meaning - How do you say that tree rings (are - will be) closer if there isn't much rain [in a year]?

Which of these sentences is true?

• If there is not much rain in a year, the rings in a tree are close together OR


• If there is not much rain in a year, the rings in a tree will be close together

If I removed "in a year" from the sentence would this make any difference?

A picture for illustration:

thanks ..

Answer

Your first sentence is correct. It's an example for Conditional Zero.

You use conditional zero when talking about something which is true in general. You can tell from the distance between the rings whether there was a lot of rain or not. This is always true.

The pattern for Conditional Zero is:

If + Present Simple, Present Simple

You can replace if with when or if not with unless in conditional zero. For example:

Unless there is much rain in a year, the rings in a tree are close together.

Here's a link to an overview on Wikipedia about all conditionals in the English language.

For the sake of completeness, "will + inf" as you use it in the second sentence is used in Conditional 1. As you can read on Wikipedia, Conditional 1 is about "consequences of a possible future event".