Spatial patterns of the germinable soil seed bank of coexisting perennial-grass species in grazed shrublands of the Patagonian Monte

Hyparrhenia hirta (L.) Stapf (also known as Coolatai grass, South African bluestem or thatching grass) has become a serious invasive weed in Australia. Within its native range, it is generally regarded as a useful grass particularly for thatching, and seed production is low with a low soil seed bank of from 2 to 200seedsm–2. Several hundred accessions of H. hirta were deliberately introduced into Australia up until the 1980s and nearly all were discarded because of poor seed production. However, at least one introduction in the 1890s in northern New South Wales (NSW), Australia, has possibly contributed to the present serious weed problem. Annual seed production from roadside stands in northern NSW ranged from 7000 to 92000seedsm–2 in 2015. The soil seed bank under dense H. hirta infestations in the same region in 2006 and 2007, was found to be ~30000seedsm–2 mostly confined to the top 2cm, with few dormant seeds and a large reduction of these numbers over the next 12 months when further seed input was prevented. Similar studies of other perennial grass weeds have found seed banks of similar sizes, but dormancy mechanisms ensure that their seed banks last for at least 10 years without further seed input. These results suggest that the present weedy populations of H. hirta have dramatically increased fecundity enabling a large seed bank to develop beneath dense stands. The development of seed dormancy and consequently a long-lived seed bank would make this weed even more difficult to control. Until seed dormancy develops, control of H. hirta in northern NSW can be effective provided further input into the seed bank can be prevented.

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Establishment of native and exotic grasses on mine overburden and topsoil in the Hunter Valley, New South Wales

The Rangeland Journal ◽

10.1071/rj05006 ◽

2005 ◽

Vol 27 (2) ◽

pp. 73 ◽

Cited By ~ 12

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.

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Relating sampling effort to the detection of spatial patterns of species richness in the soil seed bank of a mediterranean shrubland.

10.5194/egusphere-egu2020-18218 ◽

2020 ◽

Author(s):

Iván Torres ◽

José M. Moreno

Keyword(s):

Species Richness ◽

Spatial Pattern ◽

Spatial Patterns ◽

Seed Bank ◽

Soil Seed Bank ◽

Spherical Model ◽

Sampling Effort ◽

Long Distance ◽

Mediterranean Shrubland ◽

Heated Soil

<p>Studying the soil seed bank is a time and space-consuming task, and therefore only a small fraction of the soil is sampled. It is then critical to optimize sampling effort to reliably estimate soil seed bank properties. Here, we test whether the spatial patterns of species richness in the soil seed bank differ under increasing sampling effort. For this, we used data of germination from soils in a mediterranean shrubland in Central Spain. Two data sets were used, one of the seedlings emerging after heating the soil to break dormancy, and one with the combined germinations of heated and non-heated soil subsamples. We simulated increased sampling effort with sample-based rarefaction curves, extrapolating the species richness corresponding to a 2x and 3x increase in the number of individuals (seedlings) per sample. We then analyzed the spatial pattern of the original and extrapolated species richness using linear regression and semivariograms. Species richness increased by 34% and 52% in the 2x and 3x estimations, however the spatial pattern of species richness remained largely unchanged. For the long-distance spatial pattern, the slope of the plot-scale trend (i.e., the regression coefficient) increased only slightly with increasing sampling effort, while the adjusted R-squared of the regression decreased with increasing sampling effort. For the short-distance spatial pattern we could only fit spherical model semivariograms to the data from soils exposed to a heat shock, and the intensity of the spatial pattern (spatial dependence) increased very slightly with increased sampling effort. These results suggest that even with a doubled or tripled sampling effort, as provided by the simulations, the spatial pattern of species richness would have remained unchanged. We argue that increased effort in detecting species in the seed bank needs not necessarily improve the detection of spatial pattern.</p>

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Effect of conspecific adult plants on the spatial patterns of the soil seed bank of Calligonum rubicundum

South African Journal of Botany ◽

10.1016/s0254-6299(15)30150-2 ◽

2005 ◽

Vol 71 (1) ◽

pp. 61-66 ◽

Cited By ~ 2

Author(s):

J. Ren ◽

L. Tao ◽

J. van Staden

Keyword(s):

Spatial Patterns ◽

Seed Bank ◽

Soil Seed Bank ◽

Conspecific Adult ◽

Adult Plants

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Temporal and spatial variation in the soil seed bank of Nassella trichotoma (serrated tussock) in its native range

