According to the Minecraft Wiki
Trees grow normally, and their leaves take a dead-looking brownish
color like in desert biomes.
So trees can be grown as normal (as long as you are careful about making sure that lava doesn't just burn them all down), however
There is no way to place water in the Nether in a Survival game
Placing water source blocks with the bucket causes the water to instantly evaporate (with a hissing sound). You can still grow wheat in the Nether, however it will grow very slowly without water (also see the Wheat page on the wiki).
This also makes growing sugar cane impossible, however I believe that growing Pumpkin and Melon is largely unaffected by this as water only affects the rate at which the stem grows (which can be sped up with bonemeal), not the rate at which the Melon and Pumpkin themselves spawn. (The wiki does mention that Pumpkin cannot be grown in The End, but doesn't mention the Nether. I believe that Melon should grown there successfully but I haven't verified this).
Finally
Overworld mobs like pigs and zombies do not randomly spawn in the Nether, but throwing chicken eggs and constructing golems works as normal
So you will be unable to breed cows or pigs for food without using mods, however you can breed chickens by throwing eggs.
Its also worth mentioning that Nether Wart only spawns in the Nether, but can be grown in the overworld if you take a block of Soul sand with you.
You should use the /fill
command to replace nether portal blocks with air. You don't want this running all of the time though, only when a player uses flint and steel. First, create an objective to track when flint and steel is used:
/scoreboard objectives add usedFaS stat.useItem.minecraft.flint_and_steel
Then, run these two commands on a clock in this order to clear nether portals around the player who just used a flint and steel:
/execute @a[score_usedFaS_min=1] ~ ~ ~ /fill ~-6 ~-6 ~-6 ~6 ~6 ~6 air 0 replace portal
/scoreboard players set @a[score_usedFaS_min=1] usedFaS 0
Note that this will replace any portals nearby, so you should have something to relight the portals that you want to stay lit.
Best Answer
Best Solution
From they way you posed the question it sounded like you intended to use minecraft's built-in portals, particularly the nether portal, impossible to do without a mod or script. (which you should provide more information about)
However the best, most well rounded solution I can come up with is a teleportation pad using a "special" block. The command for that would look something like this.
The command:
execute at @e[distance=..3] if block ~ ~-1 ~ ^your block^ at @s as @s run tp @e[distance=..3,limit=1] ^coordinates^ ^rotational coordinates^
Fn+F3
and looking forBlock: "some numbers/coordinates"
.By placing this command in a "repeating" command block set to "always active" right next to or under ^your block^, players will be teleported to ^coordinates^. From the side would look like...
▅ ▅ ⊞ ⊞ ⊞ ▅ ▅
▅ ▅ ▅ ▣ ▅ ▅ ▅
Or like this..
□ □ □ □ □ □ ▣ □
▅ ▅ ⊞ ⊞ ⊞ ▅ ▅
Or this..
▅ ▅ ⊞ ⊞ ⊞ ▣ ▅
▅ ▅ ▅ ▅ ▅ ▅ ▅
To add some flare to the teleport, add a similar command block with an identical command but instead of
run tp
typerun particle
. For the sake of being concise, I will link to another forum post that explains how to finish the command.How can I improve on this answer? If it was helpful mark it correct so people visiting this page know.