| Autor: |
Wilf Powell, Joe N. Perry, Mohd Norowi Hamid, Keith Rennolls |
| Rok vydání: |
1999 |
| Předmět: |
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| Zdroj: |
Acta Oecologica. 20:537-549 |
| ISSN: |
1146-609X |
| DOI: |
10.1016/s1146-609x(00)86621-7 |
| Popis: |
The effect of spatial scale on the interactions between the weevils Gymnetron pascuorum Gyll. and Mecinus pyraster Herbst and their host plant, ribwort plantain Plantago lanceolata L., was studied. Both weevils developed in plantain seedheads but occupied different niches within the seedhead. Seedheads were sampled annually from 162 plants at each of two experimental sites consisting of a series of habitat patches of two distinct sizes. Data were analysed from three site-years. Our results suggest that the density of available seedheads varied among years and this had a direct effect on abundance. M. pyraster, which develops in the stem within the seedhead, was more sensitive to changes in seedhead density than was G. pascuorum, which develops within the seeds themselves. The presence of a hedgerow along one side of the experimental site affected the pattern of colonisation of newly-created habitat patches by G. pascuorum but not by M. pyraster. Changes in spatial scale did not affect the variability of seedhead and insect densities. G. pascuorum had an aggregated distribution at all the spatial scales considered, but the distribution of M. pyraster was very scale dependent. The distributions of the two weevil species were positively associated amongst infested plants but not amongst infested seedheads. Behavioural and ecological factors that could explain the results of the data analyses are discussed. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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