I read this in the New York Times online today:

At the Polytechnic University of Catalonia in Barcelona, Dr. Ricard V. Solé and Jose M. Montoya, theoretical biologists in the Complex Systems Research Group, have recently found the same kind of patterns by studying computer models of three ecosystems: a freshwater lake, an estuary and a woods.

My question concerns the expression "a woods." I have always thought of "wood" as a collective singular, and so I would say that a forest could also be called a wood. Is this usage incorrect? Assuming that I am wrong, is there anybody else whose sense of euphony is offended by the phrase "a woods"?