Emily K. Meineke, Charles C. Davis, and Jonathan Davies. Forthcoming. “The unrealized potential of herbaria for global change biology.” Ecological Monographs, Pp. 1-21.Abstract


Plant and fungal specimens in herbaria are becoming primary resources for investigat-

ing how plant phenology and geographic distributions shift with climate change, greatly expanding

inferences across spatial, temporal, and phylogenetic dimensions. However, these specimens contain a

wealth of additional data, including nutrients, defensive compounds, herbivore damage, disease

lesions, and signatures of physiological processes, that capture ecological and evolutionary responses

to the Anthropocene but which are less frequently utilized. Here, we outline the diversity of herbarium

data, global change topics to which they have been applied, and new hypotheses they could inform.

We find that herbarium data have been used extensively to study impacts of climate change and inva-

sive species, but that such data are less commonly used to address other drivers of biodiversity loss,

including habitat conversion, pollution, and overexploitation. In addition, we note that fungal speci-

mens are under-explored relative to vascular plants. To facilitate broader application of plant and fun-

gal specimens in global change research, we consider the limitations of these data and modern

sampling and statistical tools that may be applied to surmount challenges they present. Using a case

study of insect herbivory, we illustrate how novel herbarium data may be employed to test hypotheses

for which few data exist. With the goal of positioning herbaria as hubs for global change research, we

suggest future research directions and curation priorities.

Key words: climate change; extinction; global change; habitat conversion; herbarium; historical data; invasive

species; museum specimens.


