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1. Plant diversity begets diversity at other trophic levels. While species richness is the most commonly used measure for plant diversity, the number of evolutionary lineages (i.e. phylogenetic diversity) could theoretically have a stronger influence on the community structure of co‐occurring organisms. However, this prediction has only rarely been tested in complex real‐world ecosystems. 2. Using a comprehensive multitrophic dataset of arthropods and fungi from a species‐rich subtropical forest, we tested whether tree species richness or tree phylogenetic diversity relates to the diversity and composition of organisms. 3. We show that tree phylogenetic diversity but not tree species richness determines arthropod and fungi community composition across trophic levels and increases the diversity of predatory arthropods but decreases herbivorous arthropod diversity. The effect of tree phylogenetic diversity was not mediated by changed abundances of associated organisms, indicating that evolutionarily more diverse plant communities increase niche opportunities (resource diversity) but not necessarily niche amplitudes (resource amount). 4. Our findings suggest that plant evolutionary relatedness structures multitrophic communities in the studied species‐rich forests and possibly other ecosystems at large. As global change non‐randomly threatens phylogenetically distinct plant species, far‐reaching consequences on associated communities are expected. A free Plain Language Summary can be found within the Supporting Information of this article.

Climate and land-use change are key drivers of global change. Full-factorial field experiments in which both drivers are manipulated are essential to understand and predict their potentially interactive effects on the structure and functioning of grassland ecosystems. Here, we present 8 years of data on grassland dynamics from the Global Change Experimental Facility in Central Germany. On large experimental plots, temperature and seasonal patterns of precipitation are manipulated by superimposing regional climate model projections onto background climate variability. Climate manipulation is factorially crossed with agricultural land-use scenarios, including intensively used meadows and extensively used (i.e., low-intensity) meadows and pastures. Inter-annual variation of background climate during our study years was high, including three of the driest years on record for our region. The effects of this temporal variability far exceeded the effects of the experimentally imposed climate change on plant species diversity and productivity, especially in the intensively used grasslands sown with only a few grass cultivars. These changes in productivity and diversity in response to alterations in climate were due to immigrant species replacing the target forage cultivars. This shift from forage cultivars to immigrant species may impose additional economic costs in terms of a decreasing forage value and the need for more frequent management measures. In contrast, the extensively used grasslands showed weaker responses to both experimentally manipulated future climate and inter-annual climate variability, suggesting that these diverse grasslands are more resistant to climate change than intensively used, species-poor grasslands. We therefore conclude that a lower management intensity of agricultural grasslands, associated with a higher plant diversity, can stabilize primary productivity under climate change.

Climate and land-use change are key drivers of global change. Full-factorial field experiments in which both drivers are manipulated are essential to understand and predict their potentially interactive effects on the structure and functioning of grassland ecosystems. Here, we present 8 years of data on grassland dynamics from the Global Change Experimental Facility in Central Germany. On large experimental plots, temperature and seasonal patterns of precipitation are manipulated by superimposing regional climate model projections onto background climate variability. Climate manipulation is factorially crossed with agricultural land-use scenarios, including intensively used meadows and extensively used (i.e., low-intensity) meadows and pastures. Inter-annual variation of background climate during our study years was high, including three of the driest years on record for our region. The effects of this temporal variability far exceeded the effects of the experimentally imposed climate change on plant species diversity and productivity, especially in the intensively used grasslands sown with only a few grass cultivars. These changes in productivity and diversity in response to alterations in climate were due to immigrant species replacing the target forage cultivars. This shift from forage cultivars to immigrant species may impose additional economic costs in terms of a decreasing forage value and the need for more frequent management measures. In contrast, the extensively used grasslands showed weaker responses to both experimentally manipulated future climate and inter-annual climate variability, suggesting that these diverse grasslands are more resistant to climate change than intensively used, species-poor grasslands. We therefore conclude that a lower management intensity of agricultural grasslands, associated with a higher plant diversity, can stabilize primary productivity under climate change.

