Fruit fate, seed germination and growth of an invasive vine - an experimental test of 'sit and wait' strategy
- Author(s): Greenberg, Cathryn H.; Smith, Lindsay M.; Levey, Douglas J.
- Date: 2001
- Source: Biological Invasions 3: 363-372, 2001
- Station ID: --
Oriental bittersweet (Celastrus orbiculutus Thunb.) is a non-indigenous, invasive woody vine in North America that proliferates in disturbed open sites. Unlike most invasive species, C. orbiculatus exhibits a `sit and wait' strategy by establishing and persisting indefinitely in undisturbed, closed canopy forest and responding to canopy disturbance with rapid growth, often overtopping trees. We compared fruit fates of C. orbiculutus and native American holly (Ilex opaca). We also explored mechanisms for this `sit and wait' invasion strategy by testing the effect of C. orbiculutus fruit crop density on removal rates and by examining the influence of seed treatment and light intensity on seed germination and seedling growth. More C. orbiculatus than I. opaca fruits became damaged, and damage occurred earlier. More fruit fell from C. orbiculutus than I. opaca, but removal rates by frugivores did not differ (76.0 ± 4.2% vs 87.5 ± 3.7%, respectively). Density (number of fruits in a patch) of C. orbiculutus did not influence removal rates. Scarification (bird-ingestion) of C. orbiculatus seed delayed germination but seeds germinated in similar proportion to manually defleshed seeds (sown either singly or all seeds from a fruit). Germination of seeds within intact fruits was inhibited and delayed compared to other treatments. Seed treatment did not affect seedling growth. The proportion of seeds germinating and time until germination was similar among five light intensity levels, ranging from full sun to closed-canopy. Seedlings in >70% photosynthetically active radiation (PAR) had more leaves, heavier shoots, and longer, heavier roots than seedlings at lower PAR levels. Results that most (>75%) C. orbiculatus seeds are dispersed, seedlings can establish in dense shade, and plants grow rapidly when exposed to high light conditions. Control strategies for this highly invasive species should likely focus on minimizing seed dispersal by vertebrates.
Pristine Version Available
An uncaptured, or “pristine” version of this publication is available. It has not been subjected to OCR and therefore does not have any errors in the text. However, it is a larger file size and some people may experience long download times.Download “Pristine” Publication (PDF; 1.3 MB)
You can order print copies of our publications through our Publication Ordering System. Make a note of the publication you wish to request, and visit our Publication Order Site.
- We recommend that you print this page and attach it to the printout of the article to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
- Our on-line publications are scanned and captured using Adobe Acrobat. During the capture process some typographical errors may occur. Please contact the SRS Webmaster if you notice any errors which make this publication unuseable.
- To view this article get the latest version of the Adobe Acrobat Reader.