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Invasive annual grasses show decrease in seed size but no change in growth or carbon economy following invasion.
- Source :
- Biological Invasions; May2023, Vol. 25 Issue 5, p1613-1625, 13p
- Publication Year :
- 2023
-
Abstract
- The invasion of annual grasses into historically perennial-dominated systems is a global biodiversity threat. While significant, it is not known how evolutionary changes in functional traits during the invasion process may contribute to invader success. We examined how functional traits of a widely distributed invasive annual grass medusahead (Taeniatherum caput-medusae (L.) Nevski) differed across native-range and invaded-range populations and compared these trait values to those of a common native perennial, squirreltail (Elymus elymoides (Raf.) Swezey). In greenhouse and growth chamber studies we screened a range of plant, seed and seedling functional traits and determined how variation in these traits contributed to variation in plant biomass. Our results show medusahead maintains a higher relative growth rate (RGR) than squirreltail, but the mechanism differed depending on origin with native-range medusahead achieving a higher RGR through a higher specific leaf area and the invaded-range medusahead achieving a higher RGR though a higher net assimilation rate. Contrary to previous literature, we did not find that medusahead evolved traits allowing larger biomass in its invaded range. Instead, native-range medusahead populations grew bigger than invaded-range populations, primarily due to differences in seed size. While counter to expectations, smaller seed mass may provide invaded-range medusahead populations an advantage in terms of dispersal and higher seed bank density compared to native-range populations. Thus, life history differences, altered disturbance regimes, and a shift towards production of smaller but a greater number of seeds may act, in combination, to facilitate invasion of annual grasses into perennial dominated systems. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 13873547
- Volume :
- 25
- Issue :
- 5
- Database :
- Complementary Index
- Journal :
- Biological Invasions
- Publication Type :
- Academic Journal
- Accession number :
- 163045156
- Full Text :
- https://doi.org/10.1007/s10530-023-02999-4