Psychotria hoffmansegiana (Willd ex Roem. & Schult.) Mull. Arg. and Palicourea marcagravii st. Hil. (Rubiaceae): potential for forming soil seed banks in a brazilian Cerrado

The germinability of artificially buried Psychotria hoffmansegiana and Palicourea marcagravii seeds in Cerrado soil was tested, with the aim of evaluating whether dispersed seeds may be able to form a soil seed bank. The assays were carried out at a Cerrado Reserve in São Paulo State, Brazil. Seed samples were placed in nylon bags and buried at two different depths and in two different sites. Samples were periodically exhumed and germination tests were performed with both exhumed and dry stored seeds. In general, soil storage favoured seed survival and germination when compared to dry stored seeds. The seed germination was little affected by soil depth and by burial environment. Seeds of both species remained viable for at least 13 months, considering the time lapse between the collection and the end of the germination tests. It was suggested that both species can potentially form a persistent soil seed bank in Cerrado.

Download Full-text

Storage in cerrado soil and germination of Psychotria vellosiana (Rubiaceae) seeds

Brazilian Journal of Biology ◽

10.1590/s1519-69842006000400015 ◽

2006 ◽

Vol 66 (2b) ◽

pp. 709-717 ◽

Cited By ~ 5

Author(s):

C. G. Araújo ◽

V. J. M. Cardoso

Keyword(s):

Seed Bank ◽

Storage Time ◽

Soil Seed Bank ◽

Seed Viability ◽

Limiting Factor ◽

Ecological Aspects ◽

Different Depths ◽

Persistent Soil Seed Bank ◽

Viable Seeds

The regeneration of plant communities from seed depends, to a large extent, on the capacity of the seed remaining viable in the soil. The viability and germination of artificially buried Psychotria vellosiana seeds in cerrado soil were studied, with the purpose of discovering some physio-ecological aspects of dispersed seeds and evaluating their potential to constitute a soil seed bank. Seed samples were placed in nylon envelopes and buried in the soil of a Cerrado reserve at two different depths and sites. Buried seeds were retrieved periodically and tested for germination along with dry-stored seeds. In general, there was a reduction in seed germination with storage time, both in soil and dry stored conditions, and in some assays exhumed seeds germinated faster than dry stored ones. In general the soil storage favoured seed viability of ungerminated seeds as compared to dry stored ones, with the seeds remaining partially viable after 10 months of storage. The lack of germination of viable seeds suggests that seeds showed true dormancy and/or required an extended time to germinate. It was observed that some seeds had germinated while buried and such in situ germination tended to increase with rainfall. The water availability in the soil might be a limiting factor for successful germination of P. vellosiana in the field, and the seeds may constitute a persistent soil seed bank in the cerrado as dispersed seeds remain viable in the soil until the following period of seed dispersal.

Download Full-text

Seed persistence in the soil on eroded slopes in the hilly-gullied Loess Plateau region, China

Seed Science Research ◽

10.1017/s0960258511000195 ◽

2011 ◽

Vol 21 (4) ◽

pp. 295-304 ◽

Cited By ~ 11

Author(s):

Ning Wang ◽

Ju-Ying Jiao ◽

Yan-Feng Jia ◽

Dong-Li Wang

Keyword(s):

Loess Plateau ◽

Seed Bank ◽

Soil Seed Bank ◽

Seed Shape ◽

Plateau Region ◽

Soil Seed Banks ◽

Persistent Soil Seed Bank ◽

Disturbed Habitats ◽

Persistent Seed Bank

AbstractThe soil seed-bank is an important component of vegetation dynamics. Its presence affects both ecosystem resistance and resilience. A persistent seed-bank is especially important in disturbed habitats and harsh environments. In the hilly-gullied Loess Plateau region, serious soil erosion causes decreases in soil water capacity and constrains vegetation recolonization. A stable and long-term persistent soil seed-bank is necessary for natural vegetation recolonization. We used an integrated measure of the depth distribution of seeds in the soil and the seasonal dynamics of soil seed-banks to analyse the persistence of seeds in soil and to investigate the correlation of seed longevity with seed size/shape and the species' life history. The results showed a significant tendency for small seeds and seeds of annuals/biennials to persist longer in soil than large seeds and seeds of perennials. However, seed shape was not related to persistence. The main dominant speciesArtemisia scoparia, Lespedeza davurica, Heteropappus altaicus, Stipa bungeana, Artemisia gmelinii, and Bothriochloa ischaemun in the different successional stages in this region can form a persistent and stable soil seed-bank. The pioneer species A. scoparia is especially significant because it can form a large, long-term, persistent seed-bank. These species can play a role in the recolonization of the eroded abandoned slope lands by vegetation.

