CREATE TABLE table_22898 ("land formation" TEXT, "area ,  km\\u00b2" FLOAT, "of which currently forests ,  km\\u00b2" FLOAT, "% forests" TEXT, "habitat type" TEXT)

When 312 is of which currently forests, km what is the land formation?
SELECT "land formation" FROM table_22898 WHERE "of which currently forests, km\u00b2" = '312'
SELECT "land formation" FROM "table_22898" WHERE "of which currently forests, km\u00b2" = '312'