Seed Bank Analysis Research Articles

Long-term monitoring of the restoration and development of limestone grasslands in north western Germany: Vegetation screening and soil seed bank analysis

We analysed the long-term development of limestone grasslands in West- and Central Europe (Mesobromion: Gentiano-Koelerietum) under conditions of restoration comparing vegetation changes with the composition of its corresponding soil seed bank over a time period from 1992 to 2005. Because of optimal climatic, edaphic and geomorphologic conditions restoration of vegetation developed gradually into the optimal phase of the typical limestone grassland vegetation type. However, the development of the soil seed bank compared to that of the actual vegetation cover is much slower, and even after 13 years all three study plots did not reach the optimal phase compared to soil seed bank composition from well-developed control vegetation nearby. This finding agrees with the assumption that after changes of management limestone grasslands need decades or even centuries to develop into self-sustaining species-rich habitats. We also monitored the orchid Ophrys insectifera as target species and characteristic species of this type of plant association over the last 27 years. Here, population density increased continuously over time indicating that vegetation restoration efforts of the last decades have had a positive effect. We further documented that the data obtained for the soil seed bank largely depend on the applied method used for the characterization of the soil seed bank. The seedling emergence and the rinsing method provided different results, and in case of our study area the rinsing method was mostly superior. The rinsing method detected up to 20fold higher total seed numbers.

Increased weed diversity, density and above-ground biomass in long-term organic crop rotations

AbstractWhile weed management is consistently a top priority among farmers, there is also growing concern for the conservation of biodiversity. Maintaining diverse weed communities below bioeconomic thresholds may provide ecosystem services for the crop and the surrounding ecosystem. This study was conducted to determine if weed diversity, density and biomass differ within and among organic and conventional crop rotations. In 2007 and 2008, we sampled weed communities in four long-term crop rotations near Mead, Nebraska using seedbank analyses (elutriation and greenhouse emergence) and above-ground biomass sampling. Two conventional crop rotations consisted of a corn (Zea mays) or sorghum (Sorghum bicolor)–soybean (Glycine max)–sorghum or corn–soybean sequence and a diversified corn or sorghum–sorghum or corn–soybean–wheat (Triticum aestivum) sequence. Two organic rotations consisted of an animal manure-based soybean–corn or sorghum–soybean–wheat sequence and a green manure-based alfalfa (Medicago sativa)–alfalfa–corn or sorghum–wheat sequence. Species diversity of the weed seedbank and the above-ground weed community, as determined by the Shannon diversity index, were greatest in the organic green manure rotation. Averaged across all sampling methods and years, the weed diversity index of the organic green manure rotation was 1.07, followed by the organic animal manure (0.78), diversified conventional (0.76) and conventional (0.66) rotations. The broadleaf weed seedbank density in the tillage layer of the organic animal manure rotation was 1.4×, 3.1× and 5.1× greater than the organic green manure, diversified conventional and conventional rotations, respectively. The grass weed seedbank density in the tillage layer of the organic green manure rotation was 2.0×, 6.1× and 6.4× greater than the organic animal manure, diversified conventional and conventional rotations, respectively. The above-ground weed biomass was generally greatest in the organic rotations. The broadleaf weed biomass in sorghum and wheat did not differ between organic and conventional rotations (CRs), but grass weed biomass was greater in organic compared to CRs for all crops. The above-ground weed biomass did not differ within CRs, and within organic rotations the grass weed biomass was generally greatest in the organic green manure rotation. The weed seedbank and above-ground weed communities that have accumulated in these rotations throughout the experiment suggest a need for greater management in long-term organic rotations that primarily include annual crops. However, results suggest that including a perennial forage crop in organic rotations may reduce broadleaf weed seedbank populations and increase weed diversity.

雑草研究における埋土種子調査の目的と手法

雑草研究における埋土種子調査の目的と手法

Water-level regulation and coastal wetland vegetation in the upper St. Lawrence River: inferences from historical aerial imagery, seed banks, and Typha dynamics

