What Do You Call a Person Who Studies Trees?

A person who studies trees is most commonly called a dendrologist. The word comes from the Greek “dendron” (tree) and “logos” (study), and dendrology has been used to describe the scientific study of trees and other woody plants since at least the seventeenth century. But “dendrologist” is only one answer among many, because trees sit at the intersection of so many scientific disciplines that the title a tree specialist carries depends almost entirely on which questions about trees they are asking.

Dendrology and Dendrologists

Dendrology is the broadest label for the scientific study of trees and shrubs. A dendrologist identifies, classifies, and describes the biology of woody plants, from towering conifers to small ornamental shrubs. The discipline overlaps heavily with botany and taxonomy, but its focus is narrower: woody perennial plants rather than the entire plant kingdom. The term has been in formal academic use since the mid-1600s, though its precise scope has shifted over the centuries as the field matured.¹

In practice, dendrologists work in herbaria, botanical gardens, university departments, and field research stations. Their core skill set includes morphological identification (telling species apart by leaves, bark, buds, flowers, and fruit), understanding geographic distributions, and contributing to the larger project of plant taxonomy. That taxonomic tradition stretches back to the fifteenth and sixteenth centuries, when the invention of the printing press, the creation of botanic gardens, and the use of dried plant specimens accelerated the cataloguing of the world’s flora.²

If someone asks “what do you call a person who studies trees?” and they mean pure scientific study, dendrologist is the safest one-word answer. But most professionals who spend their careers working with trees do not call themselves dendrologists. They use titles tied to the specific angle of tree science they practice.

Arborists and Arboriculture

The title most people encounter in everyday life is arborist. An arborist is a practitioner of arboriculture, which focuses on the cultivation, management, and care of individual trees and shrubs, particularly in urban and suburban settings. Where a dendrologist might classify a species, an arborist prunes it, diagnoses its diseases, assesses whether it poses a hazard, and decides when it needs to come down.

Arboriculture sits closer to a skilled trade than to a purely academic science, and professional governance reflects that. In Canada, for instance, arborists are regulated through specific statutory and occupational health and safety rules, while urban foresters fall under broader forest policy frameworks. The boundary between the two roles is not always clear, and the ambiguity in their scopes of practice has been a long-running source of professional friction. Arboricultural associations have pushed voluntary trade certifications as a way to raise standards, improve safety, increase worker pay, and build public trust.³

The most widely recognized credential is the ISA Certified Arborist designation, offered by the International Society of Arboriculture. You do not need a degree to sit for the exam, but you do need a combination of education and hands-on experience with trees. Many arborists also hold specialized credentials in utility work, municipal forestry, or tree risk assessment. If your neighbor hires someone to take care of a sick oak, that person is an arborist, not a dendrologist.

Foresters and Silviculturists

A forester manages forests at the landscape scale, balancing timber production, wildlife habitat, watershed protection, recreation, and carbon storage. Silviculture is the more specific discipline within forestry that deals with controlling how forest stands establish, grow, and change over time. Silviculturists decide which trees to plant, when to thin a stand, how to regenerate a forest after logging, and how to maintain ecological integrity while still harvesting wood.⁴

Silvicultural decision-making has grown more complex as climate change reshapes forests. Researchers are now integrating carbon sequestration goals into silvicultural planning across boreal, temperate, and tropical forests, often through landscape-level zoning that tries to balance production, conservation, and carbon storage simultaneously.⁵ A silviculturist in 2025 is as much a climate strategist as a timber manager.

Foresters typically hold a bachelor’s or master’s degree in forestry or a related natural-resource field. In many jurisdictions, the title “Registered Professional Forester” is legally protected, meaning you cannot practice forestry for hire without the credential. This is a sharper regulatory boundary than what exists for arborists in most places.

Dendrochronologists

Dendrochronology is the science of dating and interpreting tree rings. Because a tree typically adds one visible growth ring per year, the width and chemistry of those rings record information about the conditions the tree experienced. Dendrochronologists use this record to reconstruct past climates, date archaeological sites, track insect outbreaks, and study how forests responded to historical droughts or volcanic eruptions.

