scholarly journals Estimation of Seed Bank and Seed Viability of the Gulf of Saint Lawrence Aster, Symphyotrichum laurentianum, (Fernald) Nesom

2004 ◽  
Vol 118 (1) ◽  
pp. 105 ◽  
Author(s):  
Joni F. Kemp ◽  
Christian R. Lacroix
Keyword(s):  
Seed Bank ◽  
Prince Edward Island ◽  
Seed Viability ◽  
Management Plan ◽  
Seed Banks ◽  
The Family ◽  
The Status ◽  
Viable Population ◽  
Tetrazolium Staining ◽  
Persistent Seed Bank

The Gulf of St. Lawrence Aster, Symphyotrichum laurentianum, is a member of the family Asteraceae and is listed as “threatened” by COSEWIC (Committee on the Status of Endangered Wildlife in Canada). This rare and vulnerable halophyte grows in only a few locations in New Brunswick, Prince Edward Island, and the Magdalen Islands, Quebec. As an annual, S. laurentianum relies exclusively on its seeds to survive to the next generation. The goal of this study was to estimate the quantity of viable S. laurentianum seeds in the persistent and transient seed banks at selected sites in Prince Edward Island. Overall, the number of seeds in the transient and persistent seed banks is low. The greatest concentration of seeds was found near the surface of the soil. In addition, only a small proportion of those seeds tested positive for viability based on Tetrazolium staining. Of the seeds in the persistent and transient seed banks combined, 53% were viable whereas only 2% of the seeds in the persistent seed bank were viable. Population surveys were also completed at the five known sites (both extinct and extant) in Prince Edward Island National Park. All sites showed signs of decline based on population estimates dating back to 1993. The Covehead Pond site showed the greatest decline: from 250-300 individuals in 1993 to only 10 individuals in 2002. The population at Dune Slack also showed a dramatic decrease from approximately 65 000 in 1999, to 2 200 individuals in 2002. Monitoring of this plant and the development of a management plan for the species are critical to its survival.

Depauperate seed banks in urban tropical seagrass meadows

2020 ◽  
Vol 71 (8) ◽  
pp. 935
Author(s):  
Glendon Hong Ming Ong ◽  
Samantha Lai ◽  
Siti Maryam Yaakub ◽  
Peter Todd
Keyword(s):  
Seed Bank ◽  
Large Scale ◽  
Seed Viability ◽  
Seed Banks ◽  
Dormant Seed ◽  
Seagrass Meadows ◽  
Halophila Ovalis ◽  
The Status ◽  
Cymodocea Rotundata

Seagrasses need to be resilient if they are to persist in the long term. Being able to build up a dormant seed bank in sediments is a key strategy that some species employ to regenerate from large-scale degradation. Much of the research on seed banks has focussed on temperate species, and little is known regarding the status of seed banks in tropical meadows. In the present study, we examined the seed bank status of three common seagrass species at six sites in Singapore and attempted to identify potential drivers of seed abundance. Our results indicated depauperate seed banks with few species setting viable seed and low seed densities. Halophila ovalis seeds were found at four sites and Halodule uninervis seeds at two sites, but Cymodocea rotundata seeds were absent from all six sites. Whereas H. ovalis seed viability ranged from 20% to 68.8%, none of the H. uninervis seeds was viable. Halophila ovalis seed densities (33–334m–2) were much higher than those of H. uninervis (9–21m–2). Of the variables examined, only H. ovalis cover was positively correlated with the number of seeds. Our study has highlighted the vulnerability of seagrass meadows in Singapore’s urban waters to future disturbances.

High seed viability recorded in an endangered endemic species, 'Isoplexis isabelliana' (Scrophulariaceae), after more than 30 years of storage in a conservation seed bank

2021 ◽  
Vol 42 ◽  
pp. e69341
Author(s):  
Miguel Ángel González Pérez ◽  
Nereida Cabrera-García ◽  
Isabel Cayon-Fernández
Keyword(s):  
Seed Bank ◽  
Germination Rate ◽  
Genetic Material ◽  
Natural Populations ◽  
Seed Viability ◽  
Seed Storage ◽  
Botanical Garden ◽  
Storage Conditions ◽  
Seed Banks ◽  
Ex Situ

