Fire can promote germination, recruitment and seed bank accumulation of the threatened annual grass Arthraxon hispidus

2020 ◽  
Vol 68 (6) ◽  
pp. 413
Author(s):  
Laura White ◽  
Claudia Catterall ◽  
Kathryn Taffs
Keyword(s):  
Seed Bank ◽  
Soil Seed Bank ◽  
Germination Rate ◽  
Life History Strategies ◽  
North Coast ◽  
Plant Recruitment ◽  
Chemical Mechanisms ◽  
Disturbance Regimes ◽  
Study Population ◽  
Persistent Seed Bank

Disturbance plays an important role in plant life history strategies and has been documented as both enhancing and threatening populations of the vulnerable grass Arthraxon hispidus (Thunb.) Makino (hairy jointgrass) on the NSW north coast. Mechanical disturbance (slashing) is often used in A. hispidus conservation management, but many Australian plants are adapted to fire-based disturbance regimes. In this study we undertook a field burning experiment, along with soil seed bank sampling and germination trials, to explore how fire influences A. hispidus population dynamics in terms of plant recruitment and seed bank fluctuations. We found that winter burning strongly promoted A. hispidus spring germination without entirely depleting the residual seedbank. Although drought affected our field study population, burning also led to increased adult cover and substantial seed bank replenishment the following autumn. Exposure to a smoke treatment almost doubled the germination rate of A. hispidus seeds in nursery trials. Our study suggests that appropriate burning regimes can help to maintain this species in the landscape, by both structural and chemical mechanisms, by enhancing plant recruitment and facilitating seed bank accumulation. However, some A. hispidus plants also successfully germinated, established, and reproduced in unburnt plots during our study, suggesting that populations of this species can persist without disturbance in some habitats, such as native wetland communities. We found that A. hispidus has a multi-year seed longevity and a persistent seed bank, providing the species a degree of resilience in the event of unpredictable disturbance regimes and climatic anomalies.

Germination asynchrony is increased by dual seed bank presence in two desert perennial halophytes

Botany ◽  
2019 ◽  
Vol 97 (11) ◽  
pp. 639-649 ◽  
Author(s):  
Arvind Bhatt ◽  
Narayana R. Bhat ◽  
Flavio Lozano-Isla ◽  
David Gallacher ◽  
Andrea Santo ◽  
...  
Keyword(s):  
Seed Bank ◽  
Environmental Conditions ◽  
Germination Rate ◽  
Soil Surface ◽  
Seed Banks ◽  
Viable Seed ◽  
Plant Recruitment ◽  
Soil Seed Banks ◽  
Desert Habitat

Maintaining a viable seed bank throughout the germination season is considered very important for plant recruitment in desert environments, where environmental conditions are unpredictable. Seeds from fully matured Seidlitzia rosmarinus Bunge ex Boiss and Halothamnus iraqensis Botsch. were collected in December 2016, then April, June, and September 2017 from both soil-surface and aerial seed banks. Both of the species were selected mainly by their capacity to rehabilitate saline coastal sites. Germination was analyzed under two photoperiods (0 or 12 h light per day), with winged or dewinged perianths. Seidlitzia rosmarinus had a shorter seasonal range in comparison with H. iraqensis (6 and 9 months, respectively), and the presence of a winged perianth reduced the germination rate of both species. A permanent winged perianth significantly inhibited the germination rate in both species. In the absence of perianth, the germination registered in December 2016 was mostly 100%, but declined to around 20% in September 2017. Seeds are thus more likely to germinate after scarification from wind mobilization, and do not require burial. Our results show that seeds of both the aerial and soil banks are transitory, and viable only during the winter months. Taken together, the combination of aerial and soil seed banks has greatly facilitated germination asynchrony in their environmentally unpredictable desert habitat.

