scholarly journals Seed bank dynamics of an invasive alien species, Helianthus annuus L.

2020 ◽  
Vol 13 (3) ◽  
pp. 313-322
Author(s):  
Alejandro Presotto ◽  
Fernando Hernández ◽  
Mauricio Casquero ◽  
Roman Vercellino ◽  
Claudio Pandolfo ◽  
...  
Keyword(s):  
Helianthus Annuus ◽  
Seed Bank ◽  
Seedling Emergence ◽  
Seed Banks ◽  
First Year ◽  
Seed Burial ◽  
Wild Sunflower ◽  
Seed Persistence ◽  
Seed Bank Dynamics

Abstract Aims The ability to form persistent seed banks is one of the best predictors of species’ potential to establish in new ranges. Wild sunflower is native to North America where the formation of persistent seed banks is promoted by disturbance and it plays a key role on the establishment and persistence of native populations. However, the role of the seed banks on the establishment and persistence of invasive populations has not been studied. Here, we evaluated the role of seed bank and disturbance on the establishment and fitness, and seed persistence in the soil in several sunflower biotypes collected in ruderal (wild Helianthus annuus) and agrestal (natural crop–wild hybrid) habitats of Argentina as well as volunteer populations (progeny of commercial cultivars). Methods In a seed-bank experiment, we evaluated emergence, survival to reproduction, survival of emerged seedlings, inflorescences per plant and per plot under disturbed and undisturbed conditions over 2 years; in a seed-burial experiment, we evaluated seed persistence in the soil over four springs (6, 18, 30 and 42 months). Important Findings Overall, seedling emergence was early in the growing season (during winter), and it was promoted by disturbance, especially in the first year. Despite this, the number of inflorescences per plot was similar under both conditions, especially in ruderals. In the second year, emergence from the seed bank was much lower, but the survival rate was higher. In the seed-burial experiment, genetic differences were observed but seeds of ruderals and agrestals persisted up to 42 months while seeds of the volunteer did not persist longer than 6 months. The agrestal biotype showed an intermediate behavior between ruderals and volunteers in both experiments. Our findings showed that wild and crop–wild sunflower can form persistent seed banks outside its native range and that disturbance may facilitate its establishment in new areas.

scholarly journals Seed-bank dynamics of native and invasive Impatiens species during a five-year field experiment under various environmental conditions

NeoBiota ◽  
2019 ◽  
Vol 50 ◽  
pp. 75-95 ◽  
Author(s):  
Hana Skálová ◽  
Lenka Moravcová ◽  
Jan Čuda ◽  
Petr Pyšek
Keyword(s):  
Invasive Species ◽  
Field Experiment ◽  
Seed Bank ◽  
Environmental Conditions ◽  
Large Body ◽  
Seed Banks ◽  
First Year ◽  
Seed Burial ◽  
The Third ◽  
Seed Bank Dynamics

Despite recent evidence on the important role of seed banks associated with plant invasions, and a large body of literature on invasive annual Impatiens species, little is known about the seed bank characteristics of Impatiens species. To bridge this gap, we conducted a five-year field experiment where we buried seeds of two invasive species (I. glandulifera and I. parviflora) and one native species (I. noli-tangere) across four localities in the Czech Republic, harbouring all three Impatiens species and differing in the environmental conditions. We found that the three Impatiens species differed in the characteristics of their seed banks. Both invasive species had a high seed germination rate of almost 100% in the first year after seed burial, while <50% of seeds of the native I. noli-tangere germinated during this year. In I. parviflora all seeds germinated in the first year after seed burial and later decomposed, i.e. the species had a transient seed bank. For I. glandulifera, the most invasive species, the survival of seeds differed among localities. At the first and second localities, the seeds decomposed in the first year after seed burial; in the third locality the seeds germinated in the second year; and in the fourth one, the seeds still germinated in the fourth year. The native I. noli-tangere formed a short-term persistent seed bank across all localities. Germinating or dormant seeds were found in the third year after burial in all localities, and in one locality the seeds persisted until the fifth year. The germination and dormancy in I. noli-tangere were constrained by low minimum temperatures during winter. In addition, germination was highest at intermediate soil moisture, and the most dormant seeds were recorded in soils with intermediate nitrogen concentration. The germination of I. glandulifera was slightly limited by low soil nitrogen. However, no such effect was found in I. parviflora. We suggest that in the invasive Impatiens species seed resistance to environmental factors and high germination at least partly explain their wide distribution.