Conservation seed banks are essential for ex-situ conservation of genetic biodiversity. These institutions are especially relevant for threatened species and play a vital role in their conservation by preserving genetic material. However, samples deposited in the seed banks must germinate when necessary to use them (i.e., recovery plans, etc.). This study uses four accessions of the endemic endangered species from Gran Canaria Island (Canary Islands), Isoplexis isabelliana (Webb & Berthel.) Masf. (Scrophulariaceae). Germination tests were carried out to measure seed viability through time and the possible impact of seed storage on their viability. These accessions have been kept in the seed bank for four months to thirty years under different storage conditions. Germination results differed for seeds after 45 days of exposition using 16 hours light and 8 hours darkness at 17 °C. Accessions kept in the seed bank, independently of storage, showed a high germination percentage (89%). Whereas the accessions with rough storage conditions showed a 0% germination rate. The results highlighted the good state of conservation of the material deposited in the Seed Bank of the Botanical Garden "Viera y Clavijo" and the reliability of the temperature and humidity conditions in which the seeds of I. isabelliana have been stored. We consider these results as momentous since several natural populations of I. isabelliana has been affected by the last forest fire on the island.

scholarly journals Rangeland Recovery Potential: Soil Seed Content and Seed Viability

1990 ◽  
Vol 14 ◽  
pp. 63-65
Author(s):  
Jack Butler ◽  
Kara Paintner
Keyword(s):  
Seed Bank ◽  
Seed Viability ◽  
Seed Banks ◽  
Vegetation Changes ◽  
Viable Seed ◽  
Recovery Potential ◽  
Potential Source ◽  
Seed Content ◽  
Recreation Area ◽  
Composition Changes

In most plant communities, soil contains a seed bank (population of dormant seeds), (Harper 1977), which provides a partial record of past and present vegetation (Major and Pyott 1966, Johnson and Anderson 1986). Seed banks are continuously rejuvenated by a "seed rain", from vegetation located on- and off-site. If existing communities are disturbed or destroyed, the seed bank provides a potential source of propagules during succession (Egler 1954, Connell and Slatyer 1977). Consequently, seed banks may serve as an index in predicting what vegetation changes might occur if environmental conditions are favorable for germination (Harper 1977). The objectives of this study are to 1. evaluate the viable seed bank within grazed and relict pinyon-juniper and blackbrush/Indian ricegrass communities in Glen Canyon National Recreation Area (GCNRA), 2. assess the ability of these communities to recover following a disturbance, using their respective seed banks as indicators of recovery potential, and 3. address the suitability of using seed banks to monitor and predict community level composition changes in response to various intensities of grazing.

scholarly journals Rangeland Recovery Potential: Soil Seed Content and Seed Viability

1991 ◽  
Vol 15 ◽  
pp. 130-135
Author(s):  
Jack Butler ◽  
Kara Paintner
Keyword(s):  
Seed Bank ◽  
Seed Viability ◽  
Seed Banks ◽  
Community Level ◽  
Viable Seed ◽  
Recovery Potential ◽  
Seed Content ◽  
Composition Changes

The objectives of this project are to 1) evaluate the viable seed bank within grazed and relict pinyon­juniper and blackbrush/lndian ricegrass communities, 2) assess the ability of these communities to recover following a disturbance using their respective seed banks as indicators of recovery potential, and 3) address the suitability of using seed banks to monitor and predict community level composition changes in response to various intensities of grazing.

Seed banks

2009 ◽  
Author(s):  
M. Anwar Maun
Keyword(s):  
Seed Bank ◽  
Soil Seed Bank ◽  
Sand Dunes ◽  
Seed Banks ◽  
Type I ◽  
Type Ii ◽  
Perennial Herbs ◽  
Viable Seeds ◽  
One Year ◽  
Persistent Seed Bank

The soil seed bank refers to a reservoir of viable seeds present on the soil surface or buried in the soil. It has the potential to augment or replace adult plants. Such reservoirs have regular inputs and outputs. Outputs are losses of seeds by germination, predation or other causes, while inputs include dispersal of fresh seeds from local sources and immigration from distant sources (Harper 1977). Since sand dunes are dynamic because of erosion, re-arrangement or burial by wind and wave action, efforts to find seed banks have largely been unsuccessful. Following dispersal, seeds accumulate in depressions, in the lee of plants, on sand surfaces, on the base of lee slopes and on the driftline. These seeds are often buried by varying amounts of sand. Buried seeds may subsequently be re-exposed or possibly lost over time. However, the existence of a seed bank can not be denied. Plant species may maintain a transient or a persistent seed bank depending on the longevity of seeds. In species with transient seed banks, all seeds germinate or are lost to other agencies and none is carried over to more than one year. In contrast, in species with a persistent seed bank at least some seeds live for more than one year. The four types of seed banks described by Thompson and Grime (1979) provide useful categories for discussion of coastal seed bank dynamics of different species. Type I species possess a transient seed bank after the maturation and dispersal of their seeds in spring that remain in the seed bank during summer until they germinate in autumn. Type II species possess a transient seed bank during winter but all seeds germinate and colonize vegetation gaps in early spring. Seeds of both types are often but not always dormant and dormancy is usually broken by high temperatures in type I and low temperature in type II. Type III species are annual and perennial herbs in which a certain proportion of seeds enters the persistent seed bank each year, while the remainder germinate soon after dispersal, and Type IV species are annual and perennial herbs and shrubs in which most seeds enter the persistent seed bank and very few germinate after dispersal.

