Summary1. Disturbances and resource availability are key factors affecting plant diversity in managed forests. As disturbance regimes vary among silvicultural systems and may simultaneously affect different types of resources, effects on biodiversity can be unpredictable. 2. We compared the effects of two silvicultural systems on understorey plant diversity, including species composition, structural attributes and functional organization. One hundred and thirty-five phytosociological relevés were sampled from 27 forest stands managed under either a traditional coppice-with-standards (CWS, n = 12) or a 'close-tonature' selective cutting system (SC, n = 15), over similar edaphic conditions. Important environmental factors affecting vegetation were deduced using Ellenberg indicator values. Structural diversity was described using traditional indices of α and β diversity. Guilds were defined within the local pool of species using a set of 14 traits and their relationship with silviculture was assessed using correspondence analysis. 3. Post-logged CWS stands share some compositional and structural characteristics with selectively cut stands, including high species richness and a dominance of early successional species. However the species pool for all coppicing areas was higher than for selectively cut areas, suggesting that the high disturbance frequency occurring in the latter may progressively eliminate the most sensitive species. 4. Functional diversity strongly differs between the two systems. Although it is conserved through the silvicultural cycle in the coppice-with-standards system, some guilds were lacking in selectively cut stands. The most negatively impacted guilds were tree and shrub saplings, prostrated ruderals, shade-tolerant perennials and vernal geophytes. The latter two comprise 'true forest species' which may also be considered as 'coppicingmaintained species'. To reach the same values of guild richness (i.e. number of guilds) or redundancy (i.e. proportion of the maximal species richness within each guild), larger areas were required in SC compared with CWS systems. 5. In the SC system, the high proportion of light reaching the forest floor induced a spectacular spread of blackberries Rubus fruticosus agg., which decreased species richness. It also caused shifts in guild composition: graminoids and ferns grew strongly to the detriment of true forest species. 6. Synthesis and applications . Our results suggest long-term negative effects of selective cutting on both structural and functional plant diversity, compared with coppice-withstandards. Cutting intervals are shorter than recovery times, so that early successional species-dominated communities are maintained. Vernal geophytes and shade-tolerant perennials seem to be limited by the frequency of disturbance rather than by the severity of disturbance. We conclude that, from a biodiversity point of view, this 'close-to-nature' system does not cope with the objective of sustainable forest management. The rotations currently in use do not match n...
-Forest management consists in anthropogenic disturbances that are able to modulate ecological features, resource availability and successional patterns. Plant communities are thus expected to react differently to contrasted silvicultural systems. We compared plant species composition between stands submitted to a traditional management since many centuries (i.e. coppice-with-standards treatment, stands intensively but infrequently disturbed) and stands recently converted into a selective cutting system (stands moderately but frequently disturbed), over uniform edaphic and topographic conditions. We found significant differences in species composition between both systems. Despite a strong shift in species composition among different stages of the coppice cycle, coppice-with-standards stands supported the highest number of true forest species. Selectively-cut stands were more homogeneous and characterized by ruderal "generalist" species. These fast changes in vegetation composition were related to differences in a group of factors that are directly or indirectly linked to the silvicultureassociated disturbance regime, including soil moisture, soil fertility, forest microclimate, light and game predation. We conclude that the conversion of a silvicultural system which has patterned plant communities since many centuries, induces early major changes in vegetation composition. The most negatively impacted species are the so-called "true forest species" that may be better labelled "coppice-woodland species". disturbance / microclimate / forest management / plant diversity / true forest species Résumé -Changements de la composition floristique induits par la sylviculture dans une forêt tempérée caducifoliée européenne. La sylviculture est une perturbation anthropogène capable de moduler les facteurs environnementaux, la disponibilité des ressources et la dynamique forestière. La végétation spontanée est donc susceptible de réagir différemment à des systèmes sylviculturaux contrastés. La composition floristique de parcelles forestières traitées en taillis-sous-futaie depuis plusieurs siècles a été comparée à celle de parcelles récemment converties en futaie irrégulière coupée « pied-à-pied », en conditions édaphique et topographique uniformes. Malgré des différences importantes en fonction du temps écoulé depuis la dernière coupe, la partie de la forêt traitée en taillis-sous-futaie hébergeait un nombre plus important d'espèces forestières. Les parcelles en futaie irrégulière étaient plus homogènes et caractérisées par des espèces rudérales « généralistes ». Ces changements précoces de la composition spécifique ont pu être reliés à des modifications du contexte environnemental, directement ou indirectement induites par la sylviculture, incluant l'humidité et la fertilité du sol, le microclimat forestier, la lumière et la prédation par le chevreuil. La conversion d'un type sylvicultural, qui a façonné les communautés végétales durant des siècles, induit donc rapidement des changements majeurs dans la compositi...
and T. polium L.) ont été réalisées dans le cadre d'une étude sur le genre Teucrium. Vingt types de poils (treize tecteurs, sept glanduleux) sont dénombrés sur les six taxons étudiés. Treize types caractérisent une seule espèce, alors que trois poils sont cantonnés à deux espèces. Seulement quatre types sont communs à toutes les espèces. Cependant parmi ces vingt trichomes, douze types de poils tecteurs sont caractéristiques d'une ou deux espèces pour seulement quatre poils glanduleux. Les poils tecteurs sont plus importants que les poils glanduleux en ce qui concerne la séparation entre les espèces de Teucrium. Cette étude montre aussi que les corolles ont le plus grand nombre (cinq sur vingt) de types de poils caractéristiques, suivies par les calices, les feuilles avec deux sur vingt et un seul poil est typique à la fois des feuilles et tiges. Davis, T. orientale L. var. orientale and T. polium L.) distributed in Lebanon wascarried out as part of the taxonomical study of the genus Teucrium. Twenty different types of trichome (13 non-glandular, 7 glandular) were found on the six studied species. Thirteen types were characteristic for one species and three types were characteristic of two species. Only four types were found on the six studied species. On the twenty different types of trichome, twelve non-glandular hairs and only four glandular hairs were characteristic of one or two species. Those results indicate that non-glandular hairs are more important than glandular hairs concerning the separation between Teucrium species. This study also show that the corolla have the most important number of typical trichome (5/20) followed by leaves and calyxes (2/20) each and only one trichome is typical to both leaves and stems.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.