Seed and vegetation dynamics in an alpine herb field: effects of disturbance type

1993 ◽  
Vol 71 (3) ◽  
pp. 471-485 ◽  
Author(s):  
Jeanne C. Chambers
Keyword(s):  
Seed Bank ◽  
Vegetation Cover ◽  
Soil Seed Bank ◽  
Vegetative State ◽  
Seed Rain ◽  
Life History Strategies ◽  
Small Scale ◽  
Pocket Gopher ◽  
Growing Seasons ◽  
Highly Correlated

Relationships among the aboveground vegetation, seed rain, and seed bank were examined on a late seral herb field characterized by pocket gopher disturbance and on an early seral gravel borrow that had been severely disturbed 35 years ago on the Beartooth Plateau, Montana. Aboveground vegetation cover was assessed by species in twelve 5-m2 plots. Seed rain was sampled during the 1988, 1989, and 1990 growing seasons with pitfall traps, and the soil seed bank was sampled in fall 1989, spring 1990, and fall 1990. The seed rain (filled seeds) on the borrow area ranged from 7730 to 14 009 seeds/m2 and was higher than that found on other alpine sites; that on the Geum turf ranged from 3375 to 6179 seeds/m2 and was similar to that for other alpine sites. Although highly variable among dates on the borrow area, the seed banks were similar to those of comparable alpine sites. Seed bank density ranged from 1980 to 6003 seeds/m2 on the borrow area and from 3202 to 4647 seeds/m2 on the Geum turf area. The Geum turf area had higher vegetation cover than the borrow area (87 vs. 25%) and higher numbers of species in the aboveground vegetation, seed rain, and seed bank. Relationships among the aboveground vegetation, seed rain, and seed bank were largely determined by the disturbance characteristics of the different sites and the life-history strategies of the dominant species. Medium-lived species, primarily grasses, with high production of small and compact seeds had colonized the borrow area. Despite establishment of other species, 35 years after disturbance the medium-lived species still dominated the aboveground vegetation, seed rain, and seed bank. Species abundances in the three different components were all highly correlated. In contrast, on the Geum turf area there were no correlations among the aboveground vegetation, seed rain, or seed bank. Long-lived forbs that produced low numbers of relatively large seeds dominated the aboveground vegetation and persisted on the area primarily in the vegetative state. The same medium-lived species that dominated the borrow area had the highest abundance in the seed rain on the Geum turf area and appeared to persist by colonizing small-scale disturbances caused by gopher burrowing. Short-lived species with small, long-lived seeds existed on the site primarily through a highly persistent seed bank. The relationships among the aboveground vegetation, seed rain, and seed bank on the Geum turf and borrow areas are compared with those observed for more temperate systems following disturbance. Key words: alpine, herb field, Geum turf, disturbance, vegetation cover, seed rain, seed bank, colonization, establishment, succession.

A persistent seed bank of the bull thistle Cirsium vulgare

1996 ◽  
Vol 74 (9) ◽  
pp. 1386-1391 ◽  
Author(s):  
Colleen Doucet ◽  
Paul B. Cavers
Keyword(s):  
Seed Bank ◽  
Germination Rate ◽  
Separate Experiment ◽  
Wetting And Drying ◽  
Cirsium Vulgare ◽  
Die Surface ◽  
Loam Soil ◽  
Bull Thistle ◽  
Persistent Seed Bank ◽  
Two Populations

Seeds of Cirsium vulgare were collected from two populations in southwestern Ontario and stored at the site of collection at three depths in the soil. After intervals of 6 to 30 months, seed samples were extracted, the seeds classed as germinated, dead, or firm, and then the firm seeds were set to germinate in a growth cabinet. Both populations established a persistent seed bank when left at the 15 cm depth; however, most seeds do not get buried at great depths. After storage at the surface or 3 cm deep, seeds in an arable sandy soil did not persist beyond 6 months. In contrast, some seeds stored in shaded conditions in a clay loam soil maintained viability for 30 months at die surface and at 3 cm. In some cases, the germination rate of seeds was retarded after storage, especially for seeds that were extracted from soils subjected to wetting and drying before seed retrieval. A separate experiment confirmed that wetting and drying can delay the germination of some seeds of C. vulgare. Key words: seed bank, germination, seed wetting and drying, Cirsium vulgare, bull thistle.

