[R] remove numbers from string of characters

[Kurt_Helf at nps.gov]

Greetings
     I want to remove numbers  from a string of characters that identify
sites so that I can merge two data frames.  For example, a site in one
frame is called  "001a Frozen Niagara Entrance" whereas the same site in
the other data frame is called "Frozen Niagara Entrance".  It seems to me
the easiest thing to do would be to remove the numbers from the first data
frame so the two will match.  How do I go about removing those numbers?
Thanks in advance.
Cheers
Kurt

***************************************************************
Kurt Lewis Helf, Ph.D.
Ecologist
EEO Counselor
National Park Service
Cumberland Piedmont Network
P.O. Box 8
Mammoth Cave, KY 42259
Ph: 270-758-2163
Lab: 270-758-2151
Fax: 270-758-2609
****************************************************************
Science, in constantly seeking real explanations, reveals the true majesty
of our world in all its complexity.
-Richard Dawkins

The scientific tradition is distinguished from the pre-scientific tradition
in having two layers.  Like the latter it passes on its theories but it
also passes on a critical attitude towards them.  The theories are passed
on not as dogmas but rather with the challenge to discuss them and improve
upon them.
-Karl Popper

...consider yourself a guest in the home of other creatures as significant
as yourself.
-Wayside at Wilderness Threshold in McKittrick Canyon, Guadalupe Mountains
National Park, TX

Cumberland Piedmont Network (CUPN) Homepage:
http://tiny.cc/e7cdx

CUPN Forest Pest Monitoring Website:
http://bit.ly/9rhUZQ

CUPN Cave Cricket Monitoring Website:
http://tiny.cc/ntcql

CUPN Cave Aquatic Biota Monitoring Website:
http://tiny.cc/n2z1o