"There are trees with leaves and trees with needles."

Translation: Det finns träd med löv och träd med barr.

[L.prJT]

That's a lot of 'ett' words in plural in one sentence. Good practice!

[torwallstrom]

Där är träd med löv och träd med barr.
eller
Där finns träd med löv och träd med barr.

[yllsson]

"Där är träd med löv" is not really grammatically correct and would be more close to when you point and say "look in the corner, there are trees with leaves". "Där finns" works well grammatically but is also more definite as in "fun fact about finland: there they have trees with leaves".
However, this sentence is more a general statement about different types of trees and thus the "det finns" is the best translation. "det finns" is thus closer to "there exists" than "over there are".

Hope that this explanation made sense.. :)

[Lundgren8]

I just wanna point out that där är and där finns is quite standard in Skåne and southern Sweden. Of course this is mainly in speech, and is not considered standard Swedish, but you do find it here and there even in newspapers.

In Skåne this is completely normal:

• Där är tre flaskor i lådan.
• Finns där något kaffe kvar?

It’s the same in Danish, as in the national anthem.

[HansLovesIce]

med nålorna is not an option?

[L.prJT]

That would mean 'with the needles' and then the needles you're talking about are sewing needles or medical needles (I think, I'm not a native speaker).

[LennartdeFraeisk]

Kan man använda "trän"?
https://sv.wiktionary.org/wiki/tr%C3%A4

[torwallstrom]

In parts of Sweden trän is used as you suggest, however the most common usage is as follows:
Trä =the material of wood, plural : trän = pieces of wood, träd =tree, plural: träd=trees,
träden=the trees