Digging deep for diversity: riparian seed bank abundance and species richness in relation to burial depth

2013 ◽  
Vol 59 (1) ◽  
pp. 100-113 ◽  
Author(s):  
Jessica O'Donnell ◽  
Kirstie Fryirs ◽  
Michelle R. Leishman
Keyword(s):  
Species Richness ◽  
Seed Bank ◽  
Burial Depth

Seed banking in ancient forest species: why total sampled area really matters

2012 ◽  
Vol 22 (2) ◽  
pp. 123-133 ◽  
Author(s):  
Jan Plue ◽  
Ken Thompson ◽  
Kris Verheyen ◽  
Martin Hermy
Keyword(s):  
Species Richness ◽  
Seed Bank ◽  
Deciduous Forests ◽  
Forest Species ◽  
Sampling Methodology ◽  
Total Species Richness ◽  
Ancient Forest Species ◽  
Ancient Forest ◽  
Temperate Deciduous ◽  
Temperate Deciduous Forests

AbstractThis study investigates how methodological aspects of seed-bank sampling affect seed-bank records in temperate deciduous forests. We focused explicitly on seed-bank records of ancient forest species, which are assumed to lack a persistent seed bank; a hypothesis suspected to be partly due to methodological shortcomings. Through a quantitative review of 31 seed-bank studies in temperate deciduous forests of central and north-west Europe, we quantified the role of sampling methodology in constraining total seed-bank records and seed-bank records of ancient forest species (γ-diversity, average species' retrieval frequency and average seed density). A major methodological trade-off was established between sampled plot area and the number of plots: at an increased number of plots, the area sampled per plot decreased significantly. The total surface area sampled in a study was the primary determinant of γ-diversity, both for overall species richness and for ancient forest species richness. A high retrieval frequency of ancient forest species indicated that few plots were intensively sampled. The parallel increase in total species richness and ancient forest species richness and the non-significance of their ratio in relation to methodological variables suggests that ancient forest species are not particularly rare in the seed bank compared to other species. These results imply that sampling methodology has a far-reaching impact on seed-bank records such as γ-diversity, the detection of ancient forest species and ultimately seed-bank composition. We formulate a set of guidelines to improve the quality of seed-bank studies in temperate deciduous forests.

Weed infestation during the transition phase from conventional to conservation agriculture

2020 ◽  
Author(s):  
Felice Sartori ◽  
Donato Loddo ◽  
Ilaria Piccoli ◽  
Antonio Berti
Keyword(s):  
Species Richness ◽  
Seed Bank ◽  
Conservation Agriculture ◽  
Soil Disturbance ◽  
Transition Phase ◽  
Effective Control ◽  
Silty Clay ◽  
Weed Species ◽  
Number Of Species ◽  
Weed Species Richness

<p>Despite conservation agriculture and, overall, the reduction of soil disturbance are considered soil improving cropping systems, these practices could conflict with weed control. Indeed, reduced tillage is usually linked to increased weed species richness and abundance and, thus, it could increase the dependence on chemical treatments. Weed management is one of the reasons behind the distrust of European farmers in the conservation agriculture, that is still not widespread, despites European subsidies. In fact, conservation agriculture is implemented only in the 2.8% of European cropland.</p><p>The aim of this study is to evaluate the effect of different tillage intensities on spring-summer weeds richness and abundance in a maize monoculture, during the transition phase from conventional to conservation agriculture.</p><p>The weed survey was conducted in June 2019 on an experiment comparing three levels of tillage management: conventional agriculture (CT), which represents the most common choice in Veneto region, involving deep ploughing and harrowing in spring; minimum tillage (MT), consisting only in harrowing at 20 cm; and no tillage (NT), namely sod seeding. The experiment started in 2018, at Padova University experimental farm, in a sub-humid area, with a silty clay loam soil. The survey was conducted with a set of random throws of a 30×30 cm square frame in each plot (ca. 3300 m<sup>2</sup>).  Weed plants found within the frame were classified and counted. Subsequently, data analysis assessed which botanical families were promoted by each treatment.</p><p>The NT resulted the treatment with the highest weed density (915 plant/m<sup>2</sup>): 6% higher than MT (823 plant/m<sup>2</sup>) and four-fold more than CT (209 plant/m<sup>2</sup>). The latter showed to be the treatment with higher diversity, according to both Shannon and Simpson indices. The survey evidenced higher weed species richness in MT, where both annual and perennial species were identified, while the lowest number of species were detected in NT. Plantago major and Chenopodium album were the species with the highest density in CT (>32 plant/m<sup>2</sup>) while they are negligible in NT and MT (7 plant/m<sup>2</sup>, on average). Digitaria sanguinalis was instead the dominant species in MT and NT (>600 plant/m<sup>2</sup>) while a lower density was observed in CT (11 plant/m<sup>2</sup>). Low levels of Asteraceae weeds were measured in all treatments. These results shows that the actual flora rapidly changes depending on tillage intensity, with an increase of both dominance and number of species in MT. Differently, only a limited number of adapted species germinated in NT, despite higher infestations if compared with the other treatments.</p><p>It should be expected that other species more adapted to conservation agriculture (namely Asteraceae), still marginally present in the seed bank, will spread in the next years. This stresses the importance of a continuous monitoring and effective control of weeds to avoid uncontrolled evolutions of the weed flora and increase of seed bank in the transition phase from conventional to conservation agriculture.</p>

