Light and propagule pressure affect invasion intensity of Prunus serotina in a 14-tree species forest common garden experiment

By

Jagodziński, Andrzej
Dyderski, Marcin
Horodecki, Paweł
Knight, Kathleen S. (Kathleen Susan)
Rawlik, Katarzyna
Szmyt, Janusz

Type

Article

Date of Publication

2019

Original Publication

NeoBiota : advancing research on alien species and biological invasions

Volume

46

Pages

1-21

Subjects

Allometric equations , biomass , invasion dynamics , Light availability , Natural regeneration , tree species effect

Contributed by

Pensoft Publishers

Language

English

Published by

Sophia, Bulgaria Pensoft Publishers

Identifiers

DOI: https://doi.org/10.3897/neobiota.46.30413

 

Abstract

Experiments testing multiple factors that affect the rate of invasions in forests are scarce. We aimed to assess how the biomass of invasive Prunusserotina changed over eight years and how this change was affected by light availability, tree stand growth, and propagule pressure. The study was conducted in Siemianice Experimental Forest (W Poland), a common garden forest experiment with 14 tree species. We investigated aboveground biomass and density of P.serotina within 53 experimental plots with initial measurements in 2005 and repeated in 2013. We also measured light availability and distance from seed sources. We used generalized additive models to assess the impact of particular predictors on P.serotina biomass in 2013 and its relative change over eight years. The relative biomass increments of P.serotina ranged from 0 to 22,000-fold. The success of P.serotina, expressed as aboveground biomass and biomass increment, varied among different tree species stands, but was greater under conifers. Total biomass of P.serotina depended on light and propagule availability while biomass increment depended on the change in tree stand biomass, a metric corresponding to tree stand maturation. Our study quantified the range of invasion intensity, expressed as biomass increment, in a forest common garden experiment with 14 tree species. Canopy cover was the most important variable to reduce susceptibility to invasion by P.serotina. Even a modest decrease of overstory biomass, e.g. caused by dieback of coniferous species, may be risky in areas with high propagule pressure from invasive tree species. Thus, P.serotina control may include maintaining high canopy closure and supporting natural regeneration of tree species with high leaf area index, which shade the understory.