Hong Qian

Illinois State Museum · Personal website: http://hqian.weebly.com

Phylogenies generated by the packages of the PhyloMaker series have been broadly used in ecological and biogeographical studies, including several studies published by us. During the review processes of our papers, we noticed that some reviewers have concerns on the appropriateness of using phylogenies generated by these packages in studies on comm...

Aim Phylogenetic niche conservatism predicts that species tend to retain the ecological traits of their ancestors. Accordingly, communities developing under more stressful conditions should be more strongly structured by environmental filtering than communities in less stressful conditions, and thus would exhibit lower phylogenetic dispersion and d...

To date, whether Bergmann's rule, initially developed for individual species or closely related taxa, can be applied to broader taxa remains elusive. Using global distribution data for birds, mammals, reptiles, and amphibians, both species-and assemblage-based, we examined the role of species richness and related climate variables in shaping body s...

Aim Most plant groups originated under tropical conditions, leading to the hypothesis of tropical niche conservatism, according to which species assemblages of a clade originating and diversifying in tropical climates are expected to have low phylogenetic diversity and dispersion in temperate climates because only few lineages have adapted to these...

diversity quantifies the change in taxonomic and phylogenetic composition between areas. It can be partitioned into two additive components (turnover and nestedness). Geographic distance, which reflects dispersal limitation, and climatic distance, which reflects environmental filtering, are major drivers of β‐diversity, but few studies have assesse...

Liverworts are one of the oldest lineages of the extant land plants but the geographic patterns and ecological determinants of their species richness have not yet been studied at a global scale until now. Here, using a comprehensive global database, we find that regional species richness of liverworts in general 1) shows a clear latitudinal diversi...

Liverworts are an ancient plant lineage that occurs worldwide with the highest species richness in cool and humid habitats such as tropical montane and temperate rain forests. It has been proposed that liverworts originated under such temperate climatic conditions and have later expanded into more tropical conditions, but how this is reflected in t...

Aim Investigating phylogenetic beta diversity, and its turnover and nestedness components, can shed light on the evolutionary causes shaping the similarity (or dissimilarity) in composition between biological assemblages. Liverworts are important constituents of most terrestrial ecosystems worldwide but studies on phylogenetic beta diversity in liv...

For clades originating in warm climates, the tropical niche conservatism hypothesis predicts that current biological assemblages in colder or drier climates are expected to have lower phylogenetic diversity, and species in colder or drier climates are expected to be more closely related to each other (i.e., higher phylogenetic clustering). Liverwor...

Aim Beta‐diversity quantifies the change in taxonomic and phylogenetic composition between areas, and is a scalar between local ( α ) and regional ( γ ) diversity. Geographic distance, which reflects dispersal limitation, and climatic distance, which reflects environmental filtering, are major drivers of β‐diversity. Here, we analyse a comprehensiv...

Background and Aims Latitudinal diversity gradients have been intimately linked to the tropical niche conservatism hypothesis, which posits that there has been a strong filter due to the challenges faced by ancestral tropical lineages to adapt to low temperatures and colonize extra-tropical regions. In liverworts, species richness is higher towards...

Species richness generally decreases with increasing latitude, a biodiversity gradient that has long been considered as one of the few laws in ecology. This latitudinal diversity gradient has been observed in many major groups of organisms. In plants, the latitudinal diversity gradient has been observed in vascular plants, angiosperms, ferns, and l...

The effect of evolutionary history on wood density variation may play an important role in shaping variation in wood density, but this has largely not been tested. Using a comprehensive global dataset including 27,297 measurements of wood density from 2621 tree species worldwide, we test the hypothesis that the legacy of evolutionary history plays...

Aim Globally, biodiversity is unevenly distributed, as a result of varying environmental conditions and regionally different historical processes. The influence of the latter on current diversity patterns is poorly understood. We explore geographic patterns of matches and mismatches between phylogenetic relatedness metrics measuring different depth...

Species range size is a central topic in macroecology, biogeography and conservation biology. Species age has been frequently regarded as a contributor to range size in previous studies on range size, but this has rarely been specifically examined. Using global data from four living terrestrial vertebrate classes (birds, mammals, reptiles and amphi...

The tendency of species to retain ancestral ecological distributions (phylo-genetic niche conservatism) is thought to influence which species from a species pool can persist in a particular environment. Thus, investigating the relationships between measures of phylogenetic structure and environmental variables at a global scale can help understand...

