Hello,About 5–6 months ago, my friends gifted me this bonsai tree. This is my first bonsai, and I’ve tried my best to water it every day. However, I went on holiday for two weeks and completely forgot to water it during that time. Since then, the tree has started losing some leaves, which have turned brown. I also noticed some mold on the soil when the tree was dry.I live in Lithuania, and the tree is placed near a window. The room temperature is consistently around 21°C. Is it possible to recover this bonsai, or is it part of a natural process because winter has begun?Additionally, I would appreciate help identifying the species of this bonsai, as I’ve had difficulty finding the correct one.Thank you for your help. I hope to bring this bonsai back to health!

ah, forgot to mention, that this bonsai always lives indoors. 

It is a Pine of some sort and it is in this condition because it is inside. It is not bonsai, yet, it need another ten years or more. But it will not get that far if it is inside. However if it is cold now where you are then it will be difficult to put it out straight away. Try to find a spot where there is no heating, the colder the better. An unheated room, or if it is not so cold then a shed or garage. Buy a book and read about care of trees, or look on this site for instructions.

May have got the species wrong. Not Pine

Could it be a budist pine? In that case you are noth right and wrong

Could it be the Pseudolarix? From the pictures, it seems to be almost exactly the same.

Yes, could be. In that case it is already doomed. Keeping hardy trees indoors until new year is a certain killer.

Beginners that are gifted a mallsai trees, do not know what species it is, grow it indoors and go for vaccation for two weeks is not far off a certain death as well.

when it comes to reviving a tree in this health, this is advanced. Nothing for unexperienced beginners.

If you want to grow bonsai, get a book and start to study. Buy locally hardy garden center materials and try to keep them alive. If successful for two or more years, start to train it into bonsai.  Every second year working on the foliage and every second year on the roots. Just slowly reduce it. This way in 10 or so years you will have a tree that are much better than the mass produced mallsais. On top of that you have for certain a tree that is adapted to your climate and you know how to keep it alive.

The fact is that 90% or more of theese imported trees do not make it a year in beginners hands. You are not the first one coming to this forum asking how to save such trees.
 

That was my very first thought, but I changed my mind, 

Hi, this very much looks like a golden larch to me. It is not a true larch, and is a species that mostly occurs in areas that are fairly warm, and does not like dry spells. Which you have noticed

In their native range they grow as evergreen conifers. They are frost-resistant up to some -10C so could (and to be honest, should) be kept cold in winter.

Right now, just water sparingly but enought to keep the roots moist. Ensure plenty of sunlight (or growlights as alternativer). I would recommend keeping this outside as trees just do not do well indoors. But d not bring it out in the middle of winter, wait till spring.