Improvement of black locust (Robinia pseudoacacia L.) growing under marginal site conditions in Hungary: case studies

Abstract

In Hungary, black locust (Robinia pseudoacacia L.) is considered as an important exotic stand-forming tree species growing mostly under unfavourable ecological conditions for forest management. Due to climate change effects, its importance is increasing in many other countries, too. As a result of a selection programme, new black locust clones were tested in clone trials. Juvenile growth of 12 micropropagated black locust clones in two plots series established at different dates were evaluated in central Hungary under marginal site conditions. At age of 7 the clone R. p. ‘Bácska’ (‘KH 56A2/5’), at age of 10 the clones R.p. ‘Homoki’ (‘MB17D3/4’) and ‘PV201E2/4’ appeared to be especially promising for mass production. Based on the data obtained from the performed trials, it can also be concluded that tissue culture can be considered as a suitable tool for propagating superior individuals and offers new prospects for the rapid cloning of selected genotypes used for plantation forestry.

Ecology, growth and management of black locust (Robinia pseudoacacia L.), a non-native species integrated into European forests

“…However, it grows best when the soil pH is slightly acid to near neutral, 5.5-7.0 (Roșu 1996;Borde 2011;Zajączkowski and Wojda 2012). Black locust tolerates dry and nutrient poor soils, but grows best on deep, nutrient-rich, moist, uncompacted, well-drained silt loams, sandy loams, or sandy soils (Haralamb 1967;Rédei et al 2011;Meyer-Münzer et al 2015). Under these conditions, the root-associated nitrogen fixing Rhizobium bacteria, which fixes up to 75 kg of N ha −1 year −1 (Boring and Swank 1984) or 150 kg of N ha −1 year −1 (Berthold et al 2005), are able to thrive.…”

“…Protection, either for individual trees or stands using tubes, grids, or fencing (a minimum height of 1.5 m), is recommended in some countries (Austria, Bulgaria, France, Germany), and is necessary when regenerating black locust 2.4 × (0.7-0.8); 2.4 × 1.0 Hungary Rédei et al (2008Rédei et al ( , 2011 and Rédei (2013a) 8900 1.5 × 0.75 Ukraine Lavnyy pers.comm. in areas with high browsing pressure (e.g., hares, roe deer, red deer as well as domestic goats or cattle) (Iby 1997;Ministry of Agriculture and Food 2013;Meyer-Münzer et al 2015;Lemonnier Nursery 2018).…”

“…After 3-4 years, this is followed by second cleaning-respacing, mostly based on positive selection, with the same aims but especially to reduce stocking to ca. 1700 or even 2000 stems ha −1 , with spacing as regular as possible to provide additional growing space to the remaining individuals (Constantinescu 1976;Halupa and Rédei 1988;Rédei et al 2011;Wojda et al 2015).…”

“…Black locust has become an economically important multipurpose species in many parts of Europe, as a nitrogen-fixing species for waste land and surface-mine reclamation, for erosion prevention and control, for carbon sequestration, as windbreaks and shelterbelts, as an ornamental tree in parks, gardens, alleys, and as a street tree as it is tolerant of air pollution and salinity and thrives in the urban environment. If managed as short rotation coppice as in, for example, Austria, Croatia, Hungary, France, Germany, Greece, Italy, Poland, Slovakia (Paris et al 2006;Facciotto et al 2008;Rédei and Veperdi 2009;Borde 2011;Rédei et al 2011;Maltoni et al 2012;Steinegger and Reh 2013;Crosti et al 2016;Giulietti 2016;Vítková et al 2016), it is used for biomass production/bioenergy generation, and produces biomass up to 14 dry matter t ha −1 a −1 (Straker et al 2015). In former mining Ecology, growth and management of black locust (Robinia pseudoacacia L.), a non-native species… areas of Germany, this species has produced 3-10 oven-dry t ha −1 a −1 , substantially higher than poplar and willow clones established on the same sites (Grünewald et al 2009).…”

“…In Italy, on poplar sites, its production can reach 10, even 12.5 dry matter t ha −1 year −1 using selected clones of Hungarian provenance (Giulietti 2016). In Hungary, where black locust is considered the most suitable species for energy plantations (Rédei and Veperdi 2009), its productivity reached 9.7 dry matter t ha −1 yr −1 (Rédei et al 2011). Black locust is also important as a raw material in the food industry, as fodder in silvopastoral systems, in biotherapy, and landscaping (Cierjacks et al 2013;Enescu and Dănescu 2015;Ciuvăț et al 2015;FOREST EUROPE 2015;Sitzia et al 2016;Vítková et al 2016).…”