Endemism of lineages lies at the core of understanding variation in community composition among geographic regions because it reflects how speciation, extinction, and dispersal have influenced current distributions. Here, we investigated geographic patterns and ecological drivers of taxonomic and phylogenetic endemism of angiosperm genera across th...

Although originating from a common Gondwanan flora, the diversity and composition of the floras of Africa and South America have greatly diverged since continental breakup of Africa from South America now having much higher plant species richness. However, the phylogenetic diversity of the floras and what this tells us about their evolution remaine...

Beta diversity (β-diversity) is the scalar between local (α) and regional (γ) diversity. Understanding geographic patterns of β-diversity is central to ecology, biogeography, and conservation biology. A full understanding of the origin and maintenance of geographic patterns of β-diversity requires exploring both taxonomic and phylogenetic β-diversi...

Invasive species may pose significant threats to biodiversity and ecosystem structure and functioning. The number of introduced species that have become invasive is substantial and is rapidly increasing. Identifying potentially invasive species and preventing their expansion are of critical importance in invasion ecology. Phylogenetic relatedness b...

Aim Mean lineage age is an important metric of evolutionary history and community structure of biological assemblages. Many studies have investigated geographic patterns and ecological drivers of mean lineage age in plant assemblages but all previous studies focused on vascular plants. Similar studies for bryophytes, a lineage of the oldest land pl...

Deep evolutionary histories can play an important role in assembling species into communities, but few studies have explored the effects of deep evolutionary histories on species assembly of angiosperms (flowering plants). Here we explore patterns of family divergence and diversification times (stem and crown ages, respectively) and phylogenetic fu...

The global cooling beginning in the Eocene has caused the coverage of tropical forests to contract from covering nearly all of Africa during the early Tertiary to about one tenth of Africa at the present time. Accompanying the climate cooling and drying was the evolution of traits tolerating cold and drought, particularly extreme drought in the Sah...

Aim The ability of predicting which naturalized non‐native species are likely to become invasive can help manage and prevent species invasions. The goal of this study is to test whether invasive angiosperm (flowering plant) species are a phylogenetically clustered subset of naturalized species at global, continental and regional scales, and to asse...

Understanding the causes and consequences of biological invasions is a great challenge in ecology and conservation biology. The ability to predict which naturalized species are likely to become invasive would be a great step forward in managing and preventing invasions. The goal of this study is to test whether invasive species are a phylogenetical...

Knowledge of relationships between phylogenetic structure of a biological assemblage and ecological factors that drive the variation of phylogenetic structure among regions is crucial for understanding the causes of variation in taxonomic composition and richness among regions, but this knowledge is lacking for the global flora of ferns. Here, we f...

Species diversity of angiosperms (flowering plants) varies greatly among regions. Geographic patterns of variation in species diversity are shaped by the interplay of ecological and evolutionary processes. Here, using a comprehensive data set for regional angiosperm floras across the world, we show geographic patterns of taxonomic (species) diversi...

The Qinghai-Tibetan Plateau (QTP) is the highest and one of the most extensive plateaus in the world. Investigating naturalized non-native plant species composition, phylogenetic relationships among naturalized plant species, and phylogenetic relationships between native and naturalized plant species on the plateau is of great importance. Here, we...

In eastern Asian subtropical forests, leaf habit shifts from evergreen to deciduous broad-leaved woody plants toward higher latitudes. This shift has been largely explained by the greater capacity of deciduous broad-leaved plants to respond to harsh climatic conditions (e.g., greater seasonality). The advantages of deciduous leaf habit over evergre...

The previously released packages of the PhyloMaker series (i.e. S.PhyloMaker, V.PhyloMaker, and V.PhyloMaker2) have been broadly used to generate phylogenetic trees for ecological and biogeographical studies. Although these packages can be used to generate phylogenetic trees for any groups of plants and animals for which megatrees are available, th...

Studies on large‐scale geographic patterns of aquatic plant diversity can promote the research on generality of macroecological patterns in different ecosystems. Here, we compiled a checklist of 889 aquatic angiosperms in China, including 738 helophytes (emergent and marshy plants) and 151 hydrophytes (submerged, free‐floating and floating‐leaved p...

Knowledge of which biological and functional traits have, or lack, phylogenetic signal in a particular group of organisms is important to understanding the formation and functioning of biological communities. Allometric biomass models reflecting tree growth characteristics are commonly used to predict forest biomass. However, few studies have exami...

