About

Katalin Szlavecz is a Research Professor in the Department of Earth & Planetary Sciences at Johns Hopkins University. She earned her PhD from Eotvos University in Hungary. Her research includes the study of the diversity and ecology of soil invertebrates, soil biogeochemical cycling, urban ecosystems, and invasive species. She is a Co-Principal Investigator of the Baltimore Ecosystem Study Long Term Ecological Research (LTER), a research associate at the Smithsonian Environmental Research Center, and a collaborator at the USDA Beltsville Agricultural Research Center Farming Systems Project. Her work focuses on belowground carbon dynamics in altered precipitation patterns in Mid-Atlantic deciduous forests, the impact of earthworm invasions on soil ecosystems, and interactions between earthworms, soil organic matter, fungi, and tree seedlings. Szlavecz's research also encompasses urban soils and soil biota, and she is involved in the Global Urban Soil Ecology and Educational Network (GLUSEEN) and the use of wireless sensors in soil ecology.

Research topics

• Ecology
• Biology
• Geography
• Environmental chemistry
• Biochemistry
• Chemistry
• Environmental science
• Organic chemistry
• Fishery

Selected publications

• Rise of terrestrial isopods in the pet trade and the need for their inclusion in trade regulation

  Conservation Biology · 2025-10-30 · 1 citations

  articleOpen accessSenior author

  Wild animals sold as pets are at a higher risk of extinction than animals that are not traded. Invertebrates are often overlooked in national and international laws designed to control the global pet trade. Among these invertebrates, terrestrial isopods-which function as detritivores-have traditionally been kept to clean terraria housing vertebrates and other arthropods. Over the past 2 decades, they have gained popularity among hobbyists due to their ease of care, vibrant colors, minimal space requirements, and harmlessness to humans. Many traded species have limited distribution areas, sometimes only a single locality. Collecting these species in the wild poses a threat to local populations. Species are continuously being added to the online market. Many of these species, especially from tropical regions in Southeast Asia, Central America, and South America, have not been described scientifically. In addition to threatening native populations, this trade in live specimens increases the probability of non-native species introductions and invasions to new regions. Given this growing interest, we advocate for including terrestrial isopods in national and international regulations. We encourage scientists to assess the scale of the terrestrial isopod pet trade, scientifically describe traded species, and collect distribution and ecological data. We ask the International Union for Conservation of Nature to establish a terrestrial isopod specialist group to assess the status of traded species, which would facilitate their inclusion in the Convention on International Trade in Endangered Species of Wild Fauna and Flora. We urge policy makers to make conservative lists of species that can be traded applying the precautionary principle in regulating the trade in species with an unknown conservation status and invasion risk.

  PublisherOA PDFDOI

• A new chapter for soil biodiversity: launch of the IUCN Species Survival Commission Woodlouse Specialist Group

  Oryx · 2025-09-01

  articleOpen access

  In early 2025, the IUCN Species Survival Commission (SSC) introduced a new Specialist Group dedicated to woodlice, formally known as terrestrial isopods (Crustacea: Isopoda: Oniscidea). This is a significant milestone in the conservation of soil biodiversity, as woodlice have long been overlooked in global conservation efforts, despite their ecological importance.

  PublisherOA PDFDOI

• Chaetophiloscia sicula Verhoeff, 1908 (Isopoda, Oniscidea), an invasive isopod currently spreading in North America

  ZooKeys · 2025-02-05 · 3 citations

  articleOpen access1st authorCorresponding

  Chaetophiloscia sicula Verhoeff, 1908 (Philosciidae) is a small terrestrial isopod of Mediterranean origin which was first reported in North America in 2000 in an urban forest in Baltimore, Maryland, and it was thought to be a recent introduction, with a restricted range. Here we report the current state of knowledge of C. sicula distribution in North America. Since the original observation, the species has been reported by citizen scientists from eight additional states. Standardized field surveys in Maryland and Washington D.C. revealed a strong habitat preference towards anthropogenic and coastal areas. The affinity of C. sicula to urban environments, including residential areas and urban parks, is reinforced by citizen-science data and is most likely key to its fast spread throughout North America. Keeping isopods as pets and trading them among hobbyists may also play a role especially in establishing core populations in urban centers. The species is likely to expand in the USA in the coming decade. This study highlights that thorough, systematic surveys, using a variety of collecting techniques, are essential to address existing knowledge gaps on terrestrial isopod distribution and spread in North America and elsewhere.

