scholarly journals Changes in vegetation and soil seed bank of meadow after waterlogging caused by Castor fiber

2015 ◽  
Vol 84 (2) ◽  
pp. 189-196 ◽  
Author(s):  
Magdalena Franczak ◽  
Bożenna Czarnecka

<p>Soil waterlogging is among abiotic stresses that influence species composition and productivity in numerous plant communities. The aim of the study was to find answer to the question of how waterlogging caused by beavers’ activity induces quantitative and qualitative changes of vegetation and soil seed bank levels of variable-moist meadows.</p><p>An immediate effect of the waterlogging at the level of vegetation was the decline in species richness and a decrease in the values of the biodiversity index. Water stress inhibited growth and development of plants already present and, primarily, impeded recruitment of new individuals of species characteristic of variable-moist meadows, e.g. <em>Cirsium rivulare</em>, <em>Filipendula ulmaria</em> and <em>Lythrum salicaria</em>, which were replaced by <em>Carex acutiformis</em>. Prolonged waterlogging did not induce equally substantial changes in the soil seed bank as in the vegetation. Both in the waterlogged and control patches, slightly decreased species richness and biodiversity index were recorded. After waterlogging withdrawal, the reserves of the soil seed bank were slightly higher than the initial values. The differences were not statistically significant.</p><p>In the waterlogged patch, the qualitative floristic similarity between taxa identified in the soil seed bank and vegetation cover declined, which was evidenced by the value of Jaccard’s index decreasing from 0.46 to 0.36. A reverse relationship was found in control patch, where the value of the similarity index slightly increased from 0.41 to 0.48.</p>

2021 ◽  
Vol 9 (2) ◽  
pp. 471
Author(s):  
Bruno Machado Araújo ◽  
Anatércia Ferreira Alves ◽  
Paulo Alexandre Fernandes Rodrigues ◽  
Leonardo Hunaldo dos Santos ◽  
Mário Luiz Ribeiro Mesquita

This study evaluated the soil seed bank’s germination potential and density in five distinct environmental areas namely: a) regenerated forest, b) secondary forest, c) degraded pasture, d) Eucalyptus sp. plantation and e) fallow corn growing area, with a view to regenerate forests in Western Amazonia using tray germination methodology. We assessed floristic similarity and diversity using the Jaccard Similarity Index and the Shannon Diversity Index, respectively. We computed each species’ phytosociological parameters: density, frequency and importance value of each species. We recorded a total 3674 individuals from 51 species and 21 families. The families with the highest species richness were Asteraceae, Malvaceae, Cyperaceae and Poaceae that contributed to 43% of the total species observed. The most important species computed in the phytosociological analysis were Chamaesyce hirta, Corchorus aestuans, Cyperus iria and Chamaesyce prostrata. All species had a herbaceous life form, which in the literature, are considered weeds. We documented the largest number of individuals in the fallow corn growing area that had 3620 plants m-2 and the smallest number in the regenerated forest that had 183 plants m-2. We observed the greatest floristic similarity between the secondary forest and Eucalyptus sp. plantation (40%), and the greatest floristic diversity in the Eucalyptus sp. plantation (H '= 2.59 nats individual-1). In conclusion, the transposition of the soil seed bank is not recommended for forest regeneration and recovery in degraded areas due to massive weed predominance in the soil seed bank.


2002 ◽  
Vol 50 (2) ◽  
pp. 197 ◽  
Author(s):  
Timothy J. Wills ◽  
Jennifer Read

Various fire-related agents, including heat, smoke, ash and charred wood, have been shown to break dormancy and promote germination of soil-stored seed in a broad range of species in mediterranean-type systems. However, relatively little work has been conducted in south-eastern Australian heathlands. This study examined the effects of heat and smoked water on germination of the soil seed bank in a mature sand heathland within the Gippsland Lakes Coastal Park, in south-eastern Australia. Heat was clearly the most successful treatment for promoting seed germination, followed by smoked water, then controls, with 55% of species present in the germinable soil seed bank requiring a heat or smoke stimulus to promote seed germination. Mean species richness of the germinable soil seed bank was found to be significantly higher in heat-treated soil than in smoke and control treatments. Seedling density of heat-treated soil was almost 10 times that of controls, while smoke-treated soil was almost five times that of controls. Seedling emergence was fastest in heat-treated soil, followed by smoke and control soils. Of the species found in the soil seed bank, 25% were absent from the extant vegetation, suggesting the existence of post-fire colonisers in the soil seed bank. The results have implications for the design of soil seed bank experiments and the use of fire as a tool in vegetation management.


