Hazel Marguerite Schmoll

AbstractAimEurasian grapevine (Vitis vinifera), one of the most important fruit crops worldwide, diverged from its wild and currently endangered relative (V. vinifera ssp. sylvestris) about 11,000 years ago. In the 19th century, detrimental phylloxera and disease outbreaks in Europe forced grapevine cultivation to use American Vitis species as rootstocks, which have now become naturalized in Europe and are starting to colonize similar habitats to the wild grapevine. Accordingly, wild grapevine now faces two additional threats: the expansion of vineyards and invasive rootstocks. Furthermore, climate change is expected to have significant impacts on the distribution of all grapevines in Europe. In this study, we quantified the distributional and bioclimatic overlap between grapewine's wild relative and the taxa associated with viticulture, under current and future climate.LocationEurope, North America.MethodsThe distributions of wild Eurasian grapevine, cultivated Eurasian grapevine and five American grapevine species used in rootstock breeding programs were linked to climate variables to model their bioclimatic niches. These ecological niche models were used to quantify the spatial and bioclimatic overlap between these seven Vitis taxa in Europe.ResultsNiche and spatial overlap is high between the wild, cultivated and rootstock grapevines, suggesting that existing conflicts between vineyards and wild grapevine conservation may be further complicated by naturalized rootstocks outcompeting the wild grapevine, especially under future scenarios of climate change. In the hottest scenario, only 76.1% of the current distribution of the Eurasian grapevine remains in suitable area.Main ConclusionsAs wild grapevine may ultimately provide a valuable gene pool for adapting viticulture to a changing world, these findings demonstrate the need for improved management of the wild grapevine and its natural habitat, to counteract the harmful effects of global change on the wild relatives of viticulture.

Predicting the likelihood that non-native species will be introduced into new areas remains one of conservation’s greatest challenges and, consequently, it is necessary to adopt adequate management measures to mitigate the effects of future biological invasions. At present, not much information is available on the areas in which non-native aquatic plant species could establish themselves in the Iberian Peninsula. Species distribution models were used to predict the potential invasion risk of (1) non-native aquatic plant species already established in the peninsula (32 species) and (2) those with the potential to invade the peninsula (40 species). The results revealed that the Iberian Peninsula contains a number of areas capable of hosting non-native aquatic plant species. Areas under anthropogenic pressure are at the greatest risk of invasion, and the variable most related to invasion risk is temperature. The results of this work were used to create the Invasion Risk Atlas for Alien Aquatic Plants in the Iberian Peninsula, a novel online resource that provides information about the potential distribution of non-native aquatic plant species. The atlas and this article are intended to serve as reference tools for the development of public policies, management regimes, and control strategies aimed at the prevention, mitigation, and eradication of non-native aquatic plant species.

Premise: Cacti are characteristic elements of the Neotropical flora and of major interest for biogeographic, evolutionary, and ecological studies. Here we test global biogeographic boundaries for Neotropical Cactaceae using specimen‐based occurrences coupled with data from visual observations, as a means to tackle the known collection biases in the family.MethodsSpecies richness and record density were assessed for preserved specimens and human observations and a bioregional scheme tailored to Cactaceae was produced using the interactive web application Infomap Bioregions based on data from 261,272 point records cleaned through automated and manual steps.Key ResultsWe find that areas in Mexico and southwestern USA, Eastern Brazil and along the Andean region have the greatest density of records and the highest species richness. Human observations complement information from preserved specimens substantially, especially along the Andes. We propose 24 cacti bioregions, among which the most species‐rich are: northern Mexico/southwestern USA, central Mexico, southern central Mexico, Central America, Mexican Pacific coast, central and southern Andes, northwestern Mexico/extreme southwestern USA, southwestern Bolivia, northeastern Brazil, Mexico/Baja California.ConclusionsThe bioregionalization proposed shows biogeographical boundaries specific to cacti, and can thereby aid further evolutionary, biogeographic, and ecological studies by providing a validated framework for further analyses. This classification builds upon, and is distinctive from, other expert‐derived regionalization schemes for other taxa. Our results showcase how observation data, including citizen‐science records, can complement traditional specimen‐based data for biogeographic research, particularly for taxa with specific specimen collection and preservation challenges and those that are threatened or internationally protected.This article is protected by copyright. All rights reserved.