Human activities have caused the exchange of species among different parts of the world. When introduced species become naturalized and invasive, they may cause great negative impacts on the environment and human societies, and pose significant threats to biodiversity and ecosystem structure. Knowledge on phylogenetic relatedness between native and...

China covers a vast territory harbouring a large number of aquatic plants. Although there are many studies on the β-diversity of total, herbaceous or woody plants in China and elsewhere, few studies have focused on aquatic plants. Here, we analyse a comprehensive data set of 889 aquatic angiosperm species in China, and explore the geographic patter...

Many biodiversity hotspots are located in montane regions, thus, understanding the underlying mechanisms driving species assembly along elevational gradients is of major interest in ecology and biogeography. Here, we assess spatial patterns and climatic drivers, and the effects of clade age, on patterns of phylogenetic structure of ferns along the...

Aim Most studies focusing on terrestrial ecosystems have shown that non‐native species are more likely to invade phylogenetically clustered communities, that the introduction of non‐native species increases phylogenetic clustering in the recipient communities, and that the latter is more conspicuous for recipient communities at a larger spatial sca...

Aim What factors may affect species range sizes remains a central question in ecology and biogeography. Particularly, whether and how species richness may regulate average species range size remains largely elusive. Here, we explore the relationship between species diversity and species range size at a global extent and discuss its implications and...

The scientific names of organisms are key identifiers of plants and animals. Correctly treating scientific names is a prerequisite for biodiversity research and documentation. Here, we present an R package, ‘U.Taxonstand’, which can standardize and harmonize scientific names in plant and animal species lists at a fast speed and at a high rate of ma...

The role of regional species diversity in large-scale species invasions has been largely controversial. On the one hand, it has been proposed that diversity may facilitate invasion (“diversity begets diversity”) because regions with higher diversity may indicate favorable conditions for many more species. On the other hand, high diversity may indic...

Aim The introduction of exotic plants can both increase (homogenize) and decrease (differentiate) floristic similarity between areas. We have a poor understanding of the degree to which plant species introductions tend to homogenize or differentiate floras, and relevant studies covering large spatial extent are scarce. China has been heavily invade...

Aims: Despite that vascular plants constitute an important component of overall global biodiversity and have been studied well over two centuries, the questions of "How many species of vascular plants are there in the world and how many of them have been discovered and described?" remain open. Here, we address the second of the two questions. Metho...

Aims: Despite that vascular plants constitute an important component of overall global biodiversity and have been studied well over two centuries, the questions of "How many species of vascular plants are there in the world and how many of them have been discovered and described?" remain open. Here, we address the second of the two questions. Metho...

Aim The introduction of alien species may be influenced by the phylogenetic structure of the native assemblage, while at the same time altering that structure. Understanding these effects sheds light on both the factors influencing naturalization of introduced species and their impacts. Considering regional angiosperm assemblages across China, we a...

Aim We test (1) whether invasive angiosperm (flowering plant) species are a phylogenetically clustered subset of all naturalized angiosperm species within an angiosperm assemblage, (2) whether more harmful invasive species are more strongly, or less strongly, related to each other, (3) whether the result of the first test is consistent with those f...

Aim Biodiversity hotspots are regions with the highest species richness, and the most threatened species. Previous studies have shown that the extinction risk may be more related to evolutionary history than to species' traits. However, there is a knowledge gap on the relationship between evolutionary history and species extinction risk in biodiver...

There is a consensus that climate factors strongly influence species richness along elevation gradients, but which factors are crucial and how they operate are still elusive. Here, we assess the relative importance of temperature‐related versus precipitation‐related variables and the relative importance of extreme climate versus climate seasonality...

An earlier version of V.PhyloMaker has been broadly used to generate phylogenetic trees of vascular plants for botanical, biogeographical and ecological studies. Here, we update and enlarge this package, which is now called ‘V.PhyloMaker2’. With V.PhyloMaker2, one can generate a phylogenetic tree for vascular plants based on three different botanic...

Despite that several studies have shown that data derived from species lists generated from distribution occurrence records in the Global Biodiversity Information Facility (GBIF) are not appropriate for those ecological and biogeographic studies that require high sampling completeness, because species lists derived from GBIF are generally very inco...