Seed banks

2009 ◽  
Author(s):  
M. Anwar Maun
Keyword(s):  
Seed Bank ◽  
Soil Seed Bank ◽  
Sand Dunes ◽  
Seed Banks ◽  
Type I ◽  
Type Ii ◽  
Perennial Herbs ◽  
Viable Seeds ◽  
One Year ◽  
Persistent Seed Bank

The soil seed bank refers to a reservoir of viable seeds present on the soil surface or buried in the soil. It has the potential to augment or replace adult plants. Such reservoirs have regular inputs and outputs. Outputs are losses of seeds by germination, predation or other causes, while inputs include dispersal of fresh seeds from local sources and immigration from distant sources (Harper 1977). Since sand dunes are dynamic because of erosion, re-arrangement or burial by wind and wave action, efforts to find seed banks have largely been unsuccessful. Following dispersal, seeds accumulate in depressions, in the lee of plants, on sand surfaces, on the base of lee slopes and on the driftline. These seeds are often buried by varying amounts of sand. Buried seeds may subsequently be re-exposed or possibly lost over time. However, the existence of a seed bank can not be denied. Plant species may maintain a transient or a persistent seed bank depending on the longevity of seeds. In species with transient seed banks, all seeds germinate or are lost to other agencies and none is carried over to more than one year. In contrast, in species with a persistent seed bank at least some seeds live for more than one year. The four types of seed banks described by Thompson and Grime (1979) provide useful categories for discussion of coastal seed bank dynamics of different species. Type I species possess a transient seed bank after the maturation and dispersal of their seeds in spring that remain in the seed bank during summer until they germinate in autumn. Type II species possess a transient seed bank during winter but all seeds germinate and colonize vegetation gaps in early spring. Seeds of both types are often but not always dormant and dormancy is usually broken by high temperatures in type I and low temperature in type II. Type III species are annual and perennial herbs in which a certain proportion of seeds enters the persistent seed bank each year, while the remainder germinate soon after dispersal, and Type IV species are annual and perennial herbs and shrubs in which most seeds enter the persistent seed bank and very few germinate after dispersal.

Why Engelmann spruce does not have a persistent seed bank

1996 ◽  
Vol 26 (5) ◽  
pp. 872-878 ◽  
Author(s):  
E.A. Johnson ◽  
G.I. Fryer
Keyword(s):  
Seed Bank ◽  
Soil Seed Bank ◽  
Mineral Soil ◽  
Total Rate ◽  
Rapid Loss ◽  
Engelmann Spruce ◽  
Seed Loss ◽  
High Predation ◽  
Persistent Soil Seed Bank ◽  
Persistent Seed Bank

Piceaengelmannii Parry ex Engelm. becomes established after fire by dispersing seeds into a burn, not through the maintenance of a persistent soil seed bank. The objective here was to determine causes of spruce seed loss from the bank to understand its lack of a persistent seed bank. One hundred seeds placed in soil cores were enumerated for 2.5 years and divided into three treatments: (i) varying the amount of protection from predators, (ii) keeping litter intact or removing it, and (iii) placing seeds on top of litter or between litter and mineral soil. For all treatments, fewer than 5% of seeds remained at the end of the study. Predation caused the greatest loss to the seed bank, much greater than germination in all treatments. Removal of litter increased germination, but predation occurred at the same rate; therefore, the total rate of loss to the seed bank increased. Seeds placed between litter and mineral soil experienced greater germination and less predation than seeds placed above the litter layer. However, increased germination balanced the reduced predation so there was little difference in the total rate of loss to the seed bank from seeds placed in either location. Further, seeds appeared to lose viability within two seasons. Thus, there is no persistent seed bank because of high predation and a rapid loss of viability.

Seed banking in the columnar cactusStenocereus stellatus: distribution, density and longevity of seeds

2014 ◽  
Vol 24 (4) ◽  
pp. 315-320 ◽  
Author(s):  
Ricardo Álvarez-Espino ◽  
Héctor Godínez-Álvarez ◽  
Rodolfo De la Torre-Almaráz
Keyword(s):  
Seed Bank ◽  
Distribution Density ◽  
Soil Seed Bank ◽  
Seed Banks ◽  
Arid Environments ◽  
Soil Seed Banks ◽  
Information Gap ◽  
Stenocereus Stellatus ◽  
Viable Seeds ◽  
Persistent Seed Bank

