scholarly journals Predispersal Seed Predation, Postdispersal Seed Predation and Competition in the Recruitment of Seedlings of a Native Thistle in Sandhills Prairie

1990 ◽  
Vol 124 (1) ◽  
pp. 105 ◽  
Author(s):  
Svata M. Louda ◽  
Martha A. Potvin ◽  
Sharon K. Collinge
Keyword(s):  
Seed Predation ◽  
Predispersal Seed Predation

Individual crop size increases predispersal predation by beetles in a tropical palm

2020 ◽  
pp. 1-4
Author(s):  
Morgana Maria Arcanjo Bruno ◽  
Klécia Gili Massi ◽  
Alexander V. Christianini ◽  
John du Vall Hay
Keyword(s):  
Seed Predation ◽  
Positive Influence ◽  
Reproductive Phenology ◽  
Individual Plant ◽  
Crop Size ◽  
Seed Predators ◽  
Plant Trait ◽  
Predispersal Seed Predation ◽  
Total Seed ◽  
Number Of Seeds

Abstract Predispersal seed predation is one of the main causes of seed mortality in plant populations, contributing to decreased plant recruitment. Seed loss has previously been found to be related to crop size. Thus, we examined the influence of individual crop size on predispersal seed predation by beetles in the palm Syagrus flexuosa in the Brazilian savanna. The study was carried out in three tropical woodland savanna sites, where we sampled the total seed crop of 46 fruiting palms and checked the presence of beetle larvae inside all seeds per plant. We observed predispersal seed predation of S. flexuosa from all sites and a high variation in the number of seeds preyed on per individual palm. Crop size had a positive influence on the number of seeds lost to predispersal seed predators. Variations in levels of predispersal seed predation may also be accounted for by the reproductive phenology of S. flexuosa. If fruits are not available at the same time, less resource is available for predators and therefore a high proportion of seeds may be preyed on. Thus, our study demonstrates that an individual plant trait, crop size, is an important predictor of beetle seed damage per palm and a driver of the number of seeds lost to predispersal seed predators.

Predispersal Seed Predation of a Native Thistle, Cirsium canescens1

1982 ◽  
Vol 11 (4) ◽  
pp. 847-851 ◽  
Author(s):  
W. O. Lamp ◽  
M. K. Mccarty
Keyword(s):  
Seed Predation ◽  
Predispersal Seed Predation

Ecological causes, function, and evolution of abortion and parthenocarpy in Pistacia lentiscus (Anacardiaceae)

1998 ◽  
Vol 76 (1) ◽  
pp. 134-141 ◽  
Author(s):  
Miguel Verdú ◽  
Patricio García-Fayos
Keyword(s):  
Seed Predation ◽  
Water Availability ◽  
Developmental Stages ◽  
Pistacia Lentiscus ◽  
Female Fecundity ◽  
Reproductive Structures ◽  
Seedless Fruits ◽  
The Family ◽  
Predispersal Seed Predation ◽  
Viable Seeds

Parthenocarpy (the production of seedless fruits) and abortion of reproductive structures at different developmental stages are important processes limiting female fecundity in Pistacia lentiscus (Anacardiaceae), a Mediterranean endozoochorous dioecious shrub. This paper tests (i) the effects of water and pollen as the ecological causes of abortion and parthenocarpy, (ii) the function of abortion and parthenocarpy regarding the uncertainty on resources and predispersal seed predation, and (iii) reviews the evolution of parthenocarpy across the phylogeny of the genusPistacia and the family Anacardiaceae. Using experimental manipulations, we examined the effects of pollen and water availability on female fecundity. The components of female fecundity were the four sequential developmental stages in the reproductive cycle: (i) flower survival after pollination, (ii) latent ovary survival, (iii) final-sized fruit survival, and (iv) seed viability. The survival of reproductive structures along the four developmental stages in response to pollination was highly variable. The survival of pollen-excluded flowers was negligible. Water addition increased the survival of reproductive structures in the first two developmental stages but this effect was lost in the other two stages. However, irrigation had a delayed effect, significantly increasing the number of viable seeds per number of flowers at the following reproductive season. The irrigated females significantly increased the percentage of viable seeds, whereas nonirrigated females did not. These data support the hypothesis that the adjustment of progeny size to the available resources is an individual feature inherent to the life history of each individual and therefore independent on the present resource level. This adjustment may have an adaptive value in relation to uncertainty of water availability. An advantage for parthenocarpy in terms of reducing seed predation was not found and it may be a nonadaptive plesiomorphic character within the genus Pistacia and within the family Anacardiaceae. A significant negative relationship was found between the rate of seed abortion and predispersal seed predation by wasps, suggesting that abortion reduces insect predation. In support of this hypothesis, we found that fruits with aborted seeds abscised in a lower proportion than expected, while fruits with seeds parasitized by wasps fell in a greater proportion than expected. Key words: abortion, parthenocarpy, predispersal seed predation, seed production.

Effects of flower production and predispersal seed predation on reproduction in Cirsium purpuratum

2000 ◽  
Vol 78 (2) ◽  
pp. 230-236 ◽  
Author(s):  
Kazuharu Ohashi ◽  
Tetsukazu Yahara
Keyword(s):  
Reproductive Success ◽  
Seed Predation ◽  
Population Level ◽  
Production Plant ◽  
Flower Number ◽  
Flower Production ◽  
Plant Reproductive Success ◽  
Predispersal Seed Predation ◽  
Animal Interaction ◽  
Mature Seeds

Researchers have often assumed that the reproductive success of a plant increases with flower production. However, if predispersal seed predation also increases with flower production, this may counteract the increase in reproductive success expected with such increased flower production. To investigate this, we examined the effect of flower number and predispersal seed predation on seed production in two field populations of Cirsium purpuratum (Maxim.) Matsum. At both sites, the proportion of seeds or heads preyed upon per plant increased with the number of flowers (florets or heads) on each plant, while the proportion of mature seeds per plant was independent of flower number per plant. Based on these results, we predicted that an increased level of seed predation at the population level would reduce the annual flower production of each plant. The observed pattern of flower production supported this prediction. Our results suggest that increased flower production may not always improve plant reproductive success under the influence of predispersal seed predation.Key words: plant reprodutive success, predispersal seed predation, Cirsium purpuratum, flower production, plant-animal interaction.

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