Research Projects

Origin and distribution of soil fauna on a heterogeneous landscape:
biodiversity in urban environment.

This project focuses on the effect of past and present land use on diversity and distribution of soil invertebrate assemblages. We are assessing soil fauna in urban and rural forest fragments, parks, and anthropogenic land uses, such as lawns and planting beds. This study is a contribution to the Baltimore Ecosystem Study (BES). BES is part of the NSF supported LTER (Long Term Ecological Research) Network. Collaborators: Csaba Csuzdi (Hungarian Natural History Museum), Elisabeth Hornung (Szent Istvan University, Budapest), Richard Pouyat (USDA Forest Service), Zoltan Korsos (Hungarian Natural History Museum)

The soil food web in agro ecosystems

This study looks at how different cropping systems (conventionally tilled, no till and organic) affect the structure and function of soil invertebrate communities. The research is part of the USDA-ARS Farming System Project in Beltsville, MD. We also look at how the large anecic earthworm (Lumbricus friendi), which dominates the no-till system, affects sorptivity and runoff in these systems. Collaborators: Michel Cavigelli (USDA Beltsville), Sean Clark (Berea College), Nancy Kreiter (College of Notre Dame), Scott Pitz (JHU, Senior Thesis)

Effect of soil invertebrates on N-cycling

Soil invertebrates are known to greatly influence the rate and pathways of microbial decomposition. We measure how potential N-mineralization and nitrification rates might be infulenced in the presence of earthworms and terrestrial isopods. Both native (Eisenoides loennbergi) and exotic (Amynthas hilgendorfi and Lumbricus terrestris) earthworms are used. In the Mid-Atlantic area only non-native isopods occur. Given their different natural histories, their influence on microbial processes might vary. Collaborators: Peter Groffman (Institute of Ecosystem Study), Richard Pouyat (USDA Forest Service) Sarah Placella (JHU Senior Thesis), Katarina Juhaszova (JHU REU project).

Reproductive strategies of invasive soil invertebrates

Some species are extremely successful in colonizing new habitats, and may become invasive, while others (often closely related to the invasive species) cannot establish populations. The key to successful colonization at least in part lies in the life history traits of these species. We compare physiological and reproductive traits of invasive species in their native habitat, and in the new environments. We focus on three taxa: Collembola (springtails), Oligochaeta (earthworms) and Oniscidea (terrestrial isopods. Collaborators: Csaba Csuzdi (Hungarian Natural History Museum), Elisabeth Hornung (Szent Istvan University, Budapest), Miklos Dombos (Soil Science Institute, Hungary)

Feeding behavior of Narceus americanus

Narceus americanus is one of the largest native North American millipedes. In laboratory experiments we measure consumption rate, assimilation efficiency and growth patterns of this large millipede species. To determine food choice and nocturnal behavior of Narceus we use a time-lapse photography. A computer controlled camera takes images every 15 seconds. This is a senior year project for Kimberly Townsend. (See movie here)

Wireless sensors in soil ecology

The availability of inexpensive, low power wireless sensors is changing the way we can acquire environmental information. This type of monitoring is especially necessary in soil ecology, where conditions vary at different spatial and temporal scales. Our understanding of soil organism dynamics, and, more importantly the role these organisms play in important ecosystem processes is limited due to the complexity of this environment and lack of continuously collected abiotic data. The proposed research will customize, test, and deploy a network of low-cost wireless sensors to monitor the soil and aboveground conditions. The data will be collected automatically and uploaded into an online database. Collaborators: Wei Hong (Intel Berkeley Research Laboratory), Dan Wertheimer (Space Sciences Laboratory, UC Berkeley), Alex Szalay (JHU Physics and Astronomy), Jim Gray (Microsoft Research), Randal Burns and Andreas Terzis (JHU Computer Science), Josh Cogan (JHU physics major). A pilot study is supported by Microsoft Research and by the Gordon and Betty Moore Foundation.

The influence of terrestrial isopods on the organic horizons of the soil profile

We approach this question by performing controlled feeding experiments, by determining feeding rate across a gradient of soil organic substrates, and by assessing changes in C:N, %C and δ13C composition of organic matter during this process. Our model animal is Armadillidium vulgare, a common and often dominant species in open woodlands and grasslands. Collaborator: Hope Jahren (Johns Hopkins University)