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  • 51. Loydi, A.
    et al.
    Donath, T. W.
    Eckstein, Rolf Lutz
    Justus-Liebig University, Giessen, Germany.
    Otte, A.
    Non-native species litter reduces germination and growth of resident forbs and grasses: allelopathic, osmotic or mechanical effects?2015Ingår i: Biological Invasions, ISSN 1387-3547, E-ISSN 1573-1464, Vol. 17, nr 2, s. 581-595Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Non-native plant species may contain allelopathic substances that might help to out-compete native vegetation. These allelochemicals may be released from live or dead plant tissues and be accumulated in the soil. We tested whether non-native species leaf litter and their leachates reduced seedling establishment and growth of native species. We subjected seeds of six native species to the effect of litter leachates of three of the most important invasive plants in Europe and to mannitol solutions with similar osmotic potential in germination chamber experiments. Additionally, we measured the effect of the same litter on emergence and growth of the native species in an outdoor pot experiment. Litter leachates delayed and reduced germination and affected initial root growth of all native species. The effects of leachates were significantly higher than those of mannitol, indicating the action of toxic, most probably allelochemical substances. Emergence of seedlings in pots was also reduced, but total biomass per pot was not affected and biomass per seedling increased. Allelochemicals may affect germination and early stages of seedling recruitment. However, these negative effects seem to cease shortly after germination, when other mechanisms such as competition may be more important. Consequently, litter-borne allelochemicals are unlikely to drive the invasion of the studied non-native species, but they may contribute to maintain mono-dominant stands reinforcing invasion success.

  • 52. Loydi, A.
    et al.
    Donath, T. W.
    Otte, A.
    Eckstein, Rolf Lutz
    Justus-Liebig University Giessen, Giessen, Germany.
    Negative and positive interactions among plants: effects of competitors and litter on seedling emergence and growth of forest and grassland species2015Ingår i: Plant Biology, ISSN 1435-8603, E-ISSN 1438-8677, Vol. 17, nr 3, s. 667-675Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Living plant neighbours, but also their dead aboveground remains (i.e. litter), may individually exert negative or positive effects on plant recruitment. Although living plants and litter co-occur in most ecosystems, few studies have addressed their combined effects, and conclusions are ambivalent. Therefore, we examined the response in terms of seedling emergence and growth of herbaceous grassland and forest species to different litter types and amounts and the presence of competitors. We conducted a pot experiment testing the effects of litter type (grass, oak), litter amount (low, medium, high) and interspecific competition (presence or absence of four Festuca arundinacea individuals) on seedling emergence and biomass of four congeneric pairs of hemicryptophytes from two habitat types (woodland, grassland). Interactions between litter and competition were weak. Litter presence increased competitor biomass. It also had positive effects on seedling emergence at low litter amounts and negative effects at high litter amounts, while competition had no effect on seedling emergence. Seedling biomass was negatively affected by the presence of competitors, and this effect was stronger in combination with high amounts of litter. Litter affected seedling emergence while competition determined the biomass of the emerged individuals, both affecting early stages of seedling recruitment. High litter accumulation also reduced seedling biomass, but this effect seemed to be additive to competitor effects. This suggests that live and dead plant mass can affect species recruitment in natural systems, but the mechanisms by which they operate and their timing differ

  • 53.
    Loydi, Alejandro
    et al.
    Justus Liebig Univ Giessen, Tyskland.
    Eckstein, Rolf Lutz
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Gebauer, Tobias
    Univ Hamburg, Appl Plant Ecol, Bioctr Klein Flottbek.
    Ludewig, Kristin
    Justus Liebig Univ Giessen, Tyskland.
    Otte, Annette
    Justus Liebig Univ Giessen, Tyskland.
    Reisdorff, Christoph
    Univ Hamburg,.
    Jensen, Kai
    Univ Hamburg.
    Donath, Tobias W.
    Christian Albrechts Univ Kiel.
    Opposite effects of litter and hemiparasites on a dominant grass under different water regimes and competition levels2018Ingår i: Plant Ecology, ISSN 1385-0237, E-ISSN 1573-5052, Vol. 219, nr 2, s. 133-144Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Direct and indirect biotic interactions may affect plant growth and development, but the magnitude of these effects may vary depending on environmental conditions. In grassland ecosystems, competition is a strong structuring force. Nonetheless, if hemiparasitic plant species are introduced the competition intensity caused by the dominant species may be affected. However, the outcome of these interactions may change between wet or dry periods. In order to study this, we performed a pot experiment with different densities of the dominant species Schedonorus arundinaceus (1, 2 or 4 individuals) under constantly moist or intermittently dry conditions. The different Schenodorus densities were crossed with presence or absence of hemiparasites (either Rhinanthus minor or R. alectorolophus). Additionally, pots remained with bare ground or received a grass litter layer (400 g m(-2)). We expected that indirect litter effects on vegetation (here Schedonorus or Rhinanthus) vary depending on soil moisture. We measured Schedonorus and Rhinanthus aboveground biomass and C stable isotope signature (delta C-13) as response variables. Overall, Schedonorus attained similar biomass under moist conditions with Rhinanthus as in pots under dry conditions without Rhinanthus. Presence of Rhinanthus also increased delta C-13 in moist pots, indicating hemiparasite-induced water stress. Litter presence increased Schedonorus biomass and reduced delta C-13, indicating improved water availability. Plants under dry conditions with litter showed similar biomass as under wet conditions without litter. Hemiparasites and litter had opposite effects: hemiparasites reduced Schedonorus biomass while litter presence facilitated grass growth. Contrary to our expectations, litter did not compensate Schedonorus biomass when Rhinanthus was present.

  • 54.
    Loydi, Alejandro
    et al.
    Justus-Liebig-University, Giessen, Germany.
    Eckstein, Rolf Lutz
    Justus-Liebig-University, Giessen, Germany.
    Otte, Annette
    Justus-Liebig-University, Giessen, Germany.
    Donath, Tobias W.
    Justus-Liebig University, Giessen, Germany.
    Effects of litter on seedling establishment in natural and semi-natural grasslands: a meta-analysis2013Ingår i: Journal of Ecology, ISSN 0022-0477, E-ISSN 1365-2745, Vol. 101, nr 2, s. 454-464Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    1. Plant litter is a key component in terrestrial ecosystems. It plays a major role in nutrient cycles and community organization. Land use and climate change may change the accumulation of litter in herbaceous ecosystems and affect plant community dynamics. Additionally, the transfer of seeds containing plant material (i.e. litter) is a widespread technique in grassland restoration.

    2. Ecosystem responses to litter represent the outcome of interactions, whose sign and strength will depend on many variables (e. g. litter amount, seed size). A previous meta-analysis (from 1999) reported that litter had an overall negative effect on seed germination and seedling establishment in different ecosystems. However, recent studies indicated that this might not be the case in grassland ecosystems.

    3. We used 914 data from 46 independent studies to analyse the effects of litter on seedling (i) emergence, (ii) survival and (iii) biomass, employing meta-analytical techniques. Each data set was stratified according to methodology, grassland type, irrigation conditions, litter amount and seed size.

    4. We found an overall neutral effect of litter presence on seedling emergence and survival and a positive effect on seedling biomass. However, whereas for field experiments the response remained neutral, it was positive for common garden studies. In glasshouse experiments, litter effects were negative for emergence and positive for biomass.

    5. Litter may have a positive effect on seedling recruitment in dry grasslands or under water-limited conditions, or in the presence of low to medium litter amounts (< 500 g m(-2)). However, high litter amounts (> 500 g m(-2)) will inhibit seedling recruitment. Large seeds showed a more positive response to litter presence with respect to seedling emergence and survival, but not concerning biomass.

    6. Synthesis. Under dry conditions (e. g. dry grasslands or dry periods) or with low to medium litter amounts, litter presence has a positive effect on seedling establishment. However, climate and land use change may promote litter accumulation and reduce seedling establishment, affecting grasslands composition and ecosystem functions.