Download Full-text

Similarity between seed bank and herb layer in a natural deciduous temperate lowland forest

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.2010.021 ◽

2011 ◽

Vol 79 (2) ◽

pp. 157-166 ◽

Cited By ~ 3

Author(s):

Maciej Wódkiewicz ◽

Anna Justyna Kwiatkowska-Falińska

Keyword(s):

Seed Bank ◽

Soil Seed Bank ◽

Similarity Index ◽

Seed Banks ◽

Herb Layer ◽

Managed Forests ◽

Lowland Forest ◽

Soil Seed Banks ◽

Dominance Structure ◽

Species Similarity

Forest seed banks mostly studied in managed forests proved to be small, species poor and not reflecting aboveground species composition. Yet studies conducted in undisturbed communities indicate a different seed bank characteristic. Therefore we aimed at describing soil seed bank in an undisturbed forest in a remnant of European lowland temperate forests, the Białowieża Forest. We compared similarity between the herb layer and seed bank, similarity of seed bank between different patches, and dominance structure of species in the herb layer and in the seed bank of two related oak-hornbeam communities. We report relatively high values of Sorensen species similarity index between herb layer and seed bank of both patches. This suggests higher species similarity of the herb layer and soil seed bank in natural, unmanaged forests represented by both plots than in fragmented communities influenced by man. Although there was a set of core seed bank species present at both plots, yielding high Sorensen species similarity index values, considerable differences between plots in seed bank size and dominance structure of species were found, indicating spatial variability of studied seed bank generated by edaphic conditions. Dominance structure of species in the herb layer was not reflected in the underlying seed bank. This stresses, that natural forest regeneration cannot rely only on the seed bank, although some forest species are capable of forming soil seed banks. While forest seed banks may not reflect vegetation composition of past successional stages, they may inform on history and land use of a specific plot.

Download Full-text

Rainfall in growing season determines the size of an annual-dominated soil seed bank in a desert ecosystem

10.22541/au.160770873.35234932/v1 ◽

2020 ◽

Author(s):

Ya-Fei Shi ◽

Zengru Wang ◽

Bing-Xin Xu ◽

Jian-Qiang Huo ◽

Rui Hu ◽

...

Keyword(s):

Environmental Factors ◽

Species Composition ◽

Seed Bank ◽

Soil Seed Bank ◽

Growing Season ◽

Seed Banks ◽

Desert Ecosystem ◽

Perennial Herb ◽

Desert Ecosystems ◽

Soil Seed Banks

Soil seed banks may offer great potential for restoring and maintaining desert ecosystems that have been degraded by climate change and anthropogenic disturbance. However, few studies have explored the annual dynamics in the composition and relative abundance of these soil seed banks. We conducted a long-term observational study to assess the effects of environmental factors (meteorology and microtopography) and aboveground vegetation on the soil seed bank of the Tengger Desert, China. The desert seed bank was dominated by annual herbs. We found that more rainfall in the growing season increased the number of seeds in the soil seed bank, and that quadrats at relatively higher elevations had fewer seeds. The species composition had more similarity in the seed bank than in the aboveground vegetation, though the seed bank and aboveground vegetation did change synchronously due to the rapid propagation of annuals. Together, our findings suggest that the combined effects of environmental factors and plant life forms determine the species composition and size of soil seed banks in deserts. Thus, if degraded desert ecosystems are left to regenerate naturally, the lack of shrub and perennial herb seeds could crucially limit their restoration. Human intervention and management may have to be applied to enhance the seed abundance of longer-lived lifeforms in degraded deserts.

