Effect of seed predation on seed bank size and seedling recruitment of bush lupine ( Lupinus arboreus )

Oecologia ◽  
1997 ◽  
Vol 111 (1) ◽  
pp. 76-83 ◽  
Author(s):  
John L. Maron ◽  
Ellen L. Simms
Oecologia ◽  
1999 ◽  
Vol 118 (3) ◽  
pp. 288-296 ◽  
Author(s):  
G. R. Edwards ◽  
M. J. Crawley

2005 ◽  
Vol 21 (2) ◽  
pp. 223-226 ◽  
Author(s):  
D. A. Fornara ◽  
J. W. Dalling

Many tropical pioneer species depend on the presence of high seed densities in the soil for successful recruitment following canopy disturbance (Cheke et al. 1979, Dalling & Hubbell 2002, Guevara Sada & Gómez Pompa 1972, Whitmore 1983). However determinants of variation in the composition and abundance of soil seed banks remain poorly understood. Seed bank densities can be affected by rates of seed predation and pathogen infection on the surface and in the soil, by intrinsic rates of loss in viability following dispersal, and by variation in the timing and duration of fruit production (Dalling et al. 1997, Garwood 1983, Murray & Garcia 2002). Here we compare seasonal fluctuations in seed bank density in five Panamanian forests varying in elevation and seasonality of precipitation (Table 1). We predict that lowland forests should show stronger intra-annual fluctuation in seed bank densities than montane forests because seed production and loss rates should be higher under conditions of greater resource availability, and where consistent high temperatures support greater abundance or activity of seed predators and pathogens (Brühl et al. 1999). Secondly, among lowland sites, we predict greater fluctuations in seed bank densities at drier, more seasonal sites where seasonally favourable conditions for seedling recruitment may select for interspecific synchrony in fruit production (Daubenmire 1972, Garwood 1983).


2016 ◽  
Vol 51 (4) ◽  
pp. 343-360
Author(s):  
Monika Janišová ◽  
Iveta Škodová ◽  
Katarína Hegedüšová ◽  
Judita Kochjarová

2014 ◽  
Vol 65 (8) ◽  
pp. 767 ◽  
Author(s):  
M. L. Mitchell ◽  
J. M. Virgona ◽  
J. L. Jacobs ◽  
D. R. Kemp

Microlaena (Microlaena stipoides var. stipoides (Labill.) R.Br.) is a C3 perennial grass that is native to areas of south-eastern Australia. In this region, perennial grasses are important for the grazing industries because of their extended growing season and persistence over several years. This series of experiments focused on the population biology of Microlaena by studying the phenology (when seed was set), seed rain (how much seed was produced and where it fell), seed germination, germinable seedbank, seed predation and seedling recruitment in a pasture. Experiments were conducted at Chiltern, in north-eastern Victoria, on an existing native grass pasture dominated by Microlaena. Seed yields were substantial (mean 800 seeds m–2), with seed rain occurring over December–May. Microlaena has two distinct periods of high seed rain, in early summer and in early autumn. Seed predation is high. Within a 24-h period during peak seed production, up to 30% of Microlaena seed was removed from a pasture, primarily by ants. Microlaena seedlings recruited throughout an open paddock; however, seedling density was low (5 seedlings m–2). Microlaena represented only low numbers in the seedbank (0.01–0.05% of total); hence, any seedlings of Microlaena that germinate from the seedbank would face immense competition from other species. Management strategies for Microlaena-dominant pastures need to focus on the maintenance of existing plants.


1996 ◽  
Vol 18 (1) ◽  
pp. 179 ◽  
Author(s):  
MH Campbell ◽  
AM Bowman ◽  
WD Bellotti ◽  
DJ Munich ◽  
HI Nicol

The recruitment of Astrebla lappacea was studied from 1986 to 1995 in a pasture in north-western NSW where the density of plants had declined from 1 to 3 plants/m2 in 1970 to 0.023 plants/m2 in 1986. Three treatments were imposed: ungrazed-sprayed-slashed, where annual weeds were treated with herbicides and slashing to reduce competition during recruitment; ungrazed-only; and grazed-only. The seed bank of A. lappacea was measured on four occasions and densities of A. lappacea plants determined after major rainfall events mainly in summer and autumn. On the ungrazed treatments the seed bank of A. lappacea increased from 0 in 1988 to 908, 898 and 286 germinable seed/m2 in, respectively, 1992, 1993 and 1995. Flowering and seedling recruitment occurred each year from 1988 to 1995 but seedlings only survived to become mature plants from the 1988 and 1992 recruitments. The major reason for the death of seedlings was dry conditions in the latter half of the year (1 10 to 135 mm of raid6 months). Frosts and competition from Brassicaceae weeds (mainly Raphistrum rugosum) in winter and spring also contributed to death of seedlings. Recruitment of seedlings and their survival to mature plants was higher on the ungrazed-sprayed-slashed treatment than on the other treatments. Recruitment and survival on the ungrazed-only treatment occurred because Brassicaceae weeds did not establish when recruiting rains fell in summer. Plant densit increased from 0.023 plants/m2 in 1986 to, respectively, 0.86, 0.64 Y and 0.004 mature plantdm and 7.88, 6.37, 0.10 seedlings/m2 on the ungrazed-sprayed-slashed, ungrazed-only and grazed-only treatments in 1995. On the grazed-only treatment the methods used to detect seeds revealed none in the soil during the experiment. However, some seeds were present because there was a low level of recruitment none of which survived to mature plants. The number of mature plants declined from 0.023 to 0.004/m2 indicating that under the present grazing system the complete elimination of A. lappacea from pastures in north-western NSW is possible if some form of managed recruitment is not devised.


