Julius Arthur Nieuwland

Climate suitability analyses based on ecological niche modeling provide a powerful tool for biological control practitioners to assess the likelihood of establishment of different candidate agents prior to their introduction in the field. These same analyses could also be performed to understand why some agents establish more easily than others. The release of three strains of Aphalara itadori (Shinji) (Hemiptera: Pysllidae), each from a different source locality in Japan, for the biological control of invasive knotweed species, Reynoutria spp. Houtt. (Caryophyllales: Polygonaceae), provides an important opportunity to compare the utility of climate suitability analyses for identifying potential climate‐based limitations for successful biological control introductions. Here, we predict climate suitability envelopes for three target species of knotweed in Europe and two target species of knotweed in North America and compare these suitability estimates for each of these species to the source localities of each A. itadori strain. We find that source locality of one strain, the Kyushu strain, has little‐to‐no suitability compared to other locations in Japan based on knotweed records from Europe, supporting an earlier study based on North American Japanese knotweed records. The source locality of a second strain, the Murakami strain, was predicted to have medium‐to‐high suitability based on records of knotweeds from North America. In contrast, European records of Reynoutria × bohemica Chrtek & Chrtková and Reynoutria sachalinensis (F. Schmidt) Nakai predicted no suitability for this locality compared to other locations in Japan, while European records for Reynoutria japonica Houtt. predicted low suitability. The source locality of the final strain, the Hokkaido strain, was predicted as having medium‐to‐high suitability based on knotweed records of all examined species from both North America and Europe.

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.

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.

Many studies have quantified ecological impacts of individual foundation species (FS). However, emerging data suggest that FS often co‐occur, potentially inhibiting or facilitating one another, thereby causing indirect, cascading effects on surrounding communities. Furthermore, global warming is accelerating, but little is known about how interactions between co‐occurring FS vary with temperature.Shallow aquatic sedimentary systems are often dominated by three types of FS: slower‐growing clonal angiosperms, faster‐growing solitary seaweeds, and shell‐forming filter‐ and deposit‐feeding bivalves. Here, we tested the impacts of one FS on another by analyzing manipulative interaction experiments from 148 papers with a global meta‐analysis.We calculated 1,942 (non‐independent) Hedges’ g effect sizes, from 11,652 extracted values over performance responses, such as abundances, growths or survival of FS, and their associated standard deviations and replication levels. Standard aggregation procedures generated 511 independent Hedges’ g that was classified into six types of reciprocal impacts between FS.We found that (i) seaweeds had consistent negative impacts on angiosperms across performance responses, organismal sizes, experimental approaches, and ecosystem types; (ii) angiosperms and bivalves generally had positive impacts on each other (e.g., positive effects of angiosperms on bivalves were consistent across organismal sizes and experimental approaches, but angiosperm effect on bivalve growth and bivalve effect on angiosperm abundance were not significant); (iii) bivalves positively affected seaweeds (particularly on growth responses); (iv) there were generally no net effects of seaweeds on bivalves (except for positive effect on growth) or angiosperms on seaweeds (except for positive effect on ‘other processes’); and (v) bivalve interactions with other FS were typically more positive at higher temperatures, but angiosperm‐seaweed interactions were not moderated by temperature.Synthesis: Despite variations in experimental and spatiotemporal conditions, the stronger positive interactions at higher temperatures suggest that facilitation, particularly involving bivalves, may become more important in a future warmer world. Importantly, addressing research gaps, such as the scarcity of FS interaction experiments from tropical and freshwater systems and for less studied species, as well as testing for density‐dependent effects, could better inform aquatic ecosystem conservation and restoration efforts and broaden our knowledge of FS interactions in the Anthropocene.

