Title: The myth of plant species saturation
Author: Stohlgren, Thomas J.; Barnett, David T.; Jarnevich, Catherine S.; Flather, Curtis; Kartesz, John;
Source: Ecology Letters. 11: 313-326.
Publication Series: Scientific Journal (JRNL)
Description: Plant species assemblages, communities or regional floras might be termed saturated when additional immigrant species are unsuccessful at establishing due to competitive exclusion or other inter-specific interactions, or when the immigration of species is off-set by extirpation of species. This is clearly not the case for state, regional or national floras in the USA where colonization (i.e. invasion by exotic species) exceeds extirpation by roughly a 24 to 1 margin. We report an alarming temporal trend in plant invasions in the Pacific Northwest over the past 100 years whereby counties highest in native species richness appear increasingly invaded over time. Despite the possibility of some increased awareness and reporting of native and exotic plant species in recent decades, historical records show a significant, consistent long-term increase in exotic species (number and frequency) at county, state and regional scales in the Pacific Northwest. Here, as in other regions of the country, colonization rates by exotic species are high and extirpation rates are negligible. The rates of species accumulation in space in multi-scale vegetation plots may provide some clues to the mechanisms of the invasion process from local to national scales.
Keywords: biotic resistance, competitive exclusion, habitat heterogeneity, invasion, plant diversity, saturation, species richness
- We recommend that you also 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.
XML: View XML
Stohlgren, Thomas J.; Barnett, David T.; Jarnevich, Catherine S.; Flather, Curtis; Kartesz, John 2008. The myth of plant species saturation. Ecology Letters. 11: 313-326.
Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility