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O objetivo deste trabalho foi avaliar a resposta de alguns atributos da macrófita submersa Egeria najas, quando essa é exposta a diferentes períodos de seca. Em laboratório, porções apicais de E. najas foram expostas ao ambiente seco por períodos de 1, 2, 3 e 4 dias, à temperatura de 25°C. Decorridos esses intervalos de tempo, tais porções apicais foram colocadas em aquários contendo areia e aproximadamente 2 litros de água provenientes do reservatório de Itaipu. Decorridos 15 dias, os seguintes atributos foram medidos:comprimento final dos propágulos, massa seca dos propágulos, número de brotos emitido por propágulo, comprimento de cada broto, massa seca dos brotos, número de raízes por propágulo, comprimento das raízes e massa seca das raízes. Quando os propágulos foram expostos a intervalos inferiores a três dias de seca houve regeneração, evidenciada pela emissão de brotos e raízes. Porém, um período de 4 dias no seco foi suficiente para eliminar a capacidade de regeneração dos propágulos. Esses resultados indicam que a transferência depropágulos vegetativos entre ambientes aquáticos, por vias naturais (e.g., aves) ou artificiais (e.g., embarcações) pode representar uma importante forma de dispersão da espécie desde que o tempo de transporte seja inferior a 3 dias.In this study we assessed the response of some attributes of the submerged macrophyte Egeria najas to different periods of exposition to dry conditions. Ramets of E. najas were exposed to dry conditionsin the laboratory for periods of 1, 2, 3 and 4 days, at 25oC. Following the exposition, the propagules were transferred to 2-liter aquaria containing water and sand, and the following attributes were measured after 15 days: propagule length, propagule dry mass, number of sproutes per propagule, sproute length, sproute dry mass, number of roots per propagule, root length and root dry mass. The results showed that sproutes and roots emerged from propagules submitted to dry periods shorter than 3 days, indicating that this species hasgreat capacity of regeneration when submitted to dry stress. Giving this resistance to dry conditions, the transport of propagules by birds or boats may be an important mechanism of dispersion, if the time of transport is shorter than 3 days. more...

In heterogeneous landscapes, one can expect a complexity of ecological restoration outcomes. The effectiveness of management often depends on environmental conditions (environmental context) and how management indirectly affects other components of the system (community context). Although managers appreciate this context dependency, it is difficult to translate it to decision-making in restoration. We demonstrate one approach to improve this translation. We surveyed plant, soil, and landscape characteristics at 131 grassland and coastal sage sites that received herbicide treatments to remove non-native plant species and/or propagule addition to increase native species. We used path analysis to describe how each management approach influenced target non-native species and how interactions with environmental conditions and indirect effects of management influenced plant community composition. This approach enabled us to analyze a complex system with differing management histories to identify both direct and indirect effects of management. Management had the intended direct effects: the application of herbicide and propagule addition directly reduced non-native species and increased native species, respectively. We found little evidence of environmental dependency: effects occurred largely independent of environmental conditions. However, management outcomes did depend on plant community context. Specifically, although herbicide reduced the cover of target, non-native plant species, this reduction resulted in only slight increases in native species and instead led indirectly to increases in non-targeted, non-native species. We suggest that quantitative evaluation of variability in restoration outcomes allows management to be more adaptive and increase decision-making efficacy in complex managed landscapes. [ABSTRACT FROM AUTHOR] more...

The seed bank is the main reserve of propagules available to a plant community for its maintenance, regeneration and perpetuation. Controlled burnings can produce changes in its composition and distribution. The objective of this work is to evaluate and compare the performance of germinable seed bank in a calden forest region before and after a controlled burning is produced. Five vegetation patches dominated by small grasses (fodder patches) were delimited as well as five patches dominated by medium size grasses (non fodder patches) and five patches dominated by shrubs (shrubby patches). At the same time, five soil samples per patch were taken by random sampling with a metallic cylinder, whose dimensions were 7 cm diameter and 4 cm height. Samples were divided into three subsamples: brushwood, 0-2 cm depth, and 2-4 cm. depth. Subsamples were placed on a sterilized seed bed in plastic trays and were periodically irrigated into a greenhouse. When seedlings emerged they were identified, counted, and extracted. Eight grass seedlings were identified for all depths. After the burning, Piptochaetium napostaense showed an increase in its ability of germination for 0-2 cm. depth in fodder and non fodder patches (p<0.05). Poa ligularis decreased its ability of germination in all vegetation patches (p<0.05). Non forage grasses showed different performances. Jarava ichu decreased its ability of germination in all vegetation patches, while Nassella tenuissima and N. trichotoma showed an increase in the ability of germination for 0-2 cm. depth in fodder patches. The use of controlled burnings produces different effects on grass seed bank depending on the temperature reached, the burial depth and species considered. [ABSTRACT FROM AUTHOR] more...

Resilience of seagrass meadows relies on the ability of seagrass to successfully recolonise denuded areas or disperse to new areas. While seed germination and rhizome extension have been explored as modes of recovery and expansion, the contribution of seagrass viviparous propagules to meadow population dynamics has received little attention. Here, we investigated the potential of seagrass viviparous propagules to act as dispersal vectors. We performed a series of density surveys, and in situ and mesocosm-based experiments in Port Phillip Bay, VIC, Australia, using Zostera nigricaulis, a species known to produce viviparous propagules. Production of viviparous propagules was higher at sites with high wind and current exposure, compared to more sheltered environments. A number of propagules remained buoyant and healthy for more than 85 days, suggesting the capacity for relatively long-distance dispersal. Transplanted propagules were found to have improved survivorship within seagrass habitats compared to bare sediment over the short term (4 weeks); however, all propagules suffered longer-term (<100 days) mortality in field experiments. Conditions outside of meadows, including sediment scouring, reduced the likelihood of successful colonisation in bare sediment. Furthermore, sediment characteristics within meadows, such as a smaller grain size and high organic content, positively influenced propagule establishment. This research provides preliminary evidence that propagules have the potential to act as an important long-distance dispersal vector, a process that has previously gone unrecognised. Even though successful establishment of propagules may be rare, viviparous propagules show great potential for seagrass populations given they are facing global decline. [ABSTRACT FROM AUTHOR] more...

