Research Interests
My research examines the effects of non-native, invasive species on natural habitats, the mechanisms
underlying
invasion success, and insect herbivore-mediated interactions
between native and non-native plants. My research objectives include:
1) understanding ‘how’ and ‘why’ some
invasive species (but not others) are so successful, 2) elucidating
how insect herbivores alter competitive interactions between
native and non-native
species, 3) identifying host specific natural enemies and
testing their efficacy in controlling invasive species, and
4) examining conservation
and restoration strategies that complement invasive species
control or removal.
Ecological
interactions among native and non-native species
Temperate ecosystems
Northeastern North American forests,
fields, and wetlands are invaded by a diverse exotic flora -
absence of coevolved herbivores in the invasive range appears
to be the primary driver of exotic plant success. But, white-tailed
deer populations and their preference for native plants may also
have an effect
on native and exotic plant interactions. I am examining
the combined effects of insect and vertebrate herbivores on native
and exotic plant
success in this ecoregion.
Arid ecosystems
Another
project focuses on the interactions of native and non-native
plants in riparian
systems in the southwestern United States and documenting
how non-native
plant invasions in riparian areas of this arid region are
altering ecosystems. We are documenting the ecological
effects and changes in biodiversity caused by establishment
of non-native Arundo donax in riparian systems,
evaluating the current herbivore complex associated with Arundo in
the United States, and studying herbivore effects on Arundo growth
and survival.
A similar
project examines
competitive interactions of native and non-native biotypes
of Phragmites australis. The non-native biotype is rapidly invading and
changing wetland ecosystems in the United States and replacing native
biotypes. I
am studying the factors that enable the exotic biotype to out-compete
the native biotype and other native plants, and how biodiversity
changes and
declines over time as the non-native species invades. I am also looking
at the differential susceptibility of the native and non-native biotypes
to
native and non-native herbivores.
Population dynamics and distributions
I am researching genetic structuring among the different Phragmites biotypes
using molecular techniques (RFLP’s and ISSR’s). With this
information, I am constructing a GIS database to map the distribution
of native and non-native
biotypes in the southwest. This database will enhance conservation
efforts for native biotypes and control efforts for the non-native
biotype, and can be to study the spread of P. australis and and subsequent effects on biodiversity.
Another aim of this research is to develop accurate and ‘easy
to use’ genetic
techniques for identifying closely related native and non-native plants.
Tri-trophic interactions
My research often focuses on both pairwise and tri-trophic interactions
between plants and insects to elucidate complex interactions in ecosystems.
For example, one of my projects examines the multilevel relationship
between secondary chemicals and defensive structures in tomatoes, herbivores
that feed on these plants, and their insect predators. I have found that
although plants and insect predators often have mutualistic relationships,
plant defenses can have unintended and detrimental effects on predator
movement and survival. Future research will focus on the relative effects
of plant defenses on generalist insect predators versus specialist insect
predators, which may be adapted to host-specific plant defenses. I am
also interested in how allelochemicals differ among plant genotypes and
how these differences affect plant quality, competitive interactions
among closely related plants, and herbivory.
If you are a student interested in working on any of these projects,
please contact Dr. Lambert at lamberta@easternct.edu
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