How many tree species are there when the total plant species is 113?
CREATE TABLE "list_of_protected_forests" (
  "central_forest_reserve" text,
  "size_in_km" real,
  "total_plant_species" real,
  "tree_species" real,
  "endemic" real,
  "threatened_cr_vu_en" real
);
SELECT COUNT("tree_species") FROM "list_of_protected_forests" WHERE "total_plant_species"=113;