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Increased Primary Production from an Exotic Invader Does Not Subsidize Native Rodents.

Lucero JE, Allen PS, McMillan BR - PLoS ONE (2015)

Bottom Line: Invasive plants have tremendous potential to enrich native food webs by subsidizing net primary productivity.Our experiments demonstrate that increased primary productivity associated with exotic plant invasions may not necessarily subsidize consumers at higher trophic levels.In this context, cheatgrass invasion could disrupt native food webs by providing less-preferred resources that fail to enrich higher trophic levels.

View Article: PubMed Central - PubMed

Affiliation: Department of Plant and Wildlife Sciences, Brigham Young University, Provo, Utah, United States of America.

ABSTRACT
Invasive plants have tremendous potential to enrich native food webs by subsidizing net primary productivity. Here, we explored how a potential food subsidy, seeds produced by the aggressive invader cheatgrass (Bromus tectorum), is utilized by an important guild of native consumers--granivorous small mammals--in the Great Basin Desert, USA. In a series of field experiments we examined 1) how cheatgrass invasion affects the density and biomass of seed rain at the ecosystem-level; 2) how seed resources from cheatgrass numerically affect granivorous small mammals; and 3) how the food preferences of native granivores might mediate the trophic integration of cheatgrass seeds. Relative to native productivity, cheatgrass invasion increased the density and biomass of seed rain by over 2000% (P < 0.01) and 3500% (P < 0.01), respectively. However, granivorous small mammals in native communities showed no positive response in abundance, richness, or diversity to experimental additions of cheatgrass seeds over one year. This lack of response correlated with a distinct preference for seeds from native grasses over seeds from cheatgrass. Our experiments demonstrate that increased primary productivity associated with exotic plant invasions may not necessarily subsidize consumers at higher trophic levels. In this context, cheatgrass invasion could disrupt native food webs by providing less-preferred resources that fail to enrich higher trophic levels.

No MeSH data available.


Related in: MedlinePlus

Seed Production on Cheatgrass-invaded vs. Non-invaded Habitat.Comparison of the a) density (seeds/0.085 m2) and b) biomass (g) of seed rain (mean ± SE) from cheatgrass-invaded (“Invaded”) and non-invaded (“Non-Invaded”) sage-steppe habitats in a Great Basin ecosystem (n = 6).
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pone.0131564.g001: Seed Production on Cheatgrass-invaded vs. Non-invaded Habitat.Comparison of the a) density (seeds/0.085 m2) and b) biomass (g) of seed rain (mean ± SE) from cheatgrass-invaded (“Invaded”) and non-invaded (“Non-Invaded”) sage-steppe habitats in a Great Basin ecosystem (n = 6).

Mentions: Relative to non-invaded habitat, total seed production in cheatgrass-invaded habitat was over 2000% denser (P < 0.01; Table 1 and Fig 1a) and over 3500% more massive (P < 0.01; Table 1 and Fig 1b). Not surprisingly, cheatgrass accounted for the greatest proportion of seeds produced in invaded habitat (Table 1). Interestingly, however, seed production from squirreltail, a native perennial grass, was over 1100% (P < 0.01) denser in cheatgrass-invaded habitat than non-invaded habitat. Seed production from Asteraceae was nearly 300% greater in non-invaded habitat (P = 0.02; Table 1).


Increased Primary Production from an Exotic Invader Does Not Subsidize Native Rodents.

Lucero JE, Allen PS, McMillan BR - PLoS ONE (2015)

Seed Production on Cheatgrass-invaded vs. Non-invaded Habitat.Comparison of the a) density (seeds/0.085 m2) and b) biomass (g) of seed rain (mean ± SE) from cheatgrass-invaded (“Invaded”) and non-invaded (“Non-Invaded”) sage-steppe habitats in a Great Basin ecosystem (n = 6).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4526561&req=5

pone.0131564.g001: Seed Production on Cheatgrass-invaded vs. Non-invaded Habitat.Comparison of the a) density (seeds/0.085 m2) and b) biomass (g) of seed rain (mean ± SE) from cheatgrass-invaded (“Invaded”) and non-invaded (“Non-Invaded”) sage-steppe habitats in a Great Basin ecosystem (n = 6).
Mentions: Relative to non-invaded habitat, total seed production in cheatgrass-invaded habitat was over 2000% denser (P < 0.01; Table 1 and Fig 1a) and over 3500% more massive (P < 0.01; Table 1 and Fig 1b). Not surprisingly, cheatgrass accounted for the greatest proportion of seeds produced in invaded habitat (Table 1). Interestingly, however, seed production from squirreltail, a native perennial grass, was over 1100% (P < 0.01) denser in cheatgrass-invaded habitat than non-invaded habitat. Seed production from Asteraceae was nearly 300% greater in non-invaded habitat (P = 0.02; Table 1).

Bottom Line: Invasive plants have tremendous potential to enrich native food webs by subsidizing net primary productivity.Our experiments demonstrate that increased primary productivity associated with exotic plant invasions may not necessarily subsidize consumers at higher trophic levels.In this context, cheatgrass invasion could disrupt native food webs by providing less-preferred resources that fail to enrich higher trophic levels.

View Article: PubMed Central - PubMed

Affiliation: Department of Plant and Wildlife Sciences, Brigham Young University, Provo, Utah, United States of America.

ABSTRACT
Invasive plants have tremendous potential to enrich native food webs by subsidizing net primary productivity. Here, we explored how a potential food subsidy, seeds produced by the aggressive invader cheatgrass (Bromus tectorum), is utilized by an important guild of native consumers--granivorous small mammals--in the Great Basin Desert, USA. In a series of field experiments we examined 1) how cheatgrass invasion affects the density and biomass of seed rain at the ecosystem-level; 2) how seed resources from cheatgrass numerically affect granivorous small mammals; and 3) how the food preferences of native granivores might mediate the trophic integration of cheatgrass seeds. Relative to native productivity, cheatgrass invasion increased the density and biomass of seed rain by over 2000% (P < 0.01) and 3500% (P < 0.01), respectively. However, granivorous small mammals in native communities showed no positive response in abundance, richness, or diversity to experimental additions of cheatgrass seeds over one year. This lack of response correlated with a distinct preference for seeds from native grasses over seeds from cheatgrass. Our experiments demonstrate that increased primary productivity associated with exotic plant invasions may not necessarily subsidize consumers at higher trophic levels. In this context, cheatgrass invasion could disrupt native food webs by providing less-preferred resources that fail to enrich higher trophic levels.

No MeSH data available.


Related in: MedlinePlus