TY - JOUR A1 - Günther, Kerstin A1 - Schmidt, Marcus A1 - Quitt, Heinz A1 - Heinken, Thilo T1 - Veränderungen der Waldvegetation im Elbe-Havelwinkel von 1960 bis 2015 JF - Tuexenia : Mitteilungen der Floristisch-Soziologischen Arbeitsgemeinschaft N2 - Forest ecosystems are subject to a variety of influences such as forest management, nitrogen deposition, changes in the groundwater level or the immigration of invasive species. The repetition of historical releves is an important means of documenting the resulting changes in plant communities and determining their main drivers. In 2015, we examined the vegetation change in 140 semi-permanent plots in managed forests in the Elbe valley in the NE German lowlands (Saxony-Anhalt, Brandenburg). The first survey took place from 1956 to 1963. The releves cover an almost uniquely broad spectrum of different site conditions, ranging from wet forests (alluvial, swamp and bog forests of Alnion incanae, Alnion glutinosae and Betulion pubescentis) to acidic mixed oak forests (Quercion roboris) up to acidic, mostly dry pine forests with different nutrient status (Dicrano-Pinion). We analyzed the changes in the vegetation with the help of forest stand data, winner and loser species, alpha- and beta-diversity as well as the Ellenberg indicator values for nitrogen, reaction, moisture and light. In contrast to previous resurvey studies, areas were also taken into account on which a complete change of forest stand had taken place before the second survey. Particularly in the wet forests and acidic forests with a moderately good nutrient supply, changes in the main tree species have been recorded, and many pine stands have been newly established in the meantime. The species richness has decreased overall and in almost all forest types, but the beta-diversity has remained unchanged or has increased. The Ellenberg values indicate a decrease in soil moisture in the wet forests, while the acidic pine forests in particular have become darker, richer in nutrients and more humid. The number of loser species is more than twice as high as that of the winner species, but with different developments in the individual forest types. In particular, the wet forests, the acidic mixed oak forests and the lichen-pine forests have lost most of their characteristic species. The resurvey after more than 50 years shows a different development of the individual forest types. Vegetation changes in the wet forests are mainly due to local groundwater level drawdown and the resulting increased availability of nutrients. The alluvial forests were also strongly influenced by forest interventions. The reasons for the trend towards more humid and more nutrient-rich conditions in formerly dry acidic pine and oak forests are nitrogen depositions and a succession after the abandonment of historical forms of forest use (litter raking, forest pasture). Although the individual forest types have developed differently, eutrophication, falling groundwater levels and silviculture are the most important causes for the changes in vegetation. Silvicultural interventions such as clear cutting and stand conversion with a change of tree species are at the same time the main reason why the vegetation has not been homogenized despite the leveling of the site gradient as measured by the beta-diversity. N2 - Waldökosysteme unterliegen vielfältigen Einflüssen wie forstlicher Bewirtschaftung, Stickstoffdeposition, Veränderung des Grundwasserspiegels oder der Einwanderung invasiver Arten. Die Wiederholung historischer Vegetationsaufnahmen ist ein wichtiges Mittel, um Veränderungen der Pflanzengesellschaften zu dokumentieren und mögliche Hauptursachen (Treiber) zu bestimmen. Wir haben 2015 den Vegetationswandel auf 140 semi-permanenten Plots in Wirtschaftswäldern der Elbtalniederung im Nordostdeutschen Tiefland (Sachsen-Anhalt, Brandenburg) untersucht. Die Erstaufnahme erfolgte von 1956 bis 1963. Die Vegetationsaufnahmen decken ein fast einzigartig breites Spektrum unterschiedlicher Waldstandorte ab, das von Feuchtwäldern (Au-, Bruch- und Moorwäldern des Alnion incanae, Alnion glutinosae und Betulion pubescentis) über bodensaure Eichen-Mischwälder (Quercion roboris) bis hin zu bodensauren, meist trockenen Kiefernwäldern mit unterschiedlicher Nährstoffausstattung (Dicrano-Pinion) reicht. Die Veränderungen der Vegetation haben wir mit Hilfe von Bestandesdaten, Gewinner- und Verliererarten, der α- und β -Diversität sowie der Ellenberg-Zeigerwerte für