scholarly journals Longevity of seeds and soil seed bank of the Cerrado tree Miconia chartacea (Melastomataceae)

2015 ◽  
Vol 25 (4) ◽  
pp. 386-394 ◽  
Author(s):  
Diego F. Escobar E. ◽  
Victor J. M. Cardoso

AbstractMiconia chartacea is a widely distributed tree in Brazil, occurring at altitudes ranging from 300 m to 1900 m in the Caatinga, Cerrado and Atlantic Forest biomes. In this work we attempted to classify M. chartacea seeds regarding their behaviour during storage and their germination syndrome and to determine, from a storage test in Cerrado soil and laboratory conditions in situ and ex situ, the longevity of seeds, as well as the capacity of the species to form a soil seed bank. The results suggested that M. chartacea seeds form a transient soil seed bank in the Cerrado and can be classified as orthodox in terms of storage behaviour, although the seeds are dispersed with a relatively high water content. The life span of seeds was favoured in soil-stored seeds in comparison with dry storage at 25°C, whereas storage at low temperatures prevented a decrease of the seed's germinability with storage time (330 d). M. chartacea seeds are dispersed during the dry season and germinate during the next rainy season, which can be classified as an intermediate–dry germination syndrome. Seeds of this species are dispersed in the Cerrado when temperatures and soil moisture are relatively low, which favours the formation of a soil seed bank, considering that the seeds tolerate desiccation and their longevity is favoured by low temperatures. A transient seed bank type is favoured by the loss of viability in storage at warm temperatures linked to the rainy season, and the predictable seasonal variations in climate in the region, with germination being restricted to the beginning of the rainy season.

2004 ◽  
Vol 20 (6) ◽  
pp. 683-691 ◽  
Author(s):  
Bruno Hérault ◽  
Pierre Hiernaux

The soil seed bank in a 5-y-old Sahelian fallow was studied through seed extraction and compared with germinations recorded either in controlled conditions, ex situ in a glasshouse, or in the field. The influence of phosphorus fertilizer and mulch application during the preceding crop period, and that of seasonal grazing regimes applied the last 2 y of fallowing, were assessed on the composition of the seed stock. Ctenium elegans, Fimbristylis hispidula, Merremia pinnata and Phyllanthus pentandrus accounted together for 75% of extracted seeds, 72% of ex situ, and 62% of in situ seedlings. Mulch treatment was correlated with the first axis of the canonical correspondence analyses performed on the seedling datasets. Mulch and phosphorus fertilizer treatments held similar responses, as they both favoured the seed bank of erect dicotyledons such as P. pentandrus and Cassia mimosoides. On the whole, the effects of grazing remained modest compared with the residual effects of past crop management practices. However, seedling densities increased as a result of dry-season grazing, while the soil seed bank decreased with wet-season grazing. Grazing also reduced the spatial heterogeneity of the seed bank rather than the overall number of species.


2006 ◽  
Vol 66 (2b) ◽  
pp. 709-717 ◽  
Author(s):  
C. G. Araújo ◽  
V. J. M. Cardoso

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.


2013 ◽  
Vol 27 (3) ◽  
pp. 465-471 ◽  
Author(s):  
Mário Luiz Ribeiro Mesquita ◽  
Leonaldo Alves de Andrade ◽  
Walter Esfrain Pereira

Author(s):  
David Ghosh ◽  
Cyril Jeannet

AbstractPrevious investigations by others and internal investigations at Philip Morris International (PMI) have shown that the standard trapping and extraction procedure used for conventional cigarettes, defined in the International Standard ISO 4387 (Cigarettes -- Determination of total and nicotine-free dry particulate matter using a routine analytical smoking machine), is not suitable for high-water content aerosols. Errors occur because of water losses during the opening of the Cambridge filter pad holder to remove the filter pad as well as during the manual handling of the filter pad, and because the commercially available filter pad holder, which is constructed out of plastic, may adsorb water. This results in inaccurate values for the water content, and erroneous and overestimated values for Nicotine Free Dry Particulate Matter (NFDPM). A modified 44 mm Cambridge filter pad holder and extraction equipment which supports in situ extraction methodology has been developed and tested. The principle of the in situ extraction methodology is to avoid any of the above mentioned water losses by extracting the loaded filter pad while kept in the Cambridge filter pad holder which is hermetically sealed by two caps. This is achieved by flushing the extraction solvent numerous times through the hermetically sealed Cambridge filter pad holder by means of an in situ extractor. The in situ methodology showed a significantly more complete water recovery, resulting in more accurate NFDPM values for high-water content aerosols compared to the standard ISO methodology. The work presented in this publication demonstrates that the in situ extraction methodology applies to a wider range of smoking products and smoking regimens, whereas the standard ISO methodology only applies to a limited range of smoking products and smoking regimens, e.g., conventional cigarettes smoked under ISO smoking regimen. In cases where a comparison of yields between the PMI HTP and conventional cigarettes is required the in situ extraction methodology must be used for the aerosol of the PMI HTP to obtain accurate NFDPM/”tar” values. This would be for example the case if there were a need to print “tar” yields on packs or compare yields to ceilings. Failure to use the in situ extraction methodology will result in erroneous and overestimated NFDPM/”tar” values.


Author(s):  
Takao YAMAMOTO ◽  
Satoru SHIBUYA ◽  
Akihiko OHSHIMA ◽  
Tsuneharu ORIHASHI ◽  
Mitsuhiro NAMBU ◽  
...  

