Search results for "Overwintering"
showing 5 items of 55 documents
Biogeographical comparison of winter bird assemblages in urban environments in Finland
1996
We studied biogeographical variation of urban bird assemblages in Finland. Winter birds were censused by single-visit study plot method from thirty-one centres of villages or towns along 950 km latitudinal extent. A total twenty-eight bird species was observed and the average density was 61.2 ind./10 ha. The number of dominant species in study areas varied between two and seven and their proportion of the whole assemblage was over 70%. Species richness, but not the density of birds, decreased northwards in pooled data. Higher species richness in south than in north was mainly due to the higher amount of delayed migratory birds (e.g. waterbirds, finches) and southerly distributed bird specie…
Natural enemies emerging in cereal fields in spring may contribute to biological control
2022
1.Biological pest control is known to depend on landscape heterogeneity. However, such relationship shows irregular pattern and seems influenced by local farming practices and natural enemies that overwinter within crop fields. The objective of this study was to assess the contribution of emerging natural enemies in spring to biological control, and their response to the interaction between landscape heterogeneity and farming intensity. 2.We monitored the overwintering insect community using emergence traps and measured the local potential pest predation using prey cards in 30 cereal fields, in spring in France. Study fields were selected along a landscape heterogeneity gradient and farming…
Size-related mortality during overwintering in cavity-nesting ant colonies (Hymenoptera: Formicidae)
2016
The ongoing process of climate change will result in higher temperatures during winter and therefore might increase the survival of overwintering invertebrates. However, the process may also lead to a reduction in snow cover and expose overwintering invertebrates to lower temperatures, which could result in higher mortality. During a field experiment, I investigated the effects of a reduction in snow cover on the survival of the ant Temnothorax crassispinus, which overwinters in nests located on the ground. Ant colonies differed in the survival rate of the workers in the experimental (from which snow cover was removed) and control group. In the control group, the survival rate was unrelated…
Pluskwiaki różnoskrzydłe (Hemiptera: Heteroptera) zimujące pod korą platanów klonolistnych Platanus x acerifolia w Polsce
2020
The paper presents the results of three-year studies conducted at 75 locations in Poland testing the use of the London planes for overwintering of true-bugs. Insects were sampled from the bark of trunks. Altogether 25 species of Heteroptera was recorded, including three invasive species that can considerable affect plane trees: Arocatus longiceps, Corythucha ciliata and Oxycarenus lavaterae.
Vasarzaļo rododendru spraudeņu pavairošanas potenciāls atkarībā no mātes augu un spraudeņu apstrādes
2015
Darba mērķis bija noskaidrot vasarzaļo rododendru spraudeņu pavairošanas potenciālu atkarībā no mātes augu priekšapstrādes (etiolācija, steidzināšana) un spraudeņu apstrādes ar auksīnu – indol-3-sviestskābi (ISS). Mātes augu etiolācija kopā ar ISS veicināja straujāku rizoģenēzi, bet neietekmēja apsakņoto spraudeņu skaitu. Etiolācija uzlaboja pārziemošanu grūtāk apsakņojamiem spraudeņiem. Mātes augu steidzināšana kopā ar ISS uzlaboja spraudeņu rizoģenēzi grūtāk apsakņojamiem genotipiem, veicināja jauno dzinumu attīstību, uzlabojot spraudeņu pārziemošanu. Nodrošinot apsakņotajiem spraudeņiem nepārtrauktu veģetācijas periodu, var būtiski palielināt pārziemojušo spraudeņu skaitu. Cietes koncent…