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Barriers to seed and seedling survival of once-common Hawaiian palms: the role of invasive rats and ungulates.

Shiels AB, Drake DR - AoB Plants (2015)

Bottom Line: Mammalian herbivores can limit plant recruitment and affect forest composition.Loulu palms (Pritchardia spp.) once dominated many lowland ecosystems in Hawai'i, and non-native rats (Rattus spp.), ungulates (e.g. pigs Sus scrofa, goats Capra hircus) and humans have been proposed as major causes of their decline.These findings also imply that the seed stage of species in this Pacific genus is particularly vulnerable to rats; therefore, future conservation efforts involving Pritchardia should prioritize the reduction of rat predation on the plant recruitment stages preceding seedling establishment.

View Article: PubMed Central - PubMed

Affiliation: USDA, National Wildlife Research Center, Hawai'i Field Station, Hilo, HI 96721, USA ashiels@hawaii.edu.

No MeSH data available.


Related in: MedlinePlus

Percent P. maideniana and P. hillebrandii seed removal from the forest floor over 42 days of study in Hawai‘i (N = 32 seeds/species). Seeds included here were those available to vertebrates (i.e. those in the SVA and OPEN and not in the NVA).
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PLV057F3: Percent P. maideniana and P. hillebrandii seed removal from the forest floor over 42 days of study in Hawai‘i (N = 32 seeds/species). Seeds included here were those available to vertebrates (i.e. those in the SVA and OPEN and not in the NVA).

Mentions: Vertebrates readily removed Pritchardia seeds positioned on the forest floor. For P. maideniana and P. hillebrandii, all seeds remained in the NVA (control) (Fig. 1), which resulted in significant differences when the three treatment levels were compared for P. hillebrandii (d.f. = 2; χ2 = 16.1; P < 0.001; Fig. 1A) and P. maideniana (d.f. = 2; χ2 = 16.9; P < 0.001; Fig. 1B). Identical proportions of available seed (SVA and OPEN) were removed (87.5 %) at the end of the 6-week (42-day) study for P. hillebrandii (d.f. = 1; W = 32; P > 0.999; Fig. 1A), and the proportion of seed remaining after the same duration for P. maideniana was not significantly different between SVA and OPEN (d.f. = 1; W = 20; P = 0.076; Fig. 1B). The only animals photographed by the motion-sensing cameras were rats (probably R. rattus; Fig. 2), and the images of rats visiting seed of both species coincided with the removal of seed from the forest floor. Seed removal by vertebrates occurred rapidly, as indicated by at least 50 % seed removal within 6 days in stations accessible to vertebrates (SVA and OPEN) (Fig. 3). The rapid removal during the first week was followed by a slower, more gradual, removal over the next 2 weeks, whereas the final 3 weeks had a total of only two seeds removed for each species (Fig. 3).Figure 1.


Barriers to seed and seedling survival of once-common Hawaiian palms: the role of invasive rats and ungulates.

Shiels AB, Drake DR - AoB Plants (2015)

Percent P. maideniana and P. hillebrandii seed removal from the forest floor over 42 days of study in Hawai‘i (N = 32 seeds/species). Seeds included here were those available to vertebrates (i.e. those in the SVA and OPEN and not in the NVA).
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4497476&req=5

PLV057F3: Percent P. maideniana and P. hillebrandii seed removal from the forest floor over 42 days of study in Hawai‘i (N = 32 seeds/species). Seeds included here were those available to vertebrates (i.e. those in the SVA and OPEN and not in the NVA).
Mentions: Vertebrates readily removed Pritchardia seeds positioned on the forest floor. For P. maideniana and P. hillebrandii, all seeds remained in the NVA (control) (Fig. 1), which resulted in significant differences when the three treatment levels were compared for P. hillebrandii (d.f. = 2; χ2 = 16.1; P < 0.001; Fig. 1A) and P. maideniana (d.f. = 2; χ2 = 16.9; P < 0.001; Fig. 1B). Identical proportions of available seed (SVA and OPEN) were removed (87.5 %) at the end of the 6-week (42-day) study for P. hillebrandii (d.f. = 1; W = 32; P > 0.999; Fig. 1A), and the proportion of seed remaining after the same duration for P. maideniana was not significantly different between SVA and OPEN (d.f. = 1; W = 20; P = 0.076; Fig. 1B). The only animals photographed by the motion-sensing cameras were rats (probably R. rattus; Fig. 2), and the images of rats visiting seed of both species coincided with the removal of seed from the forest floor. Seed removal by vertebrates occurred rapidly, as indicated by at least 50 % seed removal within 6 days in stations accessible to vertebrates (SVA and OPEN) (Fig. 3). The rapid removal during the first week was followed by a slower, more gradual, removal over the next 2 weeks, whereas the final 3 weeks had a total of only two seeds removed for each species (Fig. 3).Figure 1.

Bottom Line: Mammalian herbivores can limit plant recruitment and affect forest composition.Loulu palms (Pritchardia spp.) once dominated many lowland ecosystems in Hawai'i, and non-native rats (Rattus spp.), ungulates (e.g. pigs Sus scrofa, goats Capra hircus) and humans have been proposed as major causes of their decline.These findings also imply that the seed stage of species in this Pacific genus is particularly vulnerable to rats; therefore, future conservation efforts involving Pritchardia should prioritize the reduction of rat predation on the plant recruitment stages preceding seedling establishment.

View Article: PubMed Central - PubMed

Affiliation: USDA, National Wildlife Research Center, Hawai'i Field Station, Hilo, HI 96721, USA ashiels@hawaii.edu.

No MeSH data available.


Related in: MedlinePlus