  • 55.
    Loydi, Alejandro
    et al.
    Justus-Liebig-University, Giessen, Germany.
    Lohse, Kerstin
    Justus-Liebig-University, Giessen, Germany.
    Otte, Annette
    Justus-Liebig-University, Giessen, Germany.
    Donath, Tobias W.
    Justus-Liebig-University, Giessen, Germany.
    Eckstein, Rolf Lutz
    Justus-Liebig-University, Giessen, Germany.
    Distribution and effects of tree leaf litter on vegetation composition and biomass in a forest-grassland ecotone2014Ingår i: Journal of Plant Ecology, ISSN 1752-9921, E-ISSN 1752-993X, Vol. 7, nr 3, s. 264-275Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Aims

    After abandonment of grasslands, secondary succession leads to the invasion by woody species. This process begins with the accumulation of tree litter in the forest-grassland ecotone. Our objectives were to determine the relationships between litter amounts and vegetation composition and cover along natural forest-grassland ecotones and to experimentally study the initial effects of tree litter accumulation on grassland vegetation and on microsite conditions.

    Methods

    We established 11 transects varying from 12 to 15 m in length in different forest-grassland ecotones in the Lahn-Dill highlands, Germany, and measured the mass and cover of tree litter and the cover and composition of vegetation at five sequential positions along each transect by using 1 m(2) plots with five replications. In a field experiment, we established plots subjected to different litter amounts (0, 200 and 600 g m(-2)) and evaluated changes in grassland vegetation, soil temperature and soil nutrient availability below the litter layer.

    Important Findings

    Tree litter amounts decrease from 650 to 65 g m(-2) across the forest-grassland ecotone. Vegetation changed from shrubs and annual species (adapted to more stressful conditions) in the forests edge to grasses, rosettes and hemirosette species (with higher competitive abilities) in the grassland. These anthropogenic forest-grassland ecotones showed abrupt edges, and the two adjacent ecosystems were characterized by different species pools and functional groups. In the field experiment, the presence of a litter layer reduced vegetation biomass and cover; the species richness was only reduced in the treatment with high litter (600 g m(-2)). Additionally, adding litter on top of vegetation also reduced thermal amplitude and the number of frost days, while increasing the availability of some nutrients, such as nitrogen and aluminium, the latter being an indicator of soil acidification. Adding a tree litter layer of 600 g m(-2) in grassland areas had strong effects on the composition and diversity of grassland vegetation by reducing the cover of several key grassland species. In, or near, forest edges, litter accumulation rapidly changes established vegetation, microsite conditions and soil nutrients.

  • 56.
    Ludewig, K.
    et al.
    Justus Liebig University Giessen, Giessen, Germany.
    Hanke, J. M.
    Justus Liebig University Giessen, Giessen, Germany.
    Wuthe, B.
    Justus Liebig University Giessen, Giessen, Germany.
    Otte, A.
    Justus Liebig University Giessen, Giessen, Germany.
    Mosner, E.
    Hochschule Geisen heim University, Geisenheim, Germany.
    Eckstein, Rolf Lutz
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013). Justus Liebig University Giessen, Giessen, Germany.
    Donath, T. W.
    Christian-Albrechts-University Kiel, Kiel, Germany.
    Differential effect of drought regimes on the seedling performance of six floodplain grassland species2018Ingår i: Plant Biology, ISSN 1435-8603, E-ISSN 1438-8677, Vol. 20, nr 4, s. 691-697Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The performance of seedlings is crucial for the survival and persistence of plant populations. Although drought frequently occurs in floodplains and can cause seedling mortality, studies on the effects of drought on seedlings of floodplain grasslands are scarce. We tested the hypotheses that drought reduces aboveground biomass, total biomass, plant height, number of leaves, leaf area and specific leaf area (SLA), and increases root biomass and root-mass fraction (RMF) and that seedlings from species of wet floodplain grasslands are more affected by drought than species of dry grasslands. In a greenhouse study, we exposed seedlings of three confamilial pairs of species (Pimpinella saxifraga, Selinum carvifolia, Veronica teucrium, Veronica maritima, Sanguisorba minor, Sanguisorba officinalis) to increasing drought treatments. Within each plant family, one species is characteristic of wet and one of dry floodplain grasslands, confamilial in order to avoid phylogenetic bias of the results. In accordance with our hypotheses, drought conditions reduced aboveground biomass, total biomass, plant height, number of leaves and leaf area. Contrary to our hypotheses, drought conditions increased SLA and decreased root biomass and RMF of seedlings. Beyond the effects of the families, the results were species-specific (V. maritima being the most sensitive species) and habitat-specific. Species indicative of wet floodplain grasslands appear to be more sensitive to drought than species indicative of dry grasslands. Because of species- and habitat-specific responses to reduced water availability, future drought periods due to climate change may severely affect some species from dry and wet habitats, while others may be unaffected.

  • 57. Ludewig, Kristin
    et al.
    Donath, Tobias W.
    Zelle, Bianka
    Eckstein, Rolf Lutz
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper. nstitute of Landscape Ecology and Resource Managementnstitute of Landscape Ecology and Resource Management, Giessen, Germany.
    Mosner, Eva
    Otte, Annette
    Jensen, Kai
    Effects of Reduced Summer Precipitation on Productivity and Forage Quality of Floodplain Meadows at the Elbe and the Rhine River2015Ingår i: PLOS ONE, E-ISSN 1932-6203, Vol. 10, nr 5, artikel-id e0124140Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Floodplain meadows along rivers are semi-natural habitats and depend on regular land use. When used non-intensively, they offer suitable habitats for many plant species including rare ones. Floodplains are hydrologically dynamic ecosystems with both periods of flooding and of dry conditions. In German floodplains, dry periods may increase due to reduced summer precipitation as projected by climate change scenarios. Against this background, the question arises, how the forage quantity and quality of these meadows might change in future.

    Methods

    We report results of two field trials that investigated effects of experimentally reduced summer precipitation on hay quantity and quality of floodplain meadows at the Rhine River (2011-2012) and at two Elbe tributaries (2009-2011). We measured annual yield, the amount of hay biomass, and contents of crude protein, crude fibre, energy, fructan, nitrogen, phosphorus, and potassium.

    Results

    The annual yield decreased under precipitation reduction at the Rhine River. This was due to reduced productivity in the second cut hay at the Rhine River in which, interestingly, the contents of nitrogen and crude protein increased. The first cut at the Rhine River was unaffected by the treatments. At the Elbe tributaries, the annual yield and the hay quantity and quality of both cuts were only marginally affected by the treatments.

    Conclusion

    We conclude that the yield of floodplain meadows may become less reliable in future since the annual yield decreased under precipitation reduction at the Rhine River. However, the first and agriculturally more important cut was almost unaffected by the precipitation reduction, which is probably due to sufficient soil moisture from winter/spring. As long as future water levels of the rivers will not decrease during spring, at least the use of the hay from the first cut of floodplain meadows appears reliable under climate change.

