Persistent soil seed banks of the globally significant invasive species, Eupatorium adenophorum, in Yunnan Province, south-western China

2006 ◽  
Vol 16 (2) ◽  
pp. 157-162 ◽  
Author(s):  
Youxin Shen ◽  
Wenyao Liu ◽  
Jerry M. Baskin ◽  
Carol C. Baskin ◽  
Min Cao

Soil cores were collected at different times between the seed germination and dispersal seasons of Eupatorium adenophorum from 19 sites at five stations with different kinds of vegetation in Yunnan, south-western China. Mother plants of E. adenophorum were absent from eight of the sites, and their frequency was low at nine other sites. However, persistent soil seed banks were present at all 19 sites. Seed density in the 0–10 cm soil layer varied from 47 to 13,806 seeds m−2, and averaged 2199 seeds m−2. Fifty-seven percent of the seeds of E. adenophorum were in the 0–2 cm soil layer, 24% in the 2–5 cm layer and 19% in the 5–10 cm layer. The percentage of cores from which seedlings emerged ranged from 33–100% across all sites. Seed density and seedling emergence percentages varied significantly among the five stations, and both were positively correlated with abundance of mother plants.

Author(s):  
Katharina Tiebel

AbstractThe natural regeneration of disturbed forest sites is becoming increasingly important due to climate change. Following disturbance events affecting large areas seed trees are often absent from the site, and regeneration solely by means of seed rain may not be successful. In these situations, soil seed banks are an important driver of the regeneration and reforestation of forest sites. The aim of the study was to determine the birch seed density in the soil of birch stands, spruce–birch stands and spruce stands dependent upon the number of seed trees (stands) and upon varying degrees of ground cover using the ‘seedling emergence method.’ The study revealed a significant link between the quantity of germinated birch seedlings in soil samples and the presence of seed sources. Seedling densities of birch in the different stand categories reached 2644–6414 seedlings per m2 [n m−2] in birch stands, 392–759 n m−2 in spruce–birch stands and 25–122 n m−2 in pure spruce stands. The density of germinated birch seedlings was also negatively affected by the soil layer. In all stand types, the factors humus thickness, litter cover, moss cover and herb cover had no significant influence on the amount of birch seedlings. Successful rapid regeneration of disturbed sites by means of the birch soil seed bank is guaranteed in cases where birch stands, or at least birch seed trees, were present before the event. The influence of ground cover on the regeneration potential of birch from the soil is negligible.


2017 ◽  
Vol 57 (2) ◽  
pp. 165-175 ◽  
Author(s):  
Petra S. Yehnjong ◽  
Michael S. Zavada ◽  
Chris Liu

AbstractSoil seed banks are important to the maintenance and restoration of floras. Extant seed banks exhibit unique characteristics with regard to the distribution of seed size and seed density. Seeds were recovered from the Upper Pennsylvanian Wise Formation in southwest Virginia. Structurally preserved seeds were also examined from coal balls of the Pennsylvanian Pottsville and Allegheny Groups, Ohio. The size distribution of the seeds from the Wise Formation is similar to that of structurally preserved seeds of the Upper Pennsylvanian Pottsville and Allegheny Group coal balls. In contrast, the seed size distributions in extant wetland, grassland, woodland and forest habitats are significantly narrower than that of seeds from the Pennsylvanian seed banks. Larger seeds are less dependent on light for germination, and aid in seedling establishment more than smaller seeds, especially in dense stable forests where disturbance events are rare. Large seed size may contribute to increased seed longevity, which reduces the effect of environmental variability on seed germination and development. The significantly larger size of the Palaeozoic seeds may have imparted an advantage for seedling establishment in the dense Palaeozoic forests. The preponderance of large seeds may be a result of the absence of large seed predators (e.g. herbivorous tetrapods), and may have been an evolutionary strategy to minimize damage to the embryo from a predator population dominated by small invertebrates with chewing or sucking mouthparts. The estimated seed density of 192 seeds/m2in the Palaeozoic seed bank falls within the range of modern seed banks, but at the lower end of modern seed bank densities in a variety of habitats.


