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1

Effect of two management techniques applied to the reduction of Juncus maritimus (Lam.) abundance in a selected temporary wetland

Sahib Nargis

Journal of Water and Land Development

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2019

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no. 41

120--132

EN

Moderate management of temporary wetlands is one of the most proper methods for their restoration and conservation. The cessation of use may lead to high biomass domination by macrophytes as Juncus maritimus (Lam.) that changes plant community structure, threatens species biodiversity, and becomes a danger for their conservation. The experiment was carried out in Sidi Boughaba coastal reserve in Morocco. Two management techniques of wetlands were tested, cutting and uprooting of the rush. Four experimental plots (4.2 × 2.9 m) within the rush belt were set up, with intact plots as a control. Vegetation structure and water levels were monitored on 96 quadrats over two years. The six visits dates, three visits per year (February, April, June), were monitored over two years. The abundance and richness of species were studied, simultaneously with the density of the seed stock in each plot. Results showed that both techniques allowed the opening of the habitat with a significant increase of richness and abundance of species, particularly the restoration of characteristic species of the temporary wetland from the seed bank. The cut technique seems to have less of an effect on the seed stock, total seeds median value was 6.5 in cut plots versus 5 in uprooting plots, being regularly applied given the rapid encroachment of the rush.

PL

Umiarkowane zarządzanie okresowymi środowiskami podmokłymi jest jedną z najbardziej właściwych metod ich odtwarzania i ochrony. Zaniechanie użytkowania może prowadzić do znaczącej dominacji biomasy makrofitów, takich jak Juncus maritimus, która zmienia strukturę zespołu roślinnego, ogranicza różnorodność gatunkową i stanowi zagrożenie dla ochrony siedlisk. Eksperyment prowadzono w przybrzeżnym rezerwacie Sidi Boughaba w Maroku. Testowano dwie techniki gospodarowania – cięcie i wykorzenianie sitowia. Założono cztery poletka doświadczalne (4.2 × 2.9 m) w pasie sitowia, stosując poletka bez jakichkolwiek zabiegów jako kontrolę. Strukturę roślinności i poziom wody monitorowano sześciokrotnie na 96 kwadratach w ciągu dwóch lat, trzykrotnie w ciągu roku (w lutym, kwietniu i czerwcu). Badano obfiobfitość i bogactwo gatunkowe oraz zagęszczenie banku nasion w każdym poletku. Wyniki dowodzą, że obie techniki umożliwiają otwarcie siedlisk ze znaczącym wzrostem bogactwa i obfitości gatunków, szczególnie przywracanie z banku nasion gatunków charakterystycznych dla siedlisk podmokłych. Technika wycinania skutkuje, jak się wydaje, słabszym wpływem na bank nasion, stosowana regularnie ułatwia gwałtowny rozrost sitowia.

2

Spatial heterogeneity of soil seed banks in sandy grasslands under fencing and grazing in Horqin sandland, Northern China

Zuo X., Zhao X., Zhao H., Zhang T., Wang S., Knops J., Kochsiek A.

Polish Journal of Ecology

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2013

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Vol. 61, nr 2

221--231

EN

Understanding composition, structure and spatial heterogeneity in soil seed banks is important for the management of grassland ecosystem. Although the effect of fencing and grazing on vegetation composition is widely known, information on species composition, seed density and spatial heterogeneity of soil seed banks in sandy grasslands under fencing and grazing is still lacking. We measured the species composition and seed density of soil seed banks in fenced grassland, grazed grassland and grazed shrubby grassland in Horqin Sand Land, Northern China. By applying the geostatistical methods, we assessed how fencing and grazing affected spatial heterogeneity of soil seed banks in sandy grasslands. Total seed density and species richness in soil seed banks were lower in fenced grassland than in either grazed grassland or grazed shrubby grassland. Seed density and species richness of annual species in soil seed banks were also lower in fenced grassland than in either grazed grassland or grazed shrubby grassland, while those of perennial species showed a reverse trend. The analysis of spatial autocorrelation ranges, fractal dimensions and distribution pattern maps from geostatistical methods showed that spatial heterogeneity of seed density and species richness in soil seed banks were also lower in fenced grassland than in either grazed grassland or grazed shrubby grassland. Continuous fencing increases the seed density and species richness of perennial species in soil seed banks, as well as results in a decrease in spatial heterogeneity of seed density and species richness in soil seed banks. So, continuous fencing should be considered to restore the degraded sandy grasslands in management of semiarid grassland ecosystems.

