Soil seed bank of the invasive Robinia pseudoacacia in planted Pinus nigra stands

Abstract

-Pinus nigra and Robinia pseudoacacia are exotic trees used for afforestation in Hungary. Pinus nigra was non-invasive, however R. pseudoacacia escaped from cultivation and invaded several vegetation types including pine plantations. It has recently been planned to cut P. nigra plantations and replace them by native tree stands, especially in nature reserves. The scattered presence of R. pseudoacacia specimens in pine stands might place constraints on planned tree replacement because of their vegetative resprouting and recolonization from an established seed bank. The aim of this study was to investigate the soil seed bank under the canopy of solitary R. pseudoacacia specimens found in P. nigra plantations. Altogether 250 soil samples were collected from the 0-6 and 6-12 cm soil layers under solitary Robinia trees of varying ages (with basal areas between 62.4 and 1089.3 cm 2 ). Seeds were separated by sieving then scarified and germinated. Seed bank density ranged between 640 and 2285 seeds m -2 with an average distribution of 82.7% and 17.3% in the upper and lower soil layer, respectively. Total density of the seed bank and also the seed bank ratio of the lower soil layer increased with tree age. The accumulated seed bank of R. pseudoacacia should be considered in the careful planning of tree replacement operations in Pinus nigra stands.

Explaining the larger seed bank of an invasive shrub in non-native versus native environments by differences in seed predation and plant size

“…While all these factors can act simultaneously, other unidentified biotic or abiotic factors may be also be at play. Finally, SV relationships may be common in plant invasion biology, especially for invasive leguminous trees and shrubs that constitute large seed banks throughout the world (Paynter et al, 2003;Richardson and Kluge, 2008;Cseresnyés and Csontos, 2012;Strydom et al, 2017). In this case, SV relationships can serve as a starting point to predict seed bank dynamics, and evaluate their state compared with native areas and the efficiency of control programs, and can help to focus on the main factors likely to contribute to the accumulation of many seeds in soil.…”

Effect of Austrian pine on naturalness and succession of vegetation in reclaimed bauxite quarries

“…Although these plantations occupy only 3.7% of the total forested lands of the country, P. nigra is responsible for some serious ecological and nature conservation problems (Tamás, 2003). Several studies called the attention to the various aftermaths of the creation of pine stands, such as to the effects on the soil and ground layer including serious impoverishment of the species-rich native grassland vegetation (Bódis, 1993;Csontos et al, 1997, Szalai et al, 2012, the promoted spreading of other alien plants (Török et al, 2003;Cseresnyés and Csontos, 2012a), as well as the highly increased fire risk as a consequence of the considerable accumulation of resinous needle litter (Cseresnyés et al, 2011).…”

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

“…As a N-fixing species, black locust creates irreversible changes in physico-chemical and biological soil properties. It influences the species composition of ground flora under its canopy by favouring ruderal and species-poor neutrophilous weed associations, eliminating oligotrophic and acidophilous ones typical of forests, thereby reducing plant diversity (Kleinbauer et al 2010;Benesperi et al 2012;Cseresnyés and Csontos 2012;Dimitrova 2012;Vuković et al 2013). In invaded stands, as soil pH is significantly lower and soil NO 3 − significantly higher, soil microarthropode communities suffer significant loss of abundance and richness while nematode taxon richness is significantly lower (Lazzaro et al 2018).…”