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Diversité et structure des communautés de Lépidoptères nocturnes en chênaie de plaine dans un contexte de conversion vers la futaie régulière

Abstract : Sustainable management of forests requires to evaluate sylvicultural treatments and forestry practices consequences on biodiversity. In french state forests, oak coppice with standards are doomed to disapear within a few decades because of its conversion to even-aged high forests which area increases.

Therefore, short term consequences of two types of felling (regeneration felling and thinning), succession and recovery (in reference to stands still waiting in conversion) of moth communities (Lepidoptera) were studied. Reponses to forest stand caracteristics were also analysed. The study was carried out in the Montargis state forest. The sampling protocol was improved thank to a first year. According to a synchronic approach, moths were captured on 35 sites representing 6 sylvicultural stages including the before-conversion stage. Analyses focused on the whole community, several ecological groups (based on habitat preferences, type and number of host-plants, overwintering stage and dispersion ability) and relatively frequent species. Studied variables are species richness, absolute abundance and species composition.

The regeneration felling, an intensive felling method which starts the even-aged high forest cycle, higly modified the community composition and led to a fall in species richness et abundance. Thinning, a less disturbance type, did not change species richness et abundance nor the species composition. Along the forest cycle, species composition, recovered in the young high forest at about 110 years. Species richness and abundance increase in the young stages and reached a maximum in pole stage, at about 45 years followed by a trend to a decrease until young high forest. The majority of species were indifferent to felling and forest cycle, but affected species showed contrasting responses. Responses of studied groups are similar to those of the community, even for the open-habitat species and species feeding on herbaceous plants. Nevertheless, observed trends allowed species classification in two groups. The more penalized species were : forest species, species feeding on trees and shrub, monophagous species, species overwintering as eggs and species of Geometridae, which are poor diperser. Less penalized species are : eurytopic species, species feeding on herbaceous plants, polyphagous species, species overwintering as larvae and species of Noctuidae which are good disperser. Surprising similar responses of groups following regeneration felling (except species feeding on lichens) could be explained by : misinformation on species traits and, in the regeneration stage, on a fewer detectability of species, unfavourable micro-climatic conditions, poor foliage quality, high predation and high parasitism. Wing span was probably less linked with species dispersion ability then with the volume available for flying.

In the aged stands, species richness of moths was positively correlated with plant species richness, but in the overall, species richness increased with stand structural heterogeneity. Species composition was especially correlated with plant species richness.

Within study contrainsts, conversion to the even-aged high forest did not seem to threaten moth diversity. However if the observed trends were confirmed in the second half of forest cycle, forest species and poorly dispersing species would be penalized.
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Contributor : Philippe Bonneil <>
Submitted on : Wednesday, January 10, 2007 - 5:43:43 PM
Last modification on : Monday, May 18, 2020 - 2:36:06 PM
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Philippe Bonneil. Diversité et structure des communautés de Lépidoptères nocturnes en chênaie de plaine dans un contexte de conversion vers la futaie régulière. Ecologie, Environnement. Museum national d'histoire naturelle - MNHN PARIS, 2005. Français. ⟨tel-00123727⟩

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