We evaluated habitat changes of tributary (drowned river mouth) wetlands in the upper St. Lawrence River with analysis of pre-and post-regulation water levels and historical vegetation reconstruction from aerial photographs. In addition, the germination response of transplanted wetland soil was compared to understand responses to moist versus saturated hydrology. Typha stem density was sampled in reference sites under the influence of water-level regulation by the International Joint Commission (IJC) and compared to treatment sites where installed control structures held levels (<0.7 m) higher. Major hydrologic changes due to regulation included a reduction of inter-annual variability with a reduction in peak levels and periodic lows, leading to a dampening of 30–40 year water-level cycles. Wetland photo interpretation indicated that flooded and mixed habitat categories were apparent at all sites for pre-regulation in 1948, but post-regulation photos (1972 and 1994) showed encroachment of robust emergent (Typha angustifolia, T. latifolia, and T. x glauca) in these habitats. Vegetation surveys (7 years, 2001–2007) indicated that reference and treatment sites were dominated by Typha, but mean stem densities were not statistically different. Typha stem density, however, declined in response to decreased summer water level. Periodic summer low water levels coupled with higher winter levels (that promote muskrat activity) were hypothesized to have the greatest effect on reducing Typha density. Seed-bank analysis indicated that a greater diversity of plant species germinated in mesic (moist) conditions than in the saturated treatment (flooded), where Typha was the dominant seedling component. Altered hydrologic regimes and invasive Typha have had a substantial effect on habitat structure within coastal wetlands and inferences from local management of levels provide useful guidance for future system-wide regulation.

Potential application of Hyptis spicigera for biological control of Striga hermonthica infestation.

Food situation has remained insecure and unpredictable in sub-Saharan Africa leading to high levels of cyclic famine and poverty. This has been exacerbated by perennial pest problems, which cause substantial pre- and post-harvest food grain losses. Production of cereal crops is threatened by Striga hermonthica weed known to infest an estimated 46000 ha of land in the traditional food producing areas in western and coastal Kenya. It is against this background that this study was designed to evaluate the efficacy of Hyptis spicigera–maize cropping systems on S. hermonthica infestation and maize grain yield and, generate a recommendation compatible with the target farmer dormains. Results showed that Striga counts were significantly (P < 0.05) reduced where maize was following fallow with H. spicigera. This was most effective in reducing S. hermonthica incidence and increased maize yield from 2.2 to 3.4 T/Ha. Intercropping maize and H. spicigera in the same plot at the same time negatively affected maize growth resulting in reduced maize yields. Indications were that root cuttings of H. spicigera stimulated Striga seed germination while their stubble (stem and leaves) reduced Striga seed bank in the soil. Striga seed bank analysis showed that Striga seed depletion increased with increase in Hyptis bushes with critical Hyptis seeding rate of 3 kg/Ha for maximum reduction in Striga seed bank. The findings of this study have implications for plant protection against S. hermonthica and improvement of cereal crop production in Striga-prone environments. Key words: Striga Incidence, seeding rates, cropping systems, maize yield.

Seasonal and spatial variance of seed bank species composition in an oligotrophic wet meadow

Seasonal and small-scale spatial variation of the seed bank in an oligotrophic wet meadow ( Molinion) was assessed by two methods: (1) direct determination of seeds extracted from soil samples (6 cm in diameter, 10 cm depth) and (2) germination of seeds according to Ter Heerdt et al. [1996. An improved method for seed bank analysis: seedling emergence after removing the soil by sieving. Funct. Ecol. 10, 144–151]. Samples were taken three times during the year (July and November 2001, March 2002) from three distinct microhabitats (moss layer, gaps, Molinia caerulea tussocks). Using the extraction method, more seeds were found in the upper 0–3 cm soil layer than in the deeper 3–7 cm layer, significant differences in the number of seeds were found among microhabitats (with the lowest seed bank densities in Molinia tussocks). The highest number of seeds was found in the spring census, but the test was not significant ( P<0.10). However, seasonal variation was found when damaged seeds were included in the analysis. Changes in damaged/undamaged and light/heavy seed ratios, and in numbers of grass/herbs/sedges seeds are also discussed. The spatial distribution of seeds is probably influenced to a great degree by abiotic factors, such as microtopography (round and heavy seeds of sedges prevail in gaps and in deeper soil layers). The species composition of the seed bank varied among microhabitats, depth, and throughout the year. No differences were found by the seed germination method.