Charles C. Davis, Julien Champ, Daniel S. Park, Ian Breckheimer, Goia M. Lyra, Junxi Xie, Alexis Joly, Dharmesh Tarapore, Aaron M. Ellison, and Pierre Bonnet. 7/31/2020. “A New Method for Counting Reproductive Structures in Digitized Herbarium Specimens Using Mask R-CNN.” Frontiers in Plant Science, 11, 1129. PDF
Haiwen Li, Bing Liu, Charles C. Davis, and Yong Yang. 6/30/2020. “Plastome phylogenomics, systematics, and divergence time estimation of the Beilschmiedia group (Lauraceae).” Molecular Phylogenetics and Evolution, 151, 106901. PDF
Camille M. M. DeSisto, Daniel S. Park, Charles C. Davis, Veronarindra Ramananjato, Jadelys L. Tonos, and Onja H. Razafindratsima. 6/18/2020. “An invasive species spread by threatened diurnal lemurs impacts rainforest structure in Madagascar.” Biological Invasions, Pp. 1-14. PDF
Charles C. Davis, Lucas C. Marinho, and André M. Amorim. 6/2020. “Andersoniella: A new genus of neotropical malpighiaceae.” Harvard Papers in Botany, 25, 1, Pp. 51-56. PDF
Katelin D Pearson, Gil Nelson, Myla FJ Aronson, Pierre Bonnet, Laura Brenskelle, Charles C Davis, Ellen G Denny, Elizabeth R Ellwood, Hervé Goëau, Mason J Herberling, Alexis Joly, Titouan Lorieul, Susan J Mazer, Emily K Meineke, Brian J Stucky, Patrick Sweeney, Alexander E White, and Pamela S Soltis. 5/13/2020. “Machine Learning Using Digitized Herbarium Specimens to Advance Phenological Research.” BioScience.Abstract
Machine learning (ML) has great potential to drive scientific discovery by harvesting data from images of herbarium specimens—preserved plant material curated in natural history collections—but ML techniques have only recently been applied to this rich resource. ML has particularly strong prospects for the study of plant phenological events such as growth and reproduction. As a major indicator of climate change, driver of ecological processes, and critical determinant of plant fitness, plant phenology is an important frontier for the application of ML techniques for science and society. In the present article, we describe a generalized, modular ML workflow for extracting phenological data from images of herbarium specimens, and we discuss the advantages, limitations, and potential future improvements of this workflow. Strategic research and investment in specimen-based ML methods, along with the aggregation of herbarium specimen data, may give rise to a better understanding of life on Earth.
Daniel S. Park, Charles G. Willis, Zhenxiang Xi, John T. Kartesz, Charles C. Davis, and Steven Worthington. 4/27/2020. “Machine learning predicts large scale declines in native plant phylogenetic diversity.” New Phytologist. PDF
Charles Davis, Goia Lyra, Caio Silva, Mariana Guimarães, Jean Wyllys, and Aaron Ellison. 4/17/2020. “As mídias sociais inflamam a destuição da Amazônia.” Estadão Política. PDF
Joel H. Nitta, James E. Watkins, and Charles C. Davis. 4/14/2020. “Life in the canopy: community trait assessments reveal substantial functional diversity among fern epiphytes.” New Phytologist. PDF
Charles Davis, Goia Lyra, Caio Silva, Mariana Guimarães, Jean Wyllys, and Aaron Ellison. 4/14/2020. “Social media are fueling the Amazon's destruction.” Nature, 580, 7803, Pp. 321. Publisher's Version
Rebecca A. Povilus, Jeffrey M. DaCosta, Christopher Grassa, Prasad R. V Satyaki, Morgan Moeglein, Johan Jaenisch, Zhenxiang Xi, Sarah Mathews, Mary Gehring, Charles C. Davis, and William E. Friedman. 4/14/2020. “Water lily (Nymphaea thermarum) genome reveals variable genomic signatures of ancient vascular cambium losses.” PNAS, 117, 15, Pp. 8649-8656.Abstract
For more than 225 million y, all seed plants were woody trees, shrubs, or vines. Shortly after the origin of angiosperms ∼140 million y ago (MYA), the Nymphaeales (water lilies) became one of the first lineages to deviate from their ancestral, woody habit by losing the vascular cambium, the meristematic population of cells that produces secondary xylem (wood) and phloem. Many of the genes and gene families that regulate differentiation of secondary tissues also regulate the differentiation of primary xylem and phloem, which are produced by apical meristems and retained in nearly all seed plants. Here, we sequenced and assembled a draft genome of the water lily Nymphaea thermarum, an emerging system for the study of early flowering plant evolution, and compared it to genomes from other cambium-bearing and cambium-less lineages (e.g., monocots and Nelumbo). This revealed lineage-specific patterns of gene loss and divergence. Nymphaea is characterized by a significant contraction of the HD-ZIP III transcription factors, specifically loss of REVOLUTA, which influences cambial activity in other angiosperms. We also found the Nymphaea and monocot copies of cambium-associated CLE signaling peptides display unique substitutions at otherwise highly conserved amino acids. Nelumbo displays no obvious divergence in cambium-associated genes. The divergent genomic signatures of convergent loss of vascular cambium reveals that even pleiotropic genes can exhibit unique divergence patterns in association with independent events of trait loss. Our results shed light on the evolution of herbaceousness—one of the key biological innovations associated with the earliest phases of angiosperm evolution.
Brandon Hedrick, Mason Heberling, Emily Meineke, Kathryn Turner, Christopher Grassa, Daniel Park, Jonathan Kennedy, Julia A. Clarke, Joseph Cook, David Blackburn, Scott V. Edwards, and Charles C. Davis. 3/1/2020. “Digitization and the future of natural history collections.” BioScience, 70, 3, Pp. 243-251. Publisher's VersionAbstract
Natural history collections (NHCs) are the foundation of historical baselines for assessing anthropogenic impacts on biodiversity. Along these lines, the online mobilization of specimens via digitization–the conversion of specimen data into accessible digital content–has greatly expanded the use of NHC collections across a diversity of disciplines. We broaden the current vision of digitization (Digitization 1.0)–whereby specimens are digitized within NHCs–to include new approaches that rely on digitized products rather than the physical specimen (Digitization 2.0). Digitization 2.0 builds upon the data, workflows, and infrastructure produced by Digitization 1.0 to create digital-only workflows that facilitate digitization, curation, and data linkages, thus returning value to physical specimens by creating new layers of annotation, empowering a global community, and developing automated approaches to advance biodiversity discovery and conservation. These efforts will transform large-scale biodiversity assessments to address fundamental questions including those pertaining to critical modern issues of global change.