Stickstoff, Reaktion, Feuchte und Licht analysiert. Dabei wurden, anders als in den meisten bisherigen Wiederholungsuntersuchungen, auch Flächen berücksichtigt, auf denen bis zur Zweitaufnahme ein vollständiger Bestandeswechsel stattgefunden hatte. Insbesondere in den Feuchtwäldern und den bodensauren Wäldern mit mäßig guter Nährstoffversorgung sind Wechsel der Hauptbaumarten zu verzeichnen; außerdem wurden viele Kiefernbestände zwischenzeitlich neu begründet. Die Artenzahl hat insgesamt und in fast allen Waldtypen abgenommen, die β-Diversität ist jedoch unverändert geblieben bzw. hat sich erhöht. Die Zeigerwerte deuten auf eine Abnahme der Bodenfeuchte in den Au-, Bruch-, und Moorwäldern hin, während insbesondere die bodensauren Kiefernwälder dunkler, nährstoffreicher und feuchter geworden sind. Die Anzahl der Verlierer-Arten ist mehr als doppelt so hoch wie die der Gewinner-Arten, jedoch mit unterschiedlicher Entwicklung in den einzelnen Waldtypen. Insbesondere die nassen und feuchten Wälder, die bodensauren Eichen-Mischwälder und die Flechten-Kiefernwälder haben die meisten ihrer charakteristischen Arten verloren. Veränderungen der Vegetation in den Feuchtwäldern gehen v. a. auf lokal gesunkene Grundwasserspiegel und eine dadurch gestiegene Nährstoffverfügbarkeit zurück; die Artenzusammensetzung der Auwälder wurde zudem sehr stark durch forstliche Eingriffe beeinflusst. Ursachen für den Trend zu feuchteren und nährstoffreicheren Bedingungen in ehemals trockenen bodensauren Kiefern- und Eichenwäldern sind Stickstoffeinträge sowie eine Sukzession nach Aufgabe historischer Waldnutzungs-formen (Streunutzung, Waldweide). Obwohl sich die einzelnen Waldtypen unterschiedlich entwickelt haben, sind Eutrophierung, sinkende Grundwasserspiegel und Waldbaumaßnahmen insgesamt die wichtigsten Ursachen für die beobachteten Vegetationsveränderungen. Forstliche Eingriffe wie Kahlschlag und Bestandesumbau mit Baumartenwechsel sind zugleich die Hauptursache dafür, dass es trotz Nivellierung des Standortsgradienten, gemessen an der β-Diversität, nicht zu einer Homogenisierung der Vegetation gekommen ist. T2 - Vegetation change in the forests between the Elbe and Havel rivers (NE Germany) from 1960 to 2015 KW - environmental gradient KW - eutrophication KW - falling groundwater level KW - homogenisation KW - phytodiversity KW - silviculture KW - vegetation change Y1 - 2021 U6 - https://doi.org/10.14471/2021.41.005 SN - 0722-494X IS - 41 SP - 53 EP - 85 PB - Floristisch-Soziologische Arbeitsgemeinschaft CY - Göttingen ER - TY - JOUR A1 - Diekmann, Martin A1 - Andres, Christian A1 - Becker, Thomas A1 - Bennie, Jonathan A1 - Blueml, Volker A1 - Bullock, James M. A1 - Culmsee, Heike A1 - Fanigliulo, Miriam A1 - Hahn, Annett A1 - Heinken, Thilo A1 - Leuschner, Christoph A1 - Luka, Stefanie A1 - Meissner, Justus A1 - Müller, Josef A1 - Newton, Adrian A1 - Peppler-Lisbach, Cord A1 - Rosenthal, Gert A1 - van den Berg, Leon J. L. A1 - Vergeer, Philippine A1 - Wesche, Karsten T1 - Patterns of long-term vegetation change vary between different types of semi-natural grasslands in Western and Central Europe JF - Journal of vegetation science N2 - Questions Has plant species richness in semi-natural grasslands changed over recent decades? Do the temporal trends of habitat specialists differ from those of habitat generalists? Has there been a homogenization of the grassland vegetation? Location Different regions in Germany and the UK. Methods We conducted a formal meta-analysis of re-survey vegetation studies of semi-natural grasslands. In total, 23 data sets were compiled, spanning up to 75 years between the surveys, including 13 data sets from wet grasslands, six from dry grasslands and four from other grassland types. Edaphic conditions were assessed using mean Ellenberg indicator values for soil moisture, nitrogen and pH. Changes in species richness and environmental variables were evaluated using response ratios. Results In most wet grasslands, total species richness declined over time, while habitat specialists almost completely vanished. The number of species losses increased with increasing time between the surveys and were associated with a strong decrease in soil moisture and higher soil nutrient contents. Wet grasslands in nature reserves showed no such changes or even opposite trends. In dry grasslands and other grassland types, total species richness did not consistently change, but the number or proportions of habitat specialists declined. There were also