FIRE IMPACT ON A MAQUIS SOIL SEED BANK IN CABAÑEROS NATIONAL PARK (CENTRAL SPAIN)

1999 ◽  
Vol 47 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Pablo Ferrandis ◽  
José M. Herranz ◽  
Juan J. Martínez-Sśnchez
Keyword(s):  
Seed Bank ◽  
Soil Seed Bank ◽  
Soil Layer ◽  
Woody Species ◽  
Soil Surface ◽  
Seed Banks ◽  
Soil Seed Banks ◽  
Seed Content ◽  
Seed Reserves ◽  
One Year

The direct impact of fire on the soil seed bank and the changes observed one year later were studied by analysis of seed content in sample layers at depths of 0–2 cm and 2–5 cm. Fire had a severe but selective impact on the soil seed bank: species with transient seed reserves accumulating on the soil surface were eliminated, whereas species with persistent buried seed reserves tended to remain in the soil after the passage of fire. Thick seed coats were shown to be an efficient mechanical protection barrier to fire. One year after fire, trade-off between input and output into seed bank produced a conspicuous recovery of seed density and species richness on the soil surface, and a pronounced impoverishment in the 2–5-cm-depth soil layer. In general, seed banks of woody species were severely depleted due to the lack of replacement following fire, with the exception of Erica, which maintained a high seed bank density in the upper soil layer. The post-fire recovery of soil seed populations was mainly due to two clearly differentiated groups of annuals. The first group was of species whose seeds survived fire, germinated, and completed their phenological cycle. They were mainly fire-ephemerals. The second group consisted of wind-dispersed species whose soil seed banks had suffered a very severe (even total) depletion by fire. They were mainly Gramineae and Compositae species which behaved as opportunistic fire-sensitive invaders.

Timing of seed dispersal and dormancy, rather than persistent soil seed-banks, control seedling recruitment of woody plants in Neotropical savannas

2011 ◽  
Vol 21 (2) ◽  
pp. 103-116 ◽  
Author(s):  
Ana Salazar ◽  
Guillermo Goldstein ◽  
Augusto C. Franco ◽  
Fernando Miralles-Wilhelm
Keyword(s):  
Moisture Content ◽  
Seed Dispersal ◽  
Species Composition ◽  
Seed Bank ◽  
Seedling Recruitment ◽  
Soil Seed Bank ◽  
Woody Species ◽  
Seed Banks ◽  
Soil Seed Banks ◽  
Seedling Bank

AbstractA large fraction of tree species forming persistent soil seed-banks and with dormant seeds are expected to be found in strongly seasonal ecosystems such as Neotropical savannas, where seedling recruitment could be highly variable. In the savannas of Central Brazil, we studied seed characteristics (type of dormancy, longevity and moisture content) of 14 representative woody species differing in seed dispersal season. We also studied the dynamics of soil seed-banks and similarity patterns in woody species composition among seed rain, soil seed-bank, seedling bank and standing vegetation along shallow topographic gradients that differ in canopy cover. Woody species composition of the soil seed-bank largely differed from the standing vegetation, the seed rain and the seedling bank species composition, suggesting low recruitment of woody species from the soil seed-bank. Seeds of the 14 woody species remained viable for less than 16 months in laboratory dry-storage conditions. Of those, most seeds dispersed in the dry season were dormant and exhibited low moisture content, while most seeds dispersed in the wet season were non-dormant and exhibited high moisture content. Longevity of these seeds dispersed in the dry and the wet seasons did not differ significantly. This study shows that both timing of seed dispersal and dormancy appear to control timing of seed germination and seedling recruitment of most Neotropical savanna woody species, which did not form persistent soil seed-banks. This study contributes to the understanding of tree/grass coexistence and tree density variations along topographic gradients in tropical savannas.

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

2011 ◽  
Vol 79 (2) ◽  
pp. 157-166 ◽  
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.

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

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.

Seasonal variation in soil seed bank size and species composition of selected habitat types in Maputaland, South Africa

Bothalia ◽  
2007 ◽  
Vol 37 (2) ◽  
pp. 249-258 ◽  
Author(s):  
M. J. S. Kellerman ◽  
M. W. Van Rooyen
Keyword(s):  
South Africa ◽  
Seasonal Variation ◽  
Species Composition ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Woody Species ◽  
Forest Edge ◽  
Seed Banks ◽  
Habitat Types ◽  
Open Woodland

Seasonal variation in seed bank size and species composition of five selected habitat types within the Tembe Elephant Park. South Africa, was investigated. At three-month intervals, soil samples were randomly collected from five different habitat types: a, Licuati forest; b, Licuati thicket; c, a bare or sparsely vegetated zone surrounding the forest edge, referred to as the forest/grassland ecotone; d, grassland; and e, open woodland. Most species in the seed bank flora were either grasses, sedges, or forbs, with hardly any evidence of woody species. The Licuati forest and thicket soils produced the lowest seed densities in all seasons.  Licuati forest and grassland seed banks showed a two-fold seasonal variation in size, those of the Licuati thicket and woodland a three-fold variation in size, whereas the forest/grassland ecotone maintained a relatively large seed bank all year round. The woodland seed bank had the highest species richness, whereas the Licuati forest and thicket soils were poor in species. Generally, it was found that the greatest correspondence in species composition was between the Licuati forest and thicket, as well as the forest/grassland ecotone and grassland seed bank floras.

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

2020 ◽  
Vol 13 (3) ◽  
pp. 256-265 ◽  
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.

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

1990 ◽  
Vol 38 (3) ◽  
pp. 261 ◽  
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.