The field is most developed in temperate regions, where seasonal variation produces distinct annual rings. Tropical dendrochronology has been trickier, because many tropical trees lack the clear ring boundaries that temperate species produce. But a growing body of evidence shows that tropical trees do exhibit rhythmic growth patterns driven mainly by water availability, opening up vast new archives for climate reconstruction.⁶

A related subfield, dendrogeomorphology, uses tree-ring evidence to study landslides, earthquakes, and other ground movements. When a slope shifts, the trees growing on it respond by forming abnormal wood. Anatomical analysis of those distortions, such as reduced vessel size or the formation of tension wood, lets researchers reconstruct when and how severely the ground moved.⁷ If you study trees to learn about earthquakes rather than about the trees themselves, you are still a kind of tree scientist, just one whose audience is geologists and civil engineers.

Forest Ecologists

A forest ecologist studies how trees interact with each other, with other organisms, and with their physical environment. The questions here are less about individual trees and more about entire communities: Why does this species dominate in one valley but disappear in the next? How do disturbances like fire or windstorms reshape a forest over decades? What role do fungi, insects, and soil microbes play in keeping a forest functioning?

One of the more striking findings in forest ecology over the past two decades involves underground networks of mycorrhizal fungi that connect the root systems of neighboring trees. Research has shown that these networks facilitate the transfer of nutrients, defense signals, and other chemical messages between plants. The behavioral changes observed in trees connected through these fungal networks depend on environmental cues and the identity of neighboring plants, and disrupting the networks measurably affects how the forest community functions.⁸ This underground “tree talk” has captured public imagination and reshaped how ecologists think about forests as interconnected systems rather than collections of individuals competing for light.

Forest Pathologists

Forest pathology is the branch of science concerned with tree diseases. Forest pathologists study the fungi, bacteria, viruses, insects, and environmental stresses that sicken or kill trees. The field has historically relied on ecological approaches, but rising rates of genetic change in both pathogen populations and tree populations, largely driven by human activities like global trade and land-use change, have pushed pathologists to incorporate evolutionary thinking into their work.⁹

This is a field operating in a rapidly changing environment. New pathogens arrive on imported nursery stock. Climate shifts allow diseases to spread into regions where they were previously excluded by cold winters. Forest pathology increasingly overlaps with invasion biology and global change science, because the biggest threats to tree health today often come from organisms that evolved on a different continent.¹⁰

Tree Physiologists

Tree physiologists investigate how trees work at the level of cells, tissues, and organs. How does a redwood move water hundreds of feet from roots to crown? What happens inside xylem tissue when a drought hits? How do trees allocate energy between growth, reproduction, and defense?

Some of the answers are surprisingly counterintuitive. Researchers studying American chestnut saplings using micro-CT imaging found that during drought, water stored in dead tissue within the xylem contributed to overall stem water storage, but this stored water was not primarily used to prevent the cavitation (air-bubble formation) that cripples the tree’s water-transport system. Vessels began to cavitate at relatively modest water stress, simultaneously or even before the stored water was released from the surrounding wood matrix.¹¹ Findings like these reshape the basic models that physiologists use to predict how trees will cope with increasingly severe droughts.

Phenologists

Phenology is the study of the timing of recurring biological events, and trees are among its most visible subjects. When do buds break in spring? When do leaves change color in autumn? When do flowers open and fruits ripen? A phenologist tracks these seasonal milestones and tries to understand what drives their timing.

The connection to climate change is direct and measurable. Data from around the world show that leaf-out is generally earlier in warmer years, and the onset of spring leaf emergence has advanced in many locations over recent decades.¹² A recent review put numbers on the shift: in temperate and boreal systems, spring leaf-out and flowering have advanced by roughly two and a half to five days for every degree Celsius of warming.¹³

Autumn is affected too, though differently. Warming during summer and autumn delayed leaf senescence, the process of leaves dying and falling, by about six to eight days per degree Celsius of warming in European beech, suggesting that when water and nutrients are not limiting, temperature alone can be a dominant factor in when trees drop their leaves.¹⁴ The practical result is a longer growing season, which sounds beneficial but can create mismatches with pollinator schedules, increase frost risk for early-leafing trees, and alter competitive dynamics in mixed forests.

Urban Foresters

Urban forestry is a distinct profession focused on managing trees in cities and suburbs. Urban foresters plan which species to plant along streets, manage park woodlands, write tree-protection ordinances, and deal with the engineering challenges of growing trees in concrete and asphalt environments.

The scientific case for urban trees has strengthened considerably. Research has documented their cooling effects on local microclimates, their role in intercepting rainfall and reducing stormwater runoff, and their capacity to improve water quality by taking up nutrients that would otherwise pollute waterways.¹⁵ These ecosystem services give urban foresters a powerful economic argument when they advocate for tree planting and preservation in city budgets.

