Seed-bank dynamics of Eleocharis: can spatial and temporal variability explain habitat segregation?

2004 ◽  
Vol 52 (1) ◽  
pp. 119 ◽  
Author(s):  
Dorothy M. Bell ◽  
Peter J. Clarke
Keyword(s):  
Life History ◽  
Seed Bank ◽  
Temporal Variability ◽  
Seedling Recruitment ◽  
Seedling Survival ◽  
Soil Seed Bank ◽  
Decay Rates ◽  
Habitat Partitioning ◽  
Spatial And Temporal Variability ◽  
Seed Bank Dynamics

Four Eleocharis species exhibit habitat partitioning in both extant vegetation and in the soil seed bank of upland temporary wetlands on the Northern Tablelands of New South Wales. Explanations for this partitioning were sought in seed-bank dynamics at three shore levels in two wetlands. Habitat partitioning (zonation) was explained in part by seedling recruitment but not by either persistence of seeds in the soil or by dormancy patterns. All four species recruited at wetland edges but only the deepwater species, Eleocharis sphacelata, recruited in deeper water. Viability of buried seeds was consistently high and species had very low decay rates and half-lives greater than 50 years. Two types of dormancy patterns with burial were shown. Most seeds of Eleocharis sphacelata and E. pusilla were non-dormant after a 3-month burial, whereas for E. acuta and E. dietrichiana seed germination percentages gradually increased over a number of years. These two dormancy patterns may contribute to coexistence, since coexistence is enhanced by a long-lived resistant phase in the life history of species and by temporal variability in germination. There were also spatial inconsistencies in patterns of dormant fractions. Burial in the deeper zones of the marsh-like Billybung Lagoon had an inhibitory effect both on germinability and on germination rates of E. acuta and E. dietrichiana seeds. All but E. acuta showed some degree of seasonal dormancy, but this pattern was also not consistent in space. Explanations for zonation should concentrate on other life-history phases, such as dispersal and seedling survival.

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.

scholarly journals Seed bank dynamics in five Panamanian forests

2005 ◽  
Vol 21 (2) ◽  
pp. 223-226 ◽  
Author(s):  
D. A. Fornara ◽  
J. W. Dalling
Keyword(s):  
Seed Bank ◽  
Seedling Recruitment ◽  
Fruit Production ◽  
Pioneer Species ◽  
Seasonal Fluctuations ◽  
Annual Fluctuation ◽  
Soil Seed Banks ◽  
Successful Recruitment ◽  
Seed Bank Dynamics ◽  
Lowland Forests

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).

scholarly journals Vegetation and seed bank dynamics highlight the importance of post-restoration management in sown grasslands

2020 ◽  
Author(s):  
Orsolya Valkó ◽  
Balázs Deák ◽  
Péter Török ◽  
Katalin Tóth ◽  
Réka Kiss ◽  
...  
Keyword(s):  
Seed Bank ◽  
Soil Seed Bank ◽  
Rapid Development ◽  
Management Plan ◽  
Landscape Scale ◽  
List Type ◽  
Restoration Management ◽  
Seed Bank Dynamics ◽  
Term Management

AbstractSowing grass seeds generally supports the rapid development of a closed perennial vegetation, which makes the method universally suitable for fast and effective landscape-scale restoration of grasslands. However, sustaining the recovered grasslands, and increasing their diversity is a challenging task. Understanding the role of seed bank compositional changes and vegetation dynamics contributes to designating management regimes that support the establishment of target species and suppress weeds. Our aim was to reveal the effect of post-restoration management on the vegetation and seed bank dynamics in grasslands restored in one of the largest European landscape-scale restoration projects. Eight years after restoration we sampled the vegetation and seed bank in a total of 96 plots located in 12 recovered grasslands in the Great Hungarian Plain. In each recovered grassland stand we designated a mown (mown from Year 1 to Year 8) and an abandoned sample site (mown from Year 1 to Year 3 then abandoned from Year 4 to Year 8). Mown and abandoned sites showed divergent vegetation and seed bank development. Abandonment led to the decline of sown grasses and higher cover of weeds, especially in the alkaline grasslands. Our study confirmed that seed bank has a limited contribution to the maintenance of biodiversity in both grassland types. We found that five years of abandonment had a larger effect on the seed bank than on the vegetation. We stress that long-term management is crucial for controlling the emergence of the weeds from their dense seed bank in restored grasslands.Implications for practiceSeed sowing of grass mixtures can be a feasible tool for restoring grasslands at large scales. However, the developed vegetation usually has low biodiversity and a high seed density of weeds is typical in the soil seed bank even several years after the restoration. Therefore, post-restoration management is necessary for suppressing weeds both aboveground and belowground.We recommend to design the long-term management of the sites subjected to grassland restoration already in the planning phase of the restoration projects and ensure that the management plan is ecologically and economically feasible.We recommend to complement the monitoring of vegetation with the analysis of soil seed bank for evaluating restoration success.

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

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.

Effects of grazing on soil seed bank dynamics: An approach with functional groups

2003 ◽  
Vol 14 (3) ◽  
pp. 375-386 ◽  
Author(s):  
Marcelo Sternberg ◽  
Mario Gutman ◽  
Avi Perevolotsky ◽  
Jaime Kigel
Keyword(s):  
Functional Groups ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Seed Bank Dynamics
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