2021 ◽  
Vol 24 (2-3) ◽  
pp. 148-151
Author(s):  
S.D. Shlotgauer

On the example of arctic and arctoalpine species of the sedge family (Cyperaceae Juss.), willow family (Salicaea Mirb.), saxifrage family (Saxifragaceae Juss.), buttercup family (Ranunculaceae Juss.) and rose family (Rosaceae Juss.) new points of their settlement in the subarctic mountain structures of Priokhotye are shown. The ecological adaptations of arctogenic element species to existence in mountainous conditions of low temperatures and high water content of habitats (nival lawns, the outskirts of ice crust fields, key bogs, etc.) are considered. This made it possible to clarify the main ways of arctic and arctic-alpine species dispersal in the subarctic mountain systems of the Boreal region.


2021 ◽  
pp. 1-28
Author(s):  
Jordan Meyer-Morey ◽  
Matthew Lavin ◽  
Jane Mangold ◽  
Catherine Zabinski ◽  
Lisa J. Rew

Abstract Non-native plant invasions can have devastating effects on native plant communities; conversely management efforts can have non-target and deleterious impacts on desirable plants. In the arid sagebrush steppe rangelands of the western United States, non-native winter annual species affect forage production and biodiversity. One method proposed to control these species is to suppress the soil seed bank using the pre-emergent herbicide indaziflam. Our goal was to evaluate the efficacy of indaziflam to control non-native annual mustards (Alyssum spp.) and to understand potential non-target effects of management on the diverse mountain sagebrush steppe plant communities within Yellowstone National Park. Six sites were established along an elevation gradient (1615 – 2437m), each with high and low Alyssum spp. infestations. We applied 63g ai ha−1 of indaziflam in late summer of 2018 and evaluated plant community cover in situ for two years after treatment, and emergence of forb species from the soil seed bank ex situ. Indaziflam was highly effective at controlling Alyssum spp. emergence for two years. Richness and Shannon’s diversity of the non-target plant community were significantly lower in sprayed plots than the control, and both decreased along the elevation gradient. These reductions were due to a decrease in perennial forbs and native annual forbs in the sprayed plots; perennial graminoids were not affected. Overall, the above ground and seed bank community composition was negatively impacted by indaziflam, and these effects were strongest for the native annual forbs that rely on annual regeneration from the seed bank. The effects of this herbicide to the non-target community should be evaluated beyond the length of our study time, however we conclude indaziflam should likely be reserved for use in areas that are severely invaded and have seed banks that are comprised of non-desirable species rather than diverse, native mountain sagebrush communities.


2024 ◽  
Vol 84 ◽  
Author(s):  
A. Ahmad ◽  
A. Saeed ◽  
A. B. Gulshan ◽  
S. Wali ◽  
F. Hadi ◽  
...  

Abstract The current focus is on the overall pattern of seed storage present in the fragments of the soil of piedmont and alluvial landscapes of the environment. The present study predicted the seed banks of both soils of alluvial and piedmont zones in different ecological conditions and evaluate the potential of seeds in the restoration of both environments. The composition of the seed bank of soil is mainly affected by the alluvial environment and the structure of cleared area shows that more species of germinating annual grasses and growable seeds with the higher total number. Extant vegetation structures have an important role in the diversity of soil seed reservoirs, whose composition corresponded with the openness of the site. When in situ soil seed bank is recruited, it helps to restore only some components of the plant community in an alluvial environment. In our current research, it was confirmed that seed richness was higher in number at lower elevation (alluvial) than that at high elevation (piedmont). Seed richness showed a significant negative correlation with anions, cations, while significantly positive with altitude that suggests the richness pattern of the overall seed bank of the area is influenced by various environmental factors.


2019 ◽  
Vol 43 (1) ◽  
Author(s):  
Wakshum Shiferaw ◽  
Tamrat Bekele ◽  
Sebsebe Demissew ◽  
Ermias Aynekulu

AbstractThe aims of the study were to analyze (1) the effects of Prosopis juliflora (Prosopis) on the spatial distribution and soil seed banks (SSB) diversity and density, (2) the effects of environmental factors on SSB diversity and density (number of seeds in the soil per unit area), and (3) the effects of animal fecal droppings on SSB diversity, density, and dispersal. Aboveground vegetation data were collected from different Prosopis-infested habitats from quadrats (20 × 20 m) in Prosopis thickets, Prosopis + native species stand, non-invaded woodlands, and open grazing lands. In each Prosopis-infested habitats, soil samples were collected from the litter layer and three successive soil layer, i.e., 0–3 cm, 3–6 cm, and 6–9 cm. Seeds from soil samples and animal fecal matter were separated in the green house using the seedling emergence technique. Invasion of Prosopis had significant effects on the soil seed bank diversity. Results revealed that the mean value of the Shannon diversity of non-invaded woodlands was being higher by 19.2%, 18.5%, and 11.0% than Prosopis thickets; Prosopis + native species stand and open grazing lands, respectively. The seed diversity and richness, recovered from 6–9-cm-deep layer were the highest. On the other hand, the density of Prosopis seeds was the highest in the litter layer. About 156 of seeds/kg (92.9%) of seeds were germinated from cattle fecal matter. However, in a small proportion of seedlings, 12 of seeds/kg (7.1%) were germinated from shot fecal matter. Thus, as the seeds in the soil were low in the study areas, in situ and ex situ conservation of original plants and reseeding of persistent grass species such as Cynodon dactylon, Cenchrus ciliaris, Chrysopogon plumulosus, and Brachiaria ramosa are recommended.


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