  • 58.
    Ludewig, Kristin
    et al.
    Justus Liebig Univ Giessen, DEU; Univ Hamburg, DEU.
    Hansen, Wiebke
    Justus Liebig Univ Giessen, DEU.
    Klinger, Yves P.
    Justus Liebig Univ Giessen, DEU.
    Eckstein, Rolf Lutz
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Otte, Annette
    Justus Liebig Univ Giessen, DEU .
    Seed bank offers potential for active restoration of mountain meadows2021Ingår i: Restoration Ecology, ISSN 1061-2971, E-ISSN 1526-100X, Vol. 29, nr 1Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The nitrogen-fixing legume Lupinus polyphyllus invaded semi-natural mountainous grasslands across Europe during the last decades. This invasion resulted in degraded habitats through changes in the structure and function of the mountain meadow vegetation. In our study, we analyzed (1) the effects of increasing cover of L. polyphyllus on the seed bank of mountain meadows, and (2) the potential of the seed bank of these stands for active restoration of mountain meadows in terms of species composition and number. We conducted a seed bank analysis on 84 plots with increasing cover of L. polyphyllus in three mountain-meadow types of the Rhon Biosphere Reserve, Germany. Seedlings from 119 species germinated from the seed bank samples, including 17 Red List species but only a few seedlings of L. polyphyllus. The species composition of the seed bank matched distinct patterns of the three meadow types, but differed from the species composition of the current aboveground vegetation in a nonmetric multidimensional scaling ordination. While the influence of L. polyphyllus on the current vegetation was visible, no effects on the seed bank were apparent. L. polyphyllus had no influence on total seed density, seed density of typical mountain-meadow species, or species numbers in the seed bank. Only the seeds of the Red List species were significantly related to the cover of L. polyphyllus. We conclude that the seed bank offers potential for active restoration of species-rich mountain meadows, but species absent from the seed bank have to be added by other measures.

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  • 59.
    Ludewig, Kristin
    et al.
    Universität Hamburg, Hamburg, Germany.
    Klinger, Yves Philippe
    Justus Liebig University Giessen, Giessen, Germany.
    Donath, Tobias W.
    Kiel University, Kiel, Germany.
    Bärmann, Lukas
    University of Trier, Trier, Germany.
    Eichberg, Carsten
    University of Trier, Trier, Germany.
    Gadegaad Thomsen, Jacob
    University of Southern Denmark, Odense, Denmark.
    Görzen, Eugen
    Kiel University, Kiel, Germany.
    Hansen, Wiebke
    Justus Liebig University Giessen, Giessen, Germany.
    Hasselquist, Eliza M.
    SLU.
    Helminger, Thierry
    National Museum of Natural History Luxembourg, .
    Kaiskog, Frida
    Karlstads universitet.
    Karlsson, Emma
    Karlstads universitet.
    Kirchner, Torsten
    Wildland-Stiftung Bayern, Oberelsbach, Germany.
    Knudsen, Carola
    Karlstads universitet.
    Lenzewski, Nikola
    Universität Hamburg, Hamburg, Germany.
    Lindmo, Sigrid
    Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
    Milberg, Per
    Linköping University, Linköping, Sweden.
    Pruchniewicz, Daniel
    Wrocław University of Environmental and Life Sciences, Wrocław, Poland.
    Richter, Elisabeth
    Biosphärenreservat Rhön, Oberelsbach, Germany.
    Sandner, Tobias M.
    Philipps-University Marburg, Marburg, Germany.
    Sarneel, Judith M.
    Umeå University.
    Schmiede, Ralf
    Myotis Büro für Landschaftsökologie, Halle (Saale), Germany.
    Schneider, Simone
    National Museum of Natural History Luxembourg, Luxembourg, Luxembourg; Naturschutzsyndikat SICONA, Olm, Luxembourg.
    Schwarz, Kathrin
    Kiel University, Kiel, Germany.
    Tjäder, Åsa
    Karlstads universitet.
    Tokarska-Guzik, Barbara
    University of Silesia in Katowice, Katowice, Poland.
    Walczak, Claudia
    Technische Universität Dresden, Dresden, Germany.
    Weber, Odile
    National Museum of Natural History Luxembourg, Luxembourg, Luxembourg.
    Żołnierz, Ludwik
    Wrocław University of Environmental and Life Sciences, Wrocław, Poland.
    Eckstein, Rolf Lutz
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Phenology and morphology of the invasive legume Lupinus polyphyllus along a latitudinal gradient in Europe2022Ingår i: NeoBiota, ISSN 1619-0033, E-ISSN 1314-2488, Vol. 78Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Plant phenology, i. e. the timing of life cycle events, is related to individual fitness and species distributionranges. Temperature is one of the most important drivers of plant phenology together with day length.The adaptation of their phenology may be important for the success of invasive plant species. The presentstudy aims at understanding how the performance and the phenology of the invasive legume Lupinuspolyphyllus vary with latitude. We sampled data across a >2000 km latitudinal gradient from Centralto Northern Europe. We quantified variation in phenology of flowering and fruiting of L. polyphyllususing >1600 digital photos of inflorescences from 220 individual plants observed weekly at 22 sites. Theday of the year at which different phenological phases were reached, increased 1.3–1.8 days per degreelatitude, whereas the growing degree days (gdd) required for these phenological phases decreased 5–16 gddper degree latitude. However, this difference disappeared, when the day length of each day included inthe calculation of gdd was considered. The day of the year of the earliest and the latest climatic zone toreach any of the three studied phenological phases differed by 23–30 days and temperature requirementsto reach these stages differed between 62 and 236 gdd. Probably, the invasion of this species will furtherincrease in the northern part of Europe over the next decades due to climate warming. For invasive speciescontrol, our results suggest that in countries with a large latitudinal extent, the mowing date should shiftby ca. one week per 500 km at sites with similar elevations.

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  • 60.
    Ludewig, Kristin
    et al.
    ustus Liebig University Giessen, 35392 Giessen, Germany;.
    Zelle, Bianka
    ustus Liebig University Giessen, 35392 Giessen, Germany;.
    Eckstein, Rolf Lutz
    ustus Liebig University Giessen, 35392 Giessen, Germany;.
    Mosner, Eva
    Otte, Annette
    ustus Liebig University Giessen, 35392 Giessen, Germany;.
    Donath, Tobias W.
    ustus Liebig University Giessen, 35392 Giessen, Germany;.
    Differential effects of reduced water potential on the germination of floodplain grassland species indicative of wet and dry habitats2014Ingår i: Seed Science Research, ISSN 0960-2585, E-ISSN 1475-2735, Vol. 24, nr 1, s. 49-61Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Floodplain meadow ecosystems are characterized by high water level fluctuations and highly variable soil water potentials. Additionally, climate change scenarios indicate an increasing risk for summer drought along the northern Upper Rhine and the Middle Elbe River, Germany. While adult plants often persist even after strong changes in water availability, early life phases, such as seed germination and seedling establishment, might be more vulnerable. Therefore we tested whether reduced soil water potentials will affect the germination of meadow species and whether the response varies between (1) forbs indicative of wet and dry habitats and (2) seeds originating from sites along the rivers Elbe and Rhine. We exposed seeds of 20 floodplain meadow species with different moisture requirements from five plant families to a water potential gradient ranging from 0 to -1.5MPa. While across species germination percentage and synchrony decreased, germination time increased at reduced water potentials. Germination of the species indicative of dry habitats decreased more strongly, was slower and less synchronous at reduced water potentials than that of species indicative of wet habitats. Seeds from sites along the rivers Elbe and Rhine did not differ in their germination characteristics. We propose that species of wet sites follow an all-or-nothing-strategy with fast and synchronous germination to maximize competitive advantages, betting on a high probability of moist conditions for establishment (optimists). In contrast, species from dry sites appear to follow a bet-hedging strategy with a moisture-sensing mechanism for unsuitable conditions (pessimists), resulting in a slower and less synchronous germination.

