Black locust (Robinia pseudoacacia) beloved and despised: A story of an invasive tree in Central Europe

Abstract

Robinia pseudoacacia, invaded many countries a long time ago and is now a common part of the Central European landscape. Positive economic but negative environmental impacts of Robinia result in conflicts of interest between nature conservation, forestry, urban landscaping, beekeepers and the public when defining management priorities. Because current legislation will determine the future distribution of Robinia in the landscape, a comprehensive view of this species is necessary. Although this species is well studied, most of the scientific papers deal with the economic aspects. Other information is published in local journals or reports. Therefore we reviewed the ecological and socio-economic impact of Robinia placing particular emphasis on the species’ history, vegetation ecology, invasiveness and management. In Central Europe, Robinia is limited climatically by late spring frost combined with a short vegetation period, soil hypoxia, shade and frequent major disturbances. The long historical tradition of using Robinia for afforestation has resulted in its popularity as a widespread forest tree and it being an important part of the economy in some countries. The main reasons are its fast growth, valuable and resistant wood, suitability for amelioration, reclamation of disturbed sites and erosion control, honey-making and recently dendromass production. On the other hand, a side-effect of planting this nitrogen-fixing pioneer tree, very tolerant of the nature of the substrate, is its propagation and spread, which pose a problem for nature conservation. Robinia is considered invasive, threatening especially dry and semi-dry grasslands, some of the most species-rich and endangered types of habitat in the region, causing extinction of many endangered light-demanding plants and invertebrates due to changes in light regime, microclimate and soil conditions. Other often invaded habitats include open dry forests and shrubland, alluvial habitats, agrarian landscapes, urban and industrial environments and disturbed sites, e.g. post-fire sites, forest clearings or degraded forestry plantations. Without forestry, black locust abundance would decrease during succession in forests with highly competitive and shade tolerant trees and in mature forests it occurs only as admixture of climax trees. The limited pool of native woody species, lack of serious natural enemies and a dense cover of grasses and sedges can suppress forest succession and favour the development of Robinia monodominant stands over 70 years old. A stratified approach, which combines both tolerance in some areas and strict eradication at valuable sites, provides the best option for achieving a sustainable coexistence of Robinia with people and nature.

How much does climate change threaten European forest tree species distributions?

“…This results from constraints other than climate (Bradley, Early, & Sorte, ) and the small amount of time since introduction (Kowarik, ). The latter point may be supported by better performance of R. pseudoacacia , introduced in 1635 as an ornamental, and used for the first large‐scale afforestation in 1750 (290 ha; Vítková, Müllerová, Sádlo, Pergl, & Pyšek, ), than P. menziesii (1827; Schmid, Pautasso, & Holdenrieder, ) and Q. rubra , which was also introduced in 17th century as an ornamental plant, but was not further spread by foresters until the late 19th century (Woziwoda et al., ). Therefore, their true dispersal capacity has not yet been manifested; thus, these results are biased by the highest uncertainty among the species studied.…”

A few north Appalachian populations are the source of European black locust

“…This can lead us to conclude that the origins of the central European cluster are related to human selection. As from the second half of the 18th century, extensive afforestation programs have been conducted in central Europe (in particular Germany, Hungary, and the Czech republic) promoting black locust for forestry purposes (Cierjacks et al, ; Vítková, Müllerová, Sádlo, Pergl, & Pyšek, ). Moreover, a genetic breeding program has been conducted since the beginning of the 20th century in Hungary (Keresztesi, ).…”

Spontaneous revegetation versus forestry reclamation—Vegetation development in coal mining spoil heaps across Central Europe

“…pseudoacacia stands on the herb layer on sandy substrates (Matus, Tóthmérész, & Papp, ; Řehounková & Prach, ). Together to its invasive potential outside reclaimed sites (Vítková, Müllerová, Sádlo, Pergl, & Pyšek, ), other studies have repeatedly documented the undesirable effects of R . pseudoacacia on species composition and direction of vegetation development (Řehounková & Prach, ; Török et al, ; von Holle, Joseph, Largay, & Lohnes, ).…”