Bouget C.,IRSTEA |
Parmain G.,IRSTEA |
Parmain G.,National Laboratory of Forest Entomology |
Gilg O.,Reserves Naturelles de France |
And 6 more authors.
Animal Conservation | Year: 2014
The decline of many saproxylic species results from the decrease in old-growth structures in European harvested forests. Among conservation tools, protected reserves withdrawn from regular harvesting and extended rotations have been employed to restore old-growth attributes in structurally simplified managed forests, even if the effects of such management actions on forest habitats and biodiversity remain largely unknown. In this study, we compared structural stand features and saproxylic beetle assemblages in two stand classes - recently harvested stands and long-established reserves, where less or more than 30 years had elapsed since last harvest. Habitat and saproxylic beetle data were collected according to standardized protocols in 153 plots in seven lowland deciduous forests. Tangible contrasts in stand features were found between long-established reserves and recently harvested plots. Indeed, most higher-value densities and volumes were found in unharvested areas. The difference was weaker for microhabitat-bearing tree density than for deadwood; some deadwood features, such as volume of large downed and standing deadwood showed a very pronounced difference, thus indicating a marked deleterious effect of forest harvesting on these elements. Deadwood diversity, on the other hand, was only slightly affected and the level of stand openness did not change. The response of saproxylic beetles to delayed harvesting was weaker than the structural changes in deadwood features. Indeed even if only some guilds weakly increased in non-harvested plots, harvesting classes significantly affected the abundance of a quarter of the species tested. Our results tend to question measures such as rotating and temporarily ageing patches. We argue in favor of permanent strict fixed-location reserves. Future work should examine how stands recover old-growth forest attributes and how the associated saproxylic fauna colonizes in the long term. © 2014 The Zoological Society of London.
Paillet Y.,IRSTEA |
Pernot C.,IRSTEA |
Boulanger V.,Office National des Forets |
Debaive N.,Reserves Naturelles de France |
And 4 more authors.
Forest Ecology and Management | Year: 2015
Over the past centuries in Western Europe, the long history of forest management has shaped both landscape- and local-scale forest structures. In France, a network of strict forest reserves was created in the 1950s to serve as a reference for nature conservation and forest dynamics. However, few studies to date have quantitatively compared the structural characteristics between managed stands and the reserves, where management has been (more or less recently) abandoned. In addition, the time needed for old-growth characteristics to restore themselves in strict forest reserves remains poorly known.We analysed the differences in stand characteristics between managed and unmanaged stands in 17 French forests (233 plots) located in both lowland and in mountainous regions. We quantitatively showed that overall basal area, very large trees and deadwood features were significantly higher in unmanaged forests, though this pattern was mainly found in the lowland forests while in mountainous regions, managed and unmanaged forests showed far fewer differences. In addition, most structural characteristics that were higher in unmanaged forests also increased with the time since last harvesting.Compared to the remaining old-growth forests elsewhere in Europe, the strict forest reserves in France often appear less mature, since they are still recovering from centuries of intensive management. Our results also show lower levels than those observed in other European studies on the restoration of old-growth characteristics over time; this indicates that it will take French reserves a very long time to reach values comparable to old-growth references in Europe. Our study constitutes one of the first references on unmanaged forests in France and may serve practitioners in their everyday management. © 2015 Elsevier B.V.
BOUVET A.,IRSTEA |
PAILLET Y.,IRSTEA |
ARCHAUX F.,IRSTEA |
TILLON L.,University Paris Est Creteil |
And 3 more authors.
Environmental Conservation | Year: 2016
Sustainable forest management aims to produce wood while preserving habitats for biodiversity, which is particularly challenging for vertebrates with local and landscape scale requirements, such as birds or bats. Managers need additional scientific evidence to help them balance conservative and integrative management methods. In this study, the relative influence of management abandonment, stand structure and landscape features on bird and bat communities in 14 managed and unmanaged forests in France is evaluated. Total birds and bats richness, richness for forest and threatened birds and edge-specialized bats significantly increased with total deadwood quantities. Richness of generalist, omnivorous and cavity-nesting birds was higher in unmanaged stands and richness of gleaner bats was positively influenced by the density of standing deadwood. By contrast, landscape variables had little influence on the different ecological groups but did have effects on individual species. Though the effects showed relatively limited magnitude, this study supports the value of deadwood and the importance of management abandonment for forest vertebrates. This study confirms that for integrated conservation strategies to be fully efficient they must be complemented by designating strict forest reserves because some target species groups depend on structural features found only at sufficient levels in those areas. Copyright © Foundation for Environmental Conservation 2016
Impact of discontinuing logging activity on the dendrometric structure of mixed beech forests in france [Impact de l'arrêt d'exploitation forestière sur la structure dendrométrique des hêtraies mélangées en france]
Pernot C.,IRSTEA |
Paillet Y.,IRSTEA |
Boulanger V.,OFFICE NATIONAL DES FORETS |
Debaive N.,RESERVES NATURELLES DE FRANCE |
And 4 more authors.
Revue Forestiere Francaise | Year: 2013
Based on a comparison between managed and unmanaged forests, the aim of our study is to provide managers with a tentative quantitative analysis of the structural differences between managed and unmanaged mixed beech forests in France from a sample of 213 plots located in 15 lowland and mountain forests. Most structural descriptors were significantly higher in unmanaged forests. There were more very large living trees (+ 105 %) in unmanaged than in managed forests. These trees were also bigger (+ 145 %). The volume of dead wood was four times higher in unmanaged forests. Because of its nationwide scope, our investigation is a first French benchmark study for biodiversity-oriented forest policy, and contributes additional knowledge to a poorly researched area in France. © AgroParisTech, 2013.