Germination asynchrony is increased by dual seed bank presence in two desert perennial halophytes

Botany ◽  
2019 ◽  
Vol 97 (11) ◽  
pp. 639-649 ◽  
Author(s):  
Arvind Bhatt ◽  
Narayana R. Bhat ◽  
Flavio Lozano-Isla ◽  
David Gallacher ◽  
Andrea Santo ◽  
...  
Keyword(s):  
Seed Bank ◽  
Environmental Conditions ◽  
Germination Rate ◽  
Soil Surface ◽  
Seed Banks ◽  
Viable Seed ◽  
Plant Recruitment ◽  
Soil Seed Banks ◽  
Desert Habitat

Maintaining a viable seed bank throughout the germination season is considered very important for plant recruitment in desert environments, where environmental conditions are unpredictable. Seeds from fully matured Seidlitzia rosmarinus Bunge ex Boiss and Halothamnus iraqensis Botsch. were collected in December 2016, then April, June, and September 2017 from both soil-surface and aerial seed banks. Both of the species were selected mainly by their capacity to rehabilitate saline coastal sites. Germination was analyzed under two photoperiods (0 or 12 h light per day), with winged or dewinged perianths. Seidlitzia rosmarinus had a shorter seasonal range in comparison with H. iraqensis (6 and 9 months, respectively), and the presence of a winged perianth reduced the germination rate of both species. A permanent winged perianth significantly inhibited the germination rate in both species. In the absence of perianth, the germination registered in December 2016 was mostly 100%, but declined to around 20% in September 2017. Seeds are thus more likely to germinate after scarification from wind mobilization, and do not require burial. Our results show that seeds of both the aerial and soil banks are transitory, and viable only during the winter months. Taken together, the combination of aerial and soil seed banks has greatly facilitated germination asynchrony in their environmentally unpredictable desert habitat.

Heat and smoke effects on the germination of seeds from soil seed banks across forest edges between subtropical rainforest and eucalypt forest at Lamington National Park, south-eastern Queensland, Australia

2003 ◽  
Vol 51 (3) ◽  
pp. 227 ◽  
Author(s):  
Y. Tang ◽  
S. L. Boulter ◽  
R. L. Kitching
Keyword(s):  
Seed Bank ◽  
National Park ◽  
Soil Seed Bank ◽  
Seed Banks ◽  
Forest Edges ◽  
Abrupt Transition ◽  
Soil Seed Banks ◽  
Eucalypt Forest ◽  
Sclerophyll Forest ◽  
Physical Changes

Physical changes and flows of energy at the interface between two contrasting ecosystems affect the distribution of species across the ecotone. The maintenance and stability of the, often abrupt, transition between Australian rainforest and non-rainforests is often attributed to fire. We use pre-germination treatments of smoke and heat on soil seed bank samples to determine plant distributions across the edge between subtropical rainforest and an adjacent eucalypt-dominated wet sclerophyll forest. Soil seed bank collections at 15 m within the eucalypt forest had both significantly higher density and diversity of seedlings than those at 30 m, at the edge itself or at any site within the rainforest. This response was most apparent when a pre-germination smoke treatment was applied. We suggest that smoke is an important germination trigger for species regenerating at this interface. Our results confirm the importance of fire in determining and maintaining the nature of this ecotone.

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.

scholarly journals Soil Seed Bank and Aboveground Vegetation in Grazing Lands of Southern Marmara, Turkey

2011 ◽  
Vol 39 (1) ◽  
pp. 96 ◽  
Author(s):  
Altıngül ÖZASLAN PARLAK ◽  
Ahmet GÖKKUŞ ◽  
Hasan Can DEMİRAY
Keyword(s):  
Species Richness ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Common Species ◽  
Seed Banks ◽  
Grazing Pressure ◽  
Perennial Grasses ◽  
Vegetation Survey ◽  
Soil Seed Banks ◽  
Grazing Lands

The composition and conservation of plant communities is greatly influenced by the soil seed bank. Information on the soil seed banks and the remaining vegetation in these ecosystems is crucial for guiding the restoration efforts. This study examines the size, species richness, diversity, uniformity, and similarity of soil seed banks and aboveground vegetation in 6 different grazing lands including coastal pasture, reseeded pasture, artificial pasture, lowland shrubland, ungrazed pasture, and hillside shrubland. Forty-eight soil samples were taken by cores with a diameter and depth of 10 cm from each of grazing lands in August of 2007. A vegetation survey was conducted using a 0.5 x 0.5-m quadrant in both the spring and fall. Eighty species were observed in soil seed banks and aboveground vegetation. The largest seed bank was observed in reseeded pasture (7,715 seed/m2), while the smallest seed bank was found in coastal pasture (2,755 seed/m2). Coastal pasture also possessed the least amount of aboveground vegetation (131 plants/m2). The most aboveground vegetation was found in ungrazed pasture (155 plants/m2). The most common species in seed banks were annual and perennial grasses in reseeded pasture, annual forbs in artificial pasture and hillside shrubland, and perennial forbs in low shrubland and ungrazed pasture. Species richness, diversity, and uniformity in seed banks were highest in lowland shrubland and lowest in artificial pasture. The seed bank and aboveground vegetation were similar in ungrazed pasture, coastal pasture, reseeded pasture, low shrubland, hillside shrubland and artificial pasture. Shrublands play an important role in species richness and the number of germinated seeds from seed banks of grazing lands in southern Marmara. The results showed that reseeding or a decrease in grazing pressure may improve the condition of grazing lands.

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