Seed Banks and Vegetation of Three Contrasting Sites in an Urban Eucalypt Forest Reserve

1994 ◽  
Vol 42 (4) ◽  
pp. 371 ◽  
Author(s):  
BM Odgers
Keyword(s):  
Seed Bank ◽  
Native Species ◽  
Seed Banks ◽  
Species Density ◽  
Grass Species ◽  
Forest Site ◽  
The Road ◽  
Eucalypt Forest ◽  
Exotic Grass ◽  
Germinable Seed

Grass species, sedges and dicotyledons in the vegetation and the buried germinable seed of a natural subtropical eucalypt forest, a mown and a road bank site were identified in four consecutive seasons and the data pooled to give a more precise assessment of taxa present each year. Differences in the relative proportions of taxa, differences in species density, origin and life history of grass species in the seed bank and vegetation, as well as differences in biomass and rate of germination of buried germinable grass seed, in the three sites were investigated. In all three sites, grasses were the dominant taxa of the ground stratum of the vegetation with each site having its own group of mainly perennial grasses. The seed banks were dominated by grasses in the forest site, sedges in the mown site and dicotyledons in the road bank site. There were significant differences in species density of grasses in both the vegetation and buried germinable seed between sites, with the forest site having a significantly lower species density in its seed bank than the mown and road bank sites, and the vegetation of the forest and mown sites having a lower species density than the road bank site. However, there was a high correlation between the grass species of the vegetation and the buried germinable seed in each of the three sites - the species which dominated the vegetation also dominated the biomass of buried germinable seed in each site. The mown and road bank sites had larger numbers and biomass of buried germinable grass seed than the natural forest site. There were no differences in the number of days to first germination and the number of days to 50% germination of the buried germinable seed between any of the sites. Exotic grass species were present in the seed banks of the forest, mown and road bank sites. Exotics were prevalent in the vegetation of the mown and road bank sites but not evident in the vegetation of the forest site. Exotic species with higher buried germinable seed numbers and similar germination rates to the native species are likely to have a competitive advantage over the native species. It appears that the mown and road bank sites, may act as reservoirs for the more competitive exotic grass species, enabling them to invade the seed banks of the forest areas.

Seasonal Variation in Buried Germinable Seed Banks of Grass Species in an Urban Eucalypt Forest Reserve

1999 ◽  
Vol 47 (4) ◽  
pp. 623 ◽  
Author(s):  
B. M. Odgers
Keyword(s):  
Seasonal Variation ◽  
Seed Banks ◽  
Grass Species ◽  
Seasonal Patterns ◽  
Forest Reserve ◽  
Native Grass ◽  
Eucalypt Forest ◽  
Disturbed Forest ◽  
Exotic Grass ◽  
Germinable Seed

Grass species in the buried germinable seed banks of selected forest, mown and road-bank sites in the Mt Coot-tha Reserve, south-eastern Queensland were quantified for five consecutive seasons to determine seasonal patterns in the seed banks, and differences in seasonal patterns between native and exotic grass species, and between grasses in natural and disturbed forest areas. Ten types of seed banks were identified. While native and exotic species had similar seed banks most native grass species had transient seed banks whereas most exotic grass species had persistent seed banks.

Fire, Buried Germinable Seed Banks and Grass Species Establishment in an Urban Eucalypt Forest Reserve

1996 ◽  
Vol 44 (4) ◽  
pp. 413 ◽  
Author(s):  
BM Odgers
Keyword(s):  
Seed Banks ◽  
Grass Species ◽  
Similar Species ◽  
Forest Reserve ◽  
Eucalypt Forest ◽  
Open Forest ◽  
Forest Sites ◽  
Before And After ◽  
Species Establishment ◽  
Germinable Seed

The buried germinable seed banks of two natural contrasting savanna open-forest sites were investigated before and after a wildfire. It was found that while the number of buried germinable grass and sedge seeds remained the same, the number of buried germinable dicotyledon seeds in both sites increased after the fire. It was also found that there were similar species of grasses present in the buried germinable seed banks before and after the fire. When germinating grass seedlings in the burnt and unburnt sites were compared, similar species of grasses were found in the germinating seedlings at both sites; however, more grass seedlings germinated in the burnt site than in the unburnt site.