3

Seed banks and forest recruitment after disturbance: the composition and abundance of seed after clear-cut of stone pine (Pinus pinea L.) plantations

Arduini I., Orlandi C., Mariotti M., Masoni A.

Polish Journal of Ecology

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2013

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Vol. 61, nr 3

457--470

EN

Seed banks play a key role in the recruitment of forest vegetation after severe disturbance, but can originate an undesired plant community. Thus, investigations on seed bank structure, and early changes occurring after clear cut, are of primary interest for sustainable forest management. Researches were carried out in two mature stone pine (Pinus pinea L.) plantations located in Tuscany (Italy), along the Mediterranean coast. Soil samples were collected in March, July and October of the 2nd and 3rd year after clear-cut, in cut strips and adjacent intact stands. Seed bank size and composition were evaluated through the number of seedlings and species emerged from soil samples. Intact plantations differed in seed bank richness and composition, but not in abundance that was approximately 1,200 seeds m-2. Clear-cut doubled seed density in soil, did not change seed bank richness, and affected markedly composition. Seed banks of cut strips were richer in annual and open space species, and poorer in perennial, forest and disturbed sites species. Seeds of Erica scoparia dominated the seed bank, with a relative abundance of 60% in intact stands and 43% in cut strips. Proportion of annual seeds was slightly less than 20% in intact stands, but increased up to 50% after clear-cut. Between the 2nd and 3rd year from clear-cut, the proportion of seeds from species typical of stone pine forests decreased, while that of non-forest species and aliens increased. The scarcity of seeds from most forest species and the lack of tree seeds make the recruitment of understorey vegetation from seed banks critical. In addition, the increased seed density of alien and disturbed site species in intact seed banks with time from clear-cut, suggests that disturbance caused by cutting in narrow strips threatens the integrity of intact plantations.

4

Plasticity in dynamics and hygrochastic persistence in Anastatica hierochuntica (Brassicaceae) populations under simulated rainfall treatments

Hegazy A. K., Kabiel H. F., Alatar A. A., Lovett-Doust J.

Polish Journal of Ecology

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2013

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Vol. 61, nr 3

493--504

EN

Anastatica hierochuntica is a monocarpic desert annual whose dry skeletons, enclosing mature fruits, often persist for a number of years. The aerial seed bank in these hygrochastic ‘resurrection plants’ therefore persists too. Life tables and fecundity schedules were constructed for A. hierochuntica populations raised under four water treatments, equivalent to 100, 200, 500 and 1000 mm rainfall. Seedling survivorship showed a Deevey type III curve for 100 mm, and a type II curve for 200 mm, while 500 and 1000 mm treatments produced Deevey type I curves. Fewer seeds germinated and seedling survivorship was lower in the low water treatments. The stage-specific mortality rate reached 0.75 under the 100 mm treatment in the seed germination stage, compared to 0.08 under the 1000 mm treatment. Increased water availability resulted in greater plant growth and reproductive output, in terms of both number of seeds per individual and reproductive value. In field studies, aerial seed banks of small plant size-classes (from 1 to 32 cm3) were depleted within 3-to-7 years. For the large size-classes, > 32 cm3, only a portion (79.7-44.4%) of the seeds produced were dispersed during the observational experiment (the rest remaining within the tumbleweed ball, available for subsequent germination). The projected seed bank life-time for populations raised under different water treatments increased more than fivefold (from 3 to 17 years) for the 100 mm compared to the 1000 mm rainfall treatments. Local persistence of populations was thus likely to be reduced by water stress. Populations of A. hierochuntica characterized by weak plant growth and a preponderance of small size-classes will be more vulnerable to extinction due to their low reproductive output and reduced aerial seed bank reserve.