Seed bank classification of the Strandveld Succulent Karoo, South Africa

2002 ◽  
Vol 12 (1) ◽  
pp. 57-67 ◽  
Author(s):  
A.J. De Villiers ◽  
M.W. Van Rooyen ◽  
G.K. Theron
Keyword(s):  
South Africa ◽  
Seed Dispersal ◽  
Seed Bank ◽  
Dominant Species ◽  
Vegetation Type ◽  
Seed Banks ◽  
Perennial Species ◽  
Succulent Karoo ◽  
Persistent Seed Bank

Laboratory characteristics of seeds of 37 species (41 seed types) from the Strandveld Succulent Karoo were used to predict seed bank types according to a modified key of ). Five seed bank strategies were recognized for this vegetation type, i.e. two with transient and three with persistent seed bank strategies. Of the 37 species investigated, 32% (all perennial species) had transient seed bank strategies, while 68% had persistent seed bank strategies. Seed dispersal of these 37 species was mainly anemochorous, although antitelechoric elements such as myxospermy, hygrochasy, heterodiaspory and synaptospermy were found among these species. The seed bank alone will not be sufficient to restore the vegetation of damaged land in the Strandveld Succulent Karoo, since many of the dominant species in the vegetation do not produce persistent seed banks. Many of these species may, however, be dispersed by wind into revegetation areas from surrounding vegetation. Topsoil replacement, seeding and transplanting of selected species will be essential for the successful revegetation of mined areas in this part of Namaqualand.

Seed banking in the columnar cactusStenocereus stellatus: distribution, density and longevity of seeds

2014 ◽  
Vol 24 (4) ◽  
pp. 315-320 ◽  
Author(s):  
Ricardo Álvarez-Espino ◽  
Héctor Godínez-Álvarez ◽  
Rodolfo De la Torre-Almaráz
Keyword(s):  
Seed Bank ◽  
Distribution Density ◽  
Soil Seed Bank ◽  
Seed Banks ◽  
Arid Environments ◽  
Soil Seed Banks ◽  
Information Gap ◽  
Stenocereus Stellatus ◽  
Viable Seeds ◽  
Persistent Seed Bank

AbstractThe soil seed bank is the reserve of viable seeds found in the soil. This reserve contributes to plant population persistence in unpredictable environments; thus, determining its presence is basic to understanding recruitment patterns and population dynamics. Studies of soil seed banks in the Cactaceae are scarce, although these plants are ecologically dominant in American arid and semi-arid environments. Most studies have inferred the presence of seed banks by analysing morphological seed traits or germination of seeds stored in the laboratory for different periods of time. Few studies have determined their presence through evaluation of distribution, density and longevity of seeds in the field. To fill this information gap, we determined the existence of, and studied, the soil seed bank ofStenocereus stellatus, a columnar cactus endemic to central Mexico. This study reports the evaluation of these characteristics in the field and discusses whether this species forms a soil seed bank. We found a higher number of seeds under shrubs than in areas lacking vegetation. Recently dispersed seeds did not germinate because they have primary dormancy. This dormancy was broken after 6 months of burial in the soil. Seeds buried for 10 months entered secondary dormancy and they were not viable at 24 months, probably because of pathogen attack. Considering dormancy and seed longevity, we suggest thatS. stellatushas the potential to form a short-term persistent seed bank. However, this should be confirmed by conducting studies on otherS. stellatuspopulations throughout their geographical distribution.