Seed rain and seed bank along an alpine altitudinal gradient in Swedish Lapland

2000 ◽  
Vol 78 (6) ◽  
pp. 728-747 ◽  
Author(s):  
Ulf Molau ◽  
Eva-Lena Larsson
Keyword(s):  
Seed Bank ◽  
Altitudinal Gradient ◽  
Vascular Plant ◽  
Seed Rain ◽  
Forest Site ◽  
Long Distance ◽  
Empetrum Hermaphroditum ◽  
Study Sites ◽  
Total Seed ◽  
Germinable Seed

We studied the seed flux, including seed rain and seed bank (germinable and total), at twelve sites along an altitudinal gradient in the Abisko area in northernmost Swedish Lapland during a period of 3 years with contrasting summer climates. The study sites were evenly spaced in altitude from the timberline at 700 m above sea level to the highest peaks in the area (1560 m). A subalpine birch forest site was included for comparison. Each site was equipped with seed traps, replaced and emptied directly upon snow-melt each summer. Soil samples for seed bank assessment were taken at all sites, and inventories of the vascular plant flora were carried out in the 10 m radius neighborhood of the traps. The results revealed high variation among years with regard to seed rain and its partitioning over various functional types of plants. Even though most of the seed rain could be attributed to species present in the plant community of the trap sites themselves, some more long-distance dispersal takes place every year. A number of extrazonal recoveries are reported, often several hundred m above the distributional limit of the species. Even though seed number and species diversity declined rapidly from seed rain over total seed bank to germinable seed bank, the correlation among all three aspects of the seed pool was high. The dominant species in the seed flux at moderate altitudes, Empetrum hermaphroditum Hagerup, has a persistent seed bank with an average turnover of more than 200 years.Key words: seed rain, seed bank, total seed bank, germinable seed bank, alpine, dispersal.

Contrasting Diaspore and Vegetation Attributes of Grasses From Natural and Disturbed Habitats in an Urban Eucalypt Forest Reserve

1993 ◽  
Vol 41 (6) ◽  
pp. 637 ◽  
Author(s):  
BM Odgers ◽  
RW Rogers
Keyword(s):  
Grass Species ◽  
Forest Species ◽  
Forest Reserve ◽  
Morphological Attributes ◽  
The Road ◽  
Eucalypt Forest ◽  
Disturbed Areas ◽  
Undisturbed Forest ◽  
Mowing Regime ◽  
Disturbed Habitats

Forty one species of grasses from a eucalypt forest reserve near Brisbane, Australia, were allocated to groups characteristic of undisturbed forest, regularly mown areas, and road banks. Morphological attributes of diaspores, height and growth habit of mature plants, species origin, flowering times and life history were determined for each species. Species characteristic of the mown areas had lighter diaspores than the forest gasses and did not possess awns; if a callus was present it was blunt and did not have antrorse hairs. Species from mown areas also differed from the forest species in being mainly short stoloniferous exotics which flowered for longer than the forest species. Species characteristic of the natural forest and road bank areas had diaspores of similar mass, similar diaspores attributes (awns, callus and antrorse hairs) and species of both habitats were mainly tall and tufted. The road bank species differed from the forest species in being mainly of exotic origin and in flowering for up to 9 months per year longer than the forest species. That grass species of mown areas successfully compete with forest species in mown areas may be because of a mowing regime which selects for short, mainly stoloniferous, species which have longer periods of diaspore production than the forest species. As road banks are not subjected to regular mowing, an extended pattern of flowering which ensures a continuous supply of diaspores may account for road bank species successfully competing with forest species in disturbed areas.

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.

Heat and smoke effects on the germination of seeds from soil seed banks across forest edges between subtropical rainforest and eucalypt forest at Lamington National Park, south-eastern Queensland, Australia

2003 ◽  
Vol 51 (3) ◽  
pp. 227 ◽  
Author(s):  
Y. Tang ◽  
S. L. Boulter ◽  
R. L. Kitching
Keyword(s):  
Seed Bank ◽  
National Park ◽  
Soil Seed Bank ◽  
Seed Banks ◽  
Forest Edges ◽  
Abrupt Transition ◽  
Soil Seed Banks ◽  
Eucalypt Forest ◽  
Sclerophyll Forest ◽  
Physical Changes

