Dendrochronological and limnological expedition.

During August 2020, a team from the “Laboratory for Complex Studies of Forest Dynamics in Eurasia” organized a joint expedition in the Ergaki Nature Park to collect lake sediments and wood cores. The study aims to evaluate the atmospheric deposition of nitrogen and phosphorus in aquatic and terrestrial ecosystems. Sediments were sampled in three lakes (Oyskoe, Zolotarnoe and Karovoe), and Pinus sibirica wood cores were collected nearby the lakes.

Daniel Diaz de Quijano (senior researcher from the laboratory) was in charge of the lake’s sediment sampling. “Remote high mountain ecosystems with small watersheds are ideal for studying the effect of global ecological changes because they are highly influenced by atmospheric processes such as atmospheric nitrogen deposition and climate, the second and third most important global ecological issues”, says Daniel. In a recent study with colleagues from the Institute of Biophysics from the Siberian Federal University (SFU), we determined atmospheric nitrogen and phosphorus deposition to be very low in Ergaki. Therefore, this is a privileged site to disentangle the interactive effects of climate warming and nitrogen fertilization that co-occur in many other world regions. Of course, it will also shed light on the ecological dynamics as they used to be under pre-industrial and pre-green revolution nutrient conditions.

Five people integrated the expedition, three researchers from the laboratory, and two bachelor students from the Institute of Ecology and Geography (SFU). “Although wood cores and lake's sediments have been previously collected in Ergaki, this is the first expedition organized by the SFU orientated to combine both disciplines. Dendrochronology and paleolimnology cover different temporal resolutions; however, the combination of both proxies might provide unique material for a better understanding of ecological dynamics in the park", says Alberto Arzac (head of the laboratory). “Besides the important potential results, the expedition was an excellent opportunity for the students to gain experience in the field”.

In this joint study, we will determine the history of these key nutrients for Ergaki aquatic and terrestrial primary producers, with the combined benefits of yearly resolution provided by tree rings and time range provided by lake sediments.

The expedition was supported by the project [FSRZ-2020-0014] from the Ministry of Science and Higher Education of the Russian Federation Education, project [#18-74-10048] from the Russian Science Foundation and the project [20-04-00960] from the Russian Foundation for Basic Research. The expedition team is indebted to the Natural Park for allowing access to the park.