Gebietseigenes Saatgut für Begrünungen und Renaturierungen in der freien Landschaft wird in Deutschland nach Regeln des Regiosaatgutkonzepts in 22 Ursprungsgebieten (UG) produziert. Das Projekt RegioDiv untersuchte die genetische Diversität von über 30 Pflanzenarten des Grünlands deutschlandweit, um zu überprüfen, wie gut die beobachtete räumliche Verteilung der genetischen Strukturen dem geographischen Zuschnitt der UG entspricht. Jede Art zeigte ein artspezifisches innerartliches räumlich-genetisches Diversitätsmuster, aber fast alle Arten zeigten das Muster von "Isolation-durch-Distanz", also zunehmende genetische Distanz mit zunehmender räumlicher Entfernung. Bei einigen Arten mit mehreren Ploidiestufen, d. h. innerartlichen Taxa mit verschiedenen Anzahlen an Chromosomensätzen, die eigenständige biologische Arten darstellen können, konnten auf Basis ihrer Verbreitungsgebiete spezifische Regeln entwickelt werden. Die Synthese der Verbreitungsmuster der innerartlichen Gruppen über alle Arten hinweg identifizierte Schwächen des aktuellen UG-Systems. Im vorliegenden Beitrag werden wichtige Einzelergebnisse vorgestellt und Empfehlungen für die Praxis gegeben. Unter anderem werden Vorschläge für alternative Zuschnitte der UG, die die genetische Vielfalt besser repräsentieren, vorgestellt. Diese bilden die Grundlage für mögliche Änderungen am UG-System, die in naher Zukunft mit den relevanten Akteuren erarbeitet werden müssen.

In Deutschland ist für die Ausbringung von Pflanzen in der freien Natur nach § 40 BNatschGgebietseigenes Saat- und Pflanzgut zu verwenden. Für die praktische Umsetzung dieser Vor-gabe werden im Regiosaatgutsystem 22 Ursprungsgebiete (UG) unterschieden. Der Zuschnittder UG beruht im Wesentlichen auf naturräumlichen Einteilungen. Dies kann kritisch betrach-tet werden, da keine spezifischen, empirischen Informationen über diejenigen Pflanzenarteneingingen, für welche das System geschaffen wurde. Da die UG generell für alle Arten in glei-cher Weise gelten, muss eine große Zahl an Arten untersucht werden, um die Plausibilität derUG zu prüfen. Das Projekt RegioDiv hatte das Ziel, eine breite empirische Datenbasis der ge-netischen Vielfaltsmuster von Wiesenpflanzen zu erarbeiten, um auf dieser Basis Empfehlun-gen für das Regiosaatgutsystem ableiten zu können.Insgesamt sammelten 160 SammlerInnen an über 2.500 Grünlandflächen Pflanzenproben von28 Arten. Wir charakterisierten den individuellen Genotyp (SNP-Marker, single nucleotide po-lymorphism) von ca. 12.000 Proben. Die Datenanalyse für jede Art umfasste unter anderemHauptkomponenten- und Clusteranalysen. Außerdem analysierten wir den Zusammenhangder genetischen und der geographischen Distanz zwischen UG-Paaren, die jeweils als Popula-tionen interpretiert wurden.

For terrestrial plant communities, the increase in frequency and intensity of drought events is considered as one of the most severe consequences of climate change. While single-species studies demonstrate that drought can lead to relatively rapid adaptive genetic changes, the evolutionary potential and constraints to selection need to be assessed in comparative approaches to draw more general conclusions. In a greenhouse experiment, we compare the phenotypic response and evolutionary potential of two co-occurring grassland plant species, Bromus erectus and Trifolium pratense, in two environments differing in water availability. We quantified variation in functional traits and reproductive fitness in response to drought and compared multivariate genetic variance–covariance matrices and predicted evolutionary responses between species. Species showed different drought adaptation strategies, reflected in both their species-specific phenotypic plasticity and predicted responses to selection indicating contrasting evolutionary potential under drought. In T. pratense we found evidence for stronger genetic constraints under drought compared to more favourable conditions, and for some traits plastic and predicted evolutionary responses to drought had opposing directions, likely limiting the potential for adaptive change. Our study contributes to a more detailed understanding of the evolutionary potential of species with different adaptive strategies in response to climate change and may help to inform future scenarios for semi-natural grassland ecosystems.

