Andrew L. Hipp

• PhD, Botany, U. of Wisconsin
• Senior Researcher at Morton Arboretum

Aim We addressed the role of climate and historical biogeography on the temperate‐tropical divide in Mexico, also known as the “Mexican Transition Zone” (MTZ). We asked: (1) How phylogenetic structure and species composition vary across the MTZ, (2) What roles dispersal, in situ speciation and climatic filtering play in assembling regional floras,...

Freezing tolerance plays a pivotal role in shaping the distribution and diversification of organisms. We investigated the dynamics of adaptation to climate and potential trade‐offs between stem freezing tolerance and growth rate in 48 Quercus species. Species from colder regions exhibited higher freezing tolerance, lower growth rates and higher win...

The effects of single chromosome number change—dysploidy – mediating diversification remain poorly understood. Dysploidy modifies recombination rates, linkage, or reproductive isolation, especially for one‐fifth of all eukaryote lineages with holocentric chromosomes. Dysploidy effects on diversification have not been estimated because modeling chro...

Ongoing climate change will negatively impact tree populations unless they are able to acclimate to the changes in their local environment. Effective planning for climate adaptation management requires an understanding of the current state of local adaptation and physiological performance to assess whether populations are at risk of local extinctio...

The study of natural history, combined with the study of the environmental drivers that explains actual and past species distributions significantly enhanced our understanding of the evolution of Quercus forests in the Iberian Peninsula. A full Herbaria review provided insight into the distribution and diversity of Iberian Oaks and their hybrids, r...

Societal Impact Statement Increasing evidence indicates gene flow commonly occurs between closely related species in diverse plant genera and can involve numerous species. Here, we present a simple method to quantify and characterize the potential for gene flow among “sympatric” species (they share some part of their geographic distribution), using...

The Iberian Peninsula is a wide known hotspot and refugia for the Eurasian white oak species. In classic literature, this group of oaks are traditionally assumed to form common hybrid swarms, and their resulting nothotaxa have suffered of nomenclatural uncertainty. This comes from natural history artifacts and the unknown validation of putative par...

The sympatric nature of Quercus (oak) clades in the Americas offers insights into evolutionary dynamics and environmental adaptations across broad environmental conditions. While species occupy similar regions, it is unknown if species use similar strategies to adapt to different ecological niche. We explored these patterns using herbarium surveys...

Mediterranean climate induces different leaf syndromes in oaks (Quercus sp.) occupying such a climate. Measuring different morphological traits we proved how, despite of the different origins of the lineages within oaks, a group of species (those with small-rounded sclerophyllous evergreen leaves) reach a convergence in their leaf morphology.

Key message Despite been grown under the same climate, oak species are able to correlate with looser, but still identifiable, leaf morphological syndromes, composed by morphological traits with an ecological role in their respective macroclimates. Context Environmental restrictions imposed by climate have been shown to modulate leaf morphology. A...

Background and Aims Introgressive hybridization poses a challenge to taxonomic and phylogenetic understanding of taxa, particularly when there are high numbers of co-occurring, intercrossable species. The genus Quercus exemplifies this situation. Oaks are highly diverse in sympatry and cross freely, creating syngameons of interfertile species. Alth...

Most foundational work on the evolution and migration of plant species relies on genomic data from contemporary samples. Ancient plant samples can give us access to allele sequences and distributions on the landscape dating back to the mid Holocene or earlier (Gugerli et al., 2005). Nuclear DNA from ancient wood, however, has been mostly inaccessib...

Phylogenetic and functional diversity are theorised to increase invasion resistance. Experimentally testing whether plant communities higher in these components of diversity are less invasible is an important step for guiding restoration designs. To investigate how phylogenetic and functional diversity of vegetation affect invasion resistance in a...

Most foundational work on the evolution and migration of plant species relies on genomic data from contemporary samples. Ancient plant samples can give us access to allele sequences and distributions on the landscape dating back to the mid Holocene or earlier (Gugerli et al., 2005). Nuclear DNA from ancient wood, however, has been mostly inaccessib...

Holocentric organisms, unlike typical monocentric organisms, have kinetochore activity distributed along almost the whole length of the chromosome. Because of this, chromosome rearrangements through fission and fusion are more likely to become fixed in holocentric species, which may account for the extraordinary rates of chromosome evolution that m...

Studies investigating the evolution of flowering plants have long focused on isolating mechanisms such as pollinator specificity. Some recent studies have proposed a role for introgressive hybridization between species, recognizing that isolating processes such as pollinator specialization may not be complete barriers to hybridization. Occasional h...

Phylogenetic diversity (PD), the evolutionary history of the organisms comprising a community, is increasingly recognized as an important driver of ecosystem function. However, biodiversity–ecosystem function experiments have rarely included PD as an a priori treatment. Thus, PD's effects in existing experiments are often confounded by covarying di...

Distinct survival strategies can result from trade‐offs in plant function under contrasting environments. Investment in drought resistance mechanisms can enhance survivorship but result in conservative growth. We tested the hypothesis that the widespread oaks (Quercus spp.) of the Americas exhibit an interspecific trade‐off between drought resistan...

Botanic garden collections are increasingly seeking to quantify and improve the value of their collections for science, horticulture, conservation and other uses. Quantifying the value of a collection depends on the mission of the institution. Many botanic gardens are prioritising the conservation of rare and threatened species towards preventing p...

Background and Aims Cork oaks (Quercus sect. Cerris) comprise 15 extant species in Eurasia. Despite being a small clade, they display a range of leaf morphologies comparable to the largest sections (>100 spp.) in Quercus. Their fossil record extends back to the Eocene. Here, we explore how cork oaks achieved their modern ranges and how legacy effec...

Addressing global biodiversity loss requires an expanded focus on multiple dimensions of biodiversity. While most studies have focused on the consequences of plant interspecific diversity, our mechanistic understanding of how genetic diversity within plant species affects plant productivity remains limited. Here, we use a tree species × genetic div...

Broˇzov´a et al. (2022) present a study, “Toward finally unraveling the phylogenetic relationships of Juncaceae with respect to another cyperid family, Cyperaceae”, with the premise of revising the phylogenetic re-lationships in Juncaceae and Cyperaceae based on Sanger sequencing of one nuclear rDNA (ITS) and two plastid regions (the gene rbcL and t...

Based on available molecular phylogenetic data, we describe four new Carex sections to accommodate 15 species from Asia, Europe and North America. All the sections form strongly supported monophyletic groups in the most recent phylogenetic hypotheses for the genus and are diagnosable by morphological characters, therefore distinct from closely rela...

Phylogenetic and functional diversity are relevant for restoration planning, as they influence important ecosystem functions and services. However, it is unknown whether initial phylogenetic and functional diversity of restorations as planned and planted are maintained over time, i.e., the extent to which diversity of the restoration planting is re...

Traditional classification of speciation modes has focused on physical barriers to gene flow. Allopatric speciation with complete reproductive isolation is viewed as the most common mechanism of speciation. Parapatry and sympatry, by contrast, entail speciation in the face of ongoing gene flow, making them more difficult to detect. The genus Iberod...

Addressing global biodiversity loss requires an expanded focus on multiple dimensions of biodiversity. While most studies have focused on the consequences of plant interspecific diversity, our mechanistic understanding of how the diversity within a given plant species (genetic diversity) affects plant productivity remains limited. Here, we use a tr...

Oaks (genus Quercus) are foundation tree species significantly affecting community assembly and ecosystem functions. Their ecological importance, high diversity in adaptive traits and genes, and rapidly growing genomic resources make them model species for the integration of population, evolutionary, and ecological research. Their demonstrated repl...

Plant biodiversity is often partitioned into taxonomic diversity (species composition and abundance), phylogenetic diversity (breadth of evolutionary lineages) and functional diversity (resource‐use strategies or physical traits). Evaluating the effects and interplay of these dimensions can provide insights into how assembly processes drive composi...

The prediction that higher biodiversity leads to denser niche packing and thus higher community resistance to invasion has long been studied, with species richness as the predominant measure of diversity. However, few studies have explored how phylogenetic and functional diversity, which should represent niche space more faithfully than taxonomic d...

Differentiation among populations, sometimes despite ongoing gene exchange, is a key step in speciation. Therefore, comparison of intra- and interspecific differentiation patterns is of great significance to understanding speciation. The genus Quercus is an interesting system to test speciation models in the presence of gene flow, due to its weak i...

A RAD-seq phylogeny is presented for the genus Ulmus , and a revised infrageneric classification is given, with keys, descriptions, and range maps for the subgenera and sections. The previously accepted classification was based on a cpDNA phylogeny, but several well-marked clades in the chloroplast phylogeny are not recovered in the RAD-seq phyloge...

Phylogenetic ecology uses evolutionary history to improve understanding of plant interactions. Phylogenetic distance can mediate plant interactions such as competition (e.g., via limiting similarity) and facilitation (e.g., via niche complementarity), influencing community assembly patterns. Previous research has found evidence both for and against...

1) Introduction and objectives: Near half of the European white oaks inhabit the Iberian Peninsula, a hotspot of diversity in the Mediterranean Basin and a priority area for oak conservation globally. The Iberian oaks have suffered from a history of nomenclatural complications and taxonomic confusion, with the number of taxa poorly resolved and inf...

Premise: Leaf shape and size figure strongly in plants' adaptation to their environments. Among trees, oaks are notoriously variable in leaf morphology. Our study examines the degree to which within-tree, among-tree, and among-site variation contribute to latitudinal variation in leaf shape and size of bur oak (Quercus macrocarpa: Fagaceae), one o...

We present a densely sampled phylogenomic study of the mulberry tribe (Moreae, Moraceae), an economically important clade with a global distribution, revealing multiple losses of inflexed stamens, a character traditionally used to circumscribe Moreae. Inflexed stamens facilitate ballistic pollen release and are associated with wind pollination, and...

The oak flora of North America north of Mexico is both phylogenetically diverse and species-rich, including 92 species placed in five sections of subgenus Quercus, the oak clade centered on the Americas. Despite phylogenetic and taxonomic progress on the genus over the past 45 years, classification of species at the subsectional level remains uncha...

Adaptive divergence is widely accepted as a contributor to speciation and the maintenance of species integrity. However, the mechanisms leading to reproductive isolation, the genes involved in adaptive divergence, and the traits that shape the adaptation of wild species to changes in climate are still largely unknown. In studying the role of ecolog...

Cyperaceae (sedges) are the third largest monocot family and are of considerable economic and ecological importance. Sedges represent an ideal model family to study evolutionary biology because of their species richness, global distribution, large discrepancies in lineage diversity, broad range of ecological preferences, and adaptations including m...

Genetic diversity is a critical resource for species’ survival during times of environmental change. Conserving and sustainably managing genetic diversity requires understanding the distribution and amount of genetic diversity (in situ and ex situ) across multiple species. This paper focuses on three emblematic and IUCN Red List threatened oaks (Qu...

Ecological opportunity has been associated with increases in diversification rates across the tree of life. Under an ecological diversification model, the emergence of novel environments promotes morpho‐ and ecospace evolution. Whether this model holds at the clade‐level within the most species‐rich angiosperm genus found in North America (Carex, C...

Carex section Schiedeanae (subg. Euthyceras) has long been thought to comprise at most five species of Mexican sedges. Our morphological studies in the field and herbarium, however, supported by more recent DNA sequencing work, demonstrate that the section is in fact three times as species‐rich, making it one of the largest sections in Mexico. Its...

Carex section Phacocystis (Cyperaceae) is one of the most diverse and taxonomically complex groups of sedges (between 116‐147 spp.) with a worldwide distribution in a wide array of biomes. It has a very complicated taxonomic history, with numerous disagreements among different treatments. We studied the biogeography and niche evolution in a phyloge...

Changes in chromosome number as a result of fission and fusion in holocentric chromosomes have direct and immediate effects on genome structure and recombination rates. These in turn may influence ecology and evolutionary trajectories profoundly. Sedges of the genus Carex (Cyperaceae) comprise ca. 2000 species with holocentric chromosomes that evol...

Restriction‐site associated DNA sequencing (RAD‐seq) and related methods have become relatively common approaches to resolving species‐level phylogeny. It is not clear, however, whether RAD‐seq data matrices are well suited to relaxed‐clock inference of divergence times, given the size of the matrices and the abundance of missing data. We investiga...

