scholarly journals Banco de semillas después de un incendio en un matorral xerófilo

2019 ◽  
Vol 86 ◽  
pp. 11
Author(s):  
Yuriana Martínez Orea ◽  
Silvia Castillo Argüero ◽  
M. Patricia Guadarrama Chávez ◽  
Irene Sánchez
Keyword(s):  
Seed Bank ◽  
Life Form ◽  
Soil Seed Bank ◽  
Seedling Emergence ◽  
Species Number ◽  
Seedling Emergence Method ◽  
Perennial Herbs ◽  
Abundance And Diversity ◽  
One Year ◽  
Determinant Factor

Through the seedling emergence method we studied the effects of fire on the soil seed bank of a xerophytic shrubland in two consecutive years. We compared its composition and abundance in two sites, one burned and one unburned. An important proportion of seeds died due to the high temperatures reached by fire. In addition, species richness and, diversity were also negatively affected. These variables showed statistical differences between sites and years. After one year, seed bank abundance and diversity reached higher values. Dominant species were perennial herbs in terms of species number, and in terms of seedling abundance the dominant life form was a tree. However, fire was not a determinant factor in terms of species composition. These results are important to explain the changes in vegetation after a fire, specially if we consider that this site is a natural preserve immersed in an urban area.

scholarly journals Longevidad y germinación de semillas de Syagrus romanzoffiana (Arecaceae) y sus implicaciones ecológicas

2015 ◽  
Vol 63 (2) ◽  
pp. 333 ◽  
Author(s):  
Túlio Gabriel Soares Oliveira ◽  
Anderson Cleiton José ◽  
Leonardo Monteiro Ribeiro ◽  
José Marcio Rocha Faria
Keyword(s):  
Seed Bank ◽  
Soil Seed Bank ◽  
Seedling Emergence ◽  
Seed Viability ◽  
Palm Tree ◽  
Forest Fragment ◽  
Seedling Mortality ◽  
Viable Seeds ◽  
One Year ◽  
Syagrus Romanzoffiana

<strong><em>Syagrus romanzoffiana</em> is a palm tree native and widely distributed of South America.</strong> <strong>The present study investigated the longevity and germination of the buried seeds of this species in an experimental seed bank.</strong> <strong>Laboratory germination and</strong> <strong>viability tests were performed for comparison with field results. Pyrenes (seeds enclosed by the endocarp) were buried in a forest fragment edge in July (dry season) in July 2012 and exhumed monthly during one year, for the assessment of water content</strong> <strong>and percentage of germinated and viable seeds.</strong> <strong>Germination tests</strong> <strong>were conducted in a Mangelsdorf-type germinator at 30°C under constant light and the viability was </strong><strong>assessed by the tetrazolium test. An additional sample of</strong> <strong>pyrenes was buried to evaluate the percentage of seedling emergence and survival. Climatic</strong> <strong>and soil moisture</strong> <strong>data</strong> <strong>were recorded.</strong> <strong>In the laboratory, the pyrenes were stored for one year in a temperature-controlled room at 20ºC and 75% (±10%) relative air humidity to assess changes in the percentage of germination and viability over time.</strong> <strong>In the field, a reduction in seed viability</strong> <strong>was observed over the study period, with a total loss of viability of non-germinated seeds at seven months after burial.</strong> <strong>The maximum germination (close to 26%) was observed in the samples that were exhumed between five and seven months after burial. In the field, seedling emergence did not exceed 10% and seedling mortality was not observed. The percentages of germination and of viable seeds decreased both in burial and stored seeds. The stored seeds maintained viability at up to six months, with marked reduction thereafter. After the germination tests (four months) in the laboratory, all of the remaining seeds were nonviable. The ecological, physiological</strong> <strong>and reproductive characteristics of the species are discussed, and we concluded that</strong> <strong><em>S. romanzoffiana</em></strong> <strong>seeds have short longevity after imbibition, and low potential for soil seed bank formation.</strong>

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.