2000 ◽  
Vol 78 (5) ◽  
pp. 577-582 ◽  
Author(s):  
Catherine Zabinski ◽  
Todd Wojtowicz ◽  
David Cole

We investigated the soil seed bank in a subalpine ecosystem with patchy disturbance from camping. Soil cores were collected from three site types, heavily impacted, lightly impacted, and undisturbed, that differed in area of bare ground and depth of surface organic matter. We hypothesized that the density and composition of the seed bank would vary with depth of surface organic matter and distance from established vegetation. Seedling emergence was determined in the greenhouse. Seed density was significantly lower on disturbed sites, averaging 441 seeds/m2 on heavily impacted sites, 1495 seeds/m2 on lightly impacted sites, and 4188 seeds/m2 on undisturbed sites. Seed density declined exponentially with distance from established vegetation and increased with depth of surface organic matter. The number of species present did not vary across site types, but 10 species that occurred on lightly impacted and undisturbed sites were not present on heavily impacted sites. We concluded that disturbance that causes removal of surface organic matter can affect natural revegetation by lowering the density of propagules and affecting the species represented in the seed bank.Key words: seed bank, subalpine, patchy disturbance, recreation impacts.


1990 ◽  
Vol 12 (1) ◽  
pp. 25 ◽  
Author(s):  
A Bogusiak ◽  
B Rice ◽  
M Westoby ◽  
MH Friedel

The ecology of hummock-grass vegetation involves recurring fires. The hypothesis was tested that soil seed banks of hummock grass species are stimulated to germinate by the heat of fire or by ash addition. Hummocks of Plectrachne schinzii Henr., Triodia basedowii E. Pritz., and Triodia pungens R. Br. were burned, removed, or removed with the ash returned, and subsequent regeneration was recorded, in Ulum National Park. Regeneration of hummock grass was by seedlings only. Seedling emergence averaged 5/m2, with no differences between treatments or hummock grass species. This indicates the heat of fires and ash addition may not be important in stimulating seed germination of these hummock grass populations. Gemination was distributed over more than one rainfall event following the treatments.


2007 ◽  
Vol 37 (3) ◽  
pp. 552-567 ◽  
Author(s):  
Scott R. Abella ◽  
Judith D. Springer ◽  
W. Wallace Covington

We measured soil seed banks in 102 plots within a 110 000 ha Arizona Pinus ponderosa landscape, determined seed-bank responses to fire cues and tree canopy types (open or densely treed patches), compared seed-bank composition among ecosystem types, and assessed the utility of seed banks for ecological restoration. Liquid smoke was associated with increased community-level emergence from seed banks in greenhouse experiments, whereas heating to 100 °C had minimal effect and charred P. ponderosa wood decreased emergence. We detected 103 species in seed-bank samples and 280 species in aboveground vegetation. Erigeron divergens was the commonest seed-bank species; with the exception of Gnaphalium exilifolium , species detected in seed banks also occurred above ground. Although a dry, sandy-textured black-cinder ecosystem exhibited the greatest seed density, seed-bank composition was more ecosystem-specific than was seed density. Native graminoids (e.g., Carex geophila and Muhlenbergia montana ) were common in seed banks, whereas perennial forbs were sparse, particularly under dense tree canopies. Our results suggest that (i) smoke may increase emergence from seed banks in these forests, (ii) seed banks can assist establishment of major graminoids but not forbs during ecological restoration, and (iii) seed-bank composition is partly ecosystem-specific across the landscape.


2021 ◽  
Vol 15 (2) ◽  
pp. 437-451
Author(s):  
Ayomiposi Olayinka Akinkuolie ◽  
Rafiu Olugbenga Sanni ◽  
Augustine. O. Isichei ◽  
Samson. O. Oke

The study investigated the composition of native and alien invasive species in soil seed banks of five different vegetation physiognomies in Akure Forest Reserve Ondo State, Nigeria. This was done with a view to determining and providing an insight into the population dynamics of alien, invasive species for subsequent prediction of potential plant population of the extant population. Five distinct sites (Natural forest, Teak plantation, Taungya system, Taungya + Teak + Gmelina and Teak + Gmelina + Pinus Plantation) designated as A, B, C, D and E were selected in the Forest Reserve. Two plots 25 m x 25 m each were selected for sampling in each of the five distinct physiognomies. Five replicates soil samples were randomly collected at 0-15 cm soil depth in dry and rainy seasons in each site and they were subjected to seedlings emergence for six months to determine the density and species composition (natives or aliens and percentage contribution) of the seed bank. The results of the seedling emergence revealed that the seed bank was dominated by herbaceous stems and also the proportion of aliens to natives was low. Analysis of variance revealed that there was no significant difference (P>0.05) in the density of both the aliens and native species in sites A, B and C indicating similarities in the seed bank density of the aliens and natives in the three sites while in sites D and E, there was a significant difference (P<0.05) indicating dissimilarity in the seed bank density of the aliens and natives in the two sites.Keywords: Plant Ecology, Forest, Seedling Emergence, Seed Bank, Alien Species, Conservation.


