Rodent seed predators and a dominant grass competitor affect coexistence of co‐occurring forb species that vary in seed size

Maron, John L.; Hajek, Karyn L.; Hahn, Philip G.; Pearson, Dean E.

doi:10.1111/1365-2745.13027

Cited by 18 publications

(53 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Owing to higher seed inputs (to mimic their higher fecundity), and limited evidence for microsite limitation, across species there was a strongly linear relationship between seed input at average fecundity and the number of seedlings that established in both 2017 (Maron et al 2018) and across both years (ANOVA; F 1,56 = 53, P < 0.0001). Owing to higher seed inputs (to mimic their higher fecundity), and limited evidence for microsite limitation, across species there was a strongly linear relationship between seed input at average fecundity and the number of seedlings that established in both 2017 (Maron et al 2018) and across both years (ANOVA; F 1,56 = 53, P < 0.0001).…”

Section: Discussionmentioning

confidence: 99%

“…Theory predicts that more fecund, smallseeded species are likely to occupy most microsites, and thus recruitment of these species is often thought to be microsite limited rather than limited by the absolute number of seeds produced (Harper 1977, Turnbull et al 2000, Levine and Rees 2002. For example, in systems where mice are the major postdispersal seed predator, sizedependent seed predation can result in large-seeded species being more vulnerable to seed predation than small-seeded species (Brown and Heske 1990, Reader 1993, Larios et al 2017, Maron et al 2018. In annual grasslands smallseeded species may also compete with themselves for germination sites, but in perennial grasslands, most microsite preemption comes from long-lived dominant bunchgrasses.…”

Section: Introductionmentioning

confidence: 99%

“…Based on only 1 yr of recruitment data, we previously reported that proportional recruitment was suppressed to a greater extent for large-vs. smallseeded species (Maron et al 2018). We also estimated the fecundity of each focal species, so we could add seeds to plots that bracketed the natural fecundity of each species so as to mimic the density of dispersed seeds.…”

Section: Introductionmentioning

confidence: 99%

“…However, consumers can influence these dynamics. For example, in systems where mice are the major postdispersal seed predator, sizedependent seed predation can result in large-seeded species being more vulnerable to seed predation than small-seeded species (Brown and Heske 1990, Reader 1993, Larios et al 2017, Maron et al 2018. Hence, seed losses to mice could alter the slope of recruitment functions of larger-seeded species, although this is seldom examined (but see Bricker et al 2010).…”

Section: Introductionmentioning

confidence: 99%

“…For example, if more fecund small-seeded species are able to disperse to unoccupied microsites, they have inherent advantages over less fecund large-seeded species that cannot reach all of these sites because of poorer dispersal and, more importantly, lower seed numbers (Levine and Rees 2002). However, large-seeded species may have advantages over small-seeded species in productive sites where they can better tolerate local hazards such as deep litter and/or dominant competitors (Leishman and Westoby 1994, Leishman et al 2000, Moles and Westoby 2004, Maron et al 2018. Alternatively, if less productive sites are particularly abiotically stressful, large-seeded species might have even greater advantages at these sites (Muller-Landau 2010).…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Seedling recruitment correlates with seed input across seed sizes: implications for coexistence

Maron

Hajek

Hahn

et al. 2019

Ecology

Self Cite

View full text Add to dashboard Cite

Understanding controls on recruitment is critical to predicting community assembly, diversity, and coexistence. Theory posits that at mean fecundity, recruitment of highly fecund small-seeded plants should be primarily microsite limited, which is indicated by a saturating recruitment function. In contrast, species that produce fewer large seeds are more likely to be seed-limited, which is characterized by a linear recruitment function. If these patterns hold in nature, seed predation that disproportionately affects larger-seeded species can limit their establishment. We tested these predictions by comparing recruitment functions among 16 co-occurring perennial forb species that vary by over two orders of magnitude in seed size. We also assessed how postdispersal seed predation by mice influenced recruitment. We added seeds at densities from zero to three times natural fecundity of each species to undisturbed plots and examined spatial variation in recruitment by conducting experiments across 10 grassland sites that varied in productivity and resource availability. Consistent across two replicated years, most species had linear recruitment functions across the range of added seed densities, indicative of seed-limited recruitment. Depending on year, the recruitment functions of only 19-37% of target species saturated near their average fecundity, and this was not associated with seed size. Recruitment was strongly inhibited by rodent seed predation for largeseeded species but not for smaller-seeded species. Proportional recruitment was more sensitive to spatial variation in recruitment conditions across sites for some small-seeded species than for large-seeded species. These results contradict the common belief that highly fecund smallseeded species suffer from microsite-limited recruitment. Rather, they imply that, at least episodically, recruitment can be strongly correlated to plant fecundity. However, proportional recruitment of small-seeded species was inhibited at productive sites to a greater extent than large-seeded species. Results also show that in a system where the dominant granivore prefers larger seeds, low-fecundity large-seeded species can suffer from even greater seed-limited recruitment than would occur in the absence of predators.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Seedling recruitment correlates with seed input across seed sizes: implications for coexistence