considerable changes in species composition, especially in wet grasslands that often have been converted into intensively managed, highly productive meadows or pastures. We did not find a general homogenization of the vegetation in any of the grassland types. Conclusions The results document the widespread deterioration of semi-natural grasslands, especially of those types that can easily be transformed to high production grasslands. The main causes for the loss of grassland specialists are changed management in combination with increased fertilization and nitrogen deposition. Dry grasslands are most resistant to change, but also show a long-term trend towards an increase in more mesotrophic species. KW - dry grasslands KW - fragmentation KW - homogenization KW - management KW - meta-analysis KW - nitrogen deposition KW - quasi-permanent plot KW - re-survey KW - species richness KW - wet grasslands Y1 - 2019 U6 - https://doi.org/10.1111/jvs.12727 SN - 1100-9233 SN - 1654-1103 VL - 30 IS - 2 SP - 187 EP - 202 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Schöpke, Benito A1 - Heinze, Johannes A1 - Pätzig, Marlene A1 - Heinken, Thilo T1 - Do dispersal traits of wetland plant species explain tolerance against isolation effects in naturally fragmented habitats? JF - Plant ecology : an international journal N2 - The effects of habitat fragmentation and isolation on plant species richness have been verified for a wide range of anthropogenically fragmented habitats, but there is currently little information about their effects in naturally small and isolated habitats. We tested whether habitat area, heterogeneity, and isolation affect the richness of wetland vascular plant species in kettle holes, i.e., small glacially created wetlands, in an agricultural landscape of 1 km(2) in NE Germany. We compared fragmentation effects with those of forest fragments in the same landscape window. Since wetland and forest species might differ in their tolerance to isolation, and because isolation effects on plant species may be trait dependent, we asked which key life history traits might foster differences in isolation tolerance between wetland and forest plants. We recorded the flora and vegetation types in 83 isolated sites that contained 81 kettle holes and 25 forest fragments. Overall, the number of wetland species increased with increasing area and heterogeneity, i.e., the number of vegetation types, while area was not a surrogate for heterogeneity in these naturally fragmented systems. Isolation did not influence the number of wetland species but decreased the number of forest species. We also found that seeds of wetland species were on average lighter, more persistent and better adapted to epizoochory, e.g., by waterfowl, than seeds of forest species. Therefore, we suggest that wetland species are more tolerant to isolation than forest species due to their higher dispersal potential in space and time, which may counterbalance the negative effects of isolation. KW - Forest species KW - Habitat fragmentation KW - Isolation KW - Kettle holes KW - Life history traits KW - Wetland species Y1 - 2019 U6 - https://doi.org/10.1007/s11258-019-00955-8 SN - 1385-0237 SN - 1573-5052 VL - 220 IS - 9 SP - 801 EP - 815 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Heim, Ramona J. A1 - Hölzel, Norbert A1 - Heinken, Thilo A1 - Kamp, Johannes A1 - Thomas, Alexander A1 - Darman, Galina F. A1 - Smirenski, Sergei M. A1 - Heim, Wieland T1 - Post-burn and long-term fire effects on plants and birds in floodplain wetlands of the Russian Far East JF - Biodiversity and conservation N2 - Wildfires affect biodiversity at multiple levels. While vegetation is directly changed by fire events, animals are often indirectly affected through changes in habitat and food availability. Globally, fire frequency and the extent of fires are predicted to increase in the future. The impact of fire on the biodiversity of temperate wetlands has gained little attention so far. We compared species richness and abundance of plants and birds in burnt and unburnt areas in the Amur floodplain/Russian Far East in the year of fire and 1 year after. We also analysed vegetation recovery in relation to time since fire over a period of 18 years. Plant species richness was higher in burnt compared to unburnt plots in the year of the fire, but not in the year after. This suggests that fire has a positive short-term effect on plant diversity. Bird species richness and abundance were lower on burnt