2016 ◽  
Vol 59 (3) ◽  
pp. 133-138
Author(s):  
Hafiz Muhammad Zia Ullah Ghazali ◽  
Abdul Hamid ◽  
Muhammad Arshad ◽  
Mansoor Hameed ◽  
Malik Muhammad Yousaf ◽  
...  

Soil seed banks were assessed in three soil layers (L1, from 0 to 2 cm, L2, 2 to 4 cm and L3,4 to 6 cm depth ) from five microhabitats i.e., Lee-ward side of sand dune (S1), Wind-ward side of sanddune (S2), Clayey area covered with sand (S3), Interdunal sandy area (S4) and Shifting sand dune of siteDingarh Fort area (S5) in Cholistan desert of Pakistan to analyse differences of soil seed bank among thesehabitats. Ten soil samples were collected from each microhabitat and from each layer i.e., 0-2 cm depth(L1), 2-4 cm depth (L2) and 4-6 cm depth (L3) by using 15´15´6 cm metallic sampler. Consistentdifferences in seed composition were observed among these microhabitats. Seedling emergence approachwas used to assess the soil seed bank of Cholistan desert. Canonical correspondence analysis (CCA) wasused for the soil seed bank and the plant species analysis. The microhabitats S3 (Clayey area covered withsand) and S4 (Interdunal sandy area) contributed prominently to the total variance in the species and hadmaximum density of seed bank and soil layer L1 contained maximum number of seeds.


2021 ◽  
pp. 167-180
Author(s):  
Patsavipich Rungrojtrakool ◽  
Pimonrat Tiansawat ◽  
Arunothai Jampeetong ◽  
Dia Panitnard Shannon ◽  
Sutthathorn Chairuangsri

Soil seed banks have been used for investigation of natural regeneration of forests. In this study, we compared seed density and species composition of soil seed banks of trees among natural forests, restored forests of different ages, and abandoned agricultural land. The soil seed banks were collected from a natural forest (NF), 12-year-old and 17-year-old restoration sites (RF12y and RF17y), and 17-year-old abandoned site (AA) at Ban Mae Sa Mai, Chiang Mai, Thailand. A seedling emergence technique was used to assess seed density and species of emerged seedlings was identified. We found 5-8 tree species at each site. Seed densities in the study areas ranged from 43 to 298 seeds/m2. The seed density of RF12y was significantly higher than that of both NF and AA but not significantly different than RF17y (p < 0.01). Although there was no significant relationship between the restoration ages and the seed densities of the soil seed banks, the species composition of standing vegetation was related to the seed bank species. Sorensen’s similarities between the species composition of the soil seed banks and the existing trees in each area were between 0 and 13.79%, suggesting seed dispersal of both within and across study sites. Eight out of fourteen species in the soil seed banks were dispersed into restoration sites without standing vegetation of those species. Seven of those were animal-dispersed species. The selected native trees, framework species, attracted small seed dispersers into the study areas, especially at the restoration sites. This finding suggests that active forest restoration improved natural regeneration in restoration sites as well as neighboring areas via seed dispersal.


Author(s):  
Josephine Esaete ◽  
Augustine Bongo ◽  
Thomas Lado ◽  
Tomor Bojoi ◽  
Henry Busulwa

Soil seed banks are important for regeneration of degraded wetlands ecosystems. The Sudd wetlands of Juba city have long been encroached for crop cultivation. Seedling germination was monitored in a greenhouse to establish possible natural regeneration in Mindiari, Rejaf and Roton wetlands in the Sudd. Sixty-four species germinated from the soil seed bank of which 12.5% were dominated by Cyperus difformis and Typha capensis. The findings showed that median wetland species richness in Mindiari was 1.5 (interquartile range = 0.75?3.5), Rejaf 2.5 (interquartile range = 1.0 ? 4.0), Roton 3 (interquartile range = 1.0 ? 5.0) while median Shannon-Wiener diversity was 1.5 (1.14 ?1.73), 1.43 (1.01?1.66), 1.15 (0.98?1.67) for Mindiari, Rejaf and Roton respectively. Both the median seed species richness and diversity were not significantly different among the study wetlands. The median of seed density (56.1) was significantly higher in Roton than in Mindiari (36.7) and Rejaf (29.4) wetlands. The NMDS results showed that species composition of Mindiari and Rejaf was different from Roton. It is concluded that growing crops in wetlands did not influence species richness and diversity but it reduced seed density and altered species composition. Although wetland species were not significantly different in the three-wetland categories, dominance of canopy species belonging to Typhaceae and Cyperaceae indicates that these species are resilient to cultivation and could facilitate natural regeneration of cultivated wetlands edges of the Sudd region in Juba. Further research should examine effect of cultivation duration and flooding regimes on soil seed bank species richness, diversity, and density and composition.


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