Phylogenetic studies of Carex L. (Cyperaceae) have consistently demonstrated that most subgenera and sections are para‐ or polyphyletic. Yet taxonomists continue to use subgenera and sections in Carex classification. Why? The Global Carex Group here takes the position that the historical and continued use of subgenera and sections serves to (1) org...

Premise: Measuring plant productivity is critical to understanding complex community interactions. Many traditional methods for estimating productivity, such as direct measurements of biomass and cover, are resource intensive, and remote sensing techniques are emerging as viable alternatives. Methods: We explore drone-based remote sensing tools...

Fine roots mediate below‐ground resource acquisition, yet understanding of how fine‐root functional traits vary along environmental gradients, within branching orders and across phylogenetic scales remains limited. Morphological and architectural fine‐root traits were measured on individual root orders of 20 oak species (genus Quercus) from diverge...

The field of systematics is experiencing a new molecular revolution driven by the increased availability of high-throughput sequencing technologies. As these techniques become more affordable, the increased genomic resources have increasingly far-reaching implications for our understanding of the Tree of Life. With c. 2000 species, Carex (Cyperacea...

Interannual variability of seed crops (CVp) has profound consequences for plant populations and food webs, where high CVp is termed ‘masting’. Here we ask: is global variation in CVp better predicted by plant or habitat differences consistent with adaptive economies of scale, in which flower and seed benefits increase disproportionately during mast...

PREMISE Oaks are notoriously variable in leaf morphology, but little is known regarding the partial contributions of climate, population, latitude, and individual tree to total variation in leaf morphology. This study examines the contributions of within-tree, among-tree, and among-site variation to the total variation in leaf morphology in bur oak...

Effectively conserving biodiversity with limited resources requires scientifically informed and efficient strategies. Guidance is particularly needed on how many living plants are necessary to conserve a threshold level of genetic diversity in ex situ collections. We investigated this question for 11 taxa across five genera. In this first study ana...

We present a densely-sampled phylogenomic study of the mulberry tribe (Moreae, Moraceae), an economically important clade with a global distribution, revealing multiple losses of inflexed stamens, a character traditionally used to circumscribe Moreae. Inflexed stamens facilitate ballistic pollen release and are associated with wind pollination, and...

In phylogenetic studies across angiosperms, at various taxonomic levels, polytomies have persisted despite efforts to resolve them by increasing sampling of taxa and loci. The large amount of genomic data now available and statistical tools to analyze them provide unprecedented power for phylogenetic inference. Targeted sequencing has emerged as a...

Plant traits—the morphological, anatomical, physiological, biochemical and phenological characteristics of plants—determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research sp...

It is hypothesised that tree distributions in Europe are largely limited by their ability to cope with the summer drought imposed by the Mediterranean climate in the southern areas and by their competitive potential in central regions with more mesic conditions. We investigated the extent to which leaf and plant morphology, gas exchange, leaf and s...

- Traditional classification of speciation modes has focused on physical barriers to gene flow. While allopatry has been viewed as the most common mechanism of speciation, parapatry and sympatry, both entail speciation in the face of ongoing gene flow and thus both are far more difficult to detect and demonstrate. Iberodes (Boraginaceae, NW Europe)...

Carex (Cyperaceae) is a megadiverse genus which ranks among the five largest angiosperm genera, with about 2000 species. The authors investigated the main biogeographic and lineage diversification history in the genus using a global phylogenetic sampling comprising 66% of accepted species. The study suggests that there may not be just one answer to...

The genus Quercus is among the most widespread and species‐rich tree genera in the northern hemisphere. The extraordinary species diversity in America and Asia together with the continuous continental distribution of a limited number of European species raise questions about how macro‐ and microevolutionary processes made the genus Quercus an evolu...

Background: Understanding the origin of genetic variation is the key to predict how species will respond to future climate change. The genus Quercus is a species-rich and ecologically diverse woody genus that dominates a wide range of forests and woodland communities of the Northern Hemisphere. Quercus thus offers a unique opportunity to investiga...

The megadiverse genus Carex (c. 2000 species, Cyperaceae) has a nearly cosmopolitan distribution, displaying an inverted latitudinal richness gradient with higher species diversity in cold‐temperate areas of the Northern Hemisphere. Despite great expansion in our knowledge of the phylogenetic history of the genus and many molecular studies focusing...