The Potential for Horses to Disperse Alien Plants Along Recreational Trails

Plant invasions are rapidly becoming an important threat to the conservation of wildlands. Understanding how potentially invasive plants are dispersed to new habitats is a critical step in the process of understanding such invasions. Our objective was to characterize the potential for long-distance transport of plant species in the digestive tract of horses along recreational trails. We sampled horse dung along the first 4 000 m of the Lower Piney River trail in the White River Forest of western Colorado. We evaluated the seed content of each sample by applying standard methods for soil seed bank analysis. We found 20 species and 564 seedlings. Twelve of the species were graminoids, 6 were forbs, 1 was a shrub, and 1 was a tree. The species were evenly divided between natives and aliens, but 85% of the seedlings were aliens. An average of 47 seedlings emerged per sample, but the range was from 4 to 192. Our results make it clear that horses, and very likely all pack stock used on recreational trails, represent a potentially important dispersal vector for alien plants into western wildlands.

Comparison of two methods characterising the seed bank of amphibious plants in submerged sediments

We analysed the submerged soil seed bank of three fishponds in the Waldviertel region in Austria. We aimed our study at comparing the efficiency of two methods in detecting seeds quantitatively from soil samples of four characteristic mud-flat species, i.e. Carex bohemica, Coleanthus subtilis, Elatine hexandra, and Eleocharis ovata: the seedling-emergence and the rinsing method. Additionally, the actual vegetation was described based on 65 phytosociological relevés. Soil seed bank analyses were based on 31 samples representing the vegetation zonation. Mixed soil samples were portioned into 62 subsamples further treated with the two methods in parallel. Analysis of vegetation revealed a typical zonation with Isoëto-Nanojuncetea communities from the centre of dried-up fishponds to Phragmition/Magnocaricion communities at the shorelines. The study species were detected in the soil seed banks of all vegetation types, but seed abundances were generally higher in two fishponds characterised by muddy substrate than in one sandy mesotrophic pond (with the exception of E. hexandra). Therefore beside the water regime and the vegetation cover, additional factors such as soil type are likely to influence the soil seed bank composition of submerged sediments. The quantitative comparison of the seedling-emergence and the rinsing method revealed significantly higher seed numbers by the rinsing method. As we obtained 5.7 times ( Elatine hexandra) to 17.5 times ( Coleanthus subtilis) more seeds by rinsing, the averaged detection failure across the four study species was at least 89.7% with the seedling-emergence method. In addition to this advantage in the quantitative description of submerged soil seed bank compositions, the rinsing method enables us to use seeds subsequently for conservation management and revegetation purposes.

Soil seed bank analysis of planted and naturally revegetating thermally-disturbed riparian wetland forests

Accelerating the reestablishment of a mature, biotic community following a disturbance is a common goal of restoration ecology. In this study, we describe the relative successional status of a recently disturbed riparian seed bank when compared with less recently disturbed and undisturbed systems, and the short-term effects of restoration on seed bank development within the recently disturbed system. The study location, the U.S. Department of Energy's Savannah River Site in South Carolina, provides a unique opportunity to investigate the development of wetland seed banks following a severe disturbance, in this case the release of elevated temperature and flow effluent from nuclear reactor operations. To assess the recovery of wetland seed banks over time, we compared seed banks of naturally recovering riparian corridor and swamp delta sites of two different ages since disturbance (nine years and 30 years) with undisturbed forested corridor and swamp sites. To assess the potential effects of restoration efforts (site preparation and planting of seedlings) on seed bank development, we compared seed banks of naturally recovering (unplanted) and planted riparian corridor and swamp delta sites in the more recently disturbed system. We expected total germinants and species richness to be highest in the recently disturbed sites and decline as wetland systems matured. Within recently disturbed sites, we expected planted sites to have higher abundance and richness than unplanted sites. We also expected a greater abundance of woody species in the undisturbed forested sites. The number of germinants differed among the sites, ranging from 748 individuals per m 2 in the undisturbed swamp area to 10,322 individuals per m 2 in the recently disturbed planted swamp delta. When corridor and delta sites within a stream system were combined, the mean number of germinants was greater in the recently disturbed system, intermediate in the 30-year (mid-successional) system, and lowest in the undisturbed system. Seed banks from the recently disturbed and mid-successional sites were more similar in composition than they were to the undisturbed systems. Across all stream systems, riparian corridors had greater mean species richness than swamp deltas, though differences in seed bank abundances were not significant. Sedges and rushes were the predominant life forms in the recently disturbed and mid-successional sites, while undisturbed sites had a greater proportion of herbs and woody seedlings. In addition, there were more germinants from planted sites than from unplanted sites. The dominance by early successional species at recently disturbed planted sites may be an unintended consequence of site preparation treatments, and such potential effects should be recognized and weighed during the development of restoration plans.