Maron

Hajek

Hahn

et al. 2019

Ecology

Self Cite

View full text Add to dashboard Cite

show abstract

Does increasing the diversity of seeds broadcast for restoration alter post‐dispersal seed predation and its community‐determining effects?

Drescher,

Nolan

2023

Ecol Sol and Evidence

View full text Add to dashboard Cite

Native seeds broadcast for restoration are often consumed by predators before they can germinate. However, it is unclear how the composition of a seed mix affects seed predation. We excluded vertebrates from small plots seeded with native grassland plants to evaluate how seed diversity affects predation. There were two seeding treatments: a less diverse mix with a focal cohort of eight species on which we focused our analyses, and a more diverse mix that consisted of the focal cohort plus eight additional species. The focal cohort experienced greater predation when dispersed with the additional species, but this effect was unevenly distributed throughout the focal cohort. The species of the focal cohort that experienced the greatest increase in predation when in the high‐diversity treatment were also the ones favoured by predators when in the treatment without additional species. This suggests that when more species of palatable seed are available in a dispersed seed patch, predators may exert a stronger community‐filtering effect on such a seed patch. Increasing the number of species dispersed together for land stewardship efforts may increase predation of these seeds, which is a concern if their dispersal is intended to restore native plant diversity. We recommend strategies to minimize this potential detriment, such as staggering seed dispersal over time, for practitioners who seek to disperse a high diversity of seeds for native restoration.

show abstract

Climate mediates long‐term impacts of rodent exclusion on desert plant communities

Maron

Lightfoot

Rodríguez‐Cabal

et al. 2022

Ecological Monographs

Self Cite

View full text Add to dashboard Cite

Determining how climate affects biotic interactions can improve understanding of drivers of context-dependence and inform predictions of how interactions may influence plants under future climates. In arid environments, the communitylevel impacts of seed predators may depend strongly on aridity; yet, long-term studies documenting impacts of granivores on plant communities over variable climate conditions remain scarce. We evaluated how rodent exclusion interacted with climate to influence grassland and shrubland forb communities and the community-scale distribution of seed mass over 15 years in the climatically variable northern Chihuahuan Desert. In this dynamic system, two seasonally distinct plant community phases occur annually, one in spring and the other during the summer monsoon. Rodent exclusion significantly altered the community composition of monsoon season plant communities in both grassland and shrubland, but did not affect spring plant composition. Rodents suppressed the abundance of larger-seeded forb species and promoted smaller-seeded species. As a consequence, rodent exclusion increased community seed mass (CWM) in monsoon forb communities, most strongly in grassland. The magnitude of impacts of rodents on seed mass varied substantially from year-to-year, tracking variation in climate. Specifically, rodent exclusion increased community mean seed mass the most in dry years (grassland) or in years following dry years (shrubland). Rodent exclusion had relatively weak effects on plant species diversity and richness. Our results indicate that climate interacts with the presence of rodents to structure not only the composition but also the traits of desert plant communities.

show abstract

Rodent seed predators and a dominant grass competitor affect coexistence of co‐occurring forb species that vary in seed size

Cited by 18 publications

References 50 publications

Seedling recruitment correlates with seed input across seed sizes: implications for coexistence

Seedling recruitment correlates with seed input across seed sizes: implications for coexistence

Does increasing the diversity of seeds broadcast for restoration alter post‐dispersal seed predation and its community‐determining effects?

Climate mediates long‐term impacts of rodent exclusion on desert plant communities

Contact Info

Product

Resources

About