I'm assuming that is 30cm of compressed spruce boughs they used for the test. That would be about a foot of compressed spruce boughs (again assuming, can't read it), which would be about 4 feet of uncompressed boughs from my experience. I wish they had a translated chart.
The thickness of the layer of boughs
is not stated on the article, I estimated the uncompressed thickness based on the photograph on the second last page of the article. The compressed thickness would be perhaps only a half or a third of the uncompressed one. The test subject was 185 cm tall male weighing 75 kg.
Translation for the table on the last page (column by column, "ei" = n/a, red = the best values, blue = the worst values):
1. Name of the product (porontalja = reindeer hide, havupatja + avaruushuopa = spruce boughs + space blanket)
2. Type of the product (air, down, cell, other kind of mat)
3. Average temperature measured during a period of 10 minutes (lower value indicates less loss of heat to the surrounding environment)
4. Angle of friction (higher value indicates better ability to stay in place during sleep)
5. Weight of the product in grams
6. Dimensions of the product in centimeters, advertised
7. Dimensions of the product in centimeters, measured
8. Score given based on the insulative qualities of the product
9. Score given based on the weight of the product
10. Score given based on the angle of friction of the product
11. Overall score