Traditional classification of speciation modes has focused on physical barriers to gene flow. While allopatry has been viewed as the most common mechanism of speciation, parapatry and sympatry, both entail speciation in the face of ongoing gene flow and thus both are far more difficult to detect and demonstrate. Iberodes (Boraginaceae, NW Europe) w...

The tree of life is highly reticulate, with the history of population divergence emerging from populations of gene phylogenies that reflect histories of introgression, lineage sorting and divergence. In this study, we investigate global patterns of oak diversity and test the hypothesis that there are regions of the oak genome that are broadly infor...

Holocentric chromosomes are characterised by the presence of kinetochoric activity along the chromosome length. This atypical chromosomal architecture has evolved independently in a wide array of lineages across the tree of life. Different mechanisms have been developed to overcome meiotic problems posed by holocentry, such as inverted meiosis and...

The eastern North American white oaks, a complex of approximately 16 potentially interbreeding species, have become a classic model for studying the genetic nature of species in a syngameon. Genetic work over the past two decades has demonstrated the reality of oak species, but gene flow between sympatric oaks raises the question of whether there a...

Evolutionary history and adaptation to climate shape plant traits. Some include leaf traits that influence litter quality. Thus, evolutionary history should affect litter decomposition, a crucial ecosystem process. In addition, litter decomposition is directly influenced by climate. We consequently expect plant phylogeny, adaptation and climate to...

Climatic niche modeling is widely used in modern macroecology and evolutionary biology to model species' distributions and ecological niches. Frequently, Global Biodiversity Information Facility (GBIF) distribution data are used as raw data for such models. Unfortunately, the accuracy of resulting niche estimates is difficult to assess, and GBIF us...

Aim Many subtropical organisms exhibit an East Asian‐Tethyan disjunction, a distribution split between East Asia and the Mediterranean. The underlying mechanisms and timing have remained unclear to date. The evolutionary history of Quercus section Ilex Loudon, a representative East Asian‐Tethyan disjunct lineage with a rich and widespread fossil re...

Recent studies have demonstrated that reproductive isolation in combination with relatively strong natural selection or genetic drift may cause rapid speciation. Dramatic isolation scenarios such as allopolyploidy or differentiation among islands are often invoked to explain such cases of rapid speciation, but rapid speciation may also be driven by...

Background: Diversification patterns in the Himalayas have been important to our understanding of global biodiversity. Despite recent broad-scale studies, the most diverse angiosperm genus of the temperate zone-Carex L. (Cyperaceae), with ca. 2100 species worldwide-has not yet been studied in the Himalayas, which contains 189 Carex species. Here t...

When we look at an oak, we see one organism, despite the fact that each of the estimated 25,808 genes in the oak genome has a unique history. Here I review why the evolutionary history of oaks comprises a variety of phylogenetic histories that trace disparate histories of introgression, stochastic allele extinction, and population divergence. I des...

Botanists have long recognised interspecific gene flow as a common occurrence within white oaks (Quercus section Quercus). Historical allele exchange, however, has not been fully characterised and the complex genomic signals resulting from the combination of vertical and horizontal gene transmission may confound phylogenetic inference and obscure o...

The eastern North American white oaks, a complex of approximately 16 potentially interbreeding species, have become a classic model for studying the genetic nature of species in a syngameon. Genetic work over the past two decades has demonstrated the reality of oak species, but gene flow between sympatric oaks raises the question of whether there a...

The tree of life is highly reticulate, with the history of population divergence buried amongst phylogenies deriving from introgression and lineage sorting. In this study, we test the hypothesis that there are regions of the oak ( Quercus , Fagaceae) genome that are broadly informative about phylogeny and investigate global patterns of oak diversit...

Carex L., representing approximately 2,100 species, is one of the world's largest angiosperm genera and nearly cosmopolitan in distribution. However, limited studies are conducted on this genus in the Western Himalayas, from both a molecular and a morphologic perspective. In this study, Carex species were explored across the Western Himalayan range...

Recent studies have demonstrated that reproductive isolation in combination with relatively strong natural selection or genetic drift may cause rapid speciation. Dramatic isolation scenarios such as allopolyploidy or differentiation among islands are often invoked to explain such cases of rapid speciation, but rapid speciation may also be driven by...

