Exploring the myriad ways in which we go about preserving what might otherwise be forfeited.   Whether trained specialists or lay people who care about something, preservationists come from every stratum of life. The archivist, the linguist, the local town historian. The paleontologist, the heirloom seed-saver, the family photographer, the Monuments Men. Old two-by-two Noah and taxonomist Linnaeus. The suburban girl who collects enough yard sale books to build up a library and thereby safeguards that most fragile of things: knowledge. All can be preservationists.   This issue includes contributions from Diane Ackerman, Elizabeth Robinson, Peter Gizzi, Kyra Simone, Heather Altfeld, Richard Powers, Arthur Sze, Joanna Ruocco, Andrew Ervin, Julia Elliott, Jessica Reed, Peter Orner, Erin Singer, Daniel Torday, Toby Olson, Mary Jo Bang, Troy Jollimore, Maya Sonenberg, Rae Gouirand, Mauro Javier Cardenas, Nam Le, Maria Lioutaia, Bryon Landry, Rae Armantrout, Robin Hemley, Madeline Kearin, Donald Revell, S. P. Tenhoff, Debra Nystrom, Donna Stonecipher, Robert Karron, Andrew Mossin, J’Lyn Chapman, Frederic Tuten, and Marshall Klimasewiski.