(lively music)
-: Change and life is something we can all count on.
As a plant ecologist, believe it or not, I study change.
In particular, I study the way
that we as a species change our environment.
As humans move round the planet,
we introduce species to new ecosystems.
This is a global phenomenon
that also occurs here in Mississippi.
As you can see in the bar graph at the top left of the slide
as of 2016, there are 15 times as many introduced species
in the state as there were at the turn of the 20th century.
Now about a decade ago, my advisor, Dr. Gary Ervin,
sampled 472 sites across the state of Mississippi,
using funding from the USGS and USDA to compile
the invasive plant atlas of the mid-South.
This database contains information about the ways
that land use and introduced species interact
with natural plant communities.
I used this database to study those relationships,
but I'd like to take the work a step further.
See, plant communities change naturally through time.
It's a process ecologists call succession.
A fire or a storm kills a stand of trees, opens up space
in the canopy and allows sunlight to hit the forest floor.
Plant species that were unable to survive
in the shade of the tall trees, are now able to thrive.
But in time they're overtaken by other species
that are themselves overtaken by the very same tall trees
that fell in the first place.
It's a cyclical process.
I liken this process to that of a dance.
A dance takes a lot of practice to coordinate,
and likewise these species evolved over a long period
of time together to form complex successional relationships.
Introduced species did not evolve in the same context,
and therefore their impact
on natural succession is often not known.
Some of them may join the natural dance of succession.
Others might out compete or duel native species
so thoroughly as to halt or change succession altogether.
This database is a snapshot of what plant communities
looked like 10 years ago, and as such is extremely valuable.
But with your help, it can be made even more valuable
by allowing me to revisit a targeted group of sites,
sample the vegetation communities,
and see how introduced species
are affecting natural succession,
and allow me to answer the question,
do they duel or do they dance?