Effect of different treatments on the seed bank of grazed and ungrazed Baltic seashore meadows

1998 ◽  
Vol 76 (7) ◽  
pp. 1188-1197 ◽  
Author(s):  
Heli M. Jutila b. Erkkilä
Keyword(s):  
Seed Bank ◽  
Brackish Water ◽  
Salt Water ◽  
Tap Water ◽  
Cold Treatment ◽  
Abundant Species ◽  
Seed Banks ◽  
The West ◽  
Pesticide Treatment ◽  
Juncus Gerardii

Seed banks of two seashore meadows were studied on the west coast of Finland (latitude 61°30'-61°33'N, longitude 21°28'-21°41'E). Samples were taken in June to a depth of 10 cm in the geolittoral zone of the grazed and ungrazed transects. The grazed samples were halved lengthwise: one half was grown immediately, the other after cold treatment. One third of the all samples was treated as controls, one third was watered with brackish water, and one third was given a pesticide treatment. Altogether, 13 926 seedlings germinated and 25 species were identified (three annuals, two biennials, and the rest perennials). Most seedlings were perennial monocots, with Juncus gerardii Loisel. the most abundant species. The seed bank was significantly larger and richer in the ungrazed site than in the grazed site. Cold treatment reduced the number of germinating species and seedlings. In the grazed and non-cold-treated samples, the numbers of species and seedlings were highest in the pesticide treatment. In ungrazed samples there were no significant differences among treatments. After the cold treatment, the least number of species and seedlings was produced by the salt-water treatment. Changing brackish water to tap water led to a burst of germination, especially of J. gerardii. The seed bank of the upper geolittoral zone was richer than that of the middle geolittoral. The multivariate classification and ordination groupings are based on the abundances of J. gerardii and Glaux maritima L.; different treatments were not distinguishable. There was a low resemblance between the seed bank and the aboveground vegetation.Key words: seed bank, salinity, pesticide, seashore meadow, cold treatment, vegetation.

Seed-bank contributions to regeneration of shrub species after clear-cutting and burning

1988 ◽  
Vol 66 (1) ◽  
pp. 169-172 ◽  
Author(s):  
P. Morgan ◽  
L. F. Neuenschwander
Keyword(s):  
Seed Bank ◽  
Seedling Survival ◽  
Habitat Type ◽  
Canopy Cover ◽  
Abundant Species ◽  
Seed Banks ◽  
Thuja Plicata ◽  
Seed Density ◽  
Shrub Species ◽  
Clear Cutting

Seed banks contributed significantly to regeneration of early seral shrubs after clear-cutting and fall broadcast burning of dense coniferous forests of the Thuja plicata/Clintonia uniflora habitat type in northern Idaho. Seeds were separated from 36 samples of soil and surface organic matter from 15 uncut forest stands. Total seed density averaged 1151 ± 1896 seeds/m2, and seed density for individual shrub species ranged from 1 ± 3 to 690 ± 1728 seeds/m2. Canopy cover of the "obligate" seed bank species, such as Ceanothus sanguineus and Prunus emarginata, was low or nonexistent in uncut forests, seed constancy and density in seed bank were high, and seedling regeneration on 2-year-old burns was abundant. Species that were "non-reliant" on seed banks, including Symphoricarpos albus and Rosa gymnocarpa, resprouted and no seedlings were found after burning. Response of "opportunistic" seed-bank species such as Rubus parviflorus and Rubus ursinus was intermediate; both seedling and sprout regeneration occurred after cutting and burning. These species existed in uncut stands both in the seed bank and in the understory. Burn severity affected germination and (or) seedling survival of Ceanothus sanguineus. Its percent canopy cover was greater on high-severity than on low-severity 2-year-old burns.

scholarly journals PENGARUH PENYERAPAN RADIASI SURYA PADA MEDIA TIPE KOTAK DAN BERGELOMBANG BERBAHAN DASAR STAINLESS STEEL TERHADAP KEMAMPUAN DESTILASI AIR PAYAU DI PESISIR PANTAI SEBA

2017 ◽  
Vol 3 (2) ◽  
pp. 115
Author(s):  
Dedy Nataniel Ully ◽  
Rokhyadi Rokhyadi ◽  
Duma Pabiban
Keyword(s):  
Stainless Steel ◽  
Solar Radiation ◽  
Brackish Water ◽  
Glass Surface ◽  
Salt Water ◽  
The Sun ◽  
Distillation Process ◽  
The West ◽  
Water Distillation ◽  
Over Time