AbstractThe soil seed bank is the reserve of viable seeds found in the soil. This reserve contributes to plant population persistence in unpredictable environments; thus, determining its presence is basic to understanding recruitment patterns and population dynamics. Studies of soil seed banks in the Cactaceae are scarce, although these plants are ecologically dominant in American arid and semi-arid environments. Most studies have inferred the presence of seed banks by analysing morphological seed traits or germination of seeds stored in the laboratory for different periods of time. Few studies have determined their presence through evaluation of distribution, density and longevity of seeds in the field. To fill this information gap, we determined the existence of, and studied, the soil seed bank ofStenocereus stellatus, a columnar cactus endemic to central Mexico. This study reports the evaluation of these characteristics in the field and discusses whether this species forms a soil seed bank. We found a higher number of seeds under shrubs than in areas lacking vegetation. Recently dispersed seeds did not germinate because they have primary dormancy. This dormancy was broken after 6 months of burial in the soil. Seeds buried for 10 months entered secondary dormancy and they were not viable at 24 months, probably because of pathogen attack. Considering dormancy and seed longevity, we suggest thatS. stellatushas the potential to form a short-term persistent seed bank. However, this should be confirmed by conducting studies on otherS. stellatuspopulations throughout their geographical distribution.

Defining transient and persistent seed banks in species with pronounced seasonal dormancy and germination patterns

2005 ◽  
Vol 15 (3) ◽  
pp. 189-196 ◽  
Author(s):  
Jeffrey L. Walck ◽  
Jerry M. Baskin ◽  
Carol C. Baskin ◽  
Siti N. Hidayati
Keyword(s):  
Seed Bank ◽  
Soil Seed Bank ◽  
Seedling Emergence ◽  
Short Term ◽  
Time Line ◽  
Morphophysiological Dormancy ◽  
Seedling Emergence Method ◽  
To Come ◽  
Persistent Seed Bank

The most often used time-line for distinguishing a transient seed bank from a persistent seed bank is one calendar year. Thus, species whose seeds live in or on the soil for <1 year have a transient seed bank, whereas those whose seeds live for ≥1 year have a persistent seed bank. However, dormancy cycling of seeds buried in soil has not been given due consideration in these models. When dormancy cycling is considered, it is shown that seeds of both autumn-germinators and spring-germinators are in the dormant state when they are 1 year old. Thus, unless the seeds live until at least the second germination season (i.e. usually 16–18 months following dispersal), they are, in effect, part of a transient seed bank, having lived through only one germination season. We propose that for seeds of such species to be considered part of a short-term persistent seed bank, they should remain viable and germinable until at least the second germination season, and to be part of a long-term persistent seed bank, until at least the sixth germination season. Our definitions are applicable to seeds with physiological, physical or morphophysiological dormancy, which often require >1 year after maturity to come out of dormancy in nature. We discuss modifications of the seedling emergence method for detection of a soil seed bank, so that they correspond to our definitions of seed-bank strategies.

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

2013 ◽  
Vol 6 (1) ◽  
pp. 118-129 ◽  
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.

Seed persistence in the soil on eroded slopes in the hilly-gullied Loess Plateau region, China

2011 ◽  
Vol 21 (4) ◽  
pp. 295-304 ◽  
Author(s):  
Ning Wang ◽  
Ju-Ying Jiao ◽  
Yan-Feng Jia ◽  
Dong-Li Wang
Keyword(s):  
Loess Plateau ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Seed Shape ◽  
Plateau Region ◽  
Soil Seed Banks ◽  
Persistent Soil Seed Bank ◽  
Disturbed Habitats ◽  
Persistent Seed Bank

AbstractThe soil seed-bank is an important component of vegetation dynamics. Its presence affects both ecosystem resistance and resilience. A persistent seed-bank is especially important in disturbed habitats and harsh environments. In the hilly-gullied Loess Plateau region, serious soil erosion causes decreases in soil water capacity and constrains vegetation recolonization. A stable and long-term persistent soil seed-bank is necessary for natural vegetation recolonization. We used an integrated measure of the depth distribution of seeds in the soil and the seasonal dynamics of soil seed-banks to analyse the persistence of seeds in soil and to investigate the correlation of seed longevity with seed size/shape and the species' life history. The results showed a significant tendency for small seeds and seeds of annuals/biennials to persist longer in soil than large seeds and seeds of perennials. However, seed shape was not related to persistence. The main dominant speciesArtemisia scoparia, Lespedeza davurica, Heteropappus altaicus, Stipa bungeana, Artemisia gmelinii, and Bothriochloa ischaemun in the different successional stages in this region can form a persistent and stable soil seed-bank. The pioneer species A. scoparia is especially significant because it can form a large, long-term, persistent seed-bank. These species can play a role in the recolonization of the eroded abandoned slope lands by vegetation.

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