Traditional coppice forest management drives the invasion of Ailanthus altissima and Robinia pseudoacacia into deciduous forests

• Published in: Forest ecology and management Vol. 291; pp. 308 - 317
• Main Authors: Radtke, A., Ambraß, S., Zerbe, S., Tonon, G., Fontana, V., Ammer, C.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01.03.2013; Elsevier
• Subjects: Abundance; Ailanthus altissima; Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Biological invasion; Canopies; Forest management; Forest management. Stand types and stand dynamics. Silvicultural treatments. Tending of stands. Natural regeneration; Forest regeneration; Forestry; Forests; Fundamental and applied biological sciences. Psychology; Hurdle model; Indicator species; Management; Mathematical models; Non-native species; Regeneration; Rejuvenation; Robinia pseudoacacia; Spreads; Stand types and stand dynamics. Silvicultural treatments. Tending of stands. Natural regeneration; Synecology; Terrestrial ecosystems; Trees; Asia; Italy; Biological invasion; Non-native species; Indicator species; Forest regeneration; Hurdle model; Rejuvenation; Deciduous forest; Forest management; Modeling; Dicotyledones; Angiospermae; Hardwood forest tree; Ailanthus altissima; Introduced species; Forest stand; Forest ecology; Indicator; Invasion; Robinia pseudoacacia; Simaroubaceae; Invasive species; Vegetation type; Leguminosae; Coppice; Vegetation; Forestry; Spermatophyta; Models
• ISSN: 0378-1127; 1872-7042
• DOI: 10.1016/j.foreco.2012.11.022

► Coppice forest management with clear-cuttings is still widespread in Southern Europe. ► Robinia pseudoacacia and Ailanthus altissima are invasive to Europe and good colonizers. ► Thus, coppice forest management favors their spread into forest ecosystems. ► Their invasion could be retraced in a sub-Mediterranean coppice forest. The non-native tree species Black Locust (Robinia pseudoacacia L.) from N America and Tree of Heaven (Ailanthus altissima (Mill.) Swingle) from E Asia are invading both anthropogenic and near-natural habitats throughout Europe. So far, few studies have focused on their invasion into forests and none has addressed the influence of coppice management, which is characterized through regular clear-cuts. To retrace the invasion during the last 50years, we studied the abundance in the canopy as well as the natural regeneration of these species in the coppice forest of Gargazon (South Tyrol, Northern Italy), which was ideal due to its patchy mosaic of different forest age (time since last coppicing). We analyzed which factors favor the presence and abundance of A. altissima and R. pseudoacacia regeneration. Tree saplings were sampled on 113 plots each measuring 7m2 in a total study area of 25.5hectares. On each plot, the following environmental variables were recorded: canopy cover per species, total herb layer cover, distance to clearing, stone cover, slope, and aspect. Soil moisture was derived from herbaceous indicator species. Hurdle models were used for data analysis to account for the zero-inflated data structure. The results showed that R. pseudoacacia has established earlier in the studied forest than A. altissima, but A. altissima has been spreading with higher speed during the last 30years. Our study exemplifies the invasion of both species synchronously to the coppice cycle, that means they colonize fresh clear-cuts, establish, and remain. We conclude that the currently applied coppice management, which consists of repeated clear cuttings each 20–30years, favors the spread of both invasive species. Thus, an adaptation of the management system is needed to avoid further invasion.