scholarly journals Seed bank modelling of volunteer oil seed rape: from seeds fate in the soil to seedling emergence

2013 ◽  
Vol 31 (2) ◽  
pp. 267-279 ◽  
Author(s):  
E. Soltani ◽  
A. Soltani ◽  
S. Galeshi ◽  
F. Ghaderi-Far ◽  
E. Zeinali
Keyword(s):  
Oilseed Rape ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Seedling Emergence ◽  
Seed Viability ◽  
Burial Depth ◽  
Soil Seed Banks ◽  
Seed Bank Dynamics ◽  
Autumn And Winter ◽  
Lower Slope

Studies were conducted to estimate parameters and relationships associated with sub-processes in soil seed banks of oilseed rape in Gorgan, Iran. After one month of burial, seed viability decreased to 39%, with a slope of 2.03% per day, and subsequently decreased with a lower slope of 0.01 until 365 days following burial in the soil. Germinability remained at its highest value in autumn and winter and decreased from spring to the last month of summer. Non-dormant seeds of volunteer oilseed rape did not germinate at temperatures lower than 3.8 ºC and a water potential of -1.4 MPa ºd. The hydrothermal values were 36.2 and 42.9 MPa ºd for sub- and supra-optimal temperatures, respectively. Quantification of seed emergence as influenced by burial depth was performed satisfactorily (R² = 0.98 and RMSE = 5.03). The parameters and relationships estimated here can be used for modelling soil seed bank dynamics or establishing a new model for the environment.

scholarly journals Changes in the Weed Seed Bank in Long-Term Establishment Methods Trials under Rice-Wheat Cropping System

Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 292
Author(s):  
Prashant Sharma ◽  
Manoj Kumar Singh ◽  
Kamlesh Verma ◽  
Saroj Kumar Prasad
Keyword(s):  
Species Richness ◽  
Seed Bank ◽  
Weed Management ◽  
Soil Depth ◽  
Block Design ◽  
Cropping System ◽  
Field Trials ◽  
Management Program ◽  
Weed Seed ◽  
Design Factor