Glyceria maxima(Poaceae) is regarded as one of the most invasive grasses worldwide, but has only recently become naturalised in South Africa after its intentional introduction as a fodder crop in the 1940s. It invades seasonally inundated habitats. The primary reproduction mode ofG. maximawithin established infestations was studied at two sites in the KwaZulu-Natal Midlands.Glyceria maximaseeds were also collected from three sites (in KwaZulu-Natal) to understand their dormancy and determine viability. No seedlings were found within establishedG. maximainfestations. Cold stratification (4 °C) and dry storage of seeds at ambient room temperature for eight weeks did not enhanceG. maximaseed germination (means: 0.5% and 2.5%, respectively). However, tetrazolium tests revealed that a high proportion of seeds that did not germinate were still viable. After-ripening of seeds for 19 months resulted in very high germination (mean: 92% across the three sites). A combination of high seed viability, physiological dormancy, high germination following after-ripening and substantial vegetative reproduction is likely to contribute to the invasion success ofG. maximain the aquatic ecosystem. Therefore, chemical control should be investigated as a matter of priority as no control recommendations for this species exist in South Africa. [ABSTRACT FROM AUTHOR] more...

Temperate coastal estuaries worldwide, such as Narragansett Bay, Rhode Island, are influenced by seasonal macroalgal blooms (e.g., Ulva) during warm months, whereas bloom-forming macroalgae are rarely encountered during winter. We assessed the ability of distromatic Ulva to overwinter through fragments, recruits, and/or microscopic propagules. We documented (a) small tissue fragments in sediment cores and the water column, (b) recruits and microscopic propagules on field-based settlement tiles, and (c) production of reproductive propagules, throughout the winter months. Laboratory culturing experiments indicated that both fragments and propagules are viable. Our data indicate that bloom-forming overwintering Ulva simultaneously use multiple reproductive strategies. [ABSTRACT FROM AUTHOR] more...

Adequately describing the dispersal mechanisms of a species is important for understanding and predicting its distribution dynamics in space and time. For wind-dispersed species, the transportation of airborne propagules is comparatively well studied, while the mechanisms triggering propagule release are poorly understood, especially for cryptogams., We investigated the effect of wind speed and turbulence on spore release in the moss Atrichum undulatum in a wind tunnel. Specifically, we measured the amount of spores released from sporophytes when exposed to different wind speeds, in high and low turbulence, using a particle counter. We also related spore release to variation in vibrations of the sporophyte and investigated how the vibrations were affected by wind speed, turbulence and sporophyte length (here including capsule, seta and the top part of the shoot)., We show that in high turbulence, the amount of spores released increased with increasing wind speed, while in low turbulence, it did not, within the wind speed range 0.8-4.3 m s−1. However, there was a threshold in wind speed (˜2.5-3 m s−1) before large amounts of spores started to be released in turbulent flow, which coincided with incipient vibrations of the sporophyte. Thresholds in wind variation, rather than average wind speed, seemed to initiate sporophyte vibrations. The vibration threshold increased with decreasing sporophyte length., The deposition of spores near the source decreased with increasing wind variation during the time of their release, based on simulated spore deposition from another study of moss dispersal., Synthesis. We suggest that vibration of moss sporophytes is an important mechanism to regulate spore release and that turbulence and sporophyte length regulate the onset of sporophyte vibration. Spore release thresholds affect dispersal distances and have implications for our understanding and predictions of species distribution patterns, population dynamics and persistence. The mechanisms of this phase of the dispersal process are also important to explore for other species, as there may be a substantial variation depending on the species' different traits. [ABSTRACT FROM AUTHOR] more...

In order to evaluate the effect of variety and branch part on the leaf and root sprouting of propagules, five mulberry varieties (tigreada, yu-12, yu-62, murcia and universidad) were studied. The branches were divided into three parts (basal, medial and apical), which originated a total of 15 treatments. The quantity and percentage of sprouted and rooted propagules, number of branches, number of leaves and root weight, were evaluated. Yu-12 and tigreada had the highest sprouting (100 and 98 %, respectively). However, tigreada stood out in rooting (70 % of the total planted cuttings) and the root weight (2,67 g), in which it significantly differed (p < 0,05) from the other varieties. In addition, when using the basal and medial parts the highest sprouting percentage was obtained (93 and 90 %, respectively). The interaction of variety and branch part was significant; the best results were obtained in the tigreada variety –basal part‒, regarding the number of branches and leaves. Tigreada showed the best morphoagronomic performance during the experimental period; while yu-12, yu-62, universidad and murcia did not respond efficiently to reproduction from propagules. The basal and medial parts were determining in the leaf and root sprouting and in the root weight. To repeat these experiments in nursery, in different months of the year, and to use products that stimulate propagule rooting is recommended. [ABSTRACT FROM AUTHOR] more...

The objective of this study was to characterize nine Jatropha curcas provenances, collected in several provinces of Cuba, during the nursery and establishment stages. To characterize these materials the methodology for the collection and characterization of germplasm was used. In the nursery, the rooting of the propagules happened since 7 or 14 days after planting; while seedling emergence, when seeds were used, occurred 14 days after sowing. The survival percentage of the propagules fluctuated between 20 and 86,6 %, and from seed, from 86,6 to 90 %. In the field, survival varied between 66,6 and 100 % in the provenances transplanted by propagules and, in general, it was higher than the one detected in the nursery. In the provenances transplanted by seedlings no variation was detected in survival (90,9 % for the two accessions: CSSS-5 and CSS-6). It is concluded that the percentage of sprouting, emergence, rooting and survival were very variable indicators, under nursery as well as under field conditions, which was closely linked to the genotype, age and seed quality of the collected materials (propagules as well as seed). It is recommended to collect J. curcas in other zones, in order to contribute to the increase of the germplasm of this important species, which constitutes an alternative genetic resource for biofuel production. [ABSTRACT FROM AUTHOR] more...

* Premise of the study: The dispersal process involves emigration from a focal source, dispersal through the landscape, and immigration into a new population or habitat. Despite the fact that dispersal is vital for the long-term persistence of a species, key stages of the process are unknown or understudied for many species, including the importance and contribution of asexual reproduction. Focusing only on a single stage in the dispersal process may give an incomplete and potentially flawed picture of the effects of asexual reproduction on metapopulation dynamics in plant species. * Methods: Using a multifaceted approach that combines laboratory experiments, field studies, and mathematical models, we quantify the production, dispersal, and survival of immigrants of water-dispersed asexual offspring (gemmae) of the clonal liverwort Marchantia inflexa. * Key results: Compared to female plants, male plants of Marchantia inflexa produce gemmae more quickly and in higher numbers, but due to desiccation have lower gemmae survival rates. Gemmae move up to 20 cm per minute in light rain, suggesting they can leave the source population. Long distance dispersal of gemmae is supported by the mathematical analysis of unisexual metapopulations. Upon reaching the new habitat, gemmae survival is high if they stay moist. * Conclusions: By integrating multiple experiments to quantify the effects of gemmae on metapopulation dynamics, we found that different stages of dispersal can lead to different conclusions on which sex has an advantage. Gemmae are critical for the maintenance of both sexes, the persistence of single-sex metapopulations and species, and the invasibility of clonal organisms. [ABSTRACT FROM AUTHOR] more...

