forest strips the number of specific species, which don’t disperse to surroundings, increases. This conclusion may be important for landscape management.
2

Effect of shelterbelts on adjoining cultivated fields: patrolling intensity of carabid beetles [Carabidae] and spiders [Araneae]

100%
Kajak A., Oleszczuk M.
Polish Journal of Ecology
|
2004
|
tom 52
|
nr 2
The impact of wooded shelterbelts on the patrolling intensity (number of patrolling individuals per trap, per day (NP) – activity density) of spiders and ground beetles was investigated by using pitfall traps placed in parallel rows in shelterbelt centers, along margins of wood and field, and in open wheat fields at a distance of 10 and 50 m from trees. In the shelterbelt – managed areas the biomass of patrolling (BP) arthropods (ground beetles and spiders) was lower inside the fields (F₁₀, F₅₀) than at the field margins and in the shelterbelts. The BP and individual weight increased with the age of strips. However, in the control field with no wood in the vicinity, the BP of carabid beetles was as high as inside the shelterbelts. The highest similarity between the shelterbelts and the field (BP, Morisita’s similarity index, diversity index H’, individual weight) was found in the field adjoining the youngest (aged 2 years) shelterbelt. It is concluded that similarity between permanent and cultivated ecosystems is important for successful exchange of individuals between them. In the field adjacent to young shelterbelt and in the field with no woods in the vicinity the aeronautic, agrobiont species prevail. In the fields adjacent to older shelterbelts colonization by large body-size species, characteristic for permanent ecosystems was found.
3

Experimental approach for studying interrelationships between macroarthropods, soil biota, decomposion rate of litter and organic matter accumulation in soil

100%
Kajak A.
Polish Journal of Ecology
|
2000
|
tom 48
|
nr 4
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.