The use of solar radiation absorber on box and corrugated media can improve the ability orperformance of the brackish water distillation process into freshwater. This process of brackishwater distillation is to separate the excessive salt elements contained in brackish water, by heatingby using solar energy so that evaporation takes place within the distillator and under certainconditions will experience condensation, so that the hot vapor turns phase into water because itcomes into contact with a cold glass surface. Thus, the water will be obtained clean and not saltyanymore. While salt water will be left in the container destilator because there are elements ofsalt in which have a larger density. This study was conducted using real experimental method  (true experimental) on laboratory scale. The test is done at 8:00 until 16:00 with the volume of water inthe distillator as much as 35 liters. The results show that efficiency increases in parabolic over time butdecreases above at 14.00. This happens because the intensity of solar radiation will decrease along withthe sun’s incline to the west, so the heat received by the destilator decreases. The highest efficiencyoccurs at 12.00 ie on the absorbent type of box of 16.72% while the absorbent type of wave surgeshighest efficiency also occurs at 12:00 at 12.509%, this happens because at this time the sun radiatessuryanya maximum.

scholarly journals Edaphic and Seasonal Heterogeneity of Seed Banks in Agricultural Fields of a Tropical Dry Forest Region in Southern Mexico

2012 ◽  
Vol 90 (3) ◽  
pp. 287 ◽  
Author(s):  
Jorge A. Meave ◽  
Claudia Flores-Rodríguez ◽  
Eduardo A. Pérez-García ◽  
Marco Antonio Romero-Romero
Keyword(s):  
Seed Bank ◽  
Tropical Dry Forest ◽  
Abundant Species ◽  
Black Soil ◽  
Seed Banks ◽  
Dry Forest ◽  
Agricultural Fields ◽  
Tropical Region ◽  
Soil Cores ◽  
Southern Mexico

<p class="p1"><span class="s1">The slash-and-burn agriculture practiced across tropical dry regions results in the elimination of native vegetation. Upon field abandonment, the seed bank becomes a potentially important mechanism of natural regeneration at early successional stages. Soil properties and climate seasonality may affect seed bank characteristics, thus we analyzed the effects of these two factors on seed bank density and composition in agricultural fields of a seasonally dry tropical region of southern Mexico. Soil cores were collected for the rainy and the dry seasons in order to assess changes occurring in the seed bank from the time of harvest to the moment when succession could potentially start (the next rainy season). The 12 studied fields comprised three different soil types recognized by local inhabitants: sandy and stony, silty, and clayey soils, locally known as cascajo, black soil, and red soil, respectively. At each fi eld 20 soil cores (8 cm diameter, 4.5 cm depth) were collected and mixed to form four pooled samples, which were placed in a greenhouse to induce germination. A total of 4,422 seedlings (2,291 seeds m<sup>-2</sup>) representing 40 species were recorded. The most abundant species were, in decreasing order, <em>Melanthera nivea</em>, <em>Rhynchelytrum repens</em>, <em>Waltheria indica</em>, <em>Amaranthus scariosus</em>, <em>Digitaria bicornis</em>, and <em>Cenchrus pilosus</em>. Herbs were the prevailing growth form (&gt; 80% of total richness). No clear pattern was observed in the seed bank related to soil type; however, seed bank characteristics tended to be associated with the time of use of the agricultural fields, a variable that was not controlled in the study. Seed bank species richness was significantly larger in the dry season, and although seed density showed a similar trend, it was not significant. The studied seed banks contain no elements of the regional primary tropical dry forest, which suggests that seed banks in deforested areas cannot guarantee their maintenance beyond forested areas.</span></p>

Development of soil seed banks beneath synthesized meadow communities after seven years of climate manipulations

1998 ◽  
Vol 8 (4) ◽  
pp. 493-500 ◽  
Author(s):  
M. Olatunde Akinola ◽  
Ken Thompson ◽  
Susan H. Hillier
Keyword(s):  
Seed Bank ◽  
Plantago Lanceolata ◽  
Soil Surface ◽  
Abundant Species ◽  
Seed Banks ◽  
Low Fertility ◽  
Ground Vegetation ◽  
Small Contribution ◽  
Soil Seed Banks ◽  
Meadow Species