Differences between species in seed bank and vegetation helps to hold functional diversity in a floodable Neotropical savanna

2021 ◽  
Author(s):  
Evaldo B de Souza ◽  
Francielli Bao ◽  
Geraldo A Damasceno Júnior ◽  
Arnildo Pott
Keyword(s):  
Functional Diversity ◽  
Seed Bank ◽  
Plant Traits ◽  
Soil Seed Bank ◽  
Seedling Emergence ◽  
Ground Cover ◽  
Environmental Filters ◽  
Functional Richness ◽  
Seedling Emergence Method ◽  
Pantanal Wetland

Abstract Aims Our objective was to quantify the contributions of the seed bank and the established vegetation to the species composition, functional composition and diversity, and discuss the implications of these differences in regeneration and persistence of floodplain plant communities. Methods We sampled all ground cover vegetation up to 1.5 m height and seed bank in 25 plots (10 m × 1 m) distributed across five sites in dry and rainy seasons in a periodically flooded savanna in the Pantanal wetland, Brazil. We evaluated the soil seed bank by seedling emergence method. Important Findings The seed bank species had traits that conferred regeneration to the communities, while persistence traits characterized the vegetation. The seed bank had higher functional richness and lower functional evenness than the vegetation. The existence of different plant traits between seed bank and vegetation allowed the coexistence of species with functionally contrasting persistence and regeneration traits, which may help maintain functional diversity. It may allow the community to be more resilient when dealing with different environmental filters such as drought, fire and flood.

Defining transient and persistent seed banks in species with pronounced seasonal dormancy and germination patterns

2005 ◽  
Vol 15 (3) ◽  
pp. 189-196 ◽  
Author(s):  
Jeffrey L. Walck ◽  
Jerry M. Baskin ◽  
Carol C. Baskin ◽  
Siti N. Hidayati
Keyword(s):  
Seed Bank ◽  
Soil Seed Bank ◽  
Seedling Emergence ◽  
Short Term ◽  
Time Line ◽  
Morphophysiological Dormancy ◽  
Seedling Emergence Method ◽  
To Come ◽  
Persistent Seed Bank

The most often used time-line for distinguishing a transient seed bank from a persistent seed bank is one calendar year. Thus, species whose seeds live in or on the soil for <1 year have a transient seed bank, whereas those whose seeds live for ≥1 year have a persistent seed bank. However, dormancy cycling of seeds buried in soil has not been given due consideration in these models. When dormancy cycling is considered, it is shown that seeds of both autumn-germinators and spring-germinators are in the dormant state when they are 1 year old. Thus, unless the seeds live until at least the second germination season (i.e. usually 16–18 months following dispersal), they are, in effect, part of a transient seed bank, having lived through only one germination season. We propose that for seeds of such species to be considered part of a short-term persistent seed bank, they should remain viable and germinable until at least the second germination season, and to be part of a long-term persistent seed bank, until at least the sixth germination season. Our definitions are applicable to seeds with physiological, physical or morphophysiological dormancy, which often require >1 year after maturity to come out of dormancy in nature. We discuss modifications of the seedling emergence method for detection of a soil seed bank, so that they correspond to our definitions of seed-bank strategies.

Improvement of the seedling emergence method in soil seed bank studies using chemical treatments

2020 ◽  
Vol 21 (2) ◽  
pp. 183-190
Author(s):  
Reza Erfanzadeh ◽  
Maryam Daneshgar ◽  
Hassan Ghelichnia
Keyword(s):  
Seed Bank ◽  
Soil Seed Bank ◽  
Seedling Emergence ◽  
Chemical Treatments ◽  
Seedling Emergence Method

scholarly journals Flood and fire affect the soil seed bank of riparian forest in the Pantanal wetland

Rodriguésia ◽  
2020 ◽  
Vol 71 ◽  
Author(s):  
Thiago da Costa Kohagura ◽  
Evaldo Benedito de Souza ◽  
Francielli Bao ◽  
Fernando Alves Ferreira ◽  
Arnildo Pott
Keyword(s):  
Seed Bank ◽  
Satellite Images ◽  
Riparian Forest ◽  
Soil Seed Bank ◽  
Seedling Emergence ◽  
Survival Strategies ◽  
Paraguay River ◽  
Prolonged Drought ◽  
Abundance And Diversity ◽  
Pantanal Wetland

