The thesis was done based on my company’s needs. Checking the results of tending of a seedling stand is often difficult and time-consuming, because a recently cleared seedling stand is hard to walk in and the visibility in the young stand is bad even after the tending. When using foreign workforce, it is important to inspect the results and quality of work done so that possible corrections can be carried out accordingly before the group in question has left the town, or in an extreme case, the country.

The goal of this thesis is to find out if an UAV (unmanned aerial vehicle) is suitable for checking the results of tending a seedling stand and also to find the equipment best suited for the job. The thesis also studies the policies and the effects of Trafi’s statements concerning the use of a UAV.

Remote controlled aerial photography devices have become more common in the last few years. I got acquainted with these kind of devices, domestic and foreign, and aspired to find the best equipment and method for this task. When choosing the device that is best suitable for the intended use I emphasized the ease of use and quality of image taken. I ended up choosing Yuneec Typhoon Q500+ to be the device used in the study. It has a CGO2+ camera and a 3D-kimbal. The CGO2+ camera can film in full HD and take 16 megapixel photos.

In the study the quadcopter was used to film young seedling stands that had been tended, in different altitudes and with different camera angles, to find out the optimal procedure for each task. The angle of the objective could not be adjusted.

The flight altitude and the altitude in which the photographs were taken was chosen to be 30 metres. In this altitude the quality and the covered area of taken pictures were sufficient, and there was no danger of colliding with the remaining trees. The best angle of filming and taking pictures was perpendicularly to the ground. Pictures were found out to be better than a video when it comes to ease examining the material.

The material was also used to examine using the taken pictures to count the number of remaining saplings. The method was found to be accurate enough in a forest over 3 years old. In forests younger than that observation was difficult.

The equipment was found to be a usable, fast and easy accessory for multiple tasks in forestry professionals' everyday work. In addition to checking the quality of tending of seedling stands, it was found to be a great help in checking forest damage.