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