Abstract Flood and fire can harm plants but they can have survival strategies, such as the seed bank. We aimed to determine the influence of fire and flood on the richness, abundance and diversity of the seed bank. Sampling was carried out in October/2013, year of prolonged drought, and October/2014, year of a heavy flood, in ten areas along the Paraguay River. The areas were selected in satellite images, five with old burn (2010, three years before sampling) and five with recent burn (2013, three months before sampling). In each area, we marked a 20 m long transect with ten 20 × 20 cm quadrats where we collected 5 cm deep topsoil samples, five with and five without litter. Seed bank richness and abundance were determined by seedling emergence. Old burn areas presented greater abundance than recent burn. The drier year presented greater abundance, richness and diversity than flood year. Removal of litter reduced the richness only in the wetter year. There was no difference in richness in the drier year. The removal of the litter did not affect the abundance and diversity. Interaction between fire and flood did not affect richness, abundance and diversity of the seed bank.

Effects of heat and smoke on germination of soil-stored seed in a south-eastern Australian sand heathland

2002 ◽  
Vol 50 (2) ◽  
pp. 197 ◽  
Author(s):  
Timothy J. Wills ◽  
Jennifer Read
Keyword(s):  
Seed Germination ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Seedling Emergence ◽  
Type Systems ◽  
Treated Soil ◽  
South Eastern ◽  
Heat Treated ◽  
Eastern Australia ◽  
And Control

Various fire-related agents, including heat, smoke, ash and charred wood, have been shown to break dormancy and promote germination of soil-stored seed in a broad range of species in mediterranean-type systems. However, relatively little work has been conducted in south-eastern Australian heathlands. This study examined the effects of heat and smoked water on germination of the soil seed bank in a mature sand heathland within the Gippsland Lakes Coastal Park, in south-eastern Australia. Heat was clearly the most successful treatment for promoting seed germination, followed by smoked water, then controls, with 55% of species present in the germinable soil seed bank requiring a heat or smoke stimulus to promote seed germination. Mean species richness of the germinable soil seed bank was found to be significantly higher in heat-treated soil than in smoke and control treatments. Seedling density of heat-treated soil was almost 10 times that of controls, while smoke-treated soil was almost five times that of controls. Seedling emergence was fastest in heat-treated soil, followed by smoke and control soils. Of the species found in the soil seed bank, 25% were absent from the extant vegetation, suggesting the existence of post-fire colonisers in the soil seed bank. The results have implications for the design of soil seed bank experiments and the use of fire as a tool in vegetation management.

Estimating the composition of a forest seed bank: a comparison of the seed extraction and seedling emergence methods

1992 ◽  
Vol 70 (8) ◽  
pp. 1603-1612 ◽  
Author(s):  
Doug Brown
Keyword(s):  
Seed Bank ◽  
Extraction Method ◽  
Relevant Literature ◽  
Seedling Emergence ◽  
Species Number ◽  
Poor Correlation ◽  
Sample Number ◽  
Physical Separation ◽  
Verbascum Thapsus ◽  
Seed Extraction

The composition of a forest seed bank was estimated using two methods: (i) seed extraction, i.e., the physical separation of the seeds from the soil via flotation in a salt solution, and (ii) seedling emergence, i.e., the germination of seedlings from soil samples incubated under greenhouse conditions for 5 months. The extraction method predicted a density of 12 500 seeds∙m−2, while the emergence method detected 3800 émergents∙m−2. There was considerable disparity in species composition derived from the two methods. The extraction method identified 102 different taxa, with 22 species making up 99% of the seeds and 5.6 + 0.2 species per sample. In contrast, the emergence technique identified fewer species (60) but had more species per sample (7.6 + 0.2). Eleven species made up 99% of the emergents. Verbascum thapsus represented 34% of the seedlings in the emergence study but only 1 % of the extracted seeds. Members of the Polygonaceae represented 19% of the extracted seeds but less than 1 % of the seedling emergents. No tree or shrub species were found with the emergence method, although they represented 8% of the extracted seeds. There was a poor correlation between the estimates of species number, seed density, and diversity obtained from the two methods. The seed extraction method had considerably higher variability for these parameters. It is apparent from this study that the seedling emergence and seed extraction methodologies do not produce similar estimates of the seed bank composition. The differences are such that comparisons should not be drawn between studies using the different methods. Careful considerations should be given to both the objectives of the seed bank study and the relevant literature prior to the selection of an appropriate method. Key words: seed bank, method, composition, diversity, density, sample number.