When we look at an oak, we see one organism, despite the fact that each of the estimated 25,808 genes in the oak genome has a unique history. Here I review why the evolutionary history of oaks comprises a variety of phylogenetic histories that trace disparate histories of introgression, stochastic allele extinction, and population divergence. I des...

When we look at an oak, we see one organism, despite the fact that each of the estimated 25,808 genes in the oak genome has a unique history. Here I review why the evolutionary history of oaks comprises a variety of phylogenetic histories that trace disparate histories of introgression, stochastic allele extinction, and population divergence. I des...

Here we report chromosome number counts from the sedge family (Cyperaceae), most of which correspond to genus Carex from the Nearctic and western Palearctic. In addition, counts are reported for some Neotropical and Afrotropical sedges. We provide the first known chromosome counts for the subfamily Mapanioideae, 5 genera (Lagenocarpus, Afroscirpoi...

Carex in South America Representative diversity. 201 taxa (about 10% of the whole genus), belonging to the four major clades and 33 sections. At least 2 introduced spp. (+ other 3 spp.?). Multiple origins. Carex has colonized South America several independent times and via different colonization routes. Ecology. Neotropical Carex grow in cold--...

Attempting to control invasive plant species in tallgrass prairie restorations is time-consuming and costly, making improved approaches for predicting and reducing invasion imperative. Both biotic and abiotic factors mediate plant invasions, and can potentially be used by restoration managers to reduce invasion rates. Biotic factors such as plant s...

Our understanding of the effects of plant biodiversity on ecosystem function rests in large part on experiments that have disentangled environmental variables from local diversity. Yet phylogenetic diversity (PD) effects can be confounded by phylogenetic identity effects in such experiments if assemblages with low or high PD tend to be dominated by...

Systematically quantifying diversity across landscapes is necessary to understand how clade history and ecological heterogeneity contribute to the origin, distribution, and maintenance of biodiversity. Here, we chart the spatial structure of diversity among all species in the sedge family (Cyperaceae) throughout the USA and Canada. We first identif...

Premise of the Study Evolutionary and biogeographic history, including past environmental change and diversification processes, are likely to have influenced the expansion, migration, and extinction of populations, creating evolutionary legacy effects that influence regional species pools and the composition of communities. We consider the conseque...

Meiotic drive, the class of meiotic mechanisms that drive unequal segregation of alleles among gametes, may be an important force in karyotype evolution. Its role in holocentric organisms, whose chromosomes lack localized centromeres is poorly understood. We crossed two individuals of Carex scoparia (Cyperaceae) with different chromosome numbers (2...

The Oaks of the Americas Conservation Network (OACN) is an international consortium of oak experts aimed at meeting aimed at filling the gaps in oak research and conservation in North and Central America. As part of their larger effort to connect science to conservation and catalyze collaboration between important oak experts, OACN held a Workshop...

In this chapter, we review major classification schemes proposed for oaks by John Claudius Loudon, Anders Sandøe Ørsted, William Trelease, Otto Karl Anton Schwarz, Aimée Antoinette Camus, Yuri Leonárdovich Menitsky, and Kevin C. Nixon. Classifications of oaks (Fig. 2.1) have thus far been based entirely on morphological characters. They differed pr...

The evolutionary history of Quercus section Cyclobalanopsis, a dominant lineage in East Asian evergreen broadleaved forests (EBLFs), has not been comprehensively studied using molecular tools. In this study, we reconstruct the first comprehensive phylogeny of this lineage using a genomic approach (restriction-site associated DNA sequencing, RAD-seq...

PREMISE OF THE STUDY The California Floristic Province (CA‐FP) is a unique and diverse region of floral endemism, yet the timing and nature of divergence and diversification of many lineages remain underexplored. We seek to elucidate the evolutionary history of the red oaks of the CA‐FP, the Agrifoliae. METHODS We collected PstI‐associated RAD‐seq...

DNA barcoding has proved difficult in a number of woody plant genera, including the ecologically important oak genus Quercus. In this study, we utilized restrictionsite‐associated DNA sequencing (RAD‐seq) to develop an economical single nucleotide polymorphism (SNP) DNA barcoding system that suffices to distinguish eight common, sympatric eastern N...