The tribe Astereae (Asteraceae) displays an American Amphitropical Disjunction. To understand the eco-evolutionary dynamics associated with a long-distance dispersal event and subsequent colonization of extratropical South America, we compared the climatic and geographic distributions of South American species with their closest North American relatives, focusing on the diverse South American Astereae genus, Haplopappus. Phylogenetic analysis revealed that two South American genera are closely related to seven North American genera. The climatic niche overlap (D = 0.5) between South and North America exhibits high stability (0.89), low expansion (0.12), and very low unfilling (0.04). The distribution of the North American species predicted the climatic and geographic space occupied by the South American species. In central Chile, Haplopappus showed a non-random latitudinal gradient in species richness, with Mediterranean climate variables mainly explaining the variation. Altitudinal patterns indicated peak richness at 600 m, declining at lower and higher elevations. These findings support climatic niche conservatism in shaping Haplopappus species distribution and diversity. Two major endemism zones were identified in central Chile and the southern region, with a transitional zone between Mediterranean and Temperate macro-bioclimates. Our results indicate strong niche conservatism following long-distance dispersal and slight niche expansion due to unique climatic variables in each hemisphere.

Evolutionary correlations between chemical defense and protection by mutualist bodyguards have been long predicted, but tests of these pattern remain rare. We use a phylogenetic framework to test for evolutionary correlations indicative of trade-offs or synergisms between direct defense in the form of plant secondary metabolism, and indirect defense in the form of leaf domatia, across 33 species in the wild grape genus, Vitis. We also performed a bioassay with a generalist herbivore to associate our chemical phenotypes with herbivore palatability. Finally, we tested whether defensive traits correlate with the average abiotic characteristics of each species’ contemporary range and whether these correlations were consistent with plant defense theory. We found a negative evolutionary correlation between domatia size and the diversity of secondary metabolites in Vitis leaf tissue across the genus, and also that leaves with a higher diversity and richness of secondary metabolites were less palatable to a generalist herbivore, consistent with a trade-off in chemical and mutualistic defense investment. Predictions from plant defense theory were not supported by associations between investment in defense phenotypes and abiotic variables. Our work demonstrates an evolutionary pattern indicative of a trade-off between indirect and direct defense strategies across the Vitis genus.

Background Approximately 33% of plant species face extinction due to climate change. Polyploidisation, a process resulting in more than two complete sets of chromosomes, may be promoted by periods of climate fluctuations. Ecological niche modelling (ENM) using occurrences of endemic plants in the North American Coastal Plain (NACP) biodiversity hotspot could be used to evaluate the potential effects of climate change on cytotype distributions. Aims We used known diploid and polyploid taxa endemic to the NACP to test hypotheses that diploids and polyploids differed in habitat preferences, considerable overlap existed between cytotypes, and polyploid distributions would increase under climate change projections. Methods We examined niche identity and overlap of 28 congeneric ploidy level pairs and performed ENM to evaluate how climate change could affect these groups. Results Congeneric ploidy level pairs differed significantly in niche identity, and overlap varied across genera. Eleven genera showed greater than 100% increases in habitat suitability and six genera showed almost no remaining suitable habitat in at least one future climate scenario. Conclusions With 70% of the species that showed substantial declines in projected suitable habitat being of conservation concern, we propose that future studies of these genera should be a primary focus in the NACP.

Aim Many invasive plant species benefit from enemy release resulting from the absence of insect herbivores in their invaded range. However, over time, specialized herbivores may ‘catch up’ with such invasive plants. Black locust is a tree species with a relatively limited native range in North America but has invaded large areas in virtually every temperate continent including North America. We hypothesize that both intra- and intercontinental spread of black locust leads to a parallel, though delayed pattern of intra- and intercontinental spread of insect herbivores. Location Global. Taxon Black locust, Robinia pseudoacacia, and its insect herbivores. Methods We compiled historical records of the occurrence of insect herbivore species associated with R. pseudoacacia from all world regions. Based on this list, we describe taxonomic patterns and investigate associations between environmental features and numbers of non-native specialist herbivores in the portion of North America invaded by R. pseudoacacia. Results A total of 454 herbivorous species are recorded feeding on R. pseudoacacia across the world, with 23 of these being specialized on Robinia. From this group, seven species have successfully expanded their range beyond North America. Within North America, the richness of specialists is explained by a combination of road density, R. pseudoacacia density, distance from the R. pseudoacacia native range, and climate. Main Conclusion Non-native herbivore species have accumulated on invasive R. pseudoacacia in both North America and in other continents. The steady build-up of invasions likely has diminished the enemy release that this invasive tree species has benefited from – a trend that will likely continue in the future. These findings support the hypothesis that invasive plants promote parallel though delayed invasions of specialist insect herbivores.

