Spatial patterns of the germinable soil seed bank in northern Patagonia

1998 ◽  
Vol 8 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Mónica B. Bertiller
Keyword(s):  
Spatial Pattern ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Bare Soil ◽  
Perennial Grasses ◽  
Plant Distribution ◽  
Ground Vegetation ◽  
Shrub Patches ◽  
Larrea Divaricata ◽  
Vegetation Patches

AbstractThe spatial variation of the soil seed bank in the steppe of Larrea divaricata and Stipa spp. was evaluated in relation to the spatial pattern of the established vegetation, over two years. Plant distribution was expected to affect the spatial pattern of the soil seed bank. It was hypothesized that patches of bare soil are seed-limited, while soil beneath the external crown of vegetation patches contains greater numbers of seeds. The soil seed bank of the steppe of Larrea divaricata and Stipa spp. displayed a patchy distribution associated with the spatial pattern of above-ground vegetation. Seed banks in areas of bare soil showed lower numbers of seeds than those beneath vegetation. The soil seed bank was dominated by annuals, both in open areas of soil and under vegetation canopies. The relative composition of the soil seed bank varied spatially. Annuals (dicots and grasses) were more abundant in grass-shrub patches (GSP) and grass patches (GP) than in incipient grass-shrub patches (IGSP) and bare soil (BS). Seeds of perennial grasses were more abundant under GP, less abundant under grass-shrub mixed canopies (IGSP and GSP) and practically absent in BS. In addition, seeds of perennial dicots were more frequent in grass-shrub mixed canopies, scarcely represented in GP and absent in BS. The concentration of seeds of perennial grasses in GP and GSP indicates that these are essential for the maintenance of the size of grass populations. Sustainable management should be focused to maintain the structure and function of these types of vegetation patches.

scholarly journals Influence of the population spatial structure on seed rain distribution of an invasive plant under harsh environment

Polar Biology ◽  
2021 ◽  
Vol 44 (3) ◽  
pp. 587-591
Author(s):  
Halina Galera ◽  
Agnieszka Rudak ◽  
Małgorzata Pielech ◽  
Anna Znój ◽  
Katarzyna J. Chwedorzewska ◽  
...  
Keyword(s):  
Spatial Pattern ◽  
Seed Bank ◽  
Soil Removal ◽  
Invasive Plant ◽  
Soil Seed Bank ◽  
Bare Soil ◽  
Seed Rain ◽  
Significant Difference ◽  
Artificial Grass ◽  
Average Size

AbstractDistribution of seeds of an invasive species is important for the spread of the invasion and for any directed eradication action. This distribution is driven by seed rain. We studied the influence of tussocks on the spatial pattern of seed rain and resulting population spatial pattern of an invasive Antarctic Poa annua L. population. Our hypothesis was that the tussocks trap wind-dispersed seeds. We set 40 artificial grass seed traps simulating tussocks and 40 soil seed traps (control) in the area occupied by the population. The traps were exposed for a total of 3 years and exchanged periodically. We assessed the seed bank in soil extracted for installation of our control traps. Seed number was determined by the germination method. We did not find any significant difference between the types of traps regarding the number of trapped seeds and the number of traps containing seeds, however trapping events were greater for artificial grass traps. The average size of the seed rain was 13.5 seeds m−2 year−1 and the size of the soil seed bank was 216 seeds m−2. We estimated that accumulation of the soil seed bank required around 16 years. Artificial grass discs may be more efficient than bare soil in accumulating seeds, therefore grass tussocks may influence the spatial population structure not only through local seed deposition, but also by intercepting seeds dispersed by wind. Our research further supports, that directed soil removal from underneath the tussocks is the most efficient eradication method of P. annua in Antarctica.

Buried propagule bank of a high subalpine site: microsite variation and comparisons with aboveground vegetation

1993 ◽  
Vol 71 (5) ◽  
pp. 712-717 ◽  
Author(s):  
Cheryl A. Ingersoll ◽  
Mark V. Wilson
Keyword(s):  
Spatial Pattern ◽  
Key Words ◽  
Seed Bank ◽  
Vegetation Cover ◽  
Bare Soil ◽  
Soil Cores ◽  
Cascade Mountains ◽  
Greenhouse Soil ◽  
Propagule Bank ◽  
Bare Soils

We assessed the composition and spatial pattern of the persistent buried propagule bank (seeds and vegetative structures) of a treeline site in the Oregon Cascade Mountains. We monitored emergence from soil cores removed from four microsite types and recorded vegetation cover and seedling abundance on the site. Over 3100 seedlings/m2 emerged from the greenhouse soil cores; the seed bank was dominated by Juncus species. Few vegetative sprouts emerged. Vegetated microsites produced significantly more emergents than did bare soils, but even bare soils contained abundant seeds. Overall site cover was low and few seedlings occurred on the site. Discrepancies between aboveground and belowground abundance were common. Phyllodoce empetriformis and Luetkea pectinata were abundant in the vegetation and produced many seeds but were poorly represented in the seed bank and as seedlings on the site. Other species were abundant in the seed bank, but rare in the vegetation. Our results indicate that despite the abundance of seeds in bare soil, colonization is likely to be extremely slow. Key words: seed bank, subalpine, seedlings, microsite, spatial pattern.