compared to unburnt plots in the year of the fire, but not in the year after. Over a period of 18 years, high fire frequency led to an increase in herb cover and a decrease in grass cover. We show that the effects on biodiversity are taxon- and species-specific. Fire management strategies in temperate wetlands should consider fire frequency as a key driving force of vegetation structure, with carry-over effects on higher trophic levels. Designing fire refuges, i.e., areas that do not burn annually, might locally be necessary to maintain high species richness. KW - Disturbance KW - Bird species richness KW - Vegetation structure KW - Fire frequency KW - Amur River Y1 - 2019 U6 - https://doi.org/10.1007/s10531-019-01746-3 SN - 0960-3115 SN - 1572-9710 VL - 28 IS - 6 SP - 1611 EP - 1628 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Maes, Sybryn L. A1 - Blondeel, Haben A1 - Perring, Michael P. A1 - Depauw, Leen A1 - Brumelis, Guntis A1 - Brunet, Jörg A1 - Decocq, Guillaume A1 - den Ouden, Jan A1 - Haerdtle, Werner A1 - Hedl, Radim A1 - Heinken, Thilo A1 - Heinrichs, Steffi A1 - Jaroszewicz, Bogdan A1 - Kirby, Keith J. A1 - Kopecky, Martin A1 - Malis, Frantisek A1 - Wulf, Monika A1 - Verheyen, Kris T1 - Litter quality, land-use history, and nitrogen deposition effects on topsoil conditions across European temperate deciduous forests JF - Forest ecology and management N2 - Topsoil conditions in temperate forests are influenced by several soil-forming factors, such as canopy composition (e.g. through litter quality), land-use history, atmospheric deposition, and the parent material. Many studies have evaluated the effects of single factors on physicochemical topsoil conditions, but few have assessed the simultaneous effects of multiple drivers. Here, we evaluate the combined effects of litter quality, land-use history (past land cover as well as past forest management), and atmospheric deposition on several physicochemical topsoil conditions of European temperate deciduous forest soils: bulk density, proportion of exchangeable base cations, carbon/nitrogen-ratio (C/N), litter mass, bio-available and total phosphorus, pH(KCI)and soil organic matter. We collected mineral soil and litter layer samples, and measured site characteristics for 190 20 x 20 m European mixed forest plots across gradients of litter quality (derived from the canopy species composition) and atmospheric deposition, and for different categories of past land cover and past forest management. We accounted for the effects of parent material on topsoil conditions by clustering our plots into three soil type groups based on texture and carbonate concentration. We found that litter quality was a stronger driver of topsoil conditions compared to land-use history or atmospheric deposition, while the soil type also affected several topsoil conditions here. Plots with higher litter quality had soils with a higher proportion of exchangeable base cations, and total phosphorus, and lower C/N-ratios and litter mass. Furthermore, the observed litter quality effects on the topsoil were independent from the regional nitrogen deposition or the soil type, although the soil type likely (co)-determined canopy composition and thus litter quality to some extent in the investigated plots. Litter quality effects on topsoil phosphorus concentrations did interact with past land cover, highlighting the need to consider land-use history when evaluating canopy effects on soil conditions. We conclude that forest managers can use the canopy composition as an important tool for influencing topsoil conditions, although soil type remains an important factor to consider. KW - Soil fertility KW - Ancient forest KW - Post-agricultural forest KW - Coppice KW - High forest KW - pH KW - Phosphorus KW - Base cations KW - Nutrient cycling KW - Decomposition Y1 - 2019 U6 - https://doi.org/10.1016/j.foreco.2018.10.056 SN - 0378-1127 SN - 1872-7042 VL - 433 SP - 405 EP - 418 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Schwabe, Angelika A1 - Tischew, Sabine A1 - Bergmeier, Erwin A1 - Garve, Eckhard A1 - Härdtle, Werner A1 - Heinken, Thilo A1 - Hölzel, Norbert A1 - Peppler-Lisbach, Cord A1 - Remy, Dominique A1 - Dierschke, Hartmut T1 - Pflanzengesellschaft des Jahres 2020 BT - Borstgrasrasen JF - Tuexenia : Mitteilungen der Floristisch-Soziologischen Arbeitsgemeinschaft N2 - Wie erstmals 2019 wird auch für das Jahr 2020 von der „Floristisch-soziologischen Arbeitsgemeinschaft“ (FlorSoz) für Deutschland