The manuscript by Vettikkat et al. presents an impressive EC BVOC dataset focusing on  terpenes in a Boreal wetland. It is well written and publication is warranted after addressing some minor comments below.

The abstract is too long. A large part of the abstract reads more like an Introduction. The abstract could be shortened to highlight the main findings more concisely.

Line 108: What is a classical PTR-MS?

Line 185 and Fig S5. VOCUS seems to underpredict isoprene or the GC seems to overpredict isoprene– Could this perhaps be related to a transmission issue/variation of VOCUS during the campaign for low molecular weights – how was the transmission checked? For such a local isoprene source, one would expect that the flux stationarity criterium for isoprene (and others?) would be violated for a large fraction of the dataset (?). This does not seem to be the case.  Alternatively the GC measurements could be overestimating isoprene concentrations. Were the GC cartridges cross calibrated on site with the isoprene standard?

Figure 2: adding the x 10 only to the isoprene panel is somewhat confusing at first sight. Only after reading the figure caption it becomes clear that all compounds were multiplied by 10 for the first part of the campaign.

Figure 4 cc:  The reported fluxes are extremely high. Higher than in most Boral forests, particularily also for DT. MT / SQT ratios have typically been reported as a 10 : 1 ratio in Boreal forests. Here, the emissions are comparable (e.g. 1:1) DT seems 50x higher than fluxes reported over a Boreal forest.

Line 535. The authors emphasize that such high fluxes could have significant ramification for studying NPF in the Boreal region and future studies should put more emphasis on wetlands. To that end, can the authors at least qualitatively estimate how much wetlands could contribute to reactive terpene emissions compared to Boreal forests (e.g. by scaling up based on land cover).

Minor comment:

References should be douple checked for ACP style.

The manuscript of “High emission rates and strong temperature response make boreal wetlands a large source of terpenes” by Vettikkat et al. measured terpenes flux by ecosystem-scale eddy covariance (EC) and Vocus-PTR from a wetland in southern Finland. The localized EF of isoprene, MTs and SQTs were obtained and compared with the MEGAN model. The research suggested that high-latitude ecosystems can be a significant source of terpenes to the atmosphere, and anthropogenic global warming could induce much higher BVOC emissions from wetlands. This manuscript is well written and recommend to be accepted after a minor revision.

1. Line 47-48, “Terpenes, except isoprene, have a huge variety of structures. They contain one or more double bonds making them highly reactive”. Here “they” refers to “Terpenes” or “Terpenes, except isoprene”, please rephrase clearly or combine into one sentence.
2. Line 56-58, The ecological roles of BVOCs should be better phrased. For example, the related ecological interactions were missing here.
3. Line 59, It may be easy to cause confusion if you include isoprene into terpenes. Here, temperature and light intensity are the main environmental drivers of isoprene emissions; as for MTs, the light-dependence may be more complex and highly dependent on species. The information on SQTs and DTs are even scarce. Their cases are largely different and may cause confusion when regarded as “terpene emissions”.
4. Line 93-94, references should be added here.
5. Line 100-104, could you provide some references regarding DTs here?
6. Line 110-113, would you like to show some hypotheses here?
7. Line 273-276, here better to combine the sentences and use suitable conjunctions to flow better.
8. Line 300, what LoD stands for?
9. Line 277, “3.2 Fluxes of terpenes from Siikaneva”, this part I expect to see more links of your study with other studies, not only the descriptions of your study and previous studies in separate sentences.
10. Line 368, “3.3.1 Emission factors of terpenes”, some symbols in the equations better be italic, the R² better be italic.
11. Line 486, here you had some good discussion, maybe better appear in the above sections. Here it can be a concise conclusion section.