Seed-bank dynamics of the tropical weedSida rhombifolia(Malvaceae): incidence of seedling emergence, predators and pathogens

2009 ◽  
Vol 19 (4) ◽  
pp. 241-248 ◽  
Author(s):  
Claudia Rodríguez ◽  
Maria Alice Garcia
Keyword(s):  
Seed Bank ◽  
Seedling Emergence ◽  
First Year ◽  
Relative Importance ◽  
Rainy Period ◽  
Paulo State ◽  
Disturbed Areas ◽  
Seed Bank Dynamics ◽  
Depth Of Burial ◽  
Sida Rhombifolia

AbstractArrowleaf sida (Sida rhombifolia) is a tropical weed that grows in disturbed areas. Its control by hand pulling and mowing are only partially effective because arrowleaf sida is difficult to pull and quickly sprouts after cutting. We studied the seed-bank dynamics ofS. rhombifoliain the region of Campinas, São Paulo State, Brazil for 2 years, following a known number of seeds placed artificially at five burial depths. Predators and pathogens were responsible for the loss ofc.40% of the seeds during the first year of the experiment. The importance of predation declined with depth. Mortality due to fungal attack did not differ among the burial depths, except for seeds placed at the surface (where it was negligible). Seedling emergence only occurred during the first year, after the beginning of the rainy period and when the study area was still free of a dense vegetation cover. Seedlings did not emerge from depths greater than 5 cm. We conclude that seedling emergence and death are significant causes of seed losses from the seed bank ofS. rhombifoliabut their relative importance is highly dependent on depth of burial.

Changes in the size and composition of the seed bank of medic pastures grown in rotation with wheat in north Syria

1992 ◽  
Vol 43 (7) ◽  
pp. 1571 ◽  
Author(s):  
PS Cocks
Keyword(s):  
Seed Bank ◽  
Seed Banks ◽  
Wheat Crop ◽  
First Year ◽  
Botanical Composition ◽  
Seedling Density ◽  
Grazing Strategies ◽  
Medicago Species

A mixture of 84 accessions of 12 medic (Medicago) species were sown in two successive years into a two-course pasture/wheat rotation in north Syria. Changes in the size and botanical composition of the seed bank were monitored for two cycles of the rotation. At the end of the first year the seed bank consisted of 550 kg ha-1 (sowing 1) and 330 kg ha-1 (sowing 2) of medic seed. Subsequent grazing reduced these seed banks to 225 kg ha-1 and 255 kg ha-1 respectively, and germination in the following wheat crop further reduced it to 205 kg ha-1 and 150 kg ha-1. The seed banks reached 700 kg ha-1 and 790 kg ha-1 respectively, during the second pasture phase of the rotation. The seedling density of medics in the regenerating pasture was 750 m-2 (sowing 1) and 1120 m-2 (sowing 2). Medics comprised about 95% of the pasture by mid-spring in both phases, the remaining 5% being wheat and broad-leaved weeds. The productivity of regenerating pasture was 5 t ha-1 (sowing 1) and 8 t ha-1 (sowing 2). Only three medic species, M. rotata, M. noeana, and M. rigidula, increased as a proportion of the seedbank. The increase was greatest in the first year, though M. noeana and M. rigidula increased further in the next two years. M. littoralis and M. turbinata, initially unsuccessful, became more successful later, while M. scutellata and M. constricta continued to decline throughout the experiment. There were also appreciable differences in the seed bank of individual accessions of several species. The results are discussed in terms of (a) the grazing strategies required in pasture/wheat rotations, and (b) the use of mixtures to select medics suitable for such rotations.

The role of soil temperature and seed dormancy in the creation and maintenance of persistent seed banks of Nassella trichotoma (serrated tussock) on the Northern Tablelands of New South Wales

2020 ◽  
Vol 42 (2) ◽  
pp. 85
Author(s):  
Annemieke Ruttledge ◽  
Ralph D. B. Whalley ◽  
Gregory Falzon ◽  
David Backhouse ◽  
Brian M. Sindel
Keyword(s):  
Seed Bank ◽  
New South ◽  
Soil Seed Bank ◽  
Seed Banks ◽  
Early Summer ◽  
Secondary Dormancy ◽  
South Wales ◽  
The Creation ◽  
Persistent Soil Seed Bank

A large and persistent soil seed bank characterises many important grass weeds, including Nassella trichotoma (Nees) Hack. ex Arechav. (serrated tussock), a major weed in Australia and other countries. In the present study we examined the effects of constant and alternating temperatures in regulating primary and secondary dormancy and the creation and maintenance of its soil seed bank in northern NSW, Australia. One-month-old seeds were stored at 4, 25°C, 40/10°C and 40°C, in a laboratory, and germination tests were conducted every two weeks. Few seeds germinated following storage at 4°C, compared with seeds stored at 25°C, 40/10°C and 40°C. Nylon bags containing freshly harvested seeds were buried among N. trichotoma stands in early summer, and germination tests conducted following exhumation after each season over the next 12 months. Seeds buried over summer and summer plus autumn had higher germination than seeds buried over summer plus autumn plus winter, but germination increased again in the subsequent spring. Seeds stored for zero, three, six and 12 months at laboratory temperatures were placed on a thermogradient plate with 81 temperature combinations, followed by incubation at constant 25°C of un-germinated seeds. Constant high or low temperatures prolonged primary dormancy or induced secondary dormancy whereas alternating temperatures tended to break dormancy. Few temperature combinations resulted in more than 80% germination.

