| Abstrakt: |
Terrestrial exports of protons (H+), nitrate (NO3−), dissolved organic carbon including organic acid anions (A−), phosphorus (P), base cations, and ionic aluminum (Ali) underwent pronounced changes after bark beetle‐induced tree dieback (2004–2008) in a nitrogen‐saturated, chronically acidified but recovering catchment, Plešné Lake, Czech Republic. After a short decline in lake water pH immediately after tree dieback, the ecosystem recovery from acidification accelerated and the carbonate buffering system was restored by 2011, after ∼ 6 decades of depletion by acid rain. Major reasons for this rapid transition were changes in intensity of in‐lake biogeochemical (H+ producing/removing) processes caused by changing concentrations and proportions of solutes exported from soil to surface water. In‐lake denitrification, elevated NO3− assimilation (due to elevated P input), and photochemical/microbial oxidation of A− were the most important H+ removing processes, while Ali hydrolysis was the most important H+ source. Phytoplankton biomass increased with elevated P inputs and increasing P availability, which resulted from reduced in‐lake formation of Al hydroxide (and thus less adsorption of P) and more intensive P recycling by zooplankton. The rapidly changing lake water chemistry and elevated P availability after tree dieback in the catchment thus have enabled further biological recovery of Plešné Lake. [ABSTRACT FROM AUTHOR] |
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