2011 ◽  
Vol 79 (2) ◽  
pp. 157-166 ◽  
Author(s):  
Maciej Wódkiewicz ◽  
Anna Justyna Kwiatkowska-Falińska

Forest seed banks mostly studied in managed forests proved to be small, species poor and not reflecting aboveground species composition. Yet studies conducted in undisturbed communities indicate a different seed bank characteristic. Therefore we aimed at describing soil seed bank in an undisturbed forest in a remnant of European lowland temperate forests, the Białowieża Forest. We compared similarity between the herb layer and seed bank, similarity of seed bank between different patches, and dominance structure of species in the herb layer and in the seed bank of two related oak-hornbeam communities. We report relatively high values of Sorensen species similarity index between herb layer and seed bank of both patches. This suggests higher species similarity of the herb layer and soil seed bank in natural, unmanaged forests represented by both plots than in fragmented communities influenced by man. Although there was a set of core seed bank species present at both plots, yielding high Sorensen species similarity index values, considerable differences between plots in seed bank size and dominance structure of species were found, indicating spatial variability of studied seed bank generated by edaphic conditions. Dominance structure of species in the herb layer was not reflected in the underlying seed bank. This stresses, that natural forest regeneration cannot rely only on the seed bank, although some forest species are capable of forming soil seed banks. While forest seed banks may not reflect vegetation composition of past successional stages, they may inform on history and land use of a specific plot.


2007 ◽  
Vol 55 (2) ◽  
pp. 103 ◽  
Author(s):  
Jason Nicol ◽  
Sally Muston ◽  
Paula D'Santos ◽  
Bernard McCarthy ◽  
Sylvia Zukowski

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.


2020 ◽  
Author(s):  
Iván Torres ◽  
José M. Moreno

&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;


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 ◽  
...  

Check List ◽  
2021 ◽  
Vol 17 (2) ◽  
pp. 507-549
Author(s):  
Victor Camargo Keller ◽  
Erico Fernando Lopes Pereira-Silva ◽  
Elisa Hardt

Parque Estadual do Juquery is the largest protected remnant of savanna grassland in the metropolitan region of S&atilde;o Paulo (MRSP). We conducted a floristic inventory and created a photographic record of the angiosperm flora of the savanna formations in this area and compared it with those of other Cerrado sites using Jaccard&rsquo;s similarity index. We present a list with 366 species, distributed in 58 botanical families. Asteraceae and Poaceae were the families with the highest species richness. Eighty-six new occurrences were recorded in the park. According to the S&atilde;o Paulo state Red List, 14 species are threatened by extinction, of which four are presumably extinct. Most species are herbaceous (36.0%) and sub-shrub plants (26.5%). No floristic similarity was observed with other savanna formations in the countryside of the state of S&atilde;o Paulo. Our results emphasize the importance of the Parque Estadual do Juquery for the conservation of savanna grassland formations in the MRSP and the protection of locally endangered species.


Web Ecology ◽  
2000 ◽  
Vol 1 (1) ◽  
pp. 70-75 ◽  
Author(s):  
J. E. Malo

Abstract. The seed content of soils is often estimated through germination tests, though these methods are always somewhat inaccurate due to the presence of dormant seeds in the samples. The researcher thus faces the question of whether to continue the germination test or to stop it in the search for an accuracy-to-effort balance. In this paper I analyze the accuracy of seed content estimates obtained after a first-year germination test, by comparison to the germination recorded after three-year cultivation, in 48 soil seed bank samples and 389 from herbivore dung. After the first 9-month cultivation, I recorded 85 ± 1% seedlings and 90 ± 1% species in soil samples, while the accuracy in those of dung was significantly lower, 48 ± 1% seedlings and 65 ± 1% species. The accuracy of estimations varied among samples within experiments, with significant differences in the estimation of species richness in both cases. I did not find consistent differences in the accuracy of estimations linked to seedling densities in growing pots, but the taxonomic composition of samples was a major source of bias. Thus, 22% and 36% of the most frequent species showed germinabilities in the first year significantly different from the rest, and some generalities arose, like the high germinability of grasses and the hardseededness of legumes. I would thus recommend the use of at least two germination cycles for seed bank estimations and a cautious approach when comparing samples with very different origin and/or taxonomic composition.


Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1506 ◽  
Author(s):  
Alessia Restuccia ◽  
Aurelio Scavo ◽  
Sara Lombardo ◽  
Gaetano Pandino ◽  
Stefania Fontanazza ◽  
...  

Cover crops are gaining in popularity as an eco-friendly tool for weed control in organic and low-input agricultural systems. A 5-year study was carried out in a Mediterranean environment (Sicily, south Italy) to (1) quantify cover crop biomass production and (2) evaluate the effects on weed soil seed bank, aboveground biomass, species richness, species composition and associations between communities. Cover crop treatments included subterranean clover (Trifolium subterraneum L.) and spontaneous flora, both with and without burying dead mulch into the soil, compared to a conventional management treatment. Weed biomass was significantly reduced by subterranean clover, contrariwise to spontaneous flora, with season-dependent results. Cover crop biomass, which ranged from 44 to more than 290 g DW m−2, was negatively correlated to weed biomass. Moreover, subterranean clover decreased the size of the soil seed bank and species richness. Based on relative frequency, a low similarity was found between the conventional management and cover crop treatments. In addition, no significant differences in species composition across treatments were observed, whereas principal component analysis highlighted some associations. The results suggest that subterranean clover cover cropping is a good option for weed management in Mediterranean agroecosystems.


Sign in / Sign up

Export Citation Format

Share Document