  • 61.
    Marker, Jeffery
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Bergman, Eva
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Eckstein, Rolf Lutz
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Lafage, Denis
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Forested riparian buffer environmental variables are more important than size for species functional diversity in production forests2022Ingår i: Forest Ecology and Management, ISSN 0378-1127, E-ISSN 1872-7042, Vol. 526, artikel-id 120599Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Retention of forested buffers around streams following forest cutting operations is a common managementtechnique used to protect aquatic resources and conserve the surrounding ecosystem services. Species richness,or α-diversity, is commonly used as an indicator of the effects of forestry management although it provides verylittle information about those effects on ecosystem processes and function. Functional diversity links speciestraits and ecosystem function incorporating species diversity, community composition, and functional guild andis more suitable to investigate the direct and indirect effects of forestry on ecosystem function. We sampledspiders and vascular plants in buffered and unbuffered stream-forest systems in southern Sweden and used atrait-based approach to assess the effects of buffer size and environmental variables on functional diversity. Weused structural equation modeling (SEM) to explore the effects of buffer size and condition on spider and vascularplant diversity. We found no effect of buffer size on the functional richness or functional redundancy for spidersor vascular plants. Buffer size had a slight effect on the α-diversity of spiders within small buffers and fullyforested sites but the effect was small. Other buffer variables including canopy closure, buffer density, bareground coverage, and soil fertility had direct effects on spider and vascular plant functional diversity. The maindriver of functional richness was α-diversity, but our SEM analysis illustrated other environmental variablesworking jointly to drive functional diversity. Using a trait-based approach, we showed that forested buffers havea minimal overall impact on spider and vascular plant functional diversity. However, it is important to maintainhigh levels of α-diversity to preserve and promote both spider and plant functional richness in production forestsand we suggest that forest management conserves and encourages high levels of α-diversity to increase overallfunctional diversity.

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  • 62. Moora, Mari
    et al.
    Opik, Maarja
    Davison, John
    Jairus, Teele
    Vasar, Martti
    Zobel, Martin
    Eckstein, Rolf Lutz
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    AM fungal communities inhabiting the roots of submerged aquatic plant Lobelia dortmanna are diverse and include a high proportion of novel taxa2016Ingår i: Mycorrhiza, ISSN 0940-6360, E-ISSN 1432-1890, Vol. 26, nr 7, s. 735-745Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    While the arbuscular mycorrhizal (AM) symbiosis is known to be widespread in terrestrial ecosystems, there is growing evidence that aquatic plants also form the symbiosis. It has been suggested that symbiosis with AM fungi may represent an important adaptation for isoA << tid plants growing on nutrient-poor sediments in oligotrophic lakes. In this study, we address AM fungal root colonization intensity, richness and community composition (based on small subunit (SSU) ribosomal RNA (rRNA) gene sequencing) in five populations of the isoA << tid plant species Lobelia dortmanna inhabiting oligotrophic lakes in Southern Sweden. We found that the roots of L. dortmanna hosted rich AM fungal communities and about 15 % of the detected molecular taxa were previously unrecorded. AM fungal root colonization intensity and taxon richness varied along an environmental gradient, being higher in oligotrophic and lower in mesotrophic lakes. The overall phylogenetic structure of this aquatic fungal community differed from that described in terrestrial systems: The roots of L. dortmanna hosted more Archaeosporaceae and fewer Glomeraceae taxa than would be expected based on global data from terrestrial AM fungal communities.

  • 63.
    Nordström, Emil
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Eckstein, Rolf Lutz
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Lind, Lovisa
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Edge effects on decomposition in Sphagnum bogs: Implications for carbon storage2022Ingår i: Ecosphere, ISSN 2150-8925, E-ISSN 2150-8925, Vol. 13, nr 9, artikel-id e4234Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Peatlands provide multiple ecosystem services, including extensive carbon sequestration and storage, yet many peatlands have been degraded or destroyed. Peatlands' carbon storage capacity is connected to inherently low decomposition rates, causing the buildup of organic matter. This pattern could be explained by waterlogged conditions that reduce the amount of available oxygen for the decomposer community, a low pH that inhibits bacterial decomposition, or colder temperatures lowering metabolic rates. This study focused on edge effects on decomposition in the transition zone (lagg) between Sphagnum bogs and the surrounding forest, with the expectation that decomposition is lowest in the bog and highest in the forest but with a mix of factors causing intermediate decomposition rates near the bog edge. Transitional decomposition rates were measured across six bogs in central Sweden during the summer of 2021, following the Tea Bag Index. Three 20-m transects, each containing seven pairs of tea bags, were buried across the margins of each bog, centered at the edge of the Sphagnum moss. Soil moisture content, pH, and plant composition were also recorded at each burial site, and temperature loggers placed evenly among four of the bogs. Our results confirmed our hypothesis regarding edge effects, with soil moisture levels showing a strong negative interaction with decomposition rate. The interaction between pH and decomposition rate was significant, but with an unexpected negative relation, most likely due to low pH in the surrounding forest. Temperature displayed no significance, and plants indicative of low decomposition rates included Vaccinium oxycoccos, Drosera rotundifolia, and Sphagnum species. In contrast to other studies, we did not find an increase in decomposition with increased species richness among the studied bog ecosystems. In conclusion, there is an edge effect on decomposition, and maintaining, or restoring, the hydrology of a peatland is the most important factor for continued carbon storage, with a rough estimation of an area decomposition rate possible to be estimated based on its vegetation.

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  • 64.
    Pruchniewicz, Daniel
    et al.
    Wroclaw Univ Environm & Life Sci, Dept Bot & Plant Ecol, Pl Grunwaldzki 24a, PL-50363 Wroclaw, Poland..
    Donath, Tobias W.
    Univ Kiel, Inst Nat Resource Conservat, Dept Landscape Ecol, Olshausenstr 75, D-24118 Kiel, Germany..
    Otte, Annette
    Univ Giessen, Res Ctr BioSyst Land Use & Nutr IFZ, Inst Landscape Ecol & Resource Management, Heinrich Buff Ring 26-32, D-35392 Giessen, Germany..
    Zolnierz, Ludwik
    Wroclaw Univ Environm & Life Sci, Dept Bot & Plant Ecol, Pl Grunwaldzki 24a, PL-50363 Wroclaw, Poland..
    Eckstein, Rolf Lutz
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Effect of expansive species on seed rain and soil seed bank of mountain mesic meadows2016Ingår i: Tuexenia, ISSN 0722-494X, nr 36, s. 81-96Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The degradation of species-rich mountain meadows has been observed in many parts of Central Europe in the last few decades. It is reflected in decreasing species numbers and changes in the proportions of plant species in the aboveground vegetation. Some species are increasing in abundance and eventually dominate the meadow vegetation. There is still a lack of studies explaining how this process is reflected in the soil seed bank. Therefore, the goal of the current study was to test whether expansive species that degrade aboveground vegetation of mountain meadows also influence, quantitatively and qualitatively, seed rain and seed bank. Soil samples were taken from 14 plots in degraded patches and another 14 plots in non-degraded patches. Nearly the same numbers of seedlings were recorded in both meadow types. In both cases, low similarities between aboveground vegetation and soil seed rain and seed bank were observed. Expansive species causing meadow degradation (Calamagrostis epigejos, Festuca rubra, Deschampsia cespitosa and Lupinus polyphyllus) reached cover values of 60-83% in the aboveground vegetation, and a share of up to 36% in the seed rain and seed bank. The mean species richness in the aboveground vegetation and the soil of degraded meadows was lower than in the non degraded plots. However, the seed bank may buffer degradation to some extent since the degradation of aboveground vegetation was faster than impoverishment of seed bank. Consequently, seed rain and seed bank of degraded meadows still contained typical mesic meadow species in similar proportions as non-degraded meadows. This indicates that seed rain and seed bank may contribute to the restoration of degraded meadows after the removal of expansive species from the aboveground vegetation.

