## 1 Introduction  
Central Siberia is located in the middle of the Eurasian continent, a massive land with a severe continental climate. The westerlies that travel a long distance from the Atlantic deliver little precipitation to Central Siberia. Additionally, permafrost, covering about 80% of Siberia, is a powerful factor controlling the forest and tree species distribution in the dry and cold climate in interior Siberia [1]. Permanfrost limits the northward and eastward spread of Scots pine (_Pinus sylvestris_ L.). Within the permafrost zone, pine can reach high latitudes on sandy soils along big river valleys where the permafrost may thaw deep down to 1.5-2 m [1, 2, 3]. Forests of Dahurianlarch (_Larix gmelinii_ (Rupr.) Rupr. and _Larix cajanderi_ Mayr) are related to permafrost and are found in central Siberia on the shallow soils which thaw as little as 30-40 cm during the growing season [4]. For more details on forest cover, see Supplementary File S1. Scots pine and larch (_Larix_ spp.) forests dominate the boreal coniferous forest in Siberia: they comprise 13% and 49% of its territory, respectively [1] and accumulate about 14,462 Tg C in their total phytomass, of which 25% is below ground [5]. Despite their abundance, relatively little is known about what a comparative role both Scots pine and permafrost larch forests play in biophysical (energy, water) and biogeochemical (CO\({}_{2}\)) cycles at the subcontinental scale over Siberia. Analyses of carbon, water vapor, and energy fluxes at the ecosystem level have been conducted using the eddy-covariance method in a variety of Siberian boreal forest types: evergreen (Scots pine and dark conifers _Pinus sihrica_, _Abies sihrica_), small-leaved (birch) and mixed (birch-evergreen conifers) forests beyond the permafrost zone and deciduous conifer Dahurian (Gmelin + Cajander) larch forests within the permafrost zone. In the 1990s, the first eddy-covariance studies across Siberia were short-term, lasting from a month to one growing season [6; 7; 8; 9]. Later, a few continuous eddy-covariance studies were conducted covering several years in both Scots pine (see Tellus Special issue 54B 2002) and Dahurian larch forests within the permafrost zone [10; 11; 12; 13; 14; 15; 16]. Among the most recent publications on Siberia are the following: [PERSON] et al. [17] which studied only net radiation, latent heat, sensible heat and net ecosystem exchange; [PERSON] et al. [18] studied soil respiration; and [19; 20] studied transpiration and water use efficiency in the same Gmelin larch and Scots pine forests. However, none of them directly and systematically compared the functional permafrost vs. non-permafrost parameters for these two contrasting forest habitats. We compared them and found that these ecosystem parameters are very similar after a decade or so. From the summaries of the global boreal forests of [PERSON] et al. [21; 22], we are aware of three forest eddy tower sites across Siberia: one non-permafrost site Zotino (in our study), two permafrost sites Tura (in our study) and Yakutia. A permafrost larch forest in Yakutia (site Spasskaya Pad) was discussed in multiple publications [10; 11; 12]. None of those publications compared permafrost forest ecosystems to non-permafrost ecosystems in detail. In our present study, we suggested the analyses of multiple ecosystem functional parameters (heat and water vapor fluxes: LE, H, \(\beta\)); CO\({}_{2}\) exchange (NEE, Re\({}_{\text{co}}\), and GPP); and water use efficiency (WUE) of two principal forest ecosystems: Scots pine and Gmelin larch forests in interior Siberia. Recently, Arctic-boreal landscapes, including both permafrost and non-permafrost ecosystems, have been intensively studied based on eddy covariance measurements collected from many eddy sites across the circumboreal zone [23; 24; 25; 26; 27].