Declining insect abundance is occurring around the world, and some management projects are aiming to utilize roadsides and other right-of-ways as insect conservation areas. In the US, the decline of the monarch butterfly (Danaus plexippus Linnaeus [Nymphalidae]) populations has led to multiple studies focusing on a small number of milkweed species (Asclepias [Apocynaceae]) that occur in the major flyways. Here we survey a poorly studied milkweed, bract milkweed (A. brachystephana Engelm. ex Torr.), to document where it grows, which organisms make use of the plants, seed production, and concentrations of milkweed toxins (cardenolides) and to investigate if this species is suitable for roadside or right-of-ways management projects. Our results show that the range of A. brachystephana includes the Chihuahuan Desert and neighboring ecoregions. Plant populations were also observed occurring on roadsides and right-of-ways, rarely spreading into neighboring habitats. We document a variety of native pollinators utilizing floral resources and a few herbivores feeding on plant tissue. Chemical analyses show wild plants produce higher concentrations of toxic cardenolide than many other milkweed species. These data suggest A. brachystephana should be considered for roadside and right-of-way plantings, restoration projects, or seeding throughout the Chihuahuan Desert and adjoining ecoregions.

Mexico harbors ~45% of world’s cacti species richness. Their biogeography and phylogenomics were integrated to elucidate the evolutionary history of the genera Coryphantha, Escobaria, Mammillaria, Mammilloydia, Neolloydia, Ortegocactus, and Pelecyphora (Mammilloid Clade). We analyzed 52 orthologous loci from 142 complete genomes of chloroplast (103 taxa) to generate a cladogram and a chronogram; in the latter, the ancestral distribution was reconstructed with the Dispersal-Extinction-Cladogenesis model. The ancestor of these genera arose ~7 Mya on the Mexican Plateau, from which nine evolutionary lineages evolved. This region was the site of 52% of all the biogeographical processes. The lineages 2, 3 and 6 were responsible for the colonization of the arid southern territories. In the last 4 Mya, the Baja California Peninsula has been a region of prolific evolution, particularly for lineages 8 and 9. Dispersal was the most frequent process and vicariance had relevance in the isolation of cacti distributed in the south of Mexico. The 70 taxa sampled as Mammillaria were distributed in six distinct lineages; one of these presumably corresponded to this genus, which likely had its center of origin in the southern part of the Mexican Plateau. We recommend detailed studies to further determine the taxonomic circumscription of the seven genera.

Rubus (Rosaceae), one of the most complicated angiosperm genera, contains about 863 species, and is notorious for its taxonomic difficulty. The most recent (1910–1914) global taxonomic treatment of the genus was conducted by Focke, who defined 12 subgenera. Phylogenetic results over the past 25 years suggest that Focke's subdivisions of Rubus are not monophyletic, and large‐scale taxonomic revisions are necessary. Our objective was to provide a comprehensive phylogenetic analysis of the genus based on an integrative evidence approach. Morphological characters, obtained from our own investigation of living plants and examination of herbarium specimens are combined with chloroplast genomic data. Our dataset comprised 196 accessions representing 145 Rubus species (including cultivars and hybrids) and all of Focke's subgenera, including 60 endemic Chinese species. Maximum likelihood analyses inferred phylogenetic relationships. Our analyses concur with previous molecular studies, but with modifications. Our data strongly support the reclassification of several subgenera within Rubus. Our molecular analyses agree with others that only R. subg. Anoplobatus forms a monophyletic group. Other subgenera are para‐ or polyphyletic. We suggest a revised subgeneric framework to accommodate monophyletic groups. Character evolution is reconstructed, and diagnostic morphological characters for different clades are identified and discussed. Based on morphological and molecular evidence, we propose a new classification system with 10 subgenera: R. subg. Anoplobatus, R. subg. Batothamnus, R. subg. Chamaerubus, R. subg. Cylactis, R. subg. Dalibarda, R. subg. Idaeobatus, R. subg. Lineati, R. subg. Malachobatus, R. subg. Melanobatus, and R. subg. Rubus. The revised infrageneric nomenclature inferred from our analyses is provided along with synonymy and type citations. Our new taxonomic backbone is the first systematic and complete global revision of Rubus since Focke's treatment. It offers new insights into deep phylogenetic relationships of Rubus and has important theoretical and practical significance for the development and utilization of these important agronomic crops.