Australian Journal of Botany ◽

10.1071/bt20046 ◽

2021 ◽

Vol 69 (1) ◽

pp. 45

Author(s):

Andrés García ◽

Alejandro Loydi ◽

Roberto A. Distel

Keyword(s):

Seed Bank ◽

Soil Seed Bank ◽

Seedling Emergence ◽

Spatial Relationship ◽

Grass Species ◽

Seed Density ◽

Native Range ◽

Temporal And Spatial Variation ◽

Seed Extraction ◽

Temporal And Spatial

Serrated tussock (Nassella trichotoma (Nees) Hack. ex Arechav) is an unpalatable grass species that has been expanding in its native range and invading non-native ranges. In this study in its natural environment, we aimed to describe the spatial relationship between seed density, the cover and density of standing individuals of serrated tussock, the seasonal variation in the seed density in the soil seed bank, and to compare these results with those reported in non-native ranges. We took soil samples seasonally and recorded the cover and density of standing individuals of serrated tussock at two sites in the native Pampas grasslands in central-east Argentina. Seed density was evaluated by seedling emergence and seed extraction. Seed density showed a seasonality trend, with maximum values in the end of summer and minimum values in winter and spring. Seed density was independent of the cover and density of standing individuals of serrated tussock. The values of seed density were lower than those reported in the invaded ranges. Since seeds of serrated tussock are present in the seed bank regardless of the cover and density of its standing individuals, the maintenance of a high cover of desirable species may play a key role in preventing the establishment of serrated tussock in both its natural and invaded ranges.

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Spatial patterns of the soil seed bank and extant vegetation across the dry Minjiang River valley in southwest China

Journal of Arid Environments ◽

10.1016/j.jaridenv.2011.05.012 ◽

2011 ◽

Vol 75 (11) ◽

pp. 1083-1089 ◽

Cited By ~ 7

Author(s):

Y.J. Li ◽

W.K. Bao ◽

N. Wu

Keyword(s):

Spatial Patterns ◽

Seed Bank ◽

Southwest China ◽

Soil Seed Bank ◽

River Valley ◽

Minjiang River

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Soil Seed Bank Responses to Postfire Herbicide and Native Seeding Treatments Designed to Control Bromus tectorum in a Pinyon–Juniper Woodland at Zion National Park, USA

Invasive Plant Science and Management ◽

10.1614/ipsm-d-12-00048.1 ◽

2013 ◽

Vol 6 (1) ◽

pp. 118-129 ◽

Cited By ~ 11

Author(s):

Hondo Brisbin ◽

Andrea Thode ◽

Matt Brooks ◽

Karen Weber

Keyword(s):

Seed Bank ◽

Native Species ◽

National Park ◽

Soil Seed Bank ◽

Germination Rate ◽

Perennial Grass ◽

Native Plant ◽

Soil Seed Banks ◽

Zion National Park ◽

Juniper Woodland

AbstractThe continued threat of an invasive, annual brome (Bromus) species in the western United States has created the need for integrated approaches to postfire restoration. Additionally, the high germination rate, high seed production, and seed bank carryover of annual bromes points to the need to assay soil seed banks as part of monitoring programs. We sampled the soil seed bank to help assess the effectiveness of treatments utilizing the herbicide Plateau® (imazapic) and a perennial native seed mix to control annual Bromus species and enhance perennial native plant establishment following a wildfire in Zion National Park, Utah. This study is one of few that have monitored the effects of imazapic and native seeding on a soil seed bank community and the only one that we know of that has done so in a pinyon–juniper woodland. The study made use of untreated, replicated controls, which is not common for seed bank studies. One year posttreatment, Bromus was significantly reduced in plots sprayed with herbicide. By the second year posttreatment, the effects of imazapic were less evident and convergence with the controls was evident. Emergence of seeded species was low for the duration of the study. Dry conditions and possible interactions with imazapic probably contributed to the lack of emergence of seeded native species. The perennial grass sand dropseed outperformed the other species included in the seed mix. We also examined how the treatments affected the soil seed bank community as a whole. We found evidence that the herbicide was reducing several native annual forbs and one nonnative annual forb. However, overall effects on the community were not significant. The results of our study were similar to what others have found in that imazapic is effective in providing a short-term reduction in Bromus density, although it can impact emergence of nontarget species.

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