  • 65.
    Ruehl, A. T.
    et al.
    Univ Giessen, Inst Landscape Ecol & Resource Management, Heinrich Buff Ring 26-32, D-35392 Giessen, Germany..
    Eckstein, R. L.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013). Univ Giessen, Inst Landscape Ecol & Resource Management, Heinrich Buff Ring 26-32, D-35392 Giessen, Germany.
    Otte, A.
    Univ Giessen, Inst Landscape Ecol & Resource Management, Heinrich Buff Ring 26-32, D-35392 Giessen, Germany..
    Donath, T. W.
    Univ Kiel, Dept Landscape Ecol, Inst Nat Resource Conservat, Kiel, Germany..
    Distinct germination response of endangered and common arable weeds to reduced water potential2016Ingår i: Plant Biology, ISSN 1435-8603, E-ISSN 1438-8677, Vol. 18, s. 83-90Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Arable weeds are one of the most endangered species groups in Europe. Modern agriculture and intensive land-use management are the main causes of their dramatic decline. However, besides the changes in land use, climate change may further challenge the adaptability of arable weeds. Therefore, we investigated the response pattern of arable weeds to different water potential and temperature regimes during the phase of germination. We expected that endangered arable weeds would be more sensitive to differences in water availability and temperature than common arable weeds. To this end, we set up a climate chamber experiment where we exposed seeds of five familial pairs of common and endangered arable weed species to different temperatures (5/15, 10/20 degrees C) and water potentials (0.0 to -1.2 MPa). The results revealed a significant relationship between the reaction of arable weed species to water availability and their Red List status. The effects of reduced water availability on total germination, mean germination time and synchrony were significantly stronger in endangered than in common arable weeds. Therefore, global climate change may present a further threat to the survival of endangered arable weed species.

  • 66.
    Ruehl, A. Theresa
    et al.
    Univ Giessen, Inst Landscape Ecol & Resource Management, D-35392 Giessen, Germany..
    Donath, Tobias W.
    Univ Kiel, Inst Nat Resource Conservat, Dept Landscape Ecol, Olshaussenstr 40, D-24118 Kiel, Germany..
    Otte, Annette
    Univ Giessen, Inst Landscape Ecol & Resource Management, D-35392 Giessen, Germany..
    Eckstein, R. Lutz
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper.
    Impacts of short-term germination delay on fitness of the annual weed Agrostemma githago (L.)2016Ingår i: Seed Science Research, ISSN 0960-2585, E-ISSN 1475-2735, Vol. 26, nr 2, s. 93-100Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Time of seedling emergence is an important step in the life cycle of annual plants because it may determine subsequent performance and success. Timing of emergence is especially critical to plant performance in habitats like arable fields which are subject to frequent disturbances. Within-season variation in timing of germination in the range of only a few days is typical for many arable weeds. However, since it is unclear whether such small deviations in germination date translate into fitness differences in the course of the life cycle, the aim of this paper was to quantify the effects of short germination delays on plant performance. We conducted two generalized randomized block experiments in an unheated greenhouse to study the impact of delayed germination (1, 2, 3 and 7 d) with and without competition, respectively, on the fitness of the arable weed species Agrostemma githago (L.). We expected that delayed germination significantly reduces fitness in terms of several life-history traits, and that the decrease of fitness is higher in the presence of competition. Under realistic conditions with competition through barley, Agrostemma plants with delayed germination of 7 d produced 54% fewer shoots, 57% less biomass, 52% fewer flowers, 36% lighter seeds and were 23% shorter as compared to control plants without delayed germination. Without additional stress through competition with barley this pattern was less pronounced. Thus, in the situation of interspecific competition, early emerging seedlings have biologically significant fitness advantages over later emerging seedlings of the same species.

  • 67. Ruehl, A. Theresa
    et al.
    Eckstein, Rolf Lutz
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper. Justus Liebig University Giessen, Germany.
    Otte, Annette
    Donath, Tobias W.
    Future challenge for endangered arable weed species facing global warming: Low temperature optima and narrow moisture requirements2015Ingår i: Biological Conservation, ISSN 0006-3207, E-ISSN 1873-2917, Vol. 182, s. 262-269Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    As a result of the intensification of agriculture in Central Europe, many arable weed species have declined. Global climate change may further challenge the adaptability of arable weeds since plants may be more often subjected to higher temperatures and lower soil moisture during the germination period.

    A climate chamber experiment analysed the response of four familial pairs of common and endangered arable weeds from Germany. To this end we used a large range of temperatures and water potentials to assess specific traits defining their germination requirements. Using a simple response surface approach, we predicted germination response under three climate change scenarios.Results supported our expectation that endangered species, owing to their narrow germination requirements, may be more negatively affected by global warming than common species. Endangered species germinated significantly less than the common arable weeds, except at very low temperatures (3 °C and 5 °C). The preference of endangered arable weed species for low germination temperatures was confirmed by their low optimal germination temperature (15.8 °C ± 0.4). In contrast, common species germinated at significant higher temperatures (optimal temperature 18.4 °C ± 0.2), had a significantly wider range of germination temperature (endangered: 24 °C ± 3.5, common: 31 °C ± 0.5) and were also more flexible towards changes in water potential.Calculations based on response surfaces for three climate change scenarios indicated that endangered arable weed species may benefit less from climate warming than common species.

  • 68.
    Ruprecht, Eszter
    et al.
    Romania.
    Donath, Tobias W.
    Justus Liebig University Giessen, Germany.
    Otte, Annette
    Justus-Liebig-University Giessen, Germany.
    Eckstein, Rolf Lutz
    Justus-Liebig-University Giessen, Germany.
    Chemical effects of a dominant grass on seed germination of four familial pairs of dry grassland species2008Ingår i: Seed Science Research, ISSN 0960-2585, E-ISSN 1475-2735, Vol. 18, nr 4, s. 239-248Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Community composition and ecosystem processes during succession may be driven partly by traits of plant species that attain dominance. Here, we addressed the hypothesis that Stipa pulcherrima, the dominant grass of abandoned continental grasslands, controls seedling recruitment of co-occurring species through chemical effects of its litter. Eight species with successful and unsuccessful recruitment under field conditions were selected (four familial pairs) to study experimentally the effects of leaf leachate under four temperature regimes. Since fungi developed in leachate-treated Petri dishes, in another experiment seeds were surface sterilized to remove confounding effects of fungi on recruitment. Leachate affected various stages of seedling recruitment: it significantly reduced seed germination (by 33-94%) and radicle elongation, and it delayed germination of seedlings of all species. In two families, species with unsuccessful field recruitment were more negatively affected than the successful ones. In a third family, the species with successful recruitment was more negatively affected, and in the fourth there were no differences. Similar germination responses after exclusion of fungi through seed-surface sterilization suggested that leachate was responsible for the observed effects on recruitment. Besides other traits and physical/microclimatic effects of accumulating litter, S. pulcherrima influences plant community dynamics and may potentially affect ecosystem processes through its secondary compounds.

  • 69.
    Ruprecht, Eszter
    et al.
    Romania.
    Enyedi, Marton Z.
    Romania.
    Eckstein, Rolf Lutz
    Justus-Liebig-University Giessen, Germany.
    Donath, Tobias W.
    Justus-Liebig-University Giessen, Germany.
    Restorative removal of plant litter and vegetation 40 years after abandonment enhances re-emergence of steppe grassland vegetation2010Ingår i: Biological Conservation, ISSN 0006-3207, E-ISSN 1873-2917, Vol. 143, nr 2, s. 449-456Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The accumulation of biomass and of dead plant remains is a direct consequence of grassland abandonment. Litter can occupy potential microsites for seed germination and seedling establishment, and thus decrease species diversity in the long-term. This effect can be more accentuated in dry grassland of open structure where species are adapted to excessive light and bare surfaces during the recruitment phase. We conducted a field experiment with litter removal alone or in combination with vegetation cutting and studied germination and seedling survival during 2 years in two abandoned steppe sites. With our experimental treatments we intended to create microsites and to activate the seed bank, with the aim to enhance recruitment of dry-grassland species; potentially also those already absent from the established vegetation. Our results show, that while both treatments significantly increased recruitment by enhancing seed germination in the first year of the study, only litter removal combined with vegetation cutting significantly promoted seedling survival during both years. Our experiment demonstrated that even after 40 years of abandonment the applied measures favoured the re-emergence of target species that were very rare or absent from the above-ground vegetation of continental steppe-like grassland. Thus, management prescriptions which comprise removal of dead and even living biomass, such as mowing or grazing, are considered beneficial for this habitat type of high nature conservation priority. (C) 2009 Elsevier Ltd. All rights reserved.