Jianquan Liu, Charles C Davis, Xiyin Wang, Zhenxiang Xi, Zhiji Qin, Qinfeng Wang, Man Liu, Lanxing Shan, Beibei Jiao, Fanbo Meng, Xingxing Shen, Lei Zhang, Tao Ma, Ying Li, Dafu Ru, Donglei Wang, Leke Lv, Pengchuan Sun, and Yongzhi Yang. 2/24/2020. “Prickly waterlily and rigid hornwort genomes shed light on early angiosperm evolution.” Nature Plants, 2020, Pp. 1-8.Abstract
Angiosperms represent one of the most spectacular terrestrial radiations on the planet 1, but their early diversification and phylogenetic relationships remain uncertain 2, 3, 4, 5. A key reason for this impasse is the paucity of complete genomes representing early-diverging angiosperms. Here, we present high-quality, chromosomal-level genome assemblies of two aquatic species—prickly waterlily (Euryale ferox; Nymphaeales) and the rigid hornwort (Ceratophyllum demersum; Ceratophyllales)—and expand the genomic representation for key sectors of the angiosperm tree of life. We identify multiple independent polyploidization events in each of the five major clades (that is, Nymphaeales, magnoliids, monocots, Ceratophyllales and eudicots). Furthermore, our phylogenomic analyses, which spanned multiple datasets and diverse methods, confirm that Amborella and Nymphaeales are successively sister to all other …
Xiaoqing Liu, Weirui Fu, Yiwei Tang, Wenju Zhang, Zhiping Soonog, Linfeng Li, Ji Yang, Hong Ma, Jianhua Yang, Chan Zhou, Charles C. Davis, and Yugu Wang. 1/23/2020. “Diverse trajectories of plastome degradation in holoparasitic Cistanche and the whereabouts of the lost plastid genes.” Journal of Experimental Botany, 71, 3, Pp. 877-892. Publisher's VersionAbstract
The plastid genomes (plastomes) of non-photosynthetic plants generally undergoes gene loss and pseudogenization. Despite massive plastomes reported in different parasitism types of the broomrape family (Orobanchaceae), more plastomes representing different degradation patterns in a single genus are expected to be explored. Here, we sequenced and assembled the complete plastomes of three holoparasitic Cistanche species (C. salsaC. tubulosa and C. sinensis) and compared them with the available plastomes of Orobanchaceae. We identified that the diverse degradation trajectories under purifying selection existed among three Cistanche clades, showing obvious size differences on entire plastome, long single copy region and non-coding region, and different patterns of the retention/loss of functional genes. With few exception of putatively functional genes, massive plastid fragments which have been lost and transferred into the mitochondrial or nuclear genomes are nonfunctional. In contrast with the equivalents of the Orobanche species, some plastid-derived genes with diverse genomic locations are found in Cistanche. The early and initially diverged clades in different genera such as Cistanche and Aphyllon possess obvious patterns of plastome degradation, suggesting that such key lineages should be considered prior to comparative analysis of plastome evolution, especially in the same genus.
Charles C Davis, Benjamin Goulet-Scott, and Jason Beckfield. 1/21/2020. “Climate Change: How to Pack a Punch at Meetings.” Nature, 577, 7791, Pp. 472. PDF
Emily K Meineke, Charles C Davis, and Jonathan T Davies. 11/20/2019. “Herbivory through the ages: Herbarium specimens for determining effects of plant traits on changing insect damage to plants.” Entomology 11/20/2019. Abstract
Some of the most consequential interactions expected to shift with climate change are between insect herbivores and plants, both of which are highly sensitive to temperature. Historically, insect herbivores and their host plants display varying levels of synchrony that could be disrupted or enhanced by climate change. Here, we use herbarium specimens collected over the past 100+ years to explore how phenological sensitivity, bloom/leaf-out season, and plant growth form affect changing insect damage to leaves. Our results suggest that warming may lengthen growing seasons for phenologically sensitive species, exposing them to more damage from resident or novel herbivores early in the growing season.
Ricardo A. Segovia, Toby Pennington, Tim Baker, Fernanda Coelho de Souza, Danilo Neves, Charles C. Davis, Juan J. Armesto, Ary Olivera-Filho, and Kyle Dexter. 8/9/2019. “Freezing and water availability structure the evolutionary diversity of trees across the Americas.” bioRxiv, Pp. 728717. Publisher's Version PDF
Lucas Marinho, Liming Cai, Xiaoshan Duan, Brad R. Ruhfel, Pedro Fiaschi, André M. Amorim, Cássio van den Berg, and Charles C. Davis. 5/1/2019. “Plastomes resolve generic limits within tribe Clusieae (Clusiaceae) and reveal the new genus Arawakia.” Molecular Phylogenetics and Evolution, 134, Pp. 142-151. Publisher's VersionAbstract
Clusieae is an exclusively Neotropical tribe in the family Clusiaceae sensu stricto. Although tribes within Clusiaceae are morphologically and phylogenetically well-delimited, resolution among genera within these tribes remains elusive. The tribe Clusieae includes an estimated ∼500 species distributed among five genera: ChrysochlamysClusiaDystovomitaTovomita, and Tovomitopsis. In this study, we used nearly complete plastid genomes from 30 exemplar Clusieae species representing all genera recognized, plus two outgroups to infer the phylogeny of the tribe using Maximum Likelihood and Bayesian Inference. For comparison, we also inferred a phylogeny from the nuclear Internal Transcribed Spacer (ITS) region using the same methods. Our study corroborates earlier findings that Clusia is monophyletic while Tovomita is not. It also provides additional support to the hypothesis that Chrysochlamys and Tovomitopsis are not closely related despite gross morphological similarity. Tovomita is divided into three distantly related clades: (i) core Tovomita (including the type T. guianensis), (ii) T. croatii, and (iii) the T. weddelliana species complex. Members of the T. weddelliana complex are isolated from the core Tovomita, and placed in a well-supported clade that is sister to a clade composed of Chrysochlamys plus ClusiaTovomita croatii is nested within Chrysochlamys. We propose taxonomic revisions to accommodate our phylogenetic findings, including the description of the new genus Arawakia, which includes the 18 species formerly recognized in the T. weddelliana species complex. Lectotypes are also designated for nine species (i.e., Arawakia angustataA. lanceolataA. lingulataA. longicuneataA. macrocarpaA. oblanceolataA. pithecobiaA. rhizophoroides, and A. weddelliana), and a taxonomic key for the identification of the six genera of Clusieae recognized is presented.
Charles C. Davis and Sarah Matthews. 4/24/2019. “Evolution of Land Plants.” Oxford Bibliographies. Publisher's Version PDF
William D. Pearse, Charles C. Davis, David W. Inouye, RIchard B. Primack, and T. Jonathan Davis. 3/2019. “[Author Correction] A statistical estimator for determining the limits of contemporary and historic phenology.” Nature Ecology & Evolution, 3, 3, Pp. 499. Publisher's Version PDF