diff --git a/mods/default/mapgen.lua b/mods/default/mapgen.lua
index bd22413..2f9bb44 100644
--- a/mods/default/mapgen.lua
+++ b/mods/default/mapgen.lua
@@ -383,7 +383,7 @@ minetest.register_decoration(
       biomes = {"Grassland Ocean", "Grassland", "Forest", "Deep Forest", "Wilderness"},
       decoration = {"default:papyrus"},
       height = 2,
-      height_max = 3,
+      y_max = 3,
       y_min = 0,
       y_max = 31000,
    })
@@ -493,7 +493,7 @@ minetest.register_decoration(
       deco_type = "simple",
       place_on = "default:dirt_with_grass",
       sidelen = 16,
-      fill_ratio = 0.06,
+      fill_ratio = 0.008,
       biomes = {"Wilderness"},
       decoration = {"default:fern"},
       y_min = -32000,
@@ -661,8 +661,8 @@ minetest.register_ore(
       clust_scarcity = 10*10*10,
       clust_num_ores = 6,
       clust_size     = 4,
-      y_min     = -31000,
-      y_max     = 32,
+      y_min          = -31000,
+      y_max          = 32,
    })
 
 minetest.register_ore(
@@ -673,8 +673,8 @@ minetest.register_ore(
       clust_scarcity = 8*8*8,
       clust_num_ores = 8,
       clust_size     = 6,
-      y_min     = -31000,
-      y_max     = -32,
+      y_min          = -31000,
+      y_max          = -32,
    })
 
 minetest.register_ore(
@@ -685,8 +685,8 @@ minetest.register_ore(
       clust_scarcity = 9*9*9,
       clust_num_ores = 20,
       clust_size     = 10,
-      y_min     = -31000,
-      y_max     = -64,
+      y_min          = -31000,
+      y_max          = -64,
    })
 
 -- Iron
@@ -699,8 +699,8 @@ minetest.register_ore(
       clust_scarcity = 8*8*8,
       clust_num_ores = 6,
       clust_size     = 4,
-      y_min     = -31000,
-      y_max     = 0,
+      y_min          = -31000,
+      y_max          = 0,
    })
 
 minetest.register_ore(
@@ -711,8 +711,8 @@ minetest.register_ore(
       clust_scarcity = 8*8*8,
       clust_num_ores = 20,
       clust_size     = 10,
-      y_min     = -31000,
-      y_max     = -32,
+      y_min          = -31000,
+      y_max          = -32,
    })
 
 -- Steel blocks
@@ -725,8 +725,8 @@ minetest.register_ore(
       clust_scarcity = 12*12*12,
       clust_num_ores = 10,
       clust_size     = 10,
-      y_min     = -31000,
-      y_max     = -128,
+      y_min          = -31000,
+      y_max          = -128,
    })
 
 -- Water
@@ -740,8 +740,8 @@ minetest.register_ore( -- Springs
       clust_scarcity = 18*18*18,
       clust_num_ores = 1,
       clust_size     = 1,
-      y_min     = 20,
-      y_max     = 31000,
+      y_min          = 20,
+      y_max          = 31000,
    })
 
 minetest.register_ore( -- Pools
@@ -753,8 +753,8 @@ minetest.register_ore( -- Pools
       clust_scarcity = 30*30*30,
       clust_num_ores = 20,
       clust_size     = 6,
-      height_min     = 10,
-      height_max     = 40,
+      y_min          = 10,
+      y_max          = 40,
    })
 
 minetest.register_ore( -- Swamp
@@ -766,8 +766,8 @@ minetest.register_ore( -- Swamp
       clust_scarcity = 10*10*10,
       clust_num_ores = 10,
       clust_size     = 4,
-      y_min     = -31000,
-      y_max     = 31000,
+      y_min          = -31000,
+      y_max          = 31000,
    })
 
 minetest.register_ore( -- Marsh
@@ -779,8 +779,8 @@ minetest.register_ore( -- Marsh
       clust_scarcity = 6*6*6,
       clust_num_ores = 10,
       clust_size     = 6,
-      y_min     = -31000,
-      y_max     = 31000,
+      y_min          = -31000,
+      y_max          = 31000,
    })
 
-default.log("mapgen", "loaded")
+default.log("mapgen", "loaded")
\ No newline at end of file