Physical changes and flows of energy at the interface between two contrasting ecosystems affect the distribution of species across the ecotone. The maintenance and stability of the, often abrupt, transition between Australian rainforest and non-rainforests is often attributed to fire. We use pre-germination treatments of smoke and heat on soil seed bank samples to determine plant distributions across the edge between subtropical rainforest and an adjacent eucalypt-dominated wet sclerophyll forest. Soil seed bank collections at 15 m within the eucalypt forest had both significantly higher density and diversity of seedlings than those at 30 m, at the edge itself or at any site within the rainforest. This response was most apparent when a pre-germination smoke treatment was applied. We suggest that smoke is an important germination trigger for species regenerating at this interface. Our results confirm the importance of fire in determining and maintaining the nature of this ecotone.

scholarly journals Seed bank and growth comparisons of native (Virgilia divaricata) and invasive alien (Acacia mearnsii and A. melanoxylon) plants: implications for conservation

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5466 ◽  
Author(s):  
Stefan A. Goets ◽  
Tineke Kraaij ◽  
Keith M. Little
Keyword(s):  
Seed Bank ◽  
Growth Rates ◽  
Native Species ◽  
Soil Depth ◽  
Soil Seed Bank ◽  
Seed Banks ◽  
Acacia Mearnsii ◽  
Relative Growth ◽  
Sapling Growth ◽  
Study Species

Background Invasive alien plants with long-lived dormant seed banks and fast growth rates are difficult to manage. Acacia mearnsii and Acacia melanoxylon are two such invaders in the southern Cape of South Africa which occasionally co-occur with a native, ecologically analogous species, Virgilia divaricata. We compared the performance of these three species to determine potential for the native species to be used in management of the invasives. Methods We compared the study species in terms of (i) soil seed bank densities, their vertical distribution, and the viability of seeds underneath the canopies of mature trees; (ii) seedling growth from planted seeds over a period of three months; and (iii) growth rates of saplings over a period of 10 months in stands that have naturally regenerated in the field (these stands were dominated by A. mearnsii) and where saplings have been exposed to varying levels of competition from surrounding saplings. Results Seed bank densities differed significantly among species but not among soil depth classes. Acacia mearnsii had the highest seed bank densities (mean of 7,596 seeds m−2), followed by V. divaricata (938 seeds m−2) and A. melanoxylon (274 seeds m−2). Seed viability was high (87–91%) in all three study species and did not differ significantly among species or soil depth classes. As seedlings, V. divaricata significantly outgrew A. mearnsii in terms of height, root and shoot dry mass, and root:shoot ratio. Relative growth (the relationship between growth in height and initial height) was negative in the seedlings of both species. Trends during the sapling stage were opposite to those during the seedling stage; A. mearnsii (but not A. melanoxylon) saplings significantly outgrew V. divaricata saplings in height, while relative growth rates were positive in all species. Sapling growth of all species was furthermore uninfluenced by the collective biomass of surrounding competitors. Discussion Our findings suggest that amongst the measures considered, A. mearnsii’s success as an invader is primarily attributable to its large seed banks, and secondly to its vigorous growth in height as saplings. However, the superior growth performance of V. divaricata seedlings and no apparent negative effect of competition from the acacias on sapling growth show promise for its use in integrated management of the acacias.

scholarly journals Alien plant species on roadsides of the northwestern Patagonian steppe (Argentina)

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246657
Author(s):  
Giselle Ailin Chichizola ◽  
Sofía Laura Gonzalez ◽  
Adriana Edit Rovere
Keyword(s):  
Exotic Species ◽  
Plant Species ◽  
Seed Bank ◽  
Native Species ◽  
Seed Banks ◽  
Patagonian Steppe ◽  
Invasive Exotic Species ◽  
Perennial Herbs ◽  
Invasive Exotic ◽  
Reference Areas

The introduction of alien species represents one of the greatest threats to biodiversity worldwide. Highway construction increases the dispersal and invasion of exotic plant species. This study examined the assembly process of the plant communities to determine whether the roadsides of the Patagonian steppe represent a reservoir and dispersal source of invasive exotic species. We analyzed the composition of exotic and native species and functional groups present in the established vegetation and seed banks of roadsides and reference areas nearby. The type of dispersal of exotic and native species at the roadsides was also evaluated. Total cover and that of exotic and native species was lower at the roadsides than in the reference areas; however, at the roadsides the cover and seed abundance of exotic species was higher than that of native species. In the roadsides vegetation, native shrubs such as Acaena splendens predominated, along with exotic perennial herbs and grasses which were mainly represented by Rumex acetosella. In the seed bank the predominant species were exotic perennial herbs, also represented by R. acetosella, annual exotic species such as Epilobium brachycarpum and Verbascum thapsus, and annual native species such as Heliotropium paronychioides. No exotic shrubs were found either at the roadsides or in the reference areas. The species at the roadsides did not present a dominant type of dispersal. The abundance of exotic species at the roadsides, both in the aboveground vegetation and the seed bank, may be due to the stressful environment and the characteristics of the species themselves, such as the ability to form seed banks. This work revealed that the roadsides of the Patagonian steppe constitute reservoirs of invasive exotic species, highlighting the importance of identifying them and controlling their spread, with a view to generating ecosystem management programs.