Highlights: [•] We study dispersal potential of Zostera noltii propagules. [•] Z. noltii fragments show higher dispersal potential than detached individual seeds. [•] After floating for 55 days 15% of fragments were still viable and growing. [•] Spathe release occurs exclusively after the seeds ripe. [•] Detached Z. noltii seeds show small dispersal capacity of <30cm. [Copyright &y& Elsevier] more...

The Havana aeromycobiota diversity was studied from November 2010 to October 2011 using two complementary volumetric methods. A total of 35 fungal genera were characterised, 26 of them were recognised only by non-viable methods, six with viable methodology and the other three with both sampling methods. Furthermore, 47 species were identified by cultivation and the spores collected with the non-viable methodology. These could not be included in a specific genus, and thus, were categorised into five fungal types. In general, the main, spread worldwide, mitosporic fungi also predominated the Havana atmosphere. The predominant species wereCladosporium cladosporioides,Aspergillus flavusandPenicillium citrinum. Moreover, several Zygomycetes (Syncephalastrum racemosum,Rhizopus stoloniferandRhizopus oryzae), Ascomycetes (Chaetomium globosum) and Basidiomycetes such asCoprinusorGanodermawere isolated. In the present paper, the review of the airborne fungi conducted in previous studies in Cuba was completed by the detection of two new genera and the first isolation of ten new records in the Cuban atmosphere. Most of the fungi detected showed a diurnal pattern with high spore peak at 11.00–12.00. [ABSTRACT FROM PUBLISHER] more...

Ecological restoration aims to augment and steer the composition and contribution of propagules for community regeneration in degraded environments. We quantified patterns in the abundance, richness, and diversity of seed and bud banks across an 11-year chronosequence of restored prairies and in prairie remnants to elucidate the degree to which the germinable seed bank, emerged seedlings, belowground buds, and emerged ramets were related to community regeneration. There were no directional patterns in the abundance, richness, or diversity of the germinable seed bank across the chronosequence. Emerged seedling abundance of sown species decreased during restoration. Richness and diversity of all emerged seedlings and non-sown emerged seedling species decreased across the chronosequence. Conversely, abundance and richness of belowground buds increased with restoration age and belowground bud diversity of sown species increased across the chronosequence. Numbers of emerged ramets also increased across the chronosequence and was driven primarily by the number of graminoid ramets. There were no temporal changes in abundance and richness of sown and non-sown emerged ramets, but diversity of sown emerged ramets increased across the chronosequence. This study demonstrates that after initial seeding, plant community structure in restored prairies increasingly reflects the composition of the bud bank. [ABSTRACT FROM AUTHOR] more...

Mangrove phenology is important in understanding the past, present and future response of mangrove species to impacts of climate change. Our study is the first long term direct observation of the phenology of Rhizophora mucronata and Sonneratia alba in Kenya. Objective of the study was to determine, interpret and document the timing of the various phenoevents and phenophases, and to establish relationships between phenology and the climatic variables. Phenological traits were investigated in six monospecific mangrove stands in Gazi Bay, south of Mombasa, for 2 years. Leaf emergence, leaf fall, flower bud, flower and fruit initiation data were recorded every fortnight in 54 shoots of 9 trees at each site. Continuous leaf emergence and loss characterized by multimodal peaks was observed for the two species. Leaf emergence and leaf fall peaked in the wet months and was reduced in the dry months. There was a relationship between the leaf emergence and drop with the reproductive phenology in the two species. Mean leaf longevity for R. mucronata and S. alba was 12.8±1.2 and 4.9±0.5 months respectively. The reproductive cycle took approximately 16–20 months in R. mucronata and 4–5 months in S. alba. Bud initiation in R. mucronata was seasonal and occurred in October and September. Buds were observed for 8–11 months developing slowly on the shoots. Shifts were observed in the timing of flower initiation, and the flowering period lasted in total for 4–5 months. The time period from flower appearance to the developmental start of immature propagules lasted about 1 month at reforested sites and up to 5 months in stands of natural vegetation. In R. mucronata initiation of immature propagules was not seasonal and varied among the sites. Fruiting in S. alba was short and seasonal without overlap, and shifts were observed in the timing of flowering, flowering and fruiting peaks. Abscission of reproductive parts started in July and in June, respectively, in the years 2005 and 2006. Fruiting was observed starting in August in both years, and fruiting peak was reached in October in 2005 and one month earlier in 2006. In R. mucronata vegetative and reproductive phenophases significantly correlated with climatic variables, whereas in S. alba only leaf emergence and leaf fall correlated with temperature. The flowering plasticity in the reproductive phenology of the two species indicates possible sensitivity to certain climatic and environmental triggers. Our results also indicate that R. mucronata trees have a distinctly higher investment in the reproductive cycle than S. alba. [ABSTRACT FROM AUTHOR] more...

Aim As the main or sole motile stage of many aquatic taxa, propagules play a central role in their population dynamics, macroevolution and biogeography. The premises of studies concerned with dispersal, on issues as diverse as marine protected areas, sustainable fisheries and invasive species, commonly make simplified assumptions linking larval development mode (planktotrophic, lecithotrophic) and pelagic propagule duration ( PPD) or pelagic larval duration. Because general empirical tests of these connections have yielded equivocal results, we critically examined the relationship between larval mode and PPD in light of regional and taxon-specific criteria. Location Oceans world-wide. Methods We collated data from 190 species from the phylum Echinodermata and used two-way and one-way ANOVA to compare PPD among larval modes, taxonomic classes, geographic regions and climate zones. We also assessed the contribution of egg size, temperature and other continuous predictors using multiple regressions and ANCOVA, and examined whether geographic range size differed among larval modes. Results Our results depart from the common assumption that planktotrophs have longer PPDs than lecithotrophs. Instead, we detected a synergistic influence of phylogeny and climate. No significant difference in PPD between planktotrophs and lecithotrophs occurred in two of the four classes and only four out of nine major ocean basins contained species with significantly different PPDs on the basis of larval mode. Species from colder climates displayed relatively constant PPDs regardless of larval mode, whereas temperate and warm-water species displayed a clearer dichotomy. PPD did not correlate with geographic range size nor did planktotrophs and lecithotrophs exhibit significantly different range sizes. Main conclusions Our findings indicate that larval mode is not a reliable predictor of PPD across broad geographic and taxonomic scales. Instead developmental strategies may instigate shorter or longer PPDs in schemes that are influenced by evolutionary and environmental pressures. [ABSTRACT FROM AUTHOR] more...