A differentiating method for seed bank analysis: validation and application to successional stages of Koelerio-Corynephoretea inland sand vegetation

A differentiating method for seed bank analysis: validation and application to successional stages of Koelerio-Corynephoretea inland sand vegetation

Seedbank reduction after different stale seedbed techniques in organic agricultural systems

Little information is available on the stale seedbed effect on seedbank reduction. This weed management is of increasing interest overall in organic agricultural systems where is no possible to use herbicides. The emergence dynamics and related seedbank reduction were evaluated following adoption of two different stale seedbed techniques (with or without irrigation), made during the spring-summer season in 2001 in organic agricultural systems. As expected, emergence was strongly stimulated by irrigation and soil tillage.When the no-tillage technique was adopted (control), the absence of soil disturbance resulted in extremely low emergence levels, associated with a reduction in the number of the relative species. Consequently, analysis of the residual seedbank of the shallow layer (0- 10 cm) of the control (no-till) showed only small reduction (about 1%). In contrast, the tillage-only experiment led to a reduction of about 5% in the same soil layer. However only with the irrigation, a drastic reduction in the amount of seeds (roughly half) was achieved. In particular, grasses showed the highest seedbank reduction rates. Despite this different effectiveness of the stale seedbed techniques, the soil layers at greater depths (10-20 and 20- 30 cm) were found to be completely unaffected, independently of the agronomic practices carried out. Qualitative analysis of exhumed seeds demonstrated that greatest “forcing of germination” (tillage + irrigation) resulted in a percentage increase of “deep-dormant” seeds as a consequence “non-dormant” seeds decrease. Although stale seedbed appeared to be only partially effective, we believe that if this agrotechnique is properly carried out and repeated at the appropriate times, it promises to be successful in agricultural systems where herbicides are excluded.

Limits and effects of invasion by the nonindigenous wetland plant Lythrum salicaria (purple loosestrife): a seed bank analysis

We used seed bank analyses to investigate the role of dispersal in limiting invasion by Eurasian Lythrum salicaria within and among North American wetlands, and the changes in seed bank diversity associated with this invader. We compared the number and species composition of seedlings emerging from soil sampled in 11 uninvaded wetlands and paired uninvaded and invaded sites within 10 invaded wetlands under both seedling competition and noncompetitive conditions. Almost no L. salicaria emerged in samples from uninvaded wetlands, indicating dispersal limitation despite prodigious seed production in nearby wetlands. However L. salicaria emerged in all samples from uninvaded sites in invaded wetlands, suggesting environmental limits on establishment within invaded wetlands. Conditions that provided opportunities for seedlings to compete reduced survival of Typha spp. but not L. salicaria seedlings. However, this was due to species-specific differences in post-emergence mortality rather than response to competition. Competition did reduce seedling mass, but this effect did not differ among species. Species richness of emerging seedlings was lower for invaded than uninvaded wetlands. Lower seed bank richness may be a cause or consequence of L. salicaria invasion. Efforts to reduce seed dispersal to uninvaded wetlands would likely slow the spread of this invader.

Prediction of plant cover from seed bank analysis in a semi‐arid plant community on gypsum

Abstract. Question: Does the seed bank filter annual plant composition and determine cover at the species level?Location: 510 m a.s.l., central Spain.Methods: Seven transects and 136 quadrats were established in a semi‐arid gypsum system. Seed bank samples were collected in each quadrat in September. The community was sampled the following April. For each quadrat we measured slope, microslope, landform, elevation, perennial cover and crust cover. Seed bank was estimated using the direct emergence method in glasshouse. Relationship among seed bank and annual community was assessed by Mantel correlations. Above‐ground cover for the five most abundant species was modelled with GLMs.Results: Seed bank density was the best predictor for annual community cover; perennial cover and landform were also included in the model. Species composition between September seed bank and April annual community cover was also highly related according to the Mantel test. This relationship was constant, even when the effect due to other abiotic (landform, microslope) or biotic (perennial cover, crust cover) parameters were partialled out. Microslope, elevation and seed bank density were the best parameters to predict spring cover of the five most abundant species.Conclusions: Above‐ground and below‐ground community compartments are strongly related in terms of abundance and species composition. This relationship is filtered by several environmental factors (e.g. perennial cover, landform, microslope) that exert a strong control at community and individual levels. Our results support the hypothesis that annual community performance is affected by seed bank pattern.