  PublisherOA PDFDOI

• Urbanization leads to asynchronous homogenization of soil microbial communities across biomes

  Environmental Science and Ecotechnology · 2025-03-17 · 17 citations

  articleOpen access

  Soil bacterial and fungal communities play fundamental roles in biogeochemical cycles and ecosystem stability. Urbanization alters soil properties and microbial habitats, driving shifts in community composition, yet the divergent responses of bacteria and fungi and their ecological consequences remain inadequately understood. To elucidate these differential responses, we investigated soil bacterial and fungal communities along an urbanization gradient, ranging from undisturbed reference forests to urban parks, across three distinct climatic regions. To capture different disturbance intensities, urban parks were classified by tree age into old parks (>60-year-old trees) and young parks (10–20-year-old trees). Climate had a strong influence on soil microbiota, yet urbanization still significantly altered both bacterial and fungal communities in all regions. Urban disturbances homogenized soil microbial communities: average similarity among bacterial communities increased from ∼79% in forests to ∼85% in young urban parks, indicating substantial homogenization, whereas fungal communities showed little homogenization. Urbanization also homogenized microbial functional traits, with a greater reduction in trait dissimilarity for bacteria than for fungi. Bacterial communities exhibited high adjustability to urban conditions, dominated by generalist taxa (∼90%), whereas fungal communities consisted mostly of specialists (∼83%). Despite these asynchronous responses—bacteria adjusting and homogenizing more than fungi—overlapping functional traits between bacteria and fungi help maintain functional resilience in urban ecosystems. • Urbanization increases microbial community similarity from ∼79% to ∼85% across biomes. • Bacteria homogenize more than fungi, with functional traits converging faster in bacteria. • Urban soils host ∼90% bacterial generalists but ∼83% fungal specialists, revealing adaptive contrasts. • Despite divergent responses, shared microbial traits sustain ecosystem resilience.

  PublisherDOI

• Open letter: A global call to strengthen national soil biodiversity action through coordination and harmonization

  Plants People Planet · 2025-10-19

  letterOpen access

  Soil biodiversity remains one of the least systematically studied components of global biodiversity, largely invisible in policy agendas. A coordinated soil biodiversity monitoring approach is urgently needed to enable national‐level action.

  PublisherOA PDFDOI

• Changes in remnant forest soils and earthworm communities over two decades

  Applied Soil Ecology · 2024-08-03 · 1 citations

  articleSenior author
  PublisherDOI

• Urbanisation shapes microbial community composition and functional attributes more so than vegetation type in urban greenspaces across climatic zones

  Soil Biology and Biochemistry · 2024-02-09 · 26 citations

  article
  PublisherDOI

• Urban weedy plantains (Plantago spp.) do not hyperaccumulate heavy metals nor shelter their soil microarthropod communities from these metals

  Urban forestry & urban greening · 2024-12-04 · 5 citations

  article
  PublisherDOI

• Changes in Remnant Forest Soils and Earthworm Communities Over Two Decades

  SSRN Electronic Journal · 2023-01-01

  preprintOpen accessSenior author
  PublisherDOI

• Agricultural management practices impact soil properties more than soil microarthropods

  European Journal of Soil Biology · 2023-07-01 · 15 citations

  articleSenior author
  PublisherDOI

Recent grants

• IDBR: An End-to-End Sensor Based System for Environmental Monitoring

  NSF · $400k · 2008–2012

• Collaborative Research: Investigating the soil-earthworm-litter system controls on the stabilization of soil organic matter in Eastern deciduous forests

  NSF · $151k · 2008–2012

• EAGER-NEON: Earthworm Diversity at Multiple Scales: What can Genetics Tell us about the Distribution of these Important Soil Organisms?

  NSF · $286k · 2016–2018

Frequent coauthors

• Ian D. Yesilonis

  31 shared

• Richard V. Pouyat

  University of Delaware

  25 shared

• Csaba Csuzdi

  Eszterhazy Karoly Catholic University

  22 shared

• Chih‐Han Chang

  National Taiwan University

  18 shared

• Elisabeth Hornung

  University of Veterinary Medicine

  15 shared

• Miklós Dombos

  13 shared

• Melissa McCormick

  Centre for Addiction and Mental Health

  12 shared

• Heikki Setälä

  10 shared

Education

• PhD

  Eotvos Lorand University

• MSc

  Eotvos Lorand University

• BSc

  Eotvos Lorand University