Control of submerged aquatic vegetation during drawdown is known to be hindered by mounds of stranded vegetation that protect underlying stems from desiccation. This study investigated the viability of stranded cabomba (Cabomba caroliniana) during a winter drawdown of Lake Benalla, Victoria, Australia. The viability of stems and crowns, determined by their ability to generate new shoots, was related to substrate exposure status, location in lake, mound height, and soil moisture, at 34 and 69 days after exposure (DAE). Stem viability at 34 and 69 DAE was most closely associated with exposure status, where ∼20% of stems under mounds on relatively dry substrate were viable, compared to ∼95% of stems under mounds on saturated substrate, and 92% of unexposed stems. Stem viability was similar when collected 34 and 69 DAE and was similar under naturally occurring mounds of differing thickness. In contrast, viability of exposed crowns was usually 40% or less, compared to 72% for unexposed crowns, and their viability was not influenced by substrate moisture. Instead, their viability was influenced by location in the lake and was proportional to mound thickness. Like stems, viability of crowns did not decrease over the duration of the drawdown. We concluded that for drawdown to be effective in minimizing viable stems, the substrate below them needs to dry out. Even then, viable crowns may be a source of recolonization. [ABSTRACT FROM AUTHOR] more...

A field essay was conducted at the Experimental Station of Pastures and Forages "Indio Hatuey", on a Ferralitic Red soil of good surface and internal drainage in order to evaluate the effect of mineral fertilization and intercropping of Canavalia ensiformis (jack-bean), inoculated with AMF, on the multiplication of infective propagules in a mulberry (Morus alba L.) plantation. The mulberry planting frame was 1,0 by 0,50 m², (20 000 plants/ha). The plantation area was 384 m, with 40 plants in the plots. The forage was harvested with a 90-day interval at a height of 30 cm. The evaluated treatments were: control (without fertilization and without intercropping of jack-bean, WFWJBAMF); AMF incorporation through the intercropping of jack-bean, without mineral fertilization (WFJBAMF); mineral fertilization (F) and AMF incorporation through intercropping of jack -bean, with mineral fertilization (FJBAMF). The jack-bean was planted inoculated with AMF at a distance of 0,5 m from mulberry, in the first 15 days of growth of this plant since cutting, at the beginning of each season. The design was randomized blocks with factorial arrangement and three repetitions. Low content of native infective propagules was evidenced in the rhizosphere of the mulberry plantation (190-295 spores/50 g). The effect of FJBAMF was highly significant on the multiplication of infective propagules during the rainy season and during the first 45 days of the dry season (370 and 469 spores/50 g, respectively), while it contributed to increase the organic matter and K contents of the soil. It is concluded that the combination of mineral fertilization with AMF incorporation through the intercropping of jack-bean constitutes an effective procedure to multiply the AMF infective propagules up to moderate levels. [ABSTRACT FROM AUTHOR] more...

The seed bank is a pool of viable mature seeds ready to germinate on the soil surface or buried plant residues. The composition and size of the seed bank rapidly fluctuates depending on the input and seed losses. The aim of this study was to compare the viable seed bank of grasses before fruiting (October 2008) and after the spread of caryopsis (March 2009), after performing a prescribed burning and a subsequent grazinng. Delimited 5 patches dominated by forage grasses, 5 dominated by non forage and 5 shrub. In each patch were collected 5 samples of soil using a metal cylinder at various depth. It was used the seed bank seedling emergence method. We identified 8 grasses: 5 forage, Piptochaetium napostaense, Poa ligularis, Bromus catharticus v. rupestres, Hordeum stenostachys and Setaria pampeana and 3 non forage: Jarava ichu, Nassella tenuísima and Nassella trichotoma. The results indicate a higher germination of forage after the spread of caryopses at the expense of non-fodder, indicating a possible recovery of the pasture. [ABSTRACT FROM AUTHOR] more...

An extraordinary diversity of epiphytic lichens is found in the boreal rainforest of central Norway, the highest-latitude rainforest in the world. These rainforest relicts are located in ravine systems, and clear cutting has increased the distance between remaining patches. We hypothesized that the relatively small lichen populations in the remaining forest stands have suffered a depletion of genetic diversity through bottlenecks and founder events. To test this hypothesis, we assessed genetic diversity and structure in the populations of the tripartite lichen Lobaria pulmonaria using eight SSR loci. We sampled thalli growing on Picea abies branches and propagules deposited in snow at three localities. Contrary to expectations, we found high genetic diversity in lichen and snow samples, and high effective sizes of the studied populations. Also, limited genetic differentiation between populations, high historical migration rates, and a high proportion of first generation immigrants were estimated, implying high connectivity across distances <30 km. Almost all genetic variation was attributed to variation within sites; spatial genetic structures within populations were absent or appeared on small scales (5-10 m). The high genetic diversity in the remaining old boreal rainforests shows that even relict forest patches might be suitable for conservation of genetic diversity. [ABSTRACT FROM AUTHOR] more...

Dominance by free-floating plants results in a loss of plant species in many waters. An important source for re-establishment of non-floating aquatic plants can be the propagule bank. This study focuses on whether the propagule bank of free-floating plant-dominated ditch sediments can serve as potential source for recovery of a diverse plant community. The first objective was to determine differences in propagule germination from sediments of ditches in the Netherlands that differ in vegetation composition through a seedling-emergence experiment. The second objective was to analyze the effect of sediment disturbance on the number of germinating propagules. The results show that, compared to sediments from ditches with submerged vegetation, sediments from free-floating plant-dominated ditches produced significantly lower numbers of individuals and species of submerged and emergent plants, while numbers of individuals and species of free-floating plants were higher. These results suggest that sediments from free-floating plant-dominated ditches have lower potential to recover a diverse plant community probably resulting from positive feedback mechanisms caused by the vegetation present, maintaining the free-floating plant-dominated state. Sediment disturbance strongly favors the germination of free-floating plant propagules, especially from free-floating plant-dominated ditch sediments. Ditch maintenance activities such as mowing and dredging will therefore likely favor persistence of the free-floating plant-dominated state. To shift from dominance by free-floating plants to a more diverse plant community, alternative maintenance methods should be considered that cause less sediment disturbance together with measures that promote colonization such as temporary drawdown or re-introduction of species. [ABSTRACT FROM AUTHOR] more...

