Above: An image of matryoshka dolls. Image courtesy of Russian American Company.

Have you ever heard of matryoshka dolls? Originally from Russia, matryoshka dolls, also known as nesting dolls, represent the concept of “a thing within a thing.” When you open up one doll, you find a smaller yet identical doll inside the other. 

From the method of recursion in computer science to modern architecture, the idea of these matryoshka dolls emerges in many aspects of our daily lives. Nature is no exception.

One notable example is the existence of ecosystems within ecosystems. National Geographic defines an ecosystem as a community of interacting species and the abiotic factors that shape these interactions within a defined area. While most people think of ecosystems on a macroscopic scale, such as rainforests, deserts, or barrier reefs, ecosystems also exist on microscopic levels.

Above: A cluster of purple pitcher plants. Image courtesy of Richard Wong (University Program of Ecology ’26). 

You can directly observe this dichotomy between scales in pitcher plants. Found across the globe in locations with poor soil quality, pitcher plants are carnivorous plants that use a pitfall trip to capture flies, ants, and even bigger organisms, like the occasional rat. Nectar lures in unsuspecting prey, who fall into the pitcher plant’s characteristic shot-glass-shaped pitcher cup. Inside is a unique digestive fluid, collected from rainwater, which drowns and digests the captured prey. 

Above: A sample of pitcher fluid poured into a falcon tube with a spider captured inside. Image courtesy of Richard Wong (UPE ’26).

This fluid, however, is not static nor lifeless. Rather, within this pitcher fluid is a thriving microbiome, populated by larvae, bacteria, protists, and other microorganisms, that collectively feed on the bugs captured by the pitcher plant. This microbiome mirrors many concepts found in macroscopic, traditional ecosystems. For instance, pitcher fluid microbiomes have trophic levels, with midge and mosquito larvae representing higher trophic levels and bacteria, rotifers, and protists representing lower trophic levels. 

Pitcher Plants at Duke

Research on microbiomes in pitcher plants began in the mid-20th century, with more in-depth discoveries emerging alongside advancements in microbiology technology. As climate change research continues to grow, researchers at Duke University have taken the lead in studying how changing conditions affect the dynamics and interactions within the microbiome communities of pitcher plants.

To study this niche topic, Duke researchers adopt a multidisciplinary approach. To factor in both plant biology and microbiology, two ecology labs are collaborating to study these microbiome communities: the Wright Lab and the Gibert Lab.

Above: Dr. Justin Wright. Image courtesy of Duke University.

Led by Dean Justin Wright, the Wright Lab studies how plant biodiversity changes through a community-focused lens, considering spatial, temporal, and biological factors. A sample of the ideas exchanged in this lab include the impact of saltwater intrusion on terrestrial ecosystems in North Carolina, the influence of intraspecies variation on ecosystem functioning, and the effect of anthropogenic activities on nutrient cycling and consumer species identities. 

Above: Dr. Jean Philip Gibert. Image courtesy of Duke University. 

The Gibert Lab, on the other hand, is led by Dr. Jean Philip Gibert and focuses more on microbial ecology from a mathematical, computational, and experimental perspective. From analyzing how moss-associated microbes respond to stress to studying how predation by protists impacts the temperature fluctuations of a freshwater microbiome, this lab takes an interdisciplinary approach to microbe-focused ecology. 

Above: Richard Wong. Image courtesy of Richard Wong (UPE ’26).

Richard Wong’s Journey into Ecology

I recently had the opportunity to sit down with Richard Wong, the scientist leading the research on these microbiome communities. Wong is a 5th-year PhD student co-advised by Dr. Gibert and Dr. Wright.

While Wong has always been fascinated with ecology, his scientific journey is far from linear. He fell in love with plants at age 10, when he began growing carnivorous plants right in his backyard. Captivated by venus flytraps and pitcher plants, Wong was curious about virtually everything about these carnivorous plants. These never-ending questions, rabbit holes, and exceptions to rules drew Wong to the field of ecology. 

Fast-forward a decade, and Wong enrolled as a biology undergraduate at the University of Massachusetts Boston, where he began his research career in marine biology. From aquariums to salt marshes, Wong developed his expertise in marine biology and believed he had found his calling. Yet, midway through his undergraduate studies, Wong realized his passion lay elsewhere and pivoted back to his roots: plant biology. 

Above: Grainger Hall, the home of the Nicholas School of the Environment. Image courtesy of the Nicholas School of the Environment. 