AbstractMeadow microcosms were established from seed on low-fertility soil of known seed bank composition, and subjected to manipulations of simulated grazing, cutting date, temperature and fertility for seven years. The composition and density of the seed bank was then determined in five 2-cm soil layers (0–2, 2–4, 4–6, 6–8 and 8–10 cm). The seed bank contained three distinct groups of species: species present in the original soil, sown species, and ‘others’. The seed bank was little affected by the experimental treatments, presumably because the sown species made only a small contribution to the seed bank. Nearly all the species in the original soil are known to possess persistent seed banks and had survived, although at reduced density, for seven years. Density of the most abundant species in this group, Sagina procumbens, had changed very little over seven years, confirming the well-documented longevity of the seeds of this species. Seeds of sown species made up only about a quarter of the seed bank, despite accounting for virtually all the above-ground vegetation. Of the sown meadow species, only Plantago lanceolata and Alopecurus pratensis were relatively abundant in the seed bank. These results strongly support the conclusion of other authors that most meadow species, once lost owing to the effects of fertilizers or inappropriate management, will not reestablish from the seed bank. Among species which were neither sown nor present in the original soil, the majority possessed adaptations for wind dispersal and had presumably dispersed into the experimental plots from outside. The most abundant member of this group, Betula pendula, had dispersed from a nearby tree. Density of Betula seeds declined sharply with depth, consistent with the view that seeds on the soil surface are rapidly lost, mainly through germination, but seeds that become buried survive much better. Seeds of Betula appear to be persistent but not particularly long-lived.

Investigational Studies on Quantity of Salinity in Netravati River Estuary Sand-Coastal Karnataka

2018 ◽  
Vol 6 (6) ◽  
pp. 46
Author(s):  
Raveesha P ◽  
K. E. Prakash ◽  
B. T. Suresh Babu
Keyword(s):  
Brackish Water ◽  
Sea Water ◽  
Salt Water ◽  
Construction Material ◽  
Salt Content ◽  
River Estuary ◽  
Sand Sample ◽  
River Sand ◽  
Natural Aggregates

The salt water mixes with fresh water and forms brackish water. The brackish water contains some quantity of salt, but not equal to sea water. Salinity determines the geographic distribution of the number of marshes found in estuary. Hence salinity is a very important environmental factor in estuary system. Sand is one major natural aggregate, required in construction industry mainly for the manufacture of concrete. The availability of good river sand is reduced due to salinity. The quality of sand available from estuarine regions is adversely affected due to this reason. It is the responsibility of engineers to check the quality of sand and its strength parameters before using it for any construction purpose. Presence of salt content in natural aggregates or manufactured aggregates is the cause for corrosion in steel. In this study the amount of salinity present in estuary sand was determined. Three different methods were used to determine the salinity in different seasonal variations. The sand sample collected nearer to the sea was found to be high in salinity in all methods.  It can be concluded that care should be taken before we use estuary sand as a construction material due to the presence of salinity.

Seed production and seedling emergence of Giant Parramatta grass on the north coast of New South Wales

1996 ◽  
Vol 36 (3) ◽  
pp. 299 ◽  
Author(s):  
TS Andrews ◽  
RDB Whalley ◽  
CE Jones
Keyword(s):  
Seed Production ◽  
Seed Bank ◽  
New South ◽  
New South Wales ◽  
Seed Banks ◽  
North Coast ◽  
The North ◽  
South Wales ◽  
Seed Fall ◽  
The Impact

Inputs and losses from Giant Parramatta grass [GPG, Sporobolus indicus (L.) R. Br. var. major (Buse) Baaijens] soil seed banks were quantified on the North Coast of New South Wales. Monthly potential seed production and actual seed fall was estimated at Valla during 1991-92. Total potential production was >668 000 seeds/m2 for the season, while seed fall was >146000 seeds/m2. Seed fall >10000 seeds/m2.month was recorded from January until May, with further seed falls recorded in June and July. The impact of seed production on seed banks was assessed by estimating seed banks in the seed production quadrats before and after seed fall. Seed banks in 4 of the 6 sites decreased in year 2, although seed numbers at 1 damp site increased markedly. Defoliation from mid-December until February, April or June prevented seed production, reducing seed banks by 34% over 7 months. Seed banks in undefoliated plots increased by 3300 seeds/m2, although seed fall was estimated at >114 000 seeds/m2. Emergence of GPG seedlings from artificially established and naturally occurring, persistent seed banks was recorded for 3 years from bare and vegetated treatment plots. Sown seeds showed high levels of innate dormancy and only 4% of seeds emerged when sown immediately after collection. Longer storage of seeds after collection resulted in more seedlings emerging. Estimates of persistent seed banks ranged from 1650 to about 21260 seeds/m2. Most seedlings emerged in spring or autumn and this was correlated with rainfall but not with ambient temperatures. Rates of seed bank decline in both bare and vegetated treatment plots was estimated by fitting exponential decay curves to seed bank estimates. Assuming no further seed inputs, it was estimated that it would take about 3 and 5 years, respectively, for seed banks to decline to 150 seeds/m2 in bare and vegetated treatments.