Aim Studies focusing on relatively small spatial scales have shown that alien plants are more likely to invade phylogenetically clustered communities, and that the introduction of alien plants further increases phylogenetic clustering in the recipient communities. However, whether these patterns hold at a continental scale remains untested. Here, w...

Aims The tropical niche conservatism (TNC) hypothesis and the out of the tropics (OTT) hypothesis propose mechanisms generating patterns of species diversity across warm‐to‐cold thermal gradients at large spatial scales. These two hypotheses both integrate ecological and biogeography‐related evolutionary factors, but they predict opposite patterns...

We aim to assess the influence of phylogenetic scale on the relationships of taxonomic and phylogenetic turnovers with environment for angiosperms in China. Specifically, we quantify the effects of contemporary climate on β‐diversity at different phylogenetic scales representing different evolutionary depths of angiosperms. We sampled a latitudinal...

Biologists have considered both winter coldness and temperature seasonality as major determinants of the northern limits of plants and animals in the Northern Hemisphere, which in turn drive the well-known latitudinal diversity gradient. However, few studies have tested which of the two climate variables is the primary determinant. In this study, w...

Aim The Arctic is the coldest inhabited region on Earth, and it supports few terrestrial species. The tropical‐climate origin of many angiosperm clades, along with strong phylogenetic niche conservatism, likely constrained colonization of cold environments for many plants. However, invasion of the Arctic by many lineages might also have opened up a...

Aims Understanding the joint effects of plant development and environment on shifts of intraspecific leaf traits will advance the understandings of the causes of intraspecific trait variation. We address this question by focusing on a widespread species Clausena dunniana in a subtropical broad-leaved forest. Methods We sampled 262 individuals of C...

Taxonomic diversity (TD) of areas within a region is often strongly and positively correlated with phylogenetic diversity (PD) of the areas. However, variation in speciation and extinction rates and the biogeographic histories of lineages can result in significant deviation of PD from TD (i.e., relative PD after correcting for TD; hereafter PDdev)....

Phylogenies are essential to studies investigating the effect of evolutionary history on assembly of species in ecological communities and geographical and ecological patterns of phylogenetic structure of species assemblages. Because phylogenies well resolved at the species level are lacking for many major groups of organisms such as vascular plant...

Aim Differences in physiography have been proposed to explain the diversity anomaly for vascular plants between environmentally similar regions of eastern Asia (EAS) and eastern North America (ENA). Here, we use plant species within disjunct genera to examine whether differences in topography contribute to the diversity anomaly and whether the rich...

We synthesize published botanical information for the flora of Africa to address multiple questions, including the following: How many species of vascular plants are there in Africa? How are the species distributed among different phylogenetic clades or taxonomic groups of vascular plants and different geographic regions across Africa? How complete...

Aim Previous studies have found strikingly different geographical patterns of phylogenetic diversity of gymnosperms and angiosperms, which have been suggested to result, in part, from the greater age of the former. To assess the effects of clade age on phylogenetic structure, we assessed phylodiversity patterns of pteridophytes (lycophytes and fern...

Aim A full understanding of the origin and maintenance of β-diversity patterns in a region requires understanding of: (1) the relationships of both taxonomic and phylogenetic β-diversity (TBD and PBD, respectively) and their respective turnover and nestedness components with geographical and environmental distances; (2) the relative importance of t...

Aim The plant species sharing ancestors now disjunctly distributed in eastern Asia (EAS) and eastern North America (ENA) have long been a biogeographic puzzle. Species within the EAS–ENA disjunct genera are presumed to exhibit niche conservatism, the tendency of closely related species to be more ecologically similar, reflecting lineages’ common ev...

Although they experience cold climates, particularly in temperate mountains during winter, alpine floras (plants in the vegetation belts above the climatic treelines) are generally species-rich. Yet, whether these floras represent evolutionarily independent, but convergent, assemblages drawn from their regional floras, or they originated from parti...

Aim Understanding patterns and drivers of phylogenetic beta diversity in a region is important to understanding the origin and maintenance of the regional species diversity and variation in species diversity between local sites. Here we used a phylogenetic beta diversity metric quantifying deep evolutionary histories to explore geographical and eco...

Climate and land cover changes are rising threats to biodiversity globally. However, potentially varying biotic sensitivity is a major source of uncertainty for translating environmental changes to extinction risks. To reduce this uncertainty, we assessed how extinction risks will be affected by future human‐driven environmental changes, focusing o...