North American and European grasslands consist of relatively young communities that have evolved under human influences. These communities are uniformly sensitive to top-down controls and exhibit rapid changes in plant composition when the intensity and frequency of these controls are altered. These changes are intensifying due to the suite of global change factors, including the continued presence and introduction of new plant species. Establishment of nonnative plant species into grasslands requires resource opportunities generated by natural and human-induced disturbances and by niche differences of the new species. Persistence and spatial expansion require that the traits of the introduced species be compatible with a new regime of competitors, predators, pathogens, and symbionts. Plant traits of the invaders may then further facilitate the invasion process by preempting resources or by restructuring the soil microbial community and trophic food web in ways that directly or indirectly benefit the invading species. [ABSTRACT FROM AUTHOR] more...

The comparative performance of vegetative propagules (VP) grafted on 'M. 9' rootstock and own-rooted (OR) seedlings of the same genotypes was investigated for apple [ Malus x domestica (Borkh.)] fruit quality traits using offspring from 22 control-pollinated families. Fifteen fruit quality traits including fruit size and shape, skin colour, russet and sensory eating characteristics were evaluated for individual seedlings. Estimates of genetic variance-covariance matrices ( G) were obtained and compared between the two treatments (OR versus VP) using Mantel's test and regression approaches. Empirical estimates of correlations, at the individual-tree and family-mean levels, between the two treatments were compared with those obtained from deterministic simulations. Estimates of narrow-sense heritability ( h) were higher in the VP population than in the OR population for 11 of the 15 traits. The estimated G matrices were significantly different between the two treatments. Simulation study showed that with an increase in the total genetic variance, the correspondence between the two treatments at the family-mean level improved dramatically for different family sizes. As the ratio of dominance/additive variance increased from 0 to 1, the family-mean correlations between the two treatments decreased for all family sizes. The average estimated correlations between the two treatments at the family-mean level were higher than at the individual-tree level (0.78 and 0.42, respectively). These observed correlations were very similar to our theoretical expectations. In the light of these results, caution is required when comparing apple seedlings tested on their own roots with those tested on 'M. 9' rootstock, as potential cultivar breeding parents. [ABSTRACT FROM AUTHOR] more...

The article discusses a study in which the propagule method was used to investigate the development of foraminiferal assemblages under different environmental conditions. The propagule method involved experimental arrays where foraminifera were grown from propagule banks under different controlled abiotic conditions. The foraminiferal assemblages studied were collected from mudflats on Sapelo Island in Georgia. The study examined the roles played by temperature, salinity and site in structuring coastal foraminifera communities. The impact of climate change on coastal foraminiferal assemblages is explained. more...

Abstract: To understand fully the risk of biological invasions, it is necessary to quantify propagule pressure along all introduction pathways. In the Antarctic region, importation of fresh produce is a potentially high risk, but as yet unquantified pathway. To address this knowledge gap, >11,250 fruit and vegetables sent to nine research stations in Antarctica and the sub-Antarctic islands, were examined for associated soil, invertebrates and microbial decomposition. Fifty-one food types were sourced from c. 130 locations dispersed across all six of the Earth’s inhabited continents. On average, 12% of food items had soil on their surface, 28% showed microbial infection resulting in rot and more than 56 invertebrates were recorded, mainly from leafy produce. Approximately 30% of identified fungi sampled from infected foods were not recorded previously from within the Antarctic region, although this may reflect limited knowledge of Antarctic fungal diversity. The number of non-native flying invertebrates caught within the Rothera Research Station food storage area was linked closely with the level of fresh food resupply by ship and aircraft. We conclude by presenting practical biosecurity measures to reduce the risk of non-native species introductions to Antarctica associated with fresh foods. [Copyright &y& Elsevier] more...

Hydrochory, or the passive dispersal of organisms by water, is an important means of propagule transport, especially for plants. During recent years, knowledge about hydrochory and its ecological consequences has increased considerably and a substantial body of literature has been produced. Here, we review this literature and define the state of the art of the discipline. A substantial proportion of species growing in or near water have propagules (fruits, seeds or vegetative units) able to disperse by water, either floating, submerged in flowing water, or with the help of floating vessels. Hydrochory can enable plants to colonize sites out of reach with other dispersal vectors, but the timing of dispersal and mechanisms of establishment are important for successful establishment. At the population level, hydrochory may increase the effective size and longevity of populations, and control their spatial configuration. Hydrochory is also an important source of species colonizing recruitment-limited riparian and wetland communities, contributing to maintenance of community species richness. Dispersal by water may even influence community composition in different landscape elements, resulting in landscape-level patterns. Genetically, hydrochory may reduce spatial aggregation of genetically related individuals, lead to high gene flow among populations, and increase genetic diversity in populations receiving many propagules. Humans have impacted hydrochory in many ways. For example, dams affect hydrochory by reducing peak flows and hence dispersal capacity, altering the timing of dispersal, and by presenting physical barriers to dispersal, with consequences for riverine plant communities. Hydrochory has been inferred to be an important vector for the spread of many invasive species, but there is also the potential for enhancing ecosystem restoration by improving or restoring water dispersal pathways. Climate change may alter the role of hydrochory by modifying the hydrology of water-bodies as well as conditions for propagule release and plant colonization. [ABSTRACT FROM AUTHOR] more...

The article presents a study that investigates that the possibility of unintentional dispersal of aquatic invertebrates among water bodies via footwear and motor vehicles in Camargue, France. It reveals that dispersal may result in frequent dispersal of aquatic invertebrates on a local scale. It recommends cleaning before transport of any equipment which comes in contact with water of aquatic sediment due to the rapid spread in invasive zooplankton species. more...