scholarly journals Lolium multiflorum seeds in the soil: I. Soil seed bank dynamics in a no til system

2008 ◽  
Vol 30 (2) ◽  
pp. 100-110 ◽  
Author(s):  
Fernanda Costa Maia ◽  
Manoel de Souza Maia ◽  
Renée M. Bekker ◽  
Rogério Previatti Berton ◽  
Leandro Sebastião Caetano
Keyword(s):  
Seed Bank ◽  
Management Practices ◽  
Transition Period ◽  
Soil Seed Bank ◽  
Lolium Multiflorum ◽  
Storage Period ◽  
Annual Ryegrass ◽  
Seed Population ◽  
Seed Bank Dynamics ◽  
One Year

The objective of the study was to characterize annual ryegrass seed population dynamics, managed for natural re-sowing, in no til systems in rotation with soybean, in different chronosequences An area was cultivated for two years with soybean, left as fallow land for the next two years and then cultivated again with soybean for the next two years. The four chronosequences represented different management periods, two with soybean (6 and 8 years old) and the other two resting (3 and 9 years old). Soil samples were taken every month during one year and divided into two depths (0-5 and 5-10 cm). Vegetation dynamics were also evaluated (number of plants, inflorescences and seedlings). Soil seed bank (SSB) dynamics showed structural patterns in time, with a "storage period" in summer, an "exhausting period" during autumn and a "transition period" in winter and spring. Pasture establishment by natural re-sowing was totally dependent on the annual recruitment of seeds from the soil. The influence of the management practices on the SSB was more important than the number of years that these practices had been implemented. Places where soybean was sown showed the largest SSBs. Most of the seeds overcame dormancy and germinated at the end of the summer and beginning of the autumn, showing a typically transitory SSB, but with a small proportion of persistent seeds

The effects of recreation disturbance on subalpine seed banks in the Rocky Mountains of Montana

2000 ◽  
Vol 78 (5) ◽  
pp. 577-582 ◽  
Author(s):  
Catherine Zabinski ◽  
Todd Wojtowicz ◽  
David Cole
Keyword(s):  
Organic Matter ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Seedling Emergence ◽  
Seed Density ◽  
Soil Cores ◽  
Bare Ground ◽  
Recreation Impacts ◽  
Natural Revegetation ◽  
Site Types

We investigated the soil seed bank in a subalpine ecosystem with patchy disturbance from camping. Soil cores were collected from three site types, heavily impacted, lightly impacted, and undisturbed, that differed in area of bare ground and depth of surface organic matter. We hypothesized that the density and composition of the seed bank would vary with depth of surface organic matter and distance from established vegetation. Seedling emergence was determined in the greenhouse. Seed density was significantly lower on disturbed sites, averaging 441 seeds/m2 on heavily impacted sites, 1495 seeds/m2 on lightly impacted sites, and 4188 seeds/m2 on undisturbed sites. Seed density declined exponentially with distance from established vegetation and increased with depth of surface organic matter. The number of species present did not vary across site types, but 10 species that occurred on lightly impacted and undisturbed sites were not present on heavily impacted sites. We concluded that disturbance that causes removal of surface organic matter can affect natural revegetation by lowering the density of propagules and affecting the species represented in the seed bank.Key words: seed bank, subalpine, patchy disturbance, recreation impacts.

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