5

Ancient forest species and the diversity of vegetation and seed bank indicate the aptitude of transformed thermophilous oak wood patches for restoration

Kwiatkowska-Falińska A., Panufnik-Mędrzycka D., Wódkiewicz M., Sondej I., Jaroszewicz B.

Polish Journal of Ecology

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2013

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Vol. 61, nr 1

65--78

EN

Thermophilous oak wood is the most species-rich forest habitat in the zone of mixed deciduous forests. A very limited amount of it has been saved in good condition. We investigated the principal hypothesis that the vegetation and seed banks, especially of the ancient forest species, are good indicators of habitat naturalness and its aptitude for restoration. Vegetation and seed bank sampling were carried out in fragments of forest with a known management and disturbance history over the past 80 years. We predicted that natural and anthropogenic transformations of tree stands would be significant factors shaping species composition and similarity of vegetation and seed banks. The closest similarity was observed between the seed banks of plots which were never logged. The least related to others was the seed bank of the logged site, whose soil was ploughed prior to tree replantation. The highest number of ancient forest species was recorded in the vegetation (33 species) and in the soil seed bank (21 species) of the least transformed patch of thermophilous oak forest. It was decreasing gradually with increase of the tree canopy cover on the research plots. Our results indicate also that the higher the coefficient of similarity between seed bank and vegetation, especially of the ancient forest species, the higher the forest’s naturalness. We conclude that restoration of thermophilous oak wood has the highest chances for success in patches with well preserved seed banks and vegetation.

6

Podobieństwo glebowego banku nasion i aktualnego stanu zachwaszczenia w uprawie pszenicy ozimej

Sekutowski T., Smagacz J.

Journal of Research and Applications in Agricultural Engineering

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2011

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Vol. 56, nr 4

93-98

PL

W badaniach własnych porównywano zasobność glebowego banku nasion z zachwaszczeniem łanu pszenicy ozimej w zależności od systemy uprawy i produkcji. Badania obejmowały ocenę składu gatunkowego i liczebność chwastów w łanie pszenicy ozimej oraz zapasu nasion chwastów w warstwie 0-20 cm. Analizy porównawczej dokonano przy użyciu wskaźników ekologicznych: ogólnej różnorodności Shannona i dominacji Simpsona. We wszystkich systemach produkcji liczba gatunków nasion chwastów w glebie była mniejsza niż liczba gatunków chwastów w łanie pszenicy ozimej. Największą bioróżnorodnością zarówno w glebowym banku nasion, jak i w łanie pszenicy ozimej charakteryzowała się uprawa ekologiczna. Największe podobieństwo glebowego banku nasion z zachwaszczeniem łanu stwierdzono w systemie ekologicznym oraz w monokulturze w uprawie uproszczonej. Najwyższe wskaźniki różnorodności Shannona oraz najniższe wskaźniki dominacji Simpsona zarówno dla gleby, jak i dla łanu stwierdzono dla uprawy ekologicznej. Najwyższe wskaźniki dominacji Simpsona i zarazem najniższe wskaźniki różnorodności Shannona dla gleby oraz łanu stwierdzono dla monokultury (uprawa uproszczona i tradycyjna).

EN

In the experiments the soil seed bank with weeds infestation of winter wheat depending on tillage and crop production systems were compared. The experiments included assessment of weed species composition and the numbers of weeds in winter wheat and the weed seeds stock in the 0-20 cm soil layer. The analysis was conducted using ecological index: Shannon's total diversity and Simpson's domination. In all compared production systems the number of species of weed seeds was lower than in the canopy of winter wheat. The greatest biodiversity in the soil seed bank and in the canopy of winter was observed in organic farming. The greatest similarity between the soil seed bank and wheat infestation was found out organic farming and in monoculture in reduced tillage. The greatest index of Shannon diversity and bottom index of Simpson domination both for the soil and the canopy were found out in organic farming. But the greatest index of Simpson domination and bottom index of Shannon diversity for the soil and the canopy were found out in monoculture (conventional and reduced tillage).