The UN Decade on Ecosystem Restoration calls for upscaling restoration efforts, but many terrestrial restoration projects are constrained by seed availability. To overcome these constraints, wild plants are increasingly propagated on farms to produce seeds for restoration projects. During on-farm propagation, the plants face non-natural conditions with different selection pressures, and they might evolve adaptations to cultivation that parallel those of agricultural crops, which could be detrimental to restoration success. To test this, we compared traits of 19 species grown from wild-collected seeds to those from their farm-propagated offspring of up to four cultivation generations, produced by two European seed growers, in a common garden experiment. We found that some plants rapidly evolved across cultivated generations towards increased size and reproduction, lower within-species variability, and more synchronized flowering. In one species, we found evolution towards less seed shattering. These trait changes are typical signs of the crop domestication syndrome, and our study demonstrates that it can also occur during cultivation of wild plants, within only few cultivated generations. However, there was large variability between cultivation lineages, and the observed effect sizes were generally rather moderate, which suggests that the detected evolutionary changes are unlikely to compromise farm-propagated seeds for ecosystem restoration. To mitigate the potential negative effects of unintended selection, we recommend to limit the maximum number of generations the plants can be cultivated without replenishing the seed stock from new wild collections.

For terrestrial plant communities, the increase in frequency and intensity of drought events is considered as one of the most severe consequences of climate change. While single-species studies demonstrate that drought can lead to relatively rapid adaptive genetic changes, the evolutionary potential and constraints to selection need to be assessed in comparative approaches to draw more general conclusions. In a greenhouse experiment, we compare the phenotypic response and evolutionary potential of two co-occurring grassland plant species, Bromus erectus and Trifolium pratense, in two environments differing in water availability. We quantified variation in functional traits and reproductive fitness in response to drought and compared multivariate genetic variance–covariance matrices and predicted evolutionary responses between species. Species showed different drought adaptation strategies, reflected in both their species-specific phenotypic plasticity and predicted responses to selection indicating contrasting evolutionary potential under drought. In T. pratense we found evidence for stronger genetic constraints under drought compared to more favourable conditions, and for some traits plastic and predicted evolutionary responses to drought had opposing directions, likely limiting the potential for adaptive change. Our study contributes to a more detailed understanding of the evolutionary potential of species with different adaptive strategies in response to climate change and may help to inform future scenarios for semi-natural grassland ecosystems.

The genus Brachymystax is represented by three putative species that disjointedly inhabit the major river basins of central and northeast Eurasia. Brachymystax lenok and B. tumensis have been regularly misidentified throughout their range, including across sympatric populations in the upper Onon River of Mongolia. This research has focused on Mongolia’s understudied lenok populations by conducting detailed morphometric measurements and genetic analyses to confirm key metrics for accurately distinguishing between these cryptic species. While there are slight differences in colouration and patterns including size and density of their defining black spots, four key metrics were found to be significantly different between the species including gill rakers counts, snout length, lateral line scale counts and body depth. Brachymystax tumensis was also typically heavier than B. lenok at the same length. These results were supported by genetic analyses which clustered the two species into separate clades and displayed unique haplotypes for the Mongolian populations. Initial investigations of diets and gonad maturation indicated an ecological and spatial separation of these sympatric species. The current study is important for these recreationally targeted species which require further research and species-specific management measures to ensure their threatened populations are conserved in Mongolia for the future.