Mangroves are woody plants which form the dominant vegetation in tidal, saline wetlands along tropical and subtropical coasts. The current knowledge concerning the most striking feature of mangroves i.e., their unique ability to tolerate high salinity is summarized in the present review. In this review, we shall discuss recent studies that have focused on morphological, anatomical, physiological, biochemical, molecular and genetic attributes associated with the response to salinity, some of which presumably function to mediate salt tolerance in the mangroves. Here we shall also review the major advances recently made at both the genetic and the genomic levels in mangroves. Salinity tolerance in mangroves depends on a range of adaptations, including ion compartmentation, osmoregulation, selective transport and uptake of ions, maintenance of a balance between the supply of ions to the shoot, and capacity to accommodate the salt influx. The tolerance of mangroves to a high saline environment is also tightly linked to the regulation of gene expression. By integrating the information from mangroves and performing comparisons among species of mangroves and non-mangroves, we could give a general picture of salt tolerance mechanisms of mangroves, thus providing a new avenue for development of salt tolerance in crop plants through effective breeding strategies and genetic engineering techniques. [ABSTRACT FROM AUTHOR] more...

An efficient in vitro regeneration protocol and field performance of a multipurpose bamboo species Dendrocalamus hamiltonii Nees et Arn. Ex Munro has been demonstrated using single node cuttings taken from the lateral branches of a 20-year-old bush. Axillary buds on the nodal explant sprouted within 10 days of culture on Murashige and Skoog (MS) medium without any plant growth substance. High-frequency proliferation was induced on the propagules (small clusters with 3–5 multiple shoots and rhizomatous portions). Subsequent removal of the shoots (about 1.5 cm) from the rhizomatous portion of propagules (shoot cut) influenced the plantlet formation capacity. A multiplication of about 20-folds was achieved on MS medium supplemented with 8 μM BAP and 1 μM NAA. Rooting efficiency was also markedly enhanced (>90%) when the propagules, following shoot cut, were placed on to MS medium supplemented with 100 μM IBA for 10 days and then transferred to IBA-free medium. This is the first report from this species where 20-fold increment in multiplication was observed at the end of second subculture followed by >90% rooting. The hardened plants, established in the field, exhibited normal growth; their physiological performance has been monitored at 6-month intervals. The rate of photosynthesis increased from 3.55 μmol CO2 m−2 s−1 (hardened, ready for field transfer) to 5.44 μmol m−2 s−1 (6 months of field transfer); following a year of plantation net photosynthesis recorded was 14.0 μmol CO2 m−2 s−1 while after 1.5 years it was 12.76 μmol CO2 m−2 s−1. These values were compared with those observed for the mother bush. Genetic fidelity of these regenerants was established by RAPD analysis advocating clonal propagation of this species through nodal segment culture and its commercial cultivation. [ABSTRACT FROM AUTHOR] more...

Studies of seed bank development have rarely been included in evaluations of wetland restoration. We compared the seed bank of a recently restored tidal freshwater marsh in Washington, D.C., Kingman Marsh, with seed banks of another restored site (Kenilworth Marsh) and two reference marshes (Dueling Creek and Patuxent Marsh). The density and richness of emerging seedlings from Kingman Marsh seed bank samples increased from less than 4 seedlings and 2 taxa/90-cm2 sample in 2000 (the year of restoration) to more than 130 seedlings and 10 taxa/90-cm2 sample in 2003. The most important seed bank taxa at Kingman Marsh included Cyperus spp., Juncus spp., Lindernia dubia, Ludwigia palustris, and the non-native Lythrum salicaria. These taxa are not abundant in most mid-Atlantic tidal freshwater marshes but are almost identical to those described for a created tidal freshwater wetland in New Jersey. Seed banks of both the restored sites contained few seeds of several important species found at the reference sites. Flooding had a significant negative effect on emerging seedling density and taxa density, suggesting that slight decreases in soil elevation in restored wetlands will dramatically decrease recruitment from the seed bank. Because seed banks integrate processes affecting growth and reproduction of standing vegetation, we suggest that seed banks are a useful metric of wetland restoration success and urge that seed bank studies be incorporated into monitoring programs for restored wetlands. [ABSTRACT FROM AUTHOR] more...

The sensitivity of different life stages of the eulittoral green alga Urospora penicilliformis (Roth) Aresch. to ultraviolet radiation (UVR) was examined in the laboratory. Gametophytic filaments and propagules (zoospores and gametes) released from filaments were separately exposed to different fluence of radiation treatments consisting of PAR ( P = 400–700 nm), PAR + ultraviolet A (UVA) (PA, UVA = 320–400 nm), and PAR + UVA + ultraviolet B (UVB) (PAB, UVB = 280–320 nm). Photophysiological indices (ETRmax, Ek, and α) derived from rapid light curves were measured in controls, while photosynthetic efficiency and amount of DNA lesions in terms of cyclobutane pyrimidine dimers (CPDs) were measured after exposure to radiation treatments and after recovery in low PAR; pigments of propagules were quantified after exposure treatment only. The photosynthetic conversion efficiency (α) and photosynthetic capacity (rETRmax) were higher in gametophytes compared with the propagules. The propagules were slightly more sensitive to UVB-induced DNA damage; however, both life stages of the eulittoral inhabiting turf alga were not severely affected by the negative impacts of UVR. Exposure to a maximum of 8 h UVR caused mild effects on the photochemical efficiency of PSII and induced minimal DNA lesions in both the gametophytes and propagules. Pigment concentrations were not significantly different between PAR-exposed and PAR + UVR–exposed propagules. Our data showed that U. penicilliformis from the Antarctic is rather insensitive to the applied UVR. This amphi-equatorial species possesses different protective mechanisms that can cope with high UVR in cold-temperate waters of both hemispheres and in polar regions under conditions of increasing UVR as a consequence of further reduction of stratospheric ozone. [ABSTRACT FROM AUTHOR] more...

Abstract: Successful attachment of macrophyte propagules in the rocky intertidal zone requires that propagules actually arrive at the substrate (settlement). The analysis first considers the small-scale processes occurring at the propagule scale then places these results in the context of long timescale variability in wave forcing due to weather and climate. The non-dimensional scaling is developed in terms of a Particle Reynolds number, Re ⁎p, that depends on both flow and particle scales. Scaling for size, inertia and buoyancy are described in terms of the Re ⁎p. Settlement mechanics of several macrophyte species (Durvillaea antarctica, Hormosira banksii and Cystophora torulosa) are compared using direct velocity measurements and placed in an environmental context using a twenty-year wave hindcast. The forcing is shown to be more closely linked to wave orbital speeds rather than breaker-driven phase speeds, and (negative) buoyancy has the greatest influence, identified through a Buoyancy Travel Ratio (BTR). Differences in these physical scales between the species are only moderate, suggesting supply, mucous and stickiness effects must be considered to fully resolve difference in success. [Copyright &y& Elsevier] more...