7

Soil seed banks in lakeshore wetlands : relation to the extant vegetation

Peng Y., Wu N., Gao X., Fang Z., Xiao W.

Polish Journal of Ecology

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2010

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Vol. 58, nr 3

449-457

EN

Seed bank composition and germination characteristics are necessary for modeling wetland vegetation composition. Yet there are few studies about the seed bank difference between plant communities in lakeshore wetlands. Seed banks are also known to play important roles in the vegetation restoration process. Environmental factors such as water level, temperature, or nutrient levels can affect vegetation composition and seed bank composition. The relationships between environmental factors and seed banks of wetlands in the field are still unknown. The Jiuzhaigou Nature Reserve is located at the eastern edge of Qinghai-Xizang Plateau. The lakeshore wetland vegetation is dominated by Phragmites australis (Cav.)Trin. ex Steud., Typha latifolia L., Carex pamirensis C. B. Clarke, Equisetum fluviatile L. The wetlands in Jiuzhaigou (118 lakes) are under strong pressure such as trampling and enhanced construction for travel. Plant restoration is necessary for protection of these areas. We investigated the soil seed bank in six lakeshore wetlands in this area using the seedling emergence method. Sediment samples (0-2 cm, 2-5 cm, 5-10 cm intervals from surface to bottom) were taken with core (diameter 5 cm) in April and from each replicate samples were spread on two plastic trays. Trays were randomly arranged in the greenhouse and watered daily. Seedlings were counted weekly after emergence, and removed as soon as they could be identified. Our study showed that seed density in all soil layers samples was negatively correlated to water depth. Water depth can explain 45% variance of species richness in surface layer in sediment. Species richness in extant vegetation can explain 45, 48, 25% variance of species richness in total 10 cm and in 2-5 cm and 5-10 cm layer sediment respectively. Dominant species cover in extant vegetation, site altitude, total nitrogen, total phosphorus and total organic carbon in soil showed no correlation with species richness in seed bank. Mean seed densities in wetlands ranged from 0 to 15945 m[^-2]. A total of 23 species germinated in seed bank, while 85 species were found in extant vegetation. The dominant species in seed bank and extant vegetation showed great difference. The total number of species and seedlings that germinated in different layers was not significantly different. But the second layer had the greatest seed density. The relationship between seed bank and extant vegetation differed from one species to another. We should use different restoration strategies for different plant communities.

8

The potential role of nests of Black-billed Magpie Pica pica L. in accumulation and dispersal of seeds in agricultural landscape

Czarnecka J., Kitowski I.

Polish Journal of Ecology

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2008

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Vol. 56, nr 4

673-682

EN

The study aimed to describe the seed pool accumulated in the nest material of Magpie Pica pica, and to determine the importance of this mechanism of seed dispersal for such ecological processes as colonization of new habitats and expansion of alien plants. The seedling germination and seed extraction methods were used to determine seed abundance in the soil layer, the inner layer, and in the lining of 9 nests collected in three types of agricultural landscape: the first with domination of arable fields; the second with similar shares of arable fields and other landscape elements such as meadows of different types, shrubs, tree clumps and rushes; and the third with domination of lowland hay meadows. In all the nests, considerable numbers of diaspores were found (from 26 to 371 seeds per nest, belonging to more than 80 taxa). The main plant groups found in the nests are species connected with field roads, weeds and ruderal species, but also meadow and brushwood species were found there. The soil was gathered by birds from habitats with low vegetation cover and large areas of bare soil. Although the structure of seed pool of nests suggests that soil was mainly collected in the close vicinity of the nests. future location, this mechanism of seed dispersal can probably be involved in long distance dispersal. Seeds of two rare kenophytes: Erucastrum gallicum (Willd.) O. E. Schulz and Diplotaxis tenuifolia (L.) DC were found in the material of nests localized more than 100 m away from their closest populations. It can be assumed that this mechanism of seed dispersal can play a potential role in the expansion of alien plants and colonisation of new habitats.