Paleoclimate reconstructions can provide a window into the environmental conditions in Earth history when atmospheric carbon dioxide concentrations were higher than today. In the eastern USA, paleoclimate reconstructions are sparse, because terrestrial sedimentary deposits are rare. Despite this, the eastern USA has the largest population and population density in North America, and understanding the effects of current and future climate change is of vital importance. Here, we provide terrestrial paleoclimate reconstructions of the eastern USA from Miocene fossil floras. Additionally, we compare proxy paleoclimate reconstructions from the warmest period in the Miocene, the Miocene Climatic Optimum (MCO), to those of an MCO Earth System Model. Reconstructed Miocene temperatures and precipitation north of 35°N are higher than modern. In contrast, south of 35°N, temperatures and precipitation are similar to today, suggesting a poleward amplification effect in eastern North America. Reconstructed Miocene rainfall seasonality was predominantly higher than modern, regardless of latitude, indicating greater variability in intra-annual moisture transport. Reconstructed climates are almost uniformly in the temperate seasonal forest biome, but heterogeneity of specific forest types is evident. Reconstructed Miocene terrestrial temperatures from the eastern USA are lower than modeled temperatures and coeval Atlantic sea surface temperatures. However, reconstructed rainfall is consistent with modeled rainfall. Our results show that during the Miocene, climate was most different from modern in the northeastern states, and may suggest a drastic reduction in the meridional temperature gradient along the North American east coast compared to today.

Aim Museum and herbarium specimen records are frequently used to assess the conservation status of species and their responses to climate change. Typically, occurrences with imprecise geolocality information are discarded because they cannot be matched confidently to environmental conditions and are thus expected to increase uncertainty in downstream analyses. However, using only precisely georeferenced records risks undersampling of the environmental and geographical distributions of species. We present two related methods to allow the use of imprecisely georeferenced occurrences in biogeographical analysis. Innovation Our two procedures assign imprecise records to the (1) locations or (2) climates that are closest to the geographical or environmental centroid of the precise records of a species. For virtual species, including imprecise records alongside precise records improved the accuracy of ecological niche models projected to the present and the future, especially for species with c. 20 or fewer precise occurrences. Using only precise records underestimated loss of suitable habitat and overestimated the amount of suitable habitat in both the present and the future. Including imprecise records also improves estimates of niche breadth and extent of occurrence. An analysis of 44 species of North American Asclepias (Apocynaceae) yielded similar results. Main conclusions Existing studies examining the effects of spatial imprecision typically compare outcomes based on precise records against the same records with spatial error added to them. However, in real-world cases, analysts possess a mix of precise and imprecise records and must decide whether to retain or discard the latter. Discarding imprecise records can undersample the geographical and environmental distributions of species and lead to mis-estimation of responses to past and future climate change. Our method, for which we provide a software implementation in the enmSdmX package for R, is simple to use and can help leverage the large number of specimen records that are typically deemed “unusable” because of spatial imprecision in their geolocation.

Our understanding of broad-scale biodiversity and functional trait patterns is largely based on plants, and relatively little information is available on soil arthropods. Here, we investigated the distribution of termite diversity globally and morphological traits and diversity across China. Our analyses showed increasing termite species richness with decreasing latitude at both the globally, and within-China. Additionally, we detected obvious latitudinal trends in the mean community value of termite morphological traits on average, with body size and leg length decreasing with increasing latitude. Furthermore, temperature, NDVI and water variables were the most important drivers controlling the variation in termite richness, and temperature and soil properties were key drivers of the geographic distribution of termite morphological traits. Our global termite richness map is one of the first high resolution maps for any arthropod group and especially given the functional importance of termites, our work provides a useful baseline for further ecological analysis.