RELATIONSHIPS BETWEEN SOIL SEED BANK AND VEGETATION DIVERSITY ON DIFFERENT GRAZING PRESSURE

2015 ◽  
Vol 13 (2) ◽  
pp. 105-113
Author(s):  
Gantuya Jargalsaikhan
Keyword(s):  
Species Composition ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Grazing Pressure ◽  
Ground Vegetation ◽  
Agrostis Capillaris ◽  
Vegetation Diversity ◽  
Significant Difference ◽  
Bistorta Vivipara

In a case study, the main objective was to compare three sites with different grazing pressures in Hvitarsida, W-Iceland in relation to current vegetation, seed bank composition and the correlation between those. Our results show that there were significant difference in species composition in above and belowground, giving very little similarity in species composition between seed bank and current vegetation composition. The only exceptions were Agrostis capillaris and Bistorta vivipara that had close similarity between current aboveground vegetation and soil seed bank. Agrostis capillaris had a great abundance in all the sites and Bistorta vivipara proliferates mostly with bulbils that most likely were numerous in the soil. The results of our study agree with current theories on seed bank composition and similar studies,that the similarity between current above ground vegetation and soil seed bank depends on current dominant species (annual or perennial)and the productivity (high or low) of the site.Mongolian Journal of Agricultural Sciences Vol.13(2) 2014: 105-113

The soil seed bank of a montane meadow: consequences of conifer encroachment and implications for restoration

2007 ◽  
Vol 85 (6) ◽  
pp. 557-569 ◽  
Author(s):  
Nicole L. Lang ◽  
Charles B. Halpern
Keyword(s):  
Seed Bank ◽  
Soil Seed Bank ◽  
Ground Vegetation ◽  
Forest Age ◽  
Conifer Encroachment ◽  
Young Forest ◽  
Carex Pensylvanica ◽  
Montane Meadow ◽  
Forest Age Structure ◽  
Meadow Species

We examined changes in the soil seed bank associated with conifer encroachment of montane meadows in the western Cascade Range of Oregon. We asked whether, and over what period of time, meadow species maintain viable seeds in the soil, and by implication, whether the seed bank can contribute to restoration if conifers are removed. Seed bank composition, ground vegetation, and forest age structure were quantified for 209 samples representing a chronosequence of open meadow, young forest (<75 years), and old forest (95 to >200 years). The seed bank was substantial (44 taxa and 2332 germinants/m2), but dominated by native ruderals (16 species comprising 71% of germinants). Greater than 70% of meadow species were absent from the seed bank. Thirteen meadow species accounted for 21% of all germinants, but most of these were the dominant sedge, Carex pensylvanica Lam.. Seed density, richness, and composition showed weak relationships to forest age, and little resemblance to the ground vegetation, which changed markedly with forest development. Our results suggest that there is limited potential for recovery of most meadow species via the seed bank. Natural reestablishment of these species will require seed dispersal or gradual vegetative spread from existing openings, but competitive interactions with ruderal or forest species may limit recruitment or recovery.

scholarly journals Establishment of native and exotic grasses on mine overburden and topsoil in the Hunter Valley, New South Wales

2005 ◽  
Vol 27 (2) ◽  
pp. 73 ◽  
Author(s):  
C. H. A. Huxtable ◽  
T. B. Koen ◽  
D. Waterhouse
Keyword(s):  
Seed Bank ◽  
Native Species ◽  
Soil Seed Bank ◽  
Coal Mines ◽  
Climatic Conditions ◽  
Perennial Grasses ◽  
Grass Species ◽  
Native Grasses ◽  
Exotic Grasses ◽  
Mine Rehabilitation