scholarly journals Seed bank modelling of volunteer oil seed rape: from seeds fate in the soil to seedling emergence

2013 ◽  
Vol 31 (2) ◽  
pp. 267-279 ◽  
Author(s):  
E. Soltani ◽  
A. Soltani ◽  
S. Galeshi ◽  
F. Ghaderi-Far ◽  
E. Zeinali
Keyword(s):  
Oilseed Rape ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Seedling Emergence ◽  
Seed Viability ◽  
Burial Depth ◽  
Soil Seed Banks ◽  
Seed Bank Dynamics ◽  
Autumn And Winter ◽  
Lower Slope

Studies were conducted to estimate parameters and relationships associated with sub-processes in soil seed banks of oilseed rape in Gorgan, Iran. After one month of burial, seed viability decreased to 39%, with a slope of 2.03% per day, and subsequently decreased with a lower slope of 0.01 until 365 days following burial in the soil. Germinability remained at its highest value in autumn and winter and decreased from spring to the last month of summer. Non-dormant seeds of volunteer oilseed rape did not germinate at temperatures lower than 3.8 ºC and a water potential of -1.4 MPa ºd. The hydrothermal values were 36.2 and 42.9 MPa ºd for sub- and supra-optimal temperatures, respectively. Quantification of seed emergence as influenced by burial depth was performed satisfactorily (R² = 0.98 and RMSE = 5.03). The parameters and relationships estimated here can be used for modelling soil seed bank dynamics or establishing a new model for the environment.

The impact of duration of drainage on the seed banks of northern prairie wetlands

1989 ◽  
Vol 67 (6) ◽  
pp. 1878-1884 ◽  
Author(s):  
Carol E. Wienhold ◽  
A. G. van der Valk
Keyword(s):  
Seed Bank ◽  
Seed Banks ◽  
Seed Density ◽  
Prairie Wetlands ◽  
Vegetation Surveys ◽  
The Mean ◽  
Wetland Species ◽  
Total Seed ◽  
The Impact

To determine the potential role of seed banks in the restoration of drained wetlands, the seed banks of 30 extant and 52 drained and cultivated prairie potholes were sampled in Iowa, Minnesota, and North Dakota; the potholes had been drained between 5 and 70 years ago. The midsummer vegetation of most of these potholes was also sampled. The number of species in the seed bank of a pothole declined from a mean of 12.3 in extant potholes to 7.5, 5.4, 5.0, 7.4, 3.2, and 2.1 in potholes drained up to 5, 10, 20, 30, 40, and 70 years ago, respectively. The mean total seed density of extant potholes was 3600 seeds/m2. It increased to 7000 seeds/m2 up to 5 years after drainage, but then declined rapidly to 1400, 1200, 600, 300, and 160 after up to 10, 20, 30, 40, and 70 years after drainage. Changes in both species richness and seed density with increasing duration of drainage varied from state to state. About 60% of the species present in the seed banks of extant or recently drained wetlands were not detected in wetlands that had been drained for more than 20 years. Vegetation surveys of extant and drained wetlands indicated that as many or more wetland species not detected in the seed bank were present in the vegetation, as there were wetland species in the seed bank.

Seed Bank Dynamics of Three Co-Occurring Banksias in South Coastal Western Australia: the Role of Plant Age, Cockatoos, Senescence and Interfire Establishment.

1991 ◽  
Vol 39 (4) ◽  
pp. 385 ◽  
Author(s):  
ETF Witkowski ◽  
BB Lamont ◽  
SJ Connell
Keyword(s):  
Western Australia ◽  
Seed Bank ◽  
Quadratic Function ◽  
Seed Storage ◽  
Plant Age ◽  
The Other ◽  
Age Cohorts ◽  
Seed Bank Dynamics ◽  
Order Of Magnitude