Paleobotanists and the Fossil Record of Trees

Paleobotanists study plant fossils to understand how plant life evolved and how ancient ecosystems functioned. Trees are a major focus, because the evolution of large woody plants fundamentally transformed the Earth’s atmosphere, soil chemistry, and climate. Rare fossil forests provide some of the best evidence for the ecology of the earliest large land plants, including a spectacular early fossil forest discovered in China that shed light on the evolution of key rooting systems.¹⁶

This is one of the more time-spanning specialties in tree science. A paleobotanist studying Devonian-era forests is working with material roughly 380 million years old, long before flowering plants existed, when the dominant trees were relatives of modern ferns and horsetails. That deep-time perspective helps modern scientists understand how forests respond to the kinds of atmospheric and climatic disruptions the planet faces today.

Ethnobotanists

Ethnobotany examines the relationship between people and plants, including trees, with a focus on traditional and indigenous knowledge. An ethnobotanist who works with trees might document the medicinal uses of bark and leaves in a particular culture, study how traditional forest management practices maintained biodiversity for centuries, or work to preserve knowledge that is disappearing as communities modernize.

Fieldwork in this area routinely turns up impressive breadth of traditional plant knowledge. A study of the Marakwet community in Kenya, for example, documented 115 indigenous medicinal plant species through structured interviews with local traditional healers.¹⁷ Many of those species are trees or woody shrubs, and their documented uses represent generations of accumulated pharmacological experimentation conducted outside any formal laboratory.

Conservation Scientists Focused on Trees

Conservation biologists working on trees assess which species are threatened, identify the factors driving their decline, and develop strategies to prevent extinctions. The scale of the problem is large. Evidence from the Global Tree Assessment suggests that roughly a third of the world’s tree species are currently threatened with extinction, representing a major ecological crisis.¹⁸

Part of the challenge is that many tree species have never been formally assessed. Efforts like the Global Tree Assessment have been accelerating the production of IUCN Red List assessments, particularly for understudied groups with ethnobotanical significance, so that conservation priorities can be set before species slip away unnoticed.¹⁹ In biodiversity hotspots like the Atlantic Forest of South America, researchers have used millions of herbarium and forest inventory records to produce automated conservation assessments for all tree species in the region, including over a thousand species that had never been evaluated before.²⁰

Tree Geneticists and Biotechnologists

Tree genetics and biotechnology represent one of the more forward-looking corners of tree science. Geneticists working on trees may focus on traditional breeding programs to develop pest-resistant or faster-growing varieties, or they may use molecular tools to study how populations are adapting to environmental change.

Biotechnology could accelerate breeding programs that develop trees with greater pest and disease resistance, improved wood properties, higher tolerance for harsh growing conditions, and increased capacity to sequester carbon.²¹ The potential applications are wide-ranging: engineering blight-resistant American chestnuts, developing faster-growing poplar clones for bioenergy, or creating trees that thrive on degraded land where current species cannot establish. The field sits at the intersection of genetics, forestry, and molecular biology, and the people working in it might call themselves forest geneticists, tree biotechnologists, or simply plant scientists.

When One Person Wears Several Hats

In practice, few tree scientists fit neatly into a single category. A forest ecologist studying how drought kills trees will read and contribute to tree physiology, forest pathology, and dendrochronology literature. A conservation biologist assessing extinction risk leans on taxonomy, ethnobotany, and geographic information systems. A dendrochronologist reconstructing past climates is doing paleoclimatology as much as tree science.

The titles also vary by country and institution. In some European traditions, the word “dendrologist” carries strong associations with plant identification and garden curation, while in North America it sounds more academic and slightly old-fashioned. “Arboriculturist” is used interchangeably with “arborist” in some countries but carries a more formal connotation in others. And “forester” can mean anything from a university-trained resource manager to someone who operates a chainsaw for a living, depending on where you are and whether the title is legally regulated.

So the short answer to “what do you call a person who studies trees?” is that it depends on what they study about trees. If you want a single word that covers the scientific study of trees in general, dendrologist is your best bet. But the person up in the canopy with a harness is an arborist, the person analyzing a core sample under a microscope is a dendrochronologist, the person modeling carbon uptake across a thousand hectares is a silviculturist or forester, and the person documenting how a remote community uses bark as medicine is an ethnobotanist. Trees are complex enough organisms, embedded deeply enough in human life and planetary systems, that no single profession can claim them entirely.