2017 ◽  
Author(s):  
Michał Bogdziewicz ◽  
Elizabeth E. Crone ◽  
Rafał Zwolak

AbstractNumerous interactions between plants and animals vary in their outcome between antagonism and mutualism, but it has proven to be difficult to quantify their final outcome. Interactions between plants and scatterhoarding animals provide a prime example of this phenomenon. Scatterhoarders consume large quantities of seeds (potentially reducing plant establishment), yet also disperse seeds and bury them in shallow caches (potentially improving recruitment). However, it has been rarely determined which role prevails for particular plant species. We demonstrate how plant-scatterhoarder interactions can be placed at the antagonism-mutualism continuum, with interactions between rodents and two oaks species (sessile oak Quercus petraea, and red oak Q. rubra) as an empirical example. Our approach consists of quantifying the net outcome of the interaction through assembling different vital rates (e.g. probability of seedling recruitment with and without rodents; near and far from conspecific trees; with and without seed pilferage) piecewise with a simple mathematical model. Our results indicate that during the period of the study, interactions between scatterhoarding rodents and both focal oaks were antagonistic. Even though acorn burial increased the likelihood of seedling establishment, this effect was not strong enough to compensate for the costs of seed predation. Furthermore, we found no evidence that the short-distance transportation that is usually provided by small mammals benefited early oak recruitment. Our study demonstrates how readily accessible field data can be used to gauge the outcomes in conditional mutualisms.


2021 ◽  
Vol 9 (7) ◽  
pp. 407-421
Author(s):  
Nawal Al-Hajaj

In this study, we reviewed weed seed bank dynamic and main agriculture operations to come up with the weed seed management modeling designed to increase crop productivity by removing weed competition. Weed contributing with 10% loss of total global grain production. Weed seed bank regulate by five demographic processes seedling recruitment and survival, seed production, dispersal and seed survival in soil. The main agriculture operations that interference with weed seed bank are crop rotation and primary tillage. Tillage systems affect weed emergence, management, and seed production; therefore, changing tillage practices changes the composition, vertical distribution, and density of weed seed bank in agricultural soils. Weed species vary in their response to various crop rotations, due to the variability of weed-crop competition in their relative capacity to capture growth–limiting resources. Crop rotations affect weed emergence, management, composition, and density of weed seed bank. Finally, the study suggests elevating crop competitiveness against weeds, through a combination of crop rotation and reduce_ zero tillage, has strong potential to reduce weed-induced yield losses in crop.


2020 ◽  
Author(s):  
Eder Ortiz-Martínez ◽  
Jordan Golubov ◽  
María C. Mandujano ◽  
Gabriel Arroyo-Cosultchi

AbstractSeed and seedling are the most critical stages of cacti life cycle. From the thousands of seeds produced in a reproductive season, only a small fraction gets to germinate, the rest gets lost due to predation or gets potentially buried in the seed bank. These early stages depend on facilitation by nurse plants for germination and seedling recruitment. In this paper, we aim to describe some aspects of the recruitment of Cephalocereus polylophus. We tested the viability of seeds with different storage times as an indicator of their potential to form a short-term seed bank. Through the analysis of seed germination and seedlings survival under the canopy of two nurse plant species and open areas, we aimed to assess the importance of facilitation for recruitment. A predator exclusion experiment was used to evaluate the intensity of herbivory on seeds and seedlings of different developmental stages. Seeds had germination rates above 90%, even after two years of storage. Seed germination was only registered under one of the two nurses. After two years, up to 19% of the seedlings planted under both nurse plants survived. Protection against herbivores increased survival chances from 30 to 52 % for all age-group seedlings. Considering that facilitation is a crucial interaction for C. polylophus, future conservation programs should include the protection of plant communities.


1995 ◽  
Vol 43 (1) ◽  
pp. 1 ◽  
Author(s):  
JW Morgan

The seasonal dynamics of the soil seed bank of Rutidosis leptorrhynchoides F.Muell. were studied by the seedling emergence technique. Seed longevity in soil was quantified in a seed burial and retrieval experiment. The importance of annual seed production to recruitment was also determined over a 2-year-period, as was the impact of conspecific neighbour density on seed production per inflorescence. Rutidosis leptorrhynchoides appears to form a transient seed bank with little capacity to store germinable seeds in the soil from year to year. No seedlings were observed in soil sampled after the autumn germination pulse and no viable seed was present in the soil within 16 weeks of burial. The rate of seed loss was similar when seed was buried under all intact grassland canopy and in 0.25m2 canopy gaps. It appears that most seeds simply rot in moist soil or are predated by soil invertebrates. Seedling recruitment was at least 15 times greater in plots where natural seed input occurred than where it was curtailed. Less than 10% of seed shed resulted in seedling emergence. It is suggested that recruitment in the large populations studied was limited by germination rather than by microsite availability for seedling survival. Population density had an impact on seed production with sparsely distributed individuals producing fewer seeds per inflorescence than plants from denser colonies, although there was much variation. Sparse plants produced significantly fewer seeds per inflorescence than hand crosspollinated heads suggesting reduced pollinator efficacy in these colonies relative to larger colonies where there was no such difference. Rutidosis leptorrhynchoides is dependent on the maintenance of the standing population for recruitment. Any factors that influence flowering and subsequent seed production will limit the ability of the species to regenerate. Over sufficient time, this could lead to the localised extinction of the species and may explain why R. leptorrhynchoides has failed to reappear in remnants where a suitable fire regime has been re-implemented after a period of management unfavourable to the survival, flowering and regeneration of this species.


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