  • 70.
    Schmiede, Ralf
    et al.
    Justus-Liebig-University, Giessen, Germany.
    Ruprecht, Eszter
    Babeş-Bolyai University, Romania.
    Eckstein, Rolf Lutz
    Justus-Liebig-University, Giessen, Germany.
    Otte, Annette
    Justus-Liebig University, Giessen, Germany.
    Donath, Tobias W.
    Justus-Liebig-University, Giessen, Germany.
    Establishment of rare flood meadow species by plant material transfer: Experimental tests of threshold amounts and the effect of sowing position2013Ingår i: Biological Conservation, ISSN 0006-3207, E-ISSN 1873-2917, Vol. 159, s. 222-229Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The transfer of freshly cut seed-containing plant material is a widely applied method to re-establish grassland of high biodiversity. Still, the amount of plant material applied varies greatly across restoration projects. Therefore, we set up a two-year common garden experiment where we assessed the effect of plant material amount (0, 400, 800, 1600, 3200 g m2 and relative seed position (on top and beneath a litter layer) on seedling establishment, seedling fate and seedling fitness of eight target species for restoration of alluvial meadows. Most seedlings (85.6%) emerged within the first year. Cumulative seedling emergence and final seedling establishment across all species were highest on control plots and low litter plots but were very low or failed completely, at 1600 and 3200 g m2, respectively. In general, large-seeded species were significantly more successful than smaller seeded species. Relative seed position had only a small impact on seedling emergence and establishment but was decisive for seedling survival at high litter quantities. Across all species, seedlings that died had a significantly lower relative height than surviving seedlings. Interestingly, co-occurring resident grassland vegetation had a neutral rather than negative impact on the response variables. Our results suggest an upper threshold of 1000 g m2 for the amount of plant material applied in grassland restoration, since higher amounts will inhibit seedling establishment. The prompt emergence of most seedlings during the first vegetation period highlights the importance of creating optimal conditions for seedling establishment already in the early phase of vegetation development on restoration sites.

  • 71.
    Schulz, Benjamin
    et al.
    Justus Liebig University Giessen, Germany.
    Durka, Walter
    Helmholtz Centre for Environmental Research-UFZ, Germany; German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Germany..
    Danihelka, Jiri
    Masaryk University, Czech Republic; The Czech Academy of Sciences, Czech Republic..
    Eckstein, Rolf Lutz
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Differential role of a persistent seed bank for genetic variation in early vs. late successional stages2018Ingår i: PLOS ONE, E-ISSN 1932-6203, Vol. 13, nr 12, artikel-id e0209840Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Persistent seed banks are predicted to have an important impact on population genetic processes by increasing effective population size and storing past genetic diversity. Accordingly, persistent seed banks may buffer genetic effects of disturbance, fragmentation and/or selection. However, empirical studies surveying the relationship between aboveground and seed bank genetics under changing environments are scarce. Here, we compared genetic variation of aboveground and seed bank cohorts in 15 populations of the partially cleistogamous Viola elatior in two contrasting early and late successional habitats characterized by strong differences in light-availability and declining population size. Using AFLP markers, we found significantly higher aboveground than seed bank genetic diversity in early successional meadow but not in late successional woodland habitats. Moreover, individually, three of eight woodland populations even showed higher seed bank than aboveground diversity. Genetic differentiation among populations was very strong ((ST) = 0.8), but overall no significant differentiation could be detected between above ground and seed bank cohorts. Small scale spatial genetic structure was generally pronounced but was much stronger in meadow (Sp-statistic: aboveground: 0.60, seed bank: 0.32) than in woodland habitats (aboveground: 0.11; seed bank: 0.03). Our findings indicate that relative seed bank diversity (i.e. compared to aboveground diversity) increases with ongoing succession and despite decreasing population size. As corroborated by markedly lower small-scale genetic structure in late successional habitats, we suggest that the observed changes in relative seed bank diversity are driven by an increase of outcrossing rates. Persistent seed banks in Viola elatior hence will counteract effects of drift and selection, and assure a higher chance for the species' long term persistence, particularly maintaining genetic variation in declining populations of late successional habitats and thus enhancing success rates of population recovery after disturbance events.

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  • 72.
    Schulz, Benjamin
    et al.
    Justus-Liebig-University, Giessen, Germany.
    Eckstein, Rolf Lutz
    Justus-Liebig-University, Giessen, Germany.
    Durka, Walter
    Justus-Liebig-University, Giessen, Germany.
    Epigenetic variation reflects dynamic habitat conditions in a rare floodplain herb2014Ingår i: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 23, nr 14, s. 3523-3537Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Variation of DNA methylation is thought to play an important role for rapid adjustments of plant populations to dynamic environmental conditions, thus compensating for the relatively slow response time of genetic adaptations. However, genetic and epigenetic variation of wild plant populations has not yet been directly compared in fast changing environments. Here, we surveyed populations of Viola elatior from two adjacent habitat types along a successional gradient characterized by strong differences in light availability. Using amplified fragment length polymorphisms (AFLP) and methylation-sensitive amplification polymorphisms (MSAP) analyses, we found relatively low levels of genetic (H-gen' = 0.19) and epigenetic (H-epi' = 0.23) diversity and high genetic (phi(ST) = 0.72) and epigenetic (phi(ST) = 0.51) population differentiation. Diversity and differentiation were significantly correlated, suggesting that epigenetic variation partly depends on the same driving forces as genetic variation. Correlation-based genome scans detected comparable levels of genetic (17.0%) and epigenetic (14.2%) outlier markers associated with site specific light availability. However, as revealed by separate differentiation-based genome scans for AFLP, only few genetic markers seemed to be actually under positive selection (0-4.5%). Moreover, principal coordinates analyses and Mantel tests showed that overall epigenetic variation was more closely related to habitat conditions, indicating that environmentally induced methylation changes may lead to convergence of populations experiencing similar habitat conditions and thus may play a major role for the transient and/or heritable adjustment to changing environments. Additionally, using a new MSAP-scoring approach, we found that mainly the unmethylated (phi(ST) = 0.60) and CG-methylated states (phi(ST) = 0.46) of epiloci contributed to population differentiation and putative habitat-related adaptation, whereas CHG-hemimethylated states (phi(ST) = 0.21) only played a marginal role.

  • 73.
    Schulz, Benjamin
    et al.
    Justus-Liebig-University Giessen, Germany.
    Eckstein, Rolf Lutz
    Justus-Liebig-University Giessen, Germany.
    Durka, Walter
    Helmholtz Centre for Environmental Research.
    Scoring and analysis of methylation-sensitive amplification polymorphisms for epigenetic population studies2013Ingår i: Molecular Ecology Resources, ISSN 1755-098X, E-ISSN 1755-0998, Vol. 13, nr 4, s. 642-653Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    DNA methylation is an important, heritable epigenetic modification in most eukaryotic organisms that is connected with numerous biological processes. To study the impact of natural epigenetic variation in an ecological or evolutionary context, epigenetic studies are increasingly using methylation-sensitive amplification polymorphism (MSAP) for surveys at the population or species level. However, no consensus exists on how to interpret and score the multistate information obtained from the MSAP banding patterns. Here, we review the previously used scoring approaches for population epigenetic studies and develop new alternatives. To assess effects of the different approaches on parameters of epigenetic diversity and differentiation, we applied eight scoring schemes to a case study of three populations of the plant species Viola elatior. For a total number of 168 detected polymorphic MSAP fragments, the number of ultimately scored polymorphic epiloci ranged between 78 and 286 depending on the particular scoring scheme. Both, estimates of epigenetic diversity and differentiation varied strongly between scoring approaches. However, linear regression and PCoA revealed qualitatively similar patterns, suggesting that the scoring approaches are largely consistent. For single-locus analyses of MSAP data, for example the search for loci under selection, we advocate a new scoring approach that separately takes into account different methylation types and thus seems appropriate for drawing more detailed conclusions in ecological or evolutionary contexts. An R script (MSAP_score.r) for scoring and basic data analysis is provided.