A comparative study of the seed germination biology of a narrow endemic and two geographically-widespread species ofSolidago(Asteraceae). 6. Seed bank

1998 ◽  
Vol 8 (1) ◽  
pp. 65-74 ◽  
Author(s):  
Jeffrey L. Walck ◽  
Jerry M. Baskin ◽  
Carol C. Baskin
Keyword(s):  
Seed Bank ◽  
Seedling Emergence ◽  
Seed Banks ◽  
Soil Samples ◽  
Solidago Altissima ◽  
Widespread Species ◽  
Soil Seed Banks ◽  
Narrow Endemic ◽  
Disturbed Soil ◽  
Persistent Seed Bank

AbstractSeeds of the geographically-widespreadSolidago altissimaandS. nemoralisand the narrow-endemicS. shortiiwere buried in pots of soil and placed in a glasshouse without temperature control. After 0.3–4.3 years of burial, some seeds (21–60%) of all three species were viable and they germinated to 75–100% during 2 weeks of incubation in light at 30/15°C. Soil samples collected from several population sites ofS. altissima, S. nemoralisandS. shortiiwere placed in the glasshouse and monitored for seedling emergence. During the first, second, third, fourth, fifth and sixth springs, the number ofS. altissimaseedlings m−2emerging was 108–1080, 8–494, 0–520, 0–69, 0–6 and 3, respectively, ofS. nemoraliswas 108–1122, 17–667, 0–42, 0–6, 0, 0 and 0, respectively, and ofS. shortiiwas 61–1753, 0–25, 0–6, 0, 0 and 0, respectively. More seedlings emerged from disturbed than from non-disturbed soil, but the differences were not significant. Thus, although some seeds of all three species buried in pots remained viable in soil throughout the 4.3-year burial period, longevity was greater and size of seed bank larger in field-collected soil samples containing seeds of the geographically-widespread species than in those containing seeds of the narrow endemic. Although 34 studies have reported seeds of 17 species ofSolidagopresent in soil seed banks, the present study is the first to show, conclusively thatSolidagocan form a persistent seed bank.

Germination and seed bank depletion of holly (Ilex aquifolium L.) in four microhabitat types

2004 ◽  
Vol 14 (3) ◽  
pp. 305-313 ◽  
Author(s):  
Sagrario Arrieta ◽  
Francisco Suárez
Keyword(s):  
Embryo Development ◽  
Seed Bank ◽  
Seed Viability ◽  
Forest Edge ◽  
Central Spain ◽  
Ilex Aquifolium ◽  
Successional Species ◽  
Second Year ◽  
Sowing Experiment ◽  
Persistent Seed Bank

The germination dynamics ofIlex aquifoliumL. were studied in central Spain using a 3-year field sowing experiment. Ten triads of bags (n= 30 seeds per bag) were buried randomly in four different microhabitats: inside the holly woodland, along the forest edge, in open grassland and under isolated shrubs. Bags were harvested annually, and seeds were analysed for seed viability, embryo development changes and germination. Holly seeds did not germinate until the second year. Embryo development and seed germination were faster at the forest edge, with a total germination proportion of 63% of sown seeds. Germination in the holly woodland (48%), under the shrubs (46%) and in grassland (46%) were very similar. Thus, recruitment ofIlexpopulations in this region is not limited by requirements for germination. After the third year, the seed bank was reduced by 80–90% of the initial seeds, so it can be considered as a short-persistent seed bank. Holly seed behaviour can enhance recruitment in semi-open areas, such as forest edges. Linked to the short persistence of its seed bank, this species can be considered an intermediate strategist between mature forest specialists and early successional species. This work contributes to a deeper knowledge of the germination ecology ofI. aquifolium, in an effort to determine the relative importance of germination/ dormancy processes within holly population dynamics.

Is Pyrenophora semeniperda the Cause of Downy Brome (Bromus tectorum) Die-offs?

2013 ◽  
Vol 6 (1) ◽  
pp. 105-111 ◽  
Author(s):  
Owen W. Baughman ◽  
Susan E. Meyer
Keyword(s):  
Seed Bank ◽  
Fungal Pathogen ◽  
Bromus Tectorum ◽  
Seed Banks ◽  
Causal Agent ◽  
Western North America ◽  
Downy Brome ◽  
Winter Annual ◽  
Persistent Seed Bank ◽  
Semi Arid

AbstractDowny brome (cheatgrass) is a highly successful, exotic, winter annual invader in semi-arid western North America, forming near-monocultures across many landscapes. A frequent but poorly understood phenomenon in these heavily invaded areas is periodic ‘die-off’ or complete stand failure. The fungal pathogen Pyrenophora semeniperda is abundant in cheatgrass seed banks and causes high mortality. To determine whether this pathogen could be responsible for stand failure, we quantified late spring seed banks in die-off areas and adjacent cheatgrass stands at nine sites. Seed bank analysis showed that this pathogen was not a die-off causal agent at those sites. We determined that seed bank sampling and litter data could be used to estimate time since die-off. Seed bank patterns in our recent die-offs indicated that the die-off causal agent does not significantly impact seeds in the persistent seed bank.

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