The rice–wheat cropping system in the Indo-Gangetic Plains is the backbone of food security in India. In the 1990s, due to the scarcity of resources, the traditional Crop Establishment (CE) method shifted from Conventional Till Puddle Transplanted Rice (CTPTR) to CT Direct Seeded Rice (CTDSR) and Zero-Till DSR (ZTDSR) in paddy; and in wheat, from Conventional Till Wheat (CTW) to Zero Till Wheat (ZTW), with residue retention in rice (RRR) or in both rice and wheat (RRRW). Shift in CE methods led to change in Weed Seed Bank (WSB) dynamics and ultimately affected the weed management program. After five years of field trials, soil samples were drawn as per 2-factors factorial randomized block design. Factor-I comprised 4-CE methods, whereas factor-II consisted of 3-soil depths (0–10, 10–20 and 20–30 cm). Results showed CTPTR-CTW and ZTDSR-ZTW (RRRW) record the highest seed bank (SB) of grasses, sedges and BLWs as total weeds, in general; and predominant weeds like Echinochloa spp., Ammania baccifera, Commelina benghalensis and Digitaria sanguinalis, in particular. It also showed the higher species richness (DMg) and Shannon–Weaver (H’) indices. CTDSR-CTW and CTDSR-ZTW (RRR) show the lowest WSB and at par with Shannon–Weaver (H’) index; further, lowest species richness (DMg) under CTDSR-CTW. Species Evenness (J’) and Simpson index (λ) vary non-significantly with CE methods. Furthermore, 0–10 cm soil depth showed the highest SB of different category of total weed, predominant weeds as well as higher values of DMg, H’, and λ; whereas reverse trend was observed in Whittaker Statistic (βW). Interaction between CE methods and soil depth revealed most of WSB lying on the top layer in case of ZTDSR-ZTW (RRRW) and CTDSR-ZTW (RRR); while CTPTR-CTW showed almost uniform WSB distribution, and in case of CTDSR-CTW, a gradual decrease in WSB with soil depth.

scholarly journals Fatal germination in barnyardgrass (Echinochloa crus-galli)

2013 ◽  
Vol 49 (No. 4) ◽  
pp. 193-197 ◽  
Author(s):  
Z. Martinková ◽  
A. Honěk
Keyword(s):  
Seed Bank ◽  
Seedling Establishment ◽  
Burial Depth ◽  
Spring Season ◽  
Seed Burial ◽  
Pre Treatment ◽  
Germinated Seeds

Seeds of weeds buried by tillage may germinate at depths from which seedlings cannot establish. In barnyardgrass (Echinochloa crus-galli) we investigated how fatal germination was influenced by the depth and time of seed burial. The proportion of germinated seeds decreased with burial depth to 0–20% at ≥ 0.1 m depth which is fatal for seedling establishment. The percentage of fatal germination was greater for the seeds buried during the spring season than during autumn. Germination was influenced by seed pre-treatment, after ripening or stratification. Spring ploughing of non-dormant seeds below 0.1 m depth induces fatal germination, decreasing in this way seed bank of barnyardgrass.

scholarly journals Effects of grazing season and stocking rate on seed bank in sheep dung on the semiarid Loess Plateau

2019 ◽  
Vol 41 (5) ◽  
pp. 405
Author(s):  
Shulin Wang ◽  
An Hu ◽  
Jing Zhang ◽  
Fujiang Hou
Keyword(s):  
Species Richness ◽  
Loess Plateau ◽  
Seed Bank ◽  
Seed Mass ◽  
Shape Index ◽  
Stocking Rate ◽  
Seedling Density ◽  
Species Richness And Diversity ◽  
Winter Grazing ◽  
Tan Sheep

Endozoochorous dispersal of seeds by livestock has long attracted the attention of grassland scientists, but little is known about seed dispersal via Tan sheep dung on the dry grasslands of the Loess Plateau. We investigated the composition of dung seed bank of Tan sheep under summer and winter rotational grazing regimes at different stocking rates (2.7, 5.3 and 8.7sheepha–1), and assessed the relationships between seed mass and shape, egested seedling density and species richness and diversity. We also assessed the effects of stocking rate and grazing season on seedling density and species richness and diversity of the dung seed bank. Seeds of 10 pasture species germinated from Tan sheep dung with only two being annual species (Eragrostis pilosa and Chenopodium glaucum). The mean seed mass (±s.e.) was 2.59±0.23mg, ranging from 0.10mg (Cleistogenes songorica) to 10.59mg (Thermopsis lanceolata), and the mean seed shape index (±s.e.) was 0.10±0.02, ranging from 0.03 (Lespedeza bicolor) to 0.19 (Stipa bungeana). Species richness and diversity and seedling density decreased with increasing seed mass and shape index, suggesting that small, round seeds are most suitable for endozoochorous dispersal. Stocking rate had no effect on the number of germinated seeds that collected from summer or winter grazing pastures. Species richness and diversity and seedling density were greater in winter grazing pastures than in summer grazing pastures. Jaccard coefficients of similarity between the Tan sheep dung bank and aboveground vegetation were <0.5 for all stocking rates, indicating their weak relationship, but were significantly higher for winter than summer grazing. Plant seeds on the Loess Plateau could disperse through Tan sheep grazing, endozoochory can increase the heterogeneity of rotationally grazed plant communities, and this dispersal mode is an adaptation of plants to the harsh environment of the semiarid areas.