Download Full-text

Dynamics in the emergence of dormant and non-dormant herbaceous species from the soil seed bank from a Brazilian dry forest

Journal of Plant Ecology ◽

10.1093/jpe/rtaa008 ◽

2020 ◽

Vol 13 (3) ◽

pp. 256-265 ◽

Cited By ~ 1

Author(s):

José Djalma de Souza ◽

Bruno Ayron de Souza Aguiar ◽

Danielle Melo dos Santos ◽

Vanessa Kelly Rodrigues de Araujo ◽

Júlia Arruda Simões ◽

...

Keyword(s):

Seed Bank ◽

Linear Models ◽

Temporal Dynamics ◽

Soil Seed Bank ◽

Seed Banks ◽

Dry Forest ◽

Herbaceous Species ◽

Physical Dormancy ◽

Soil Seed Banks ◽

Interspecific Differences

Abstract Aims In dry tropical forests, herbaceous species may have dormancy mechanisms and form persistent and transient seed banks in the soil. Evolutionarily acquired, these mechanisms are efficient for the establishment and survival of these herbs, especially in forests with unpredictable climates, such as the Caatinga. Thus, our objective was to verify whether the studied herbaceous species adopt the physical dormancy mechanism and how these natural barriers are overcome, to understand the temporal dynamics existing in the soil seed bank from a Brazilian dry tropical forest. Methods Seeds of five native herbaceous species from the Caatinga forests were selected and submitted to pre-germinative treatments for verifying the presence of physical dormancy. We collected soil samples in the rainy and dry seasons for four consecutive years and monitored the emergence of the selected herbaceous in the greenhouse. We verified the differences in germination and seed bank emergence in the soil by generalized linear models. Important Findings The presence and absence of physical dormancy were observed in seeds from Caatinga herbaceous species. We found intraspecific and interspecific differences in the herbaceous emergence from soil seed banks between years and climatic seasons. In perennial herbs, consecutive lack of emergence between seasons and years was frequent, which suggests a direct relationship with the mechanism of physical dormancy and the environmental conditions necessary to overcome integument barriers. In these species, seed dimorphism and dormancy may confer additional advantages to their survival. Moreover, presenting intermediate levels of physical dormancy in an annual species may be an evolutionary adjustment to rainfall unpredictability. In contrast, we found that the annual herb without dormancy is more sensitive to seasonal and interannual climate changes, as evidenced by the increase and significant reduction of its emergence in the soil seed bank. These differences acquired evolutionarily are advantageous for the establishment of herbaceous populations, mainly in semiarid regions with an unpredictable climate.

Download Full-text

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

The Rangeland Journal ◽

10.1071/rj20008 ◽

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.

Download Full-text

Soil Seed Banks of Adjacent Unlogged Rain-Forest Types in North-Queensland

Australian Journal of Botany ◽

10.1071/bt9900261 ◽

1990 ◽

Vol 38 (3) ◽

pp. 261 ◽

Cited By ~ 17

Author(s):

AW Graham ◽

MS Hopkins

Keyword(s):

Seed Bank ◽

Forest Type ◽

Soil Seed Bank ◽

Floristic Composition ◽

Seed Banks ◽

Scaling Analysis ◽

Forest Types ◽

Total Size ◽

Soil Seed Banks ◽

Secondary Species

The size and floristic composition of soil seed banks under four adjacent, unlogged and structurally different rainforest types were assessed by exposing 17 surface soil samples (to 40mm depth) to germination-house conditions. The mean size of the seed bank in the undisturbed forest types was 240 seeds m-2 (s.d. 139). Seeds of secondary species dominated the soil seed banks in all forest types, although weed seeds constituted only 0.6-4.0%. Some forest types had characteristic component secondary species in the buried seed bank. Agglomerative classification and multidimensional scaling analysis of quantitative sample data indicated that the parent structural-environmental forest type was the dominant influence in determining composition of the soil seed banks. Comparisons of the seed banks of the intact rainforest with those of nearby disturbed forests showed the former to be 35 to 50% smaller in total size, and lacking in some distinctive secondary species. It was concluded that disturbance, both within and adjacent to rainforest, may influence soil seed bank compositions, and hence future patterns of regeneration.

Download Full-text

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

Planta Daninha ◽

10.1590/s0100-83582013000200004 ◽

2013 ◽

Vol 31 (2) ◽

pp. 267-279 ◽

Cited By ~ 10

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.

Download Full-text