(climate != CLIMATE_TROPIC) ||
((climate == CLIMATE_TROPIC) &&
	(nearby_tile_terrain_type(0, 0) == TILETYPE_DESERT)) ||
((climate == CLIMATE_TROPIC) &&
	(nearby_tile_terrain_type(0, 0) == TILETYPE_NORMAL) &&
	((nearby_tile_terrain_type( 1, 0) != TILETYPE_DESERT) &&
	 (nearby_tile_terrain_type(-1, 0) != TILETYPE_DESERT) &&
	 (nearby_tile_terrain_type( 0, 1) != TILETYPE_DESERT) &&
	 (nearby_tile_terrain_type(0,-1) != TILETYPE_DESERT) ) );