In his senior year, Wong began networking with researchers across the U.S. One cold email led to another, and soon he found himself in conversation with Dr. Gibert from Duke. Wong initially applied to the Gibert Lab as a lab manager. Although he was not selected for the role, Dr. Gibert found Wong’s questions exciting and encouraged him to reapply—not as a technician or manager but as a PhD student. 

Wong agreed to take the opportunity and was accepted into Duke’s Biology Department but later transferred to the University Program of Ecology (UPE). This interdisciplinary PhD program spans virtually all branches of Duke, including the medical school, the Pratt School of Engineering, and the Nicholas School of the Environment. 

Wong is now in the final years of his program. While his early years were spent attending classes, running experiments, and conducting fieldwork, Wong is now completing his dissertation—a lengthy original project that showcases a PhD student’s understanding of their field. 

The Dynamics of the Purple Pitcher Plant’s Fluid: Wong’s Project

While Wong knew he wanted to work with carnivorous plants, he still needed to select a particular species to study. Intrigued by the adaptability of pitcher plants to difficult conditions, particularly nutrient-poor soils, Wong chose Sarracenia purpurea, the purple pitcher plant, as his model organism. Found along the Atlantic coast, and even up to central and western Canada, purple pitcher plants are known for the diverse community of bacteria, larvae, and rotifers that inhabit their waters. 

Motivated by the implications of climate change, Wong was curious about the unique dynamics within the pitcher plant microbiome and how changing conditions, especially temperature and nutrient quantities, will impact these microbiomes. 

To explore the internal mechanisms of such a broad topic, Wong divided his research into three separate chapters, each focusing on a different relationship between the microbiome and the environment. 

The First Chapter: Climate Effects on Mutualists and Microbes

The first chapter dives into how mutualists—organisms that have positive relationships with other organisms in an ecosystem—and enzyme activity in pitcher plants change with varying temperatures, precipitation levels, and nutrient deposition quantities. In the system Wong is working with, mutualists that primarily inhabit upper trophic levels include organisms like mosquito larvae, mites, midge larvae, and other organisms that are visible to the naked eye.

Above: Richard Wong examines the leaf of a pitcher plant at a field site. Image courtesy of Richard Wong (UPE ’26). 

To answer this question, Wong conducted a field observational study that began in the summer of 2021. At 10 different field sites across North Carolina and Virginia, he collected samples of pitcher fluid and pitcher plant leaves and acquired the corresponding nutrient deposition data from an Environmental Protection Agency database. 

However, he met some challenges during his fieldwork. Because purple pitcher plants are endangered in certain regions, acquiring these plants was an arduous legal process. While some areas allow the collection of a limited number of specimens with a permit, pitcher plants endemic to the Southern Appalachian mountains of western North Carolina are classified as endangered, severely restricting collection in that area. 

The physical work was no easier. Not only was finding the tiny and obscure pitcher plant a herculean task, but the sites themselves were on average three hours away from the lab. Because Wong sought to capture the enzymatic and microbial profile of pitcher fluid, he needed to preserve their quality as much as possible. This meant that Wong needed to take pitcher fluid samples to his lab freezer for processing immediately after sampling—which also meant driving three whole hours back to his lab. 

With the help of fellow lab mate Katrina DeWitt, Wong sometimes spent six hours on a round-trip drive and two hours sampling for a total of eight hours. Most of Wong’s early fieldwork was characterized by these strenuous drives. 

Above: A microscope used to examine a protist community in a petri dish in the Gibert Lab. Image courtesy of Will Sun (Trinity ’27).

Once transported to the lab, Wong used a microscope to census the mutualists living in the pitcher fluid. Next, Wong used a colorimetric enzymatic assay, in which he applied the enzyme of interest to a colorless substrate. The enzyme then facilitates the reaction and converts the colorless substrate into a colored product, allowing the overall enzyme activity to be quantified by the intensity of color. 

He then combined these data with GPS-based temperature and precipitation data to identify correlations between climate conditions and the biological parameters measured.

In this first chapter of his work, Wong hypothesized that both temperature and nitrogen concentrations would affect the concentrations of enzymes and the presence of mutualists. As proteins, enzymes are sensitive to temperature. High temperatures can denature the enzymes and render them completely malfunctional while low temperatures provide insufficient energy to facilitate reactions. Thus, each enzyme has an optimal temperature at which it functions best. 

The Second Chapter: Intraspecies Nutrient Acquisition Variation 

Wong’s second chapter quantifies and investigates the mechanics of nutrient acquisition and exchange between pitcher plants and the community. 

