Обзор и обобщение воздействия повышенного уровня атмосферного углекислого газа на почвенные процессы: никаких изменений в водоемах не зафиксировано, однако отмечено увеличение потоков и ускорение циклов.

Атмосферные изменения, такие как растущая концентрация углекислого газа (CO2) - один из компонентов глобальных изменений климата, которые, в свою очередь, влияют на различные процессы и функции экосистем. Влияние повышенного уровня CO2 на подземные процессы не до конца понятно из-за сложных взаимодействий между различными компонентами экосистемы. Изучению данного взаимодействия и посвящена эта статья.

Review and synthesis of the effects of elevated atmospheric CO2 on soil processes: No changes in pools, but increased fluxes and accelerated cycles

Atmospheric change encompassing a rising carbon dioxide (CO2) concentration is one component of Global Change that affects various ecosystem processes and functions. The effects of elevated CO2 (eCO2) on belowground processes are incompletely understood due to complex interactions among various ecosystem fluxes and components such as net primary productivity, carbon (C) inputs to soil, and the living and dead soil C and nutrient pools. Here we summarize the literature on the impacts of eCO2 on 1) cycling of C and nitrogen (N), 2) microbial growth and enzyme activities, 3) turnover of soil organic matter (SOM) and induced priming effects including N mobilization/immobilization processes, and 4) associated nutrient mobilization from organic sources, 5) water budget with consequences for soil moisture, 6) formation and leaching of pedogenic carbonates, as well as 7) mobilization of nutrients and nonessential elements through accelerated weathering. We show that all effects in soil are indirect: they are mediated by plants through increased net primary production and C inputs by roots that foster intensive competition between plants and microorganisms for nutrients. Higher belowground C input from plants under eCO is compensated by faster C turnover due to accelerated microbial growth, metabolism and respiration, higher enzymatic activities, and priming of soil C, N and P pools. We compare the effects of eCO2 on pool size and associated fluxes in: soil C stocks vs. belowground C input, microbial biomass vs. CO soil efflux vs. various microbial activities and functions, dissolved organic matter content vs. its production, nutrient stocks vs. fluxes etc. Based on these comparisons, we generalize that eCO will have little impacts on pool size but will strongly accelerate the fluxes in biologically active and stable pools and consequently will accelerates biogeochemical cycles of C, nutrients and nonessential elements.