die „Pflanzengesellschaft des Jahres“ vorgestellt. Damit soll wiederum für die Öffentlichkeit die Notwendigkeit des Schutzes gefährdeter Pflanzengesellschaften aufgezeigt werden. Für das Jahr 2020 wurden die Borstgrasrasen ausgewählt. Wie alle Pflanzengemeinschaften nährstoffarmer Standorte, sind auch die Borstgrasrasen stark gefährdet und regional sogar unmittelbar vom Aussterben bedroht. Wir konzentrieren uns vor allem auf die Bestände der planaren bis montanen Stufe (Unterverband Violenion caninae: Hundsveilchen-Borstgrasrasen). Die Standorte von Violenion caninae-Gesellschaften werden nicht gedüngt und sind auf extensive Beweidung, z.T. auch auf einschürige Mahd angewiesen. Für Borstgrasrasen bezeichnend sind eine Fülle gefährdeter Pflanzenarten wie z.B. Arnica montana (Arnika) und Antennaria dioica (Zweihäusiges Katzenpfötchen). Bei den Borstgrasrasen spielen für die zunehmend hohe Gefährdung nicht nur Flächenrückgänge durch Nutzungsaufgabe, Aufforstung, Sport- und Freizeitaktivitäten und Überbauung eine Rolle, sondern auch Änderungen der Struktur und Artenzusammensetzung durch direkte Düngung sowie atmogene Stickstoffeinträge sind von Bedeutung. Nährstoffanreicherungen führen zum Verlust der konkurrenzschwachen, gefährdeten Arten zugunsten einiger allgemein verbreiteter, häufig dominanter Gräser sowie konkurrenzkräftiger Kräuter. Wir skizzieren die Bedeutung der Borstgrasrasen als gefährdete Lebensgemeinschaften, geben Hinweise zur floristisch-soziologischen Erforschung und zu weiteren Naturschutz-Aspekten (Rückgang, Erhaltung, Möglichkeiten der Restitution). Ein wirksamer Schutz ist nur bei einem integrativen Naturschutzansatz mit geeigneter Nutzung möglich. N2 - As for the first time in 2019 the ‘Floristisch-soziologische Arbeitsgemeinschaft (FlorSoz)’ intro-duces the ‘Plant Community of the Year 2020’ for Germany. The FlorSoz proposal aims to alert the public that the conservation of endangered plant communities and their biodiversity is essential.For the year 2020 the plant community of mat-grass swards (Nardus stricta grassland) has been selected. Similar to other plant communities on nutrient-poor sites, Nardus grassland is highly endan-gered and in some regions on the brink of extinction. We focus on Nardus grassland of the lowland to montane levels with the characteristic Violenion caninae suballiance (named after Viola canina,the Heath Dog-violet). The sites of Violenion caninae communities are not fertilized and depend on extensive grazing, but there are also mat-grass swards which are mown once a year. Nardus grasslands host many threatened species, e.g., Arnica montana (Arnica) and Antennaria dioica (Mountain Everlasting).The decline of Nardus grassland is not only due to abandonment, afforestation, outdoor activities and construction measures, but also due to changes in the structure and species composition through eutrophication by either direct manuring or by atmospheric nitrogen input. Eutrophication causes local decline or extinction of low-competitive, often endangered species which are replaced by ubiquists, mostly highly competitive species. For management, long-term conservation practices like extensive grazing or cutting once a year are essential. We give an outline of Nardus grassland as an endangered habitat type and summarize its current state of ecological and phytosociological research. In particular we take up the issue of conservation, including the loss of Nardus grasslands and their restoration. Effective conservation depends on an integrative nature-conservation approach, using suitable man-agement practices. Y1 - 2019 U6 - https://doi.org/10.14471/2019.39.017 SN - 0722-494X IS - 39 SP - 287 EP - 308 PB - Floristisch-soziologischen Arbeitsgemeinschaft e.V. CY - Göttingen ER - TY - GEN A1 - Dierschke, Hartmut A1 - Heinken, Thilo T1 - Vorwort T2 - Tuexenia : Mitteilungen der Floristisch-Soziologischen Arbeitsgemeinschaft Y1 - 2019 UR - https://www.tuexenia.de/publications/tuexenia/Tuexenia_2019_NS_039_0007-0007.pdf SN - 0722-494X IS - 39 SP - 7 EP - 7 PB - Floristisch-Soziologische Arbeitsgemeinschaft CY - Göttingen ER - TY - GEN A1 - Lozada Gobilard, Sissi Donna A1 - Stang, Susanne A1 - Pirhofer-Walzl, Karin A1 - Kalettka, Thomas A1 - Heinken, Thilo A1 - Schröder, Boris A1 - Eccard, Jana A1 - Jasmin Radha, Jasmin T1 - Environmental filtering predicts plant‐community trait distribution and diversity BT - Kettle holes as models of meta‐community systems T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - Meta‐communities