Crop wild relatives (CWRs) have the capacity to contribute novel traits to agriculture. Given climate change, these contributions may be especially vital for the persistence of perennial crops, because perennials are often clonally propagated and consequently do not evolve rapidly. By studying the landscape genomics of samples from five Vitis CWRs (V. arizonica, V. mustangensis, V. riparia, V. berlandieri and V. girdiana) in the context of projected climate change, we addressed two goals. The first was to assess the relative potential of different CWR accessions to persist in the face of climate change. By integrating species distribution models with adaptive genetic variation, additional genetic features such as genomic load and a phenotype (resistance to Pierce’s Disease), we predicted that accessions from one species (V. mustangensis) are particularly well‐suited to persist in future climates. The second goal was to identify which CWR accessions may contribute to bioclimatic adaptation for grapevine (V. vinifera) cultivation. To do so, we evaluated whether CWR accessions have the allelic capacity to persist if moved to locations where grapevines (V. vinifera) are cultivated in the United States. We identified six candidates from V. mustangensis and hypothesized that they may prove useful for contributing alleles that can mitigate climate impacts on viticulture. By identifying candidate germplasm, this work takes a conceptual step toward assessing the genomic and bioclimatic characteristics of CWRs.

The genus Viola (Violaceae) is among the 40–50 largest genera among angiosperms, yet its taxonomy has not been revised for nearly a century. In the most recent revision, by Wilhelm Becker in 1925, the then-known 400 species were distributed among 14 sections and numerous unranked groups. Here, we provide an updated, comprehensive classification of the genus, based on data from phylogeny, morphology, chromosome counts, and ploidy, and based on modern principles of monophyly. The revision is presented as an annotated global checklist of accepted species of Viola, an updated multigene phylogenetic network and an ITS phylogeny with denser taxon sampling, a brief summary of the taxonomic changes from Becker’s classification and their justification, a morphological binary key to the accepted subgenera, sections and subsections, and an account of each infrageneric subdivision with justifications for delimitation and rank including a description, a list of apomorphies, molecular phylogenies where possible or relevant, a distribution map, and a list of included species. We distribute the 664 species accepted by us into 2 subgenera, 31 sections, and 20 subsections. We erect one new subgenus of Viola (subg. Neoandinium, a replacement name for the illegitimate subg. Andinium), six new sections (sect. Abyssinium, sect. Himalayum, sect. Melvio, sect. Nematocaulon, sect. Spathulidium, sect. Xanthidium), and seven new subsections (subsect. Australasiaticae, subsect. Bulbosae, subsect. Clausenianae, subsect. Cleistogamae, subsect. Dispares, subsect. Formosanae, subsect. Pseudorupestres). Evolution within the genus is discussed in light of biogeography, the fossil record, morphology, and particular traits. Viola is among very few temperate and widespread genera that originated in South America. The biggest identified knowledge gaps for Viola concern the South American taxa, for which basic knowledge from phylogeny, chromosome counts, and fossil data is virtually absent. Viola has also never been subject to comprehensive anatomical study. Studies into seed anatomy and morphology are required to understand the fossil record of the genus.

Premise Historical biogeography of ferns is typically expected to be dominated by long-distance dispersal, due to their minuscule spores. However, few studies have inferred the historical biogeography of a large and widely distributed group of ferns to test this hypothesis. Our aims are to determine the extent to which long-distance dispersal vs. vicariance have shaped the history of the fern family Blechnaceae, to explore ecological correlates of dispersal and diversification, and to determine whether these patterns differ between the northern and southern hemispheres. Methods We used sequence data for three chloroplast loci to infer a time-calibrated phylogeny for 154 out of 265 species of Blechnaceae, including representatives of all genera in the family. This tree was used to conduct ancestral range reconstruction and stochastic character mapping, estimate diversification rates, and identify ecological correlates of diversification. Key results Blechnaceae originated in Eurasia and began diversifying in the late Cretaceous. A lineage comprising most extant diversity diversified principally in the austral Pacific region around the Paleocene-Eocene Thermal Maximum. Land connections that existed near the poles during periods of warm climates likely facilitated migration of several lineages, with subsequent climate-mediated vicariance shaping current distributions. Long-distance dispersal is frequent and asymmetrical, with New Zealand/Pacific Islands, Australia, and tropical America being major source areas. Conclusions Ancient vicariance and extensive long-distance dispersal have shaped the history of Blechnaceae in both the northern and southern hemispheres. The exceptional diversity in austral regions appears to reflect rapid speciation in these areas; mechanisms underlying this evolutionary success remain uncertain.