We examined the ability of vegetative propagules (small buds and branch fragments) of the green alga Codium fragile ssp. tomentosoides to attach and grow on natural substrata in laboratory and field experiments. In the laboratory, the probability of attachment (on coralline algae, mussel shell, smooth and rough rock) was greater for buds than excised apical branches (both ∼4 cm long) over 10 weeks, and greater in weak flow (1.3 cm s-1) than static conditions. Probability of attachment differed among substrata in flow (greater on coralline algae than smooth rock) but not static conditions. Attachment strength in flow was greater for buds than fragments (pooled over substrata). Growth was greater for fragments than buds in static conditions, but not in flow. Fragments grew more in static conditions than in flow. In a field experiment, buds were transplanted to three tide pools at different tidal heights on a rocky shore. After eight months, the proportion that attached and attachment strengths of transplants did not differ significantly among pools. However, transplants in the high pool grew less and were discolored and atypically branched compared to those in pools lower on the shore. These findings indicate that vegetative propagation may contribute to the invasive success of Codium fragile. [ABSTRACT FROM AUTHOR] more...

1. The role of waterbirds as vectors of plants and invertebrates within and between arid-zone wetlands is poorly understood. We present the first detailed study of passive dispersal by nomadic birds in Australasia. We investigated the numbers and types of invertebrate and plant propagules within freshly collected faecal samples as well as their viability. We compared dispersal among Grey Teal ( Anas gracilis), Eurasian Coot ( Fulica atra) and Black Swan ( Cygnus atratus) in the Macquarie Marshes, a complex of temporary to semi-permanent wetlands in New South Wales. 2. When faecal samples ( n = 60) were inundated in the laboratory and monitored over 3 weeks, ciliates (75% of samples), nematodes (22%), ostracods (13%) and rotifers (5%) were recorded, with higher taxon richness in coot samples. Faecal samples ( n = 71) were also sieved to quantify intact propagules, and ostracod eggs (70% of samples), large branchiopod eggs (31%) and bryozoan statoblasts (31%) were the most abundant invertebrates. Diaspores of 19 plant taxa were recorded, 14 of which were germinated in the laboratory or shown to be viable at the end of germination trials. The abundance and diversity of invertebrate propagules was highest in coot samples, whereas the abundance and diversity of diaspores was highest in teal samples. 3. One Australian Pelican ( Pelecanus conspicillatus) sample was obtained and found to contain more taxa and far more propagules than any sample from other waterbirds, suggesting that piscivorous birds might have an important role in the indirect dispersal of propagules ingested by fish. 4. Our results support a role for birds in explaining the distributions of cosmopolitan plant genera such as Lemna, Typha, Myriophyllum and Nitella. The alien plants Ranunculus sceleratus, Medicago polymorpha and Polygonum arenastrum were recorded, demonstrating the potential role of waterfowl in the spread of exotic species. As the frequency and duration of flooding of arid-zone wetlands decreases owing to human activities, the importance of waterbirds in facilitating recolonisation of temporary wetlands is likely to increase. [ABSTRACT FROM AUTHOR] more...

The aim of this field study was to examine how the development of arbuscular mycorrhizal fungi (AMF) on coal mine spoil banks is affected by the presence of plants with different mycorrhizal status. A 3-year trial was conducted on the freshly created spoil bank Vršany, North-Bohemian coal basin, the Czech Republic. Three plant species – non-mycotrophic annual Atriplex sagittata, highly mycotrophic annual Tripleurospermum inodorum (both dominants of early stages of succession) and facultatively mycotrophic Arrhenatherum elatius (a perennial grass species of the later stage of succession) – were planted on 1 m2 plots over 3 years in different sequences that simulated the progress of succession on spoil banks. The development of AMF populations was monitored by evaluation of mycorrhizal colonization of plant roots and by measurement of the mycorrhizal inoculation potential (MIP) of soil. These two parameters were compared between plots inoculated with the mixture of three AMF isolates – Glomus mosseae BEG95, G. claroideum BEG96 and G. intraradices BEG140 – (“inoculated plots”) and plots exposed only to natural dispersal of AMF propagules (“uninoculated plots”). Highly colonized roots of plants together with a high MIP of soil in uninoculated plots were already found at the end of the first season, indicating rapid natural dispersal of AMF propagules. Root colonization of facultatively mycotrophic and non-mycotrophic plants in later years was affected by the mycorrhizal status of the previous plant species. The MIP of soil continuously increased throughout the experiment; in uninoculated plots, the MIP was temporarily decreased if plant species of higher mycotrophy were replaced by species of lower mycotrophy. The results lead to the conclusion that AMF colonize freshly formed sites very quickly and reproduce or accumulate in the soil, which leads to increasing MIP values. However, this infective potential can be decreased if non-mycotrophic plants predominate on the site. [ABSTRACT FROM AUTHOR] more...

Ozone depletion is highest during spring and summer in Antarctica, coinciding with the seasonal reproduction of most macroalgae. Propagules are the life-stage of an alga most susceptible to environmental perturbations therefore, reproductive cells of three intertidal macroalgal species Adenocystis utricularis (Bory) Skottsberg, Monostroma hariotii Gain, and Porphyra endiviifolium (A and E Gepp) Chamberlain were exposed to photosynthetically active radiation (PAR), PAR + UV-A and PAR + UV-A + UV-B radiation in the laboratory. During 1, 2, 4, and 8 h of exposure and after 48 h of recovery, photosynthetic efficiency, and DNA damage were determined. Saturation irradiance of freshly released propagules varied between 33 and 83 μmol photons m−2 s−1 with lowest values in P. endiviifolium and highest values in M. hariotii. Exposure to 22 μmol photons m−2 s−1 PAR significantly reduced photosynthetic efficiency in P. endiviifolium and M. hariotii, but not in A. utricularis. UV radiation (UVR) further decreased the photosynthetic efficiency in all species but all propagules recovered completely after 48 h. DNA damage was minimal or not existing. Repeated exposure of A. utricularis spores to 4 h of UVR daily did not show any acclimation of photosynthesis to UVR but fully recovered after 20 h. UVR effects on photosynthesis are shown to be species-specific. Among the tested species, A. utricularis propagules were the most light adapted. Propagules obviously possess good repair and protective mechanisms. Our study indicates that the applied UV dose has no long-lasting negative effects on the propagules, a precondition for the ecological success of macroalgal species in the intertidal. [ABSTRACT FROM AUTHOR] more...