Native grasses have an important role to play in mine rehabilitation throughout Australia, but there have been few scientifically designed studies of field establishment of native grasses from sown seed in this country. Current recommendations for rehabilitation of open-cut coal mines in the Hunter Valley involve the sowing of exotic pasture species to reinstate mined land to Class IV and V under the Rural Land Capability System. Despite the importance of native grasses in the pre-mined landscape, they are currently not widely included in mine rehabilitation. To address this issue a project was conducted between 1994 and 2000 to research the use of native grasses for rehabilitation of open-cut coal mines in the Hunter Valley. This paper reports on 2 mine site experiments that aimed to assess establishment and persistence of a broad range of native and exotic grass species from an autumn sowing in both topsoil and raw spoil over a period of 61 months. The most promising natives in terms of early establishment, persistence and spread over time, included six C3 accessions (five Austrodanthonia spp. and Austrostipa bigeniculata) and one C4 accession (Cynodon dactylon). Persistence of these accessions was better in raw spoil than topsoil, despite initial low numbers, due to a lack of weed competition and their ability to spread by self-seeding. In topsoil, and in the absence of any biomass reduction, native species were mostly out-competed by vigorous exotic perennial grasses which were sown in these experiments and from seed influx from adjacent rehabilitation areas or from the soil seed bank. The effects of climatic conditions and differences in soil physical, chemical and seed bank characteristics at the 2 mine sites are also discussed.

Relating sampling effort to the detection of spatial patterns of species richness in the soil seed bank of a mediterranean shrubland.

2020 ◽  
Author(s):  
Iván Torres ◽  
José M. Moreno
Keyword(s):  
Species Richness ◽  
Spatial Pattern ◽  
Spatial Patterns ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Spherical Model ◽  
Sampling Effort ◽  
Long Distance ◽  
Mediterranean Shrubland ◽  
Heated Soil

&lt;p&gt;Studying the soil seed bank is a time and space-consuming task, and therefore only a small fraction of the soil is sampled. It is then critical to optimize sampling effort to reliably estimate soil seed bank properties. Here, we test whether the spatial patterns of species richness in the soil seed bank differ under increasing sampling effort. For this, we used data of germination from soils in a mediterranean shrubland in Central Spain. Two data sets were used, one of the seedlings emerging after heating the soil to break dormancy, and one with the combined germinations of heated and non-heated soil subsamples. We simulated increased sampling effort with sample-based rarefaction curves, extrapolating the species richness corresponding to a 2x and 3x increase in the number of individuals (seedlings) per sample. We then analyzed the spatial pattern of the original and extrapolated species richness using linear regression and semivariograms. Species richness increased by 34% and 52% in the 2x and 3x estimations, however the spatial pattern of species richness remained largely unchanged. For the long-distance spatial pattern, the slope of the plot-scale trend (i.e., the regression coefficient) increased only slightly with increasing sampling effort, while the adjusted R-squared of the regression decreased with increasing sampling effort. For the short-distance spatial pattern we could only fit spherical model semivariograms to the data from soils exposed to a heat shock, and the intensity of the spatial pattern (spatial dependence) increased very slightly with increased sampling effort. These results suggest that even with a doubled or tripled sampling effort, as provided by the simulations, the spatial pattern of species richness would have remained unchanged. We argue that increased effort in detecting species in the seed bank needs not necessarily improve the detection of spatial pattern.&lt;/p&gt;

Soil seed bank composition over desert microhabitats: patterns and plausible mechanisms

2004 ◽  
Vol 82 (12) ◽  
pp. 1809-1816 ◽  
Author(s):  
Luis Marone ◽  
Víctor R Cueto ◽  
Fernando A Milesi ◽  
Javier Lopez de Casenave
Keyword(s):  
Seed Production ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Bare Soil ◽  
Seed Density ◽  
Seed Composition ◽  
Monte Desert ◽  
Total Seed ◽  
Seed Dynamics ◽  
Primary Dispersal

We assessed soil seed bank composition and size over several microhabitats of two habitats of the central Monte Desert of Argentina (open Prosopis woodland and Larrea shrubland) to analyse differences among them. Seed densities were similar to those already reported for other deserts, but we found consistent differences in seed composition among microhabitats. Whereas grass seeds (e.g., Aristida, Pappophorum, Neobouteloua, Trichloris, Digitaria) prevailed in natural depressions of open areas, forb seeds (e.g., Phacelia, Lappula, Descurainia, Plantago, Chenopodium) were more abundant under trees. The comparison of seed production during primary dispersal (i.e., seed rain) with seed density on the ground at the end of dispersal indicated that most forb seeds entered the habitat through the micro habitats located beneath the canopy of trees and tall shrubs, and remained there after redistribution. Most grass seeds, by contrast, entered it through bare-soil and under-grass microhabitats, and reached more even distributions after secondary dispersal, especially because of dramatic losses in bare soil. Patterns of plant recruitment and seed dynamics in specific microhabitats were better understood when differences of soil seed bank composition, but not of total seed density, were taken into account.Key words: Monte Desert, seed dispersal, seed predation, seed production, seeds.

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