Seed bank dynamics of three co-occurring, non-sprouting Banksia species (B. baxteri, B. speciosa and B. coccinea) in patch-burnt scrub-heath (aged 10 and 21 years) were studied in the southern sandplains of Western Australia. In the younger plants, canopy seed storage was highest in B. coccinea. However, 21-year-old B. coccinea stored an order of magnitude fewer seeds than the other species and no more than young B. coccinea. Seed storage per year increased exponentially with plant age in B. speciosa and B. baxteri, whereas a quadratic function, peaking at 16 years, best described seed storage in B. Coccinea. Degree of serotiny was lowest in B. coccinea. Seed abortion did not vary between age cohorts but was highest in B. coccinea. Granivory ranged from 18 to 42% and was highest in the older plants and in B. baxteri. Cockatoos removed about 20% of cones in B. baxteri and B. coccinea and 10% in B. speciosa. Experimental cone removal accelerated follicle opening, especially in B. coccinea, irrespective of whether cones were placed on the ground (simulating cockatoo removal) or reattached to the plant (simulating plant death). Half the 21-year-old B. coccinea were dead and the remainder were considered senescent, as most branches showed dieback and cone fertility had fallen to 8%. Death of the other species was negligible, with cone fertility rising to a mean of 45% (B. speciosa) and 66% (B. baxteri). Interfire establishment was significant only in B. coccinea. The build-up of a viable seed bank with time occurred at a slower rate than for non-sprouting banksias in the northern sandplains.

Effect of soil water content on wild oat (Avena fatua) seed mortality and seedling emergence

Weed Science ◽  
2006 ◽  
Vol 54 (02) ◽  
pp. 255-262 ◽  
Author(s):  
James A. Mickelson ◽  
William E. Grey
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Seed Bank ◽  
Field Experiments ◽  
Seedling Emergence ◽  
Irrigation Treatment ◽  
Seed Banks ◽  
Wild Oat ◽  
Seed Mortality

Field experiments were established in fall 1999 and 2000 near Huntley, MT, to determine the effects of soil water content on wild oat seed mortality and seedling emergence. Four supplemental irrigation treatments were implemented from June through September to establish plots with varying soil water content. Wild oat seed mortality during the summer increased linearly as soil water content increased. For seed banks established in 1999 (1999SB), seed mortality increased, on average, from 36 to 55% in 2000, and 15 to 55% in 2001 as soil water content increased from 6 to 24%. For seed banks established in 2000 (2000SB), seed mortality increased, on average, from 38 to 88% in 2001 and 53 to 79% in 2002 as soil water content increased from 6 to 24%. Increasing soil water content likely increased the activity of microorganisms that cause mortality in wild oat seeds. The increasing seed mortality rates (due to increasing soil water content) resulted in greater annual declines of wild oat seed banks and 2-yr cumulative decline rates. Total season emergence percentage was not affected by irrigation treatment. Results show that weed seed bank decline is more rapid in moist than in dry soils and suggest that management practices that increase or conserve soil moisture will also increase the rate of wild oat seed bank decline.

Effects of Soil Texture and Seed Placement on Emergence of Four Subshrubs

Weed Science ◽  
1983 ◽  
Vol 31 (3) ◽  
pp. 380-384 ◽  
Author(s):  
H. S. Mayeux
Keyword(s):  
Seed Bank ◽  
Soil Texture ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Seed Burial ◽  
Seed Placement ◽  
Buried Seed ◽  
Rate Of Emergence ◽  
Gutierrezia Sarothrae

Seedling emergence of broom snakeweed [Gutierrezia sarothrae(Pursh) Britt. & Rusby], threadleaf snakeweed [G. microcephala(DC.) Gray], common goldenweed [Isocoma coronopifolia(Gray) Greene], and false broomweed (Ericameria austrotexanaM.C. Johnston) was studied in the glasshouse. Germination of these species is known to be light-stimulated. Seed of all four subshrubs germinated readily if placed on the surface or partially pressed into the soil. Emergence was reduced by covering seed with soil to a depth of less than 1 mm. Few seedlings emerged from a depth of 1 cm, and none emerged from a depth of 2 cm. Rate of emergence also decreased with increasing depth of placement. Soil texture had little effect on emergence. Rapid germination on the soil surface is consistent with other aspects of the regenerative strategy of common goldenweed and false broomweed, which do not depend upon a buried seed bank for regeneration. Seed burial probably provides a form of enforced dormancy in the small, long-lived seeds of the two snakeweed species.

Ecological Studies of the Endangered Rutidosis Leptorrhynchoides .I. Seed Production, Soil Seed Bank Dynamics, Population Density and Their Effects on Recruitment

1995 ◽  
Vol 43 (1) ◽  
pp. 1 ◽  
Author(s):  
JW Morgan
Keyword(s):  
Population Density ◽  
Seed Production ◽  
Seed Bank ◽  
Seedling Recruitment ◽  
Fire Regime ◽  
Seedling Survival ◽  
Soil Seed Bank ◽  
Seedling Emergence ◽  
Seed Bank Dynamics ◽  
The Impact

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.

Sign in / Sign up

Export Citation Format

Share Document