Hydrochory and water induced germination enhance invasion of Fraxinus pennsylvanica

FOREST ECOLOGY AND MANAGEMENT

卷:304

Article

Schmiedel, Doreen¹  Tackenberg, Oliver² 

[1] Tech Univ Dresden, Inst Gen Ecol & Environm Protect, D-01737 Tharandt, Germany

[2] Goethe Univ Frankfurt, Inst Ecol Evolut & Div, D-60438 Frankfurt, Germany

关键词: Hydrochory;    Buoyancy;    Wind dispersal;    Green ash;    Secondary dispersal;   

DOI  :  10.1016/j.foreco.2013.04.027

来源: Elsevier

【 摘 要 】

In many Central European countries Fraxinus pennsylvanica is an invasive species that spreads rapidly in floodplain forests. The aim of this study was to analyse anemochorous and hydrochorous dispersal distances and to compare the findings with dispersal data for the native Fraxinus excelsior. A simulation revealed that wind dispersal distances are similar for both species, reaching to 120-250 m. By contrast, the mean floating time (50% floating samaras) measured in an experiment was 2 days in the case of F. pennsylvanica and 0.5 days for F. excelsior. This high floating ability facilitates water dispersal over several kilometres in both species, but for the invasive species the modelled mean dispersal distance was 3.7 times higher. A germination test of F. pennsylvanica seeds revealed that the rate, onset and speed of germination increase with the duration of the inundation. After a maximum storage time in water of about 15 days the germination rate amounts to 78%, which was higher than the germination rate of seeds without storage in water (53%). We also found that regeneration was enhanced in flooded areas. Hydrochory, therefore, may be viewed as an important factor explaining the successful invasion of F. pennsylvanica in floodplain forests in Central Europe. (C) 2013 The Authors. Published by Elsevier B.V. All rights reserved.

【 授权许可】

Free