scholarly journals Major and trace-element geochemistry of Late Cretaceous clastic rocks in the Jitai Basin, southeast China

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kai Yan ◽  
Chun-lian Wang ◽  
Steffen Mischke ◽  
Jiu-yi Wang ◽  
Li-jian Shen ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
Brackish Water ◽  
Inductively Coupled Plasma ◽  
Salt Water ◽  
Trace Element Geochemistry ◽  
Element Geochemistry ◽  
Humid Climate ◽  
Southeast China ◽  
Clastic Rocks ◽  
Wide Range

AbstractMajor, trace and rare earth element (REE) geochemistry of the late Cretaceous lower Zhoutian Formation from the Jitai Basin of Southeast China were measured by inductively coupled plasma mass spectrometry (ICP-MS) analysis to infer the provenance of the sediments and to reconstruct the palaeoenvironment and palaeoclimate. The wide range of Sr/Cu ratios point to a fluctuating palaeoclimate, and the negative correlation between the FeO/MnO and Al2O3/MgO ratios and the Sr/Cu ratio indicates that the late Cretaceous climate during the lower Zhoutian Formation in the Jitai Basin can be divided into two parts. The lower part experienced two cooling periods, whilst the upper part was dominated by warm-humid climate. Mostly corresponding trends of the B/Ga, Sr/Ba and Sr/Cu ratios show that the salinity changed consistently with the late Cretaceous climate during the lower Zhoutian Formation in the Jitai Basin. During the lower part, the salinity changed from salt water to fresh/brackish water. In the upper part, water was mainly fresh/brackish, and there were many changes from fresh/brackish water to salt water. The relatively stable Ni/Co, V/Cr, V/(V + Ni) and Ce/Ce* data indicate a long period of oxic conditions. The La-Th-Sc, Th-Sc-Zr/10 and La/Th-Hf data of the silt- and sandstones of the lower Zhoutian Formation show that its provenance was mainly a mixture of felsic upper crust sediments and older sedimentary rocks.

scholarly journals Seed Banks Alter the Rate and Direction of Molecular Evolution in Bacillus subtilis

2021 ◽  
Author(s):  
William R. Shoemaker ◽  
Evgeniya Polezhaeva ◽  
Kenzie B. Givens ◽  
Jay T. Lennon
Keyword(s):  
Bacillus Subtilis ◽  
Molecular Evolution ◽  
Seed Bank ◽  
Negative Selection ◽  
Evolutionary Dynamics ◽  
Genetic Manipulation ◽  
Seed Banks ◽  
Rate Of Molecular Evolution ◽  
Over Time ◽  
Growth And Reproduction

Fluctuations in the availability of resources constrains the growth and reproduction of individuals, which in turn effects the evolution of their respective populations. Many organisms are able to respond to fluctuations by entering a reversible state of reduced metabolic activity, a phenomenon known as dormancy. This pool of dormant individuals (i.e., a seed bank) does not reproduce and is expected to act as an evolutionary buffer, though it is difficult to observe this effect directly over an extended evolutionary timescale. Through genetic manipulation, we analyze the molecular evolutionary dynamics of Bacillus subtilis populations in the presence and absence of a seed bank over 700 days. We find that the ability to enter a dormant state increases the accumulation of genetic diversity over time and alters the trajectory of mutations, findings that are recapitulated using simulations based on a simple mathematical model. While the ability to form a seed bank does not alter the degree of negative selection, we find that it consistently alters the direction of molecular evolution across genes. Together, these results show that the ability to form a seed bank affects the direction and rate of molecular evolution over an extended evolutionary timescale.

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.

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