Prediction of plant cover from seed bank analysis in a semi-arid plant community on gypsum

Abstract Question: Does the seed bank filter annual plant composition and determine cover at the species level? Location: 510 m a.s.l., central Spain. Methods: Seven transects and 136 quadrats were established in a semi-arid gypsum system. Seed bank samples were collected in each quadrat in September. The community was sampled the following April. For each quadrat we measured slope, microslope, landform, elevation, perennial cover and crust cover. Seed bank was estimated using the direct emergence method in glasshouse. Relationship among seed bank and annual community was assessed by Mantel correlations. Above-ground cover for the five most abundant species was modelled with GLMs. Results: Seed bank density was the best predictor for annual community cover; perennial cover and landform were also included in the model. Species composition between September seed bank and April annual community cover was also highly related according to the Mantel test. This relationship was constant, even when the effect du...

Population dynamics of Cardamine amara L. (Brassicaceae): Evidence from the soil seed bank and aboveground populations

KOCH, M., HUTHMANN, M. & BERNHARDT, K.-G.: Population dynamics of Cardamine amara L. (Brassicaceae): Evidence from the soil seed bank and aboveground populations. — Bot. Jahrb. Syst. 125: 405–429. 2004. — ISSN 0006-8152. In a recently presented paper we investigated the spatial distribution of genetic diversity in a strictly outcrossing cruciferous plant species, Cardamine amara, comparing surface population with subpopulations stored as seeds in the soil seed bank using isozyme analysis. Genetically, thirty-six populations from an area of approximately 900 square kilometres were investigated in a geographically well-defined region in Northwestern Germany. For ten out of these 36 populations, detailed soil seed bank analyses have been performed. Comparisons of soil seed bank composition and aboveground vegetation have been tested to serve as indicator of the environmental dynamics influencing floristic composition of the total habitat. Herein we are presenting the original and complete soil seed bank data of the different Cardamine amara habitats and comparing them to the actual vegetation cover. In total, we recovered 142 plant species (including 3 Equisetum species and Athyrium filix-femina from the pteridophytes), of which 78 were found also in the soil seed bank (including Athyrium filix-femina). These plant species have been characterized within seven groups depending on their occurrence in the soil seed bank and/or actual vegetation. Because particular attention has been paid on environmental dynamics, we fractionated the soil samples according to their depth (0–10 and 10–20 cm) and provided the according information about seed distribution. However, in four species only seeds occurred with a significantly higher frequency in the lower soil fraction than in the upper soil layer.

Miscanthus: Ornamental and Invasive Grass

Miscanthus sinensis was investigated where it has naturalized and invaded native plant communities in southeastern Pennsylvania, the Washington, D.C. area, western North Carolina, and Iowa. Plants were identified; inflorescences were collected; seed was cleaned and tested for viability; and soil was collected for seed bank analysis. Many individuals were interviewed at each location. Locations were mapped to show miscanthus. The species or “wild type” Miscanthus sinensis that has naturalized at the above locations is rarely sold in the nursery trade. The numerous, popular, ornamental cultivars derived from this species are vegetatively propagated clones that are common in the nursery trade. Miscanthus is self-incompatible and sets seed only when two or more genotypes are grown together. Individual isolated plants set little seed. Plants of the wild type which have naturalized each represent a unique individual or genotype and thus set heavy seed, quite different from ornamental cultivars. Further complicating this is the high variability of seed set due to environmental conditions. Management guidelines were developed along with recommendations which include: Do not plant the species Miscanthus sinensis. Cultivars of the species, especially when two are more are grown together, represent a high risk for self-seeding in the Mid Atlantic states. Cultivars should only be planted in areas where they can be watched and managed for self-seeding. No miscanthus should be planted where it can seed into native areas, such as highways, fields, meadows, or wooded areas. A comprehensive website with identification, pictures, management guidelines, and recommendations was developed: http://horticulture.coafes.umn.edu/miscanthus.

Extrinsic and intrinsic controls on the distribution of the critically endangered cress, Ischnocarpus exilis (Brassicaceae)

Ischnocarpus exilis, a critically endangered cress, persists in one small population in a 1m 2 section of a limestone tower in the South Island, New Zealand. The importance of intrinsic (seed production, dispersal ability and habitat specificity) and extrinsic factors (weed competition) acting to restrict the distribution of this threatened species were investigated with a field experiment, demographic monitoring and soil seed bank analysis. I. exilis is not confined to its present site because of high habitat specificity, but rather is limited by low seed production and limited dispersal as well as by competition with invasive weeds. Conservation management of this critically endangered species should focus on controlling weeds and on establishing new populations in suitable weed-free habitat.