To do so, Wong collected the leaves of various pitcher plant species from field sites across the Atlantic coast. In addition to sampling the leaves of purple pitcher plants, Wong also collected leaves from Sarracenia flava species, also known as the yellow pitcher plant. 

Above: A colony of Sarracenia flava, another pitcher plant that Richard Wong examines. Image courtesy of Richard Wong (UPE ’26).

To profile the nutrients in the collected leaves, Wong ground the samples to a fine powder and shipped them to a Stable Isotope Lab, where he later received the carbon:nitrogen ratios of the leaves. 

In his analyses, Wong expected plants with more prey to have more nitrogen. Conversely, Wong predicted a negative correlation between nitrogen quantities and mutualist concentrations. Since mutualists use the same pool of nutrients as the plant, plants with more mutualists would contain less nitrogen than plants with fewer mutualists.

Above: A cross-section of a pitcher plant cut in half vertically. The black material along the leaf is broken down prey. Image courtesy of Richard Wong (UPE ’26). 

The Third Chapter: Impacts of Temperature on the Microbiome

Wong’s last chapter focuses on the microbiome itself, exploring how the microbiome community is altered by temperature. 

To understand how food web dynamics are impacted by temperature, Wong constructed artificial “pitcher plants” using 50 mL falcon tubes, whose conical shape mimics the shot-glass form of real pitcher plants,  and filled them up with homemade ‘bug tea’—water with boiled flies. Wong then introduced different types of protists at varying time points into chambers maintained at various temperatures. This allowed him to observe which protists survived best, which temperatures fostered the most diverse communities, and the step-by-step process of how the microbiome food web is built. 

While these methods may seem unorthodox, utilizing available resources to build scientific models is a common skill in ecology. In fact, Wong himself affectionately referred to ecology as “budget-friendly science,” where big questions are answered with lots of PVC pipes, duct tape, and self-drive.

Above: A FlowCam machine, housed in the Gibert Lab, is used to capture high-resolution images of individual microscopic particles. Image courtesy of Will Sun (Trinity ’27).

The Implications of Wong’s Work

Ultimately, Wong’s work may have rippling implications in conservation, environmental science, and even human health.

Above: A field of pitcher plants in Western North Carolina. Image courtesy of The Nature Conservancy. 

Wong hopes to broaden his understanding of how different communities function and the dynamic changes in nutrient processing between different environmental conditions. As carnivorous plant research is still a small area of study within botany, Wong seeks to increase both interest in and understanding of this field. 

Additionally, Wong’s research has the potential to influence policy changes in nutrient pollution regulation and general climate change mitigation. Because purple pitcher plants are an endangered species, by elucidating how these pitcher plants are affected by changing conditions on a micro and macro scale, Wong can predict how purple pitcher plant populations will fare as climate change progresses.

Above: A collection of purple pitcher plants, growing on the ground. Image courtesy of Florida Seeds. 

Additionally, the nutrient-focused components of Wong’s research relate to large-scale nutrient pollution events. By showing how nutrient pollution can affect plants, Wong can help conservationists understand the necessary actions to alleviate negative impacts on fragile plant populations. Wong has already begun reaching out to external organizations to explore the applications of his research, including the North Carolina Native Plant Society, PhD students and faculty from other universities, and the owner of two nature preserves in Virginia.

In the distant future, continued research on plant microbiomes and their internal processes could even intersect with studies on the human gut microbiome, creating new understandings about human health. 

To aspiring scientists, Wong’s most important piece of advice is to not be afraid to ask questions. To Wong, curiosity is the crux of not just ecology, but all science. 

When Wong was an undergraduate, he was afraid to ask questions. Yet, one day, while conducting salt marsh field work with his project investigator on an isolated island, Wong experienced a turning point. Up until then, he had never conversed with his PI about his personal curiosities and only did what he was told to do. An unexpected low tide forced them to stay on the island together for six hours before a boat was able to arrive. During those six hours, with nothing else to do, Wong finally talked to his PI and discussed his own questions. To Wong’s surprise, his PI not only welcomed but also actively encouraged Wong to ask questions, explaining that they help faculty better mentor students and understand their goals. 

Wong also advises students to stay open-minded while pursuing their passion. To him, biology is a collaborative science. Just as he continues to work with a network of faculty and students, Wong encourages students to learn as much as they can from others. At the same time, Wong stresses the importance of crafting and defending your opinions in science. After all, Wong said, a PhD program is not meant to turn students into their mentors, but rather teach them to be free thinkers and eventually, their colleagues.