  • 74.
    Shakeri, Zahed
    et al.
    Iran.
    Mohadjer, Mohammad Reza Marvie
    Iran.
    Simberloff, Daniel
    USA.
    Etemad, Vahid
    Iran.
    Assadi, Mostafa
    Iran.
    Donath, Tobias W.
    Germany.
    Otte, Annette
    Germany.
    Eckstein, Rolf Lutz
    Germany.
    Plant community composition and disturbance in Caspian Fagus orientalis forests: which are the main driving factors?2012Ingår i: Phytocoenologia, ISSN 0340-269X, Vol. 41, nr 4, s. 247-263Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The oriental beech forests along the southern Caspian Sea shores of Iran are characterized by high biodiversity and high ecological value. However, there is little information concerning factors governing community composition and the presence and abundance of invasive plants. In the present study we aimed to evaluate the main drivers of community composition, diversity, and establishment of invasive plants in disturbed and undisturbed Fagus orientalis communities. We sampled 104 vegetation releves in undisturbed and disturbed sites of the "Kheiroud Investigation Forest" in northern Iran and collected data on a large number of environmental variables concerning soil properties, light conditions, and topography. Data analysis consisted of a forward selection of significant explanatory variables followed by partial CCA analyses. Additionally, we carried out indicator species analysis of groups of releves affected by different disturbance types and analyzed effects of disturbance on species richness, diversity, and evenness using general linear models. CCA results showed that disturbance, soil properties, light conditions and elevation explained 22.6% of the total variation in floristic composition. Gap and gap + grazing were the most important disturbance types affecting community composition. Disturbance had significant but rather weak effects on species richness, evenness, and the Shannon index. The most obvious effect of disturbance was on species composition, as revealed by significant groups of indicator species for different disturbance types. Most of the indicator species in grazed sites were unpalatable, poisonous, and creeping species, which are avoided by cattle. Grazing led to decreased abundance of indicator species and species characteristic of old-growth Fagus forests. The most intensive disturbance type "harvesting + gap + grazing" was associated with invasion by native vascular plant species not typically found in beech forests (apophytes).

  • 75.
    Shakeri, Zahed
    et al.
    University of Kassel, DEU.
    Simberloff, Daniel
    University of Tennessee, USA.
    Bernhardt-Roemermann, Markus
    Friedrich Schiller University, DEU.
    Eckstein, Rolf Lutz
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    The impact of livestock grazing and canopy gaps on species pool and functional diversity of ground flora in the Caspian beech forests of Iran2021Ingår i: Applied Vegetation Science, ISSN 1402-2001, E-ISSN 1654-109X, Vol. 24, nr 3, s. 1-13, artikel-id e12592Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Questions Livestock grazing is an important disturbance in many forest ecosystems. While several studies have addressed the general impact of different grazing and light intensities on temperate forest ecosystems, little is known about how the combination of these two factors can affect the species pool and functional diversity of temperate forests. Location Oriental beech forests of northern Iran. Methods Vegetation and environmental data of 104 releves were collected. These were assigned to four groups based on their light and grazing intensities. Non-metric multidimensional scaling was used to analyze vegetation compositional relationships among groups. We used nine functional traits related to growth, reproduction, and survival for a total of 147 plant species. Redundancy analysis of community-weighted means was used to determine the response of single traits to disturbance and environmental variables. Generalized additive models were applied to examine the shape of the response pattern of community-weighted mean trait values across the grazing and light intensity gradients. Functional richness and functional divergence indices were used to analyze functional diversity-disturbance relationships. Results Both light and grazing intensities significantly affected species pools, single traits, and functional divergence. Suites of trait attributes including hemicryptophytes, therophytes, grass-like, hygromorphic leaves, insect-pollinated, rhizomes, and runner plants were associated with high-light sites. In closed-canopy sites the strong filtering effect of shade resulted in suites of trait attributes including taller plants, macrophanerophytes, scleromorphic leaves, simple leaves, and berry fruits. While high-light sites had a larger species pool, they exhibited less functional diversity. Cattle grazing can mediate the filtering effect of light and increase functional diversity in both low-light and high-light sites. Conclusion Conservation measures in this region should acknowledge that moderate traditional cattle grazing combined with individual-tree and group-tree selection in these forests may maintain or even enhance functional diversity in these valuable ecosystems.

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  • 76.
    Svensson, Eva
    et al.
    Karlstads universitet, Fakulteten för humaniora och samhällsvetenskap (from 2013), Institutionen för samhälls- och kulturvetenskap (from 2013).
    Haas, Jan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Eckstein, Rolf Lutz
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Integrating Nature and Heritage in the Boreal Forests of Scandinavia? Exploration of a Low-Budget Method2020Ingår i: Landscapes, ISSN 1466-2035, Vol. 21, nr 1, s. 72-92Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The concepts landscape and biocultural heritage are based on anintegrated view of nature and cultural heritage. This paperinvestigates the potential of using a low-budget method forintegrating information on human impact and natural responsesin the vegetation of boreal forested Scandinavia. The informationfrom two national databases in Sweden – the National Inventoryof Landscapes in Sweden (NILS) covering surveyed vegetation,and the Register of Ancient Monuments (Fornsök) – werecombined and visualised using a Geographical Information System(GIS). In total, five sites were investigated. No connection betweenhuman impact and vegetation was detected at any of them. Thisnegative result is partly due to gaps in time and scale, but mainlyto sectorised survey methods not paying attention to bioculturalheritage, landscape perspectives or long-term processes. Thepaper concludes that further development of survey methods andregisters targeting contexts and processes are called for.

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  • 77.
    Voss, Nicole
    et al.
    Justus-Liebig-University Giessen, Germany.
    Eckstein, Rolf Lutz
    Justus-Liebig-University Giessen, Germany.
    Durka, Walter
    UFZ, Halle, Germany.
    Range expansion of a selfing polyploid plant despite widespread genetic uniformity2012Ingår i: Annals of Botany, ISSN 0305-7364, E-ISSN 1095-8290, Vol. 110, nr 3, s. 585-593Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Ongoing and previous range expansions have a strong influence on population genetic structure of plants. In turn, genetic variation in the new range may affect the population dynamics and the expansion process. The annual Ceratocapnos claviculata (Papaveraceae) has expanded its Atlantic European range in recent decades towards the north and east. Patterns of genetic diversity were investigated across the native range to assess current population structure and phylogeographical patterns. A test was then made as to whether genetic diversity is reduced in the neophytic range and an attempt was made to identify source regions of the expansion. Samples were taken from 55 populations in the native and 34 populations in the neophytic range (Sweden, north-east Germany). Using amplified fragment length polymorphism markers an analysis was made of genetic variation and population structure (Bayesian statistical modelling) and population differentiation was quantified. Pollen/ovule ratio was analysed as a proxy for the breeding system. Genetic diversity at population level was very low (mean H-e 0004) and two multilocus genotypes dominated large parts of the new range. Population differentiation was strong (F-ST 0812). These results and a low pollen/ovule ratio are consistent with an autogamous breeding system. Genetic variation decreased from the native to the neophytic range. Within the native range, H-e decreased towards the north-east, whereas population size increased. According to the Bayesian cluster analysis, the putative source regions of the neophytic range are situated in north-west Germany and adjacent regions. Ceratocapnos claviculata shows a cline of genetic variation due to postglacial recolonization from putative Pleistocene refugia in south-west Europe. Nevertheless, the species has expanded successfully during the past 40 years to southern Sweden and north-east Germany where it occurs as an opportunistic neophyte. Recent expansion was mainly human-mediated by single long-distance diaspore transport and was facilitated by habitat modification.