Seed banks of forested and disturbed soils in southwestern British Columbia

1993 ◽  
Vol 71 (12) ◽  
pp. 1574-1583 ◽  
Author(s):  
Ann McGee ◽  
M. C. Feller
Keyword(s):  
British Columbia ◽  
Seed Bank ◽  
Forest Floor ◽  
Vascular Plant ◽  
Seedling Emergence ◽  
Mineral Soil ◽  
Soil Surface ◽  
Seed Banks ◽  
Grass Species ◽  
Burial Depth

The species composition and density of seed banks in the forest floors and mineral soils of several undisturbed (immature, midseral forests) and disturbed (transmission line rights-of-way) ecosystems in southwestern British Columbia were estimated using the seedling-emergence method. The total soil surface area sampled was 9.4 m2. Germination behaviour of seven dominant species in response to depth of burial and substrate was also studied in a greenhouse experiment. A total of 16 289 seedlings germinated, representing 62 native and naturalized vascular plant species and several unidentified grass species. Most seedlings emerged from the forest floor, and the number of germinants generally decreased with increasing sample depth. Drier ecosystems had the lowest number and density of germinants. Burial depth significantly affected germination of all species tested. Mineral soil was equal, or superior, to forest floor as a germination substrate for all species tested. Depth–substrate interactions for several species indicated that the pattern of influence of burial depth in relation to substrate varied with species. Caution is urged extrapolating greenhouse seed-bank studies to potential weed populations in the field. Establishment of species from the seed bank will be a function of the depth to which the soil is disturbed and the kind of disturbance (burning, scarification) imposed. Key words: British Columbia, Coastal Western Hemlock zone, seed bank, seed germination, seed diversity, seed density.

Trends in the recruitment of Astrebla spp. in relation to seasonal rainfall.

1991 ◽  
Vol 13 (2) ◽  
pp. 107 ◽  
Author(s):  
DM Orr
Keyword(s):  
Seed Bank ◽  
Soil Seed Bank ◽  
Seasonal Pattern ◽  
Seed Banks ◽  
Severe Drought ◽  
Factors Affecting ◽  
History Of ◽  
Permanent Quadrats ◽  
Germinable Seed ◽  
Previous Summer

Differences in both the occurrence and size of the recruitment of Astrebla spp. (mainly A. lappacea) in Astrebla grassland have been reported from three geographically different locations. The studies reported in this paper were undertaken to develop an understanding of the factors affecting the recruitment of Astrebla spp. at Cunnamulla and Julia Creek at the southern and northern extremities of Astrebla grasslands in Queensland. The germinable seed bank of Astrebla spp. at Cunnamulla in October 1981 was 250 seeds/m2 compared with only 60 seeds/m2 at Julia Creek while the germinable seed bank of Iseilema spp. was 3020 seeds/m2 at Julia Creek compared with < 1 seed/m2 at Cunnamulla. Grazing had no effect on the germinable seed banks of Astrebla spp. but grazing at Julia Creek increased the germinable seed bank of Iseilema spp. Recruitment of Astrebla spp. was recorded at both locations. At Cunnamulla, an unusually large recruitment of 15.0 plants/m2 of Astrebla spp. was recorded in July 1983 following a severe drought in the previous summer. At Julia Creek, a density of 1.4 seedlings/m2 of Astrebla spp. was measured in 1984 and this may have been the first recorded recruitment of Astrebla spp. in the ten year history of the permanent quadrats. Recruitment at Julia Creek was associated with a low density (< 3 plants/m2) of Iseilema spp. I conclude that the seasonal pattern of rainfall, as it influences the size and composition of the soil seed bank, is the major factor affecting recruitment of Astrebla spp. An integrated understanding of Astrebla spp. persistence across its range is presented.

Sign in / Sign up

Export Citation Format

Share Document