of habitat islands may be essential to maintain biodiversity in anthropogenic landscapes allowing rescue effects in local habitat patches. To understand the species‐assembly mechanisms and dynamics of such ecosystems, it is important to test how local plant‐community diversity and composition is affected by spatial isolation and hence by dispersal limitation and local environmental conditions acting as filters for local species sorting. We used a system of 46 small wetlands (kettle holes)—natural small‐scale freshwater habitats rarely considered in nature conservation policies—embedded in an intensively managed agricultural matrix in northern Germany. We compared two types of kettle holes with distinct topographies (flatsloped, ephemeral, frequently plowed kettle holes vs. steep‐sloped, more permanent ones) and determined 254 vascular plant species within these ecosystems, as well as plant functional traits and nearest neighbor distances to other kettle holes. Differences in alpha and beta diversity between steep permanent compared with ephemeral flat kettle holes were mainly explained by species sorting and niche processes and mass effect processes in ephemeral flat kettle holes. The plant‐community composition as well as the community trait distribution in terms of life span, breeding system, dispersal ability, and longevity of seed banks significantly differed between the two habitat types. Flat ephemeral kettle holes held a higher percentage of non‐perennial plants with a more persistent seed bank, less obligate outbreeders and more species with seed dispersal abilities via animal vectors compared with steep‐sloped, more permanent kettle holes that had a higher percentage of wind‐dispersed species. In the flat kettle holes, plant‐species richness was negatively correlated with the degree of isolation, whereas no such pattern was found for the permanent kettle holes. Synthesis: Environment acts as filter shaping plant diversity (alpha and beta) and plant‐community trait distribution between steep permanent compared with ephemeral flat kettle holes supporting species sorting and niche mechanisms as expected, but we identified a mass effect in ephemeral kettle holes only. Flat ephemeral kettle holes can be regarded as meta‐ecosystems that strongly depend on seed dispersal and recruitment from a seed bank, whereas neighboring permanent kettle holes have a more stable local species diversity. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 629 KW - biodiversity KW - dispersal KW - disturbance KW - landscape diversity KW - life‐history traits KW - plant diversity KW - seed bank KW - species assembly KW - wetland vegetation Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-424843 SN - 1866-8372 IS - 629 ER - TY - JOUR A1 - Lozada Gobilard, Sissi Donna A1 - Stang, Susanne A1 - Pirhofer-Walzl, Karin A1 - Kalettka, Thomas A1 - Heinken, Thilo A1 - Schröder, Boris A1 - Eccard, Jana A1 - Jasmin Radha, Jasmin T1 - Environmental filtering predicts plant‐community trait distribution and diversity BT - Kettle holes as models of meta‐community systems JF - Ecology and Evolution N2 - Meta‐communities of habitat islands may be essential to maintain biodiversity in anthropogenic landscapes allowing rescue effects in local habitat patches. To understand the species‐assembly mechanisms and dynamics of such ecosystems, it is important to test how local plant‐community diversity and composition is affected by spatial isolation and hence by dispersal limitation and local environmental conditions acting as filters for local species sorting. We used a system of 46 small wetlands (kettle holes)—natural small‐scale freshwater habitats rarely considered in nature conservation policies—embedded in an intensively managed agricultural matrix in northern Germany. We compared two types of kettle holes with distinct topographies (flatsloped, ephemeral, frequently plowed kettle holes vs. steep‐sloped, more permanent ones) and determined 254 vascular plant species within these ecosystems, as well as plant functional traits and nearest neighbor distances to other kettle holes. Differences in alpha and beta diversity between steep permanent compared with ephemeral flat kettle holes were mainly explained by species sorting and niche processes and mass effect processes in ephemeral flat kettle holes. The plant‐community composition as well as the community trait distribution in terms of life span, breeding system, dispersal ability, and