Assessing limitations on population growth in two critically endangered Acacia taxa

Flowering phenology, soil seedbank and the impact of fire, weeds and grazing were investigated in two rare Acacia taxa restricted to the agricultural district north of Perth Western Australia. Acacia aprica is known from six extant populations and one extinct population. Five of the extant populations are restricted to linear road reserves with the sixth population located in a small native vegetation remnant. Acacia cochlocarpa ssp . cochlocarpa is known from a single population also situated on a road verge. Size class structure, levels of canopy death and an absence of juveniles indicated that all populations are in decline. Flowering intensity and success varied between populations and years in A. aprica and between years in A. cochlocarpa ssp. cochlocarpa. Seed bank analysis indicated that seeds were patchily distributed while experimental fires demonstrated that such events could break seed dormancy and promote germination. Both taxa have similar germination physiologies and showed increased germination after seeds were exposed to heat. Following emergence, however, competition with annual weeds had a negative impact on seedling growth and survival in both taxa. While vertebrate grazing had some influence, weeds were the major inhibitory influence on recruitment. Reduced fire frequencies since fragmentation may be responsible for population decline in both taxa but other site specific factors such as weeds and grazing may affect the establishment of seedlings following fire.

Aboveground Vegetation, Seed Bank and Soil Analysis of a 31-year-old Forest Restoration on Coal Mine Spoil in Southeastern Ohio

A 31-y-old forest restoration on coal mine spoil was studied to assess soil chemical composition, percent change in tree density and percent similarity of the seed bank and ground-story vegetation. Seed bank and soil chemistry results were compared to an adjacent unvegetated spoil bank. Of fifteen tree species planted on a barren, coal, spoil bank in 1966, four increased in density (indicating recruitment since 1966), seven decreased in density to 50% and four decreased in density >50% after 31 y. Nine volunteer tree species were recorded on the reforested site since the plantings in 1966. March and July soil collections in 1997 contained seeds of 18 species each, 13 in both collections. Most of the species found in the seed bank were shade-intolerant. No significant difference was found for total seed density between the March (4257 ± 490 seeds/m2) and July (3589 ± 365 seeds/m2) seed banks. Percent similarity between the seed bank and ground-story vegetation from the March and July seed collections was 9.8% and 8.2%, respectively. No seeds were found in soil collections from the adjacent unvegetated spoil bank. Soil pH and ionic content between the reforested study area and the unvegetated spoil bank differed significantly. We believe that the 1966 plantings have provided a habitat for other species to establish by reducing erosion and improving edaphic conditions.

Native woody species regeneration in exotic tree plantations at Munessa-Shashemene Forest, southern Ethiopia

Regeneration of native woody species was studied in the plantations and the adjacent natural forest at Munessa-Shashemene Forest Project Area, Ethiopia. The aim of the study was to test the hypothesis that tree plantations foster regeneration of native woody species. A total of 60 plots, having 10 × 10 m area each, were studied in monoculture plantations of 4 exotic species (Cupressus lusitanica, Eucalyptus globulus, E. saligna, Pinus patula) and an adjacent natural forest. Ages of the plantations ranged between 9 and 28 years. Soil seed bank analysis was also undertaken from soil samples collected in each of the 60 plots to examine the similarity between the soil seed flora and aboveground vegetation. A total of 56 naturally regenerated woody species were recorded beneath all plantation stands with densities ranging between 2300 and 18650 individuals / ha in different stands. There was a significant difference among plantation stands with regard to understorey density (standard deviation: 4836 ± 1341). Vegetation diversity was assessed through analyses of floristic composition, species richness and abundance. Generally, seedling populations were the most abundant components of the regeneration in most of the plantation stands, forming 68 % of the total regeneration count in all stands. A total of 77 plant species represented by 44 herbs, 13 woody species, 8 grasses and 12 unidentified species were recorded in the soil seed bank from all stands. Similarity between the soil seed bank and aboveground flora was very low implying that the role of soil seed banks is negligible rather dispersal plays an important role in the process of regeneration. These results support the concept that forest plantations can foster the regeneration of native woody species, thereby increasing biological diversity, provided that there are seed sources in the vicinity of the plantations.