The effect of amended acidic pyrite sediments on the germination and establishment of seedlings and vegetative plant propagules of some selected plant species was investigated. The results from this study indicate that the pH values of the pyrite trail ranged from 1.6 to 3.5. Seed germination of all plant species except Bidens pilosa L. was not possible in the pyrite soils (pH 1.6–4.0) in laboratory germination trials. The germination of seeds in amended pyrite soils at pH 5.5 ± 0.2 and 7.0 ± 0.2 was possible. Seeds of Panicum maximum Jacq. and Setaria sphacelata (Schumach.) Stapf and Hubbard ex. Moss were not able to germinate in the unaltered pyrite soil under laboratory conditions. Under field conditions, seed germination was possible in all the plots with amended pyrite soils at pH 5.5 ± 0.2 and 7.0 ± 0.2. Seed germination in the uncontaminated soil was much higher than in the amended pyrite soil. Seedlings were not able to survive for long in the amended soils. Only the vegetative plant propagules of Cynodon dactylon (L) Pers. were able to secure permanent establishment in all amended plots except in plot PT3. Generally, seed germination, seedling establishment, growth and the establishment of vegetative plant propagules in unaltered soils was not possible. [ABSTRACT FROM AUTHOR] more...

Changes in spore abundance of the blade-forming Sarcothalia crispata and crustose coralline seaweeds were determined to relate height above the substratum at which propagules are liberated with their dispersal potential. Recruit density was quantified on artificial substrata at the surface of the water column, mid-water, and seafloor. Spore abundance was determined in water samples obtained at the same levels during periods of calm and rough seas. Spore density was also determined along a transect running perpendicularly to the shore. Density of recruits S. crispata increased with depth, whereas coralline recruits were abundant at the seafloor level. During calm seas, spore density of S. crispata and crustose corallines increased with depth, but the latter were more variable. During rough seas, spore density was very high; spores of S. crispata increased toward the surface, or were homogenous in the water column, whereas distribution of crustose coralline spores was more variable. Finally, density of crustose coralline spores decreased more abruptly with distance from the shore than that of the bladed species. These results strongly suggest that the height at which spores are released (a correlate of algal morphology) influences spore distribution in the water column and the dispersal potential. [ABSTRACT FROM AUTHOR] more...

Abstract: A greenhouse experiment based on a dual mode of mycorrhizal inoculation simulated the formation of mycorrhizal symbiosis at two different stages of plant succession on coalmine spoil banks. The model plants were inoculated either with propagules of the arbuscular mycorrhizal fungi (AMF) Glomus mosseae BEG95, which represented the initial stages of succession, or were provided with the pre-established extraradical mycelium (ERM) network of the same AMF isolate, which simulated later succession stages. The plant species used – non-mycotrophic Atriplex sagittata and Sisymbrium loeselii, and mycotrophic Tripleurospermum inodorum, Calamagrostis epigejos and Elytrigia repens – represented succession dominants at those sites. Even though the grasses were colonised in both mycorrhizal treatments, the presence of an established ERM network increased the intensity of their colonisation and arbuscular abundance. No trace of colonisation of non-mycotrophic plants was found in the treatment inoculated with propagules. Surprisingly, marked colonisation, including abundant arbuscules, was observed when non-mycotrophic plants were grown in the presence of a pre-established ERM network. In A. sagittata, arbuscules were found at maturity and senescence of the plants after 16 weeks of growth. In S. loeselii, however, the arbuscules were found at the vegetative stage of the leaf rosette after 8 weeks and then completely disappeared during the following weeks. When the ability of propagules and ERM to induce mycorrhizal colonisation is compared, it seems that the established mycelium probably has an enhanced potential to colonise roots of plants, even if the plants belong to species usually not hosting mycorrhizal fungi. [Copyright &y& Elsevier] more...

Abstract: The reproductive phenology of Gracilaria gracilis has been followed closely in a brackish water lake in Sicily. The life history of this red alga deviated from the typical Polysiphonia-type cycle and was characterized by the predominance of the tetrasporophytic phase over gametophytes, in situ development of germinated gametophytes and the presence of sterile pleustophytic thalli. Release of spherical agglomerates of cells produced by young tetrasporophytes was observed as well. Their ability to germinate forming new thalli appears to represent an alternative reproductive strategy of this organism. The population structure appears to reflect a predominance of the diploid phase except during the warmer summer season when only vegetative juveniles were found in the lake. Release and early stages of development of carpospores and tetraspores were critically observed in culture. A Dumontia type pattern of germination was observed for both types of spores, showing an erect thallus arising from a multicellular basal disk. Compared to tetraspores, carpospores are less readily released resulting in a subsequent delay in the development of new gametophytes. [Copyright &y& Elsevier] more...

Abstract: One of the most serious problems caused by eutrophication of shallow lakes is the disappearance of submerged macrophytes and the switch to a turbid, phytoplankton-dominated state. The reduction of external nutrient loads often does not result in a change back to the macrophyte-dominated state because stabilising mechanisms that cause resilience may delay a response. Additional internal lake restoration measures may therefore be needed to decrease the concentration of total phosphorus and increase water clarity. The re-establishment of submerged macrophytes required for a long-term stability of clear water conditions, however, may still fail, or mass developments of tall-growing species may cause nuisance for recreational use. Both cases are often not taken into account when restoration measures are planned in Germany, and existing schemes to reduce eutrophication consider the topic inadequately. Here we develop a step-by-step guideline to assess the chances of submerged macrophyte re-establishment in shallow lakes. We reviewed and rated the existing literature and case studies with special regard on (1) the impact of different internal lake restoration methods on the development of submerged macrophytes, (2) methods for the assessment of natural re-establishment, (3) requirements and methods for artificial support of submerged macrophyte development and (4) management options of macrophyte species diversity and abundance in Germany. This guideline is intended to help lake managers aiming to restore shallow lakes in Germany to critically asses and predict the potential development of submerged vegetation, taking into account the complex factors and interrelations that determine their occurrence, abundance and diversity. [Copyright &y& Elsevier] more...