longevity of seed banks significantly differed between the two habitat types. Flat ephemeral kettle holes held a higher percentage of non‐perennial plants with a more persistent seed bank, less obligate outbreeders and more species with seed dispersal abilities via animal vectors compared with steep‐sloped, more permanent kettle holes that had a higher percentage of wind‐dispersed species. In the flat kettle holes, plant‐species richness was negatively correlated with the degree of isolation, whereas no such pattern was found for the permanent kettle holes. Synthesis: Environment acts as filter shaping plant diversity (alpha and beta) and plant‐community trait distribution between steep permanent compared with ephemeral flat kettle holes supporting species sorting and niche mechanisms as expected, but we identified a mass effect in ephemeral kettle holes only. Flat ephemeral kettle holes can be regarded as meta‐ecosystems that strongly depend on seed dispersal and recruitment from a seed bank, whereas neighboring permanent kettle holes have a more stable local species diversity. KW - biodiversity KW - dispersal KW - disturbance KW - landscape diversity KW - life‐history traits KW - plant diversity KW - seed bank KW - species assembly KW - wetland vegetation Y1 - 2019 U6 - https://doi.org/10.1002/ece3.4883 SN - 2045-7758 PB - John Wiley & Sons, Inc. CY - Hoboken ER - TY - JOUR A1 - Lozada Gobilard, Sissi Donna A1 - Stang, Susanne A1 - Pirhofer-Walzl, Karin A1 - Kalettka, Thomas A1 - Heinken, Thilo A1 - Schröder, Boris A1 - Eccard, Jana A1 - Joshi, Jasmin Radha T1 - Environmental filtering predicts plant-community trait distribution and diversity BT - Kettle holes as models of meta-community systems JF - Ecology and evolution N2 - Meta-communities of habitat islands may be essential to maintain biodiversity in anthropogenic landscapes allowing rescue effects in local habitat patches. To understand the species-assembly mechanisms and dynamics of such ecosystems, it is important to test how local plant-community diversity and composition is affected by spatial isolation and hence by dispersal limitation and local environmental conditions acting as filters for local species sorting.We used a system of 46 small wetlands (kettle holes)natural small-scale freshwater habitats rarely considered in nature conservation policiesembedded in an intensively managed agricultural matrix in northern Germany. We compared two types of kettle holes with distinct topographies (flat-sloped, ephemeral, frequently plowed kettle holes vs. steep-sloped, more permanent ones) and determined 254 vascular plant species within these ecosystems, as well as plant functional traits and nearest neighbor distances to other kettle holes.Differences in alpha and beta diversity between steep permanent compared with ephemeral flat kettle holes were mainly explained by species sorting and niche processes and mass effect processes in ephemeral flat kettle holes. The plant-community composition as well as the community trait distribution in terms of life span, breeding system, dispersal ability, and longevity of seed banks significantly differed between the two habitat types. Flat ephemeral kettle holes held a higher percentage of non-perennial plants with a more persistent seed bank, less obligate outbreeders and more species with seed dispersal abilities via animal vectors compared with steep-sloped, more permanent kettle holes that had a higher percentage of wind-dispersed species. In the flat kettle holes, plant-species richness was negatively correlated with the degree of isolation, whereas no such pattern was found for the permanent kettle holes.Synthesis: Environment acts as filter shaping plant diversity (alpha and beta) and plant-community trait distribution between steep permanent compared with ephemeral flat kettle holes supporting species sorting and niche mechanisms as expected, but we identified a mass effect in ephemeral kettle holes only. Flat ephemeral kettle holes can be regarded as meta-ecosystems that strongly depend on seed dispersal and recruitment from a seed bank, whereas neighboring permanent kettle holes have a more stable local species diversity. KW - biodiversity KW - dispersal KW - disturbance KW - landscape diversity KW - life-history traits KW - plant diversity KW - seed bank KW - species assembly KW - wetland vegetation Y1 - 2019 U6 - https://doi.org/10.1002/ece3.4883 SN - 2045-7758 VL - 9 IS - 4 SP - 1898 EP - 1910 PB - Wiley CY - Hoboken ER -