  • 78. Voss, Nicole
    et al.
    Simmering, Dietmar
    Peppler-Lisbach, Cord
    Carl von Ossietzky University Oldenburg.
    Durka, Walter
    Helmholtz Centre for Environmental Research, Halle, Germany.
    Eckstein, Rolf Lutz
    Justus-Liebig-University Giessen, Germany.
    Vegetation databases as a tool to analyse factors affecting the range expansion of the forest understory herb Ceratocapnos claviculata2011Ingår i: Journal of Vegetation Science, ISSN 1100-9233, E-ISSN 1654-1103, Vol. 22, nr 4, s. 726-740Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Question: The eu-atlantic forest herb Ceratocapnos claviculata showed a recent increase in frequency within its native range and an eastward and northward range expansion in Central Europe. To gain deeper understanding of factors affecting the range expansion of the species, we analyzed vegetation releves at three different scales and asked the following questions: As the species occurs in a wide range of vegetation types, is variation in community composition across the entire range related to climatic environmental zones and tree cover? Are there differences in species composition and habitat characteristics between the native range and the two invaded regions (S Sweden and NE Germany)? Did community composition and habitat characteristics within the native range (The Netherlands) change between 'before 1970' and '1990 to 2006'? Location: W, C and N Europe. Methods: We analysed vegetation-plot data with C. claviculata from various databases and own surveys using partial CCA, partial DCA, Indicator Species Analysis, MANCOVA and multiple regression. Results: Using vegetation plots from the entire distribution range, climatic environmental zones explained 68.9% of the total canonical Eigenvalue. Differences in floristic composition and habitat characteristics between the two invaded regions were as large as between native and invaded range sites. However, releves from the invaded range were generally characterized by anthropogenic disturbance. Accordingly, abundance of C. claviculata was positively linked to silvicultural intensity. New releves from 1990 to 2006 were characterized by higher Ellenberg nutrient indicator values, lower species diversity, higher proportions of neophytic and hemerobic species and showed a lower cover of the study species than old releves from before 1970. Conclusions: Across the range of C. claviculata, climatic environmental zones determine vegetation composition. Accordingly, the species is characterized by a broad macroclimatic amplitude. Vegetation composition and structure differ significantly between the two regions of the new range. Thus, the species has successfully established under various biotic and abiotic environmental conditions. Beyond potential positive effects of soil eutrophication and mild winters, anthropogenic impact may directly facilitate seed dispersal and provide sites and resource conditions suitable for germination and establishment of C. claviculata, whereas a decrease of forest management may constrain the species.

  • 79.
    Voss, Nicole
    et al.
    Justus-Liebig-University, Giessen, Germany.
    Welk, Erik
    Martin Luther Univerity, Halle, Germany.
    Durka, Walter
    UFZ, Halle, Germany.
    Eckstein, Rolf Lutz
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper. Justus-Liebig-University Giessen, Germany.
    Biological flora of Central Europe: Ceratocapnos claviculata (L.) Liden2012Ingår i: Perspectives in plant ecology, evolution and systematics, ISSN 1433-8319, E-ISSN 1618-0437, Vol. 14, nr 1, s. 61-77Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The eu-oceanic therophytic woodland herb Ceratocapnos claviculata has been expanding north- and eastwards into north temperate and subcontinental regions during the past decades. The rapid range expansion of the species may be an example of a species which is strongly profiting from global change. Against this background, in the present paper we review the taxonomy, morphology, distribution, habitat requirements, life cycle and biology of the species. (C) 2011 Elsevier GmbH. All rights reserved.

  • 80.
    Watz, Johan
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Eckstein, Rolf Lutz
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013).
    Nyqvist, Daniel
    Polytechnic University of Turin, Italy.
    Effects of fragmentation per se on slug movement2021Ingår i: Acta Oecologica, ISSN 1146-609X, E-ISSN 1873-6238, Vol. 112, artikel-id 103771Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    To predict the effects of habitat alterations on animal populations we need insight into how the habitat configuration influences local scale movements. This relationship may be particularly important for effective management of pest species. We tracked 80 PIT-tagged Spanish slugs (Arion vulgaris) in 16 × 16 m arenas with manipulated habitat fragmentation. The arenas had habitat patches consisting of high grass residing within a matrix of short grass, and the arenas with a high degree of fragmentation had 12 large (2 × 2 m), 13 medium-sized (1 × 1 m) and 12 small (0.5 × 0.5 m) patches, whereas the arenas with low fragmentation had four 4 × 4 m patches, resulting in equal amounts of total habitat patch area in the two treatments. The measured mean distance moved per day was 3.8 m, and between 0 and 25% of the slugs left the arenas each day. Fragmentation treatment had no effect on these two measurements. In the treatment with patches of different sizes, slugs distributed themselves among the patch size classes according to the total amount of habitat area for each habitat patch class, whereas patch edge did not explain the distribution pattern. All in all, fragmentation per se seems to play a minor role in the local movement and distribution of Spanish slugs.

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  • 81.
    Winter, Silvia
    et al.
    University of Natural Resources and Life Sciences Vienna, Austria.
    Jung, Linda S.
    Justus-Liebig-University, Giessen, Germany.
    Eckstein, Rolf Lutz
    Justus-Liebig-University, Giessen, Germany.
    Otte, Annette
    Justus-Liebig-University, Giessen, Germany.
    Donath, Tobias W.
    Justus-Liebig-University, Giessen, Germany.
    Kriechbaum, Monika
    University of Natural Resources and Life Sciences Vienna, Austria.
    Control of the toxic plant Colchicum autumnale in semi- natural grasslands: Effects of cutting treatments on demography and diversity2014Ingår i: Journal of Applied Ecology, ISSN 0021-8901, E-ISSN 1365-2664, Vol. 51, nr 2, s. 524-533Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Semi-natural grasslands are important habitats for the conservation of biodiversity in Europe. High population densities of toxic Colchicum autumnale in these grasslands may cause problems for livestock and the marketing of hay. Consequently, farmers may either intensify grassland management to reduce C. autumnale in the fodder or abandon the land; both practices will lead to a loss of biodiversity. Previous studies suggesting early cutting to control C. autumnale did not consider population dynamics and the effects on plant diversity. We conducted a four-year experiment in six regions within Austria and Germany, applying five cutting treatments in 16 C. autumnale populations to test the effects of cutting date and frequency on C. autumnale and co-occurring vegetation. Demographic data were evaluated with matrix population models, life-table response experiment (LTRE), anova and manova. Vegetation data were analysed with multiresponse permutation procedures (MRPP), anova and manova. Population growth rate was significantly reduced in plots cut in early and late May compared to plots cut in June (control). Plants cut in late April or early May showed the lowest survival probability. Significantly fewer large vegetative plants developed capsules in the following year when cut in early or late May. LTRE analysis showed that differences in the population growth rate between the control and early cut treatments were mainly the result of a reduced survival and growth and an increased retrogression to smaller stages. Multiresponse permutation procedures revealed no differences in vegetation composition between treatments except for one site in 2011. There were no differences in Shannon index, evenness or species turnover rate within any year. Synthesis and applications. The greatest reduction in vitality of Colchicum autumnale was observed in grasslands cut in late April or early May. After three years of early cutting, no reduction in plant species diversity was observed. The second cut should be postponed to July to enable seed shed of plants. Grassland management decisions to control toxic C. autumnale must be made in close cooperation with nature conservation authorities to consider site characteristics and requirements of endangered species. The greatest reduction in vitality of Colchicum autumnale was observed in grasslands cut in late April or early May. After three years of early cutting, no reduction in plant species diversity was observed. The second cut should be postponed to July to enable seed shed of plants. Grassland management decisions to control toxic C. autumnale must be made in close cooperation with nature conservation authorities to consider site characteristics and requirements of endangered species.

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