Impact of sheep grazing on the soil seed bank of a managed ephemeral wetland: implications for management

2007 ◽  
Vol 55 (2) ◽  
pp. 103 ◽  
Author(s):  
Jason Nicol ◽  
Sally Muston ◽  
Paula D'Santos ◽  
Bernard McCarthy ◽  
Sylvia Zukowski
Keyword(s):  
Species Richness ◽  
Plant Communities ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Floristic Composition ◽  
Seed Banks ◽  
Water Level Fluctuations ◽  
Typha Domingensis ◽  
Ephemeral Wetland ◽  
Cuscuta Campestris

The seed bank is an important mechanism for the persistence of species in ephemeral wetlands, but grazing by domestic stock may change the seed bank and in turn the capacity of the system to recover from disturbance. The sediments of two areas in Thegoa Lagoon (Murray–Darling Basin), one area grazed by sheep when dry and the other ungrazed, were examined. The objective of the study was to determine whether and how the (1) germinable seed bank and (2) final plant communities differ between the grazed and ungrazed areas. The seed banks were subjected to one of the following three water depths: 5 cm above the surface of the water, 5 cm below the surface and 50 cm below the surface. The composition of the seed bank was determined by using the seedling-emergence technique for 12 weeks, with seedlings removed every 2 weeks. The final plant communities were determined at 12 weeks without removing seedlings. The seed bank from the grazed area had a significantly lower seed density (5600 ± 593 seeds m–2) and species richness (7 species) than the ungrazed area (37 683 ± 4492 seeds m–2, 16 species) (ANOVA: F1, 10 = 50.16, P < 0.0001). The floristic composition of the seed bank was also significantly different between the areas (NPMANOVA: F1, 10 = 15.44, P = 0.0032). Glinus lotoides was in higher abundance in the grazed area and Alternanthera denticulata, Persicaria lapathifolium, Polygonum plebium, Typha domingensis and Centipeda cunninghamii in the ungrazed area. Similarly, the final communities derived from the grazed and ungrazed areas were significantly different from each other (NPMANOVA: F1, 10 = 15.53, P = 0.0032). Greater numbers of Centipeda cunninghamii were present in the community from the grazed area and Alternanthera denticulata and Cuscuta campestris were present in larger numbers in the community from the ungrazed area. Water depth also had an impact on germination; no germination occurred in seed banks flooded to 50 cm and one Typha domingensis seedling was observed in a sample flooded to 5 cm. These results showed that grazing reduces the density and species richness of the seed bank and in turn changes the plant communities derived from the seed bank; however, if grazing is removed pest plants such as Cuscuta campestris may require control. In addition, managed drawdown or water-level fluctuations are important in exposing wetland sediments and allowing for species to recruit from the seed bank.

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

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

&lt;p&gt;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.&lt;/p&gt;

Can spatial variation and inter-annual variation in precipitation explain the seed density and species richness of the germinable soil seed bank in a tropical dry forest in north-eastern Brazil?

Flora ◽  
2013 ◽  
Vol 208 (7) ◽  
pp. 445-452 ◽  
Author(s):  
Danielle Melo dos Santos ◽  
Kleber Andrade da Silva ◽  
Ulysses Paulino de Albuquerque ◽  
Josiene Maria Falcão Fraga dos Santos ◽  
Clarissa Gomes Reis Lopes ◽  
...  
Keyword(s):  
Species Richness ◽  
Spatial Variation ◽  
Seed Bank ◽  
Annual Variation ◽  
Soil Seed Bank ◽  
Tropical Dry Forest ◽  
Dry Forest ◽  
Seed Density ◽  
Eastern Brazil ◽  
North Eastern
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