Manipulating snow cover in an alpine bog: effects on ecosystem respiration and nutrient content in soil and microbes

Abstract

Snow amount is expected to decline in the Northern hemisphere as an effect of climate warming. However, snow amount in alpine regions will probably undergo stronger interannual fluctuations than elsewhere. We set up a short-term (1 year) experiment in which we manipulated snow cover in an alpine bog, with the following protocol: snow removal at the end of winter; snow removal in spring; snow addition in spring; removal of all aboveground plant tissues with no snow manipulation; no manipulation at all. We measured, at different dates from late spring to early autumn: ecosystem respiration (ER), and concentrations of carbon (C), nitrogen (N) and phosphorus (P) in the soil and in microbes. We hypothesized that longer duration of snow cover will lead to: i) higher ER rates associated with increased microbial biomass; and ii) decreased soil nutrient availability. Contrary to our first hypothesis, ER and microbial C content were unaffected by the snow cover manipulations, probably because ER was decoupled from microbial biomass especially in summer, when CO 2 efflux was dominated by autotrophic respiration. Our second hypothesis also was partially contradicted because nutrient content in the soil and in plants did not vary in relation to snow cover. However, we observed unexpected effects of snow cover manipulations on the N : P ratio in the microbial biomass, which declined after increasing snow cover. This probably depended on stimulation of microbial activity, which enhanced absorption of P, rather than N, by microbes. This may eventually reduce P availability for plant uptake

Responses of ecosystem water use efficiency to spring snow and summer water addition with or without nitrogen addition in a temperate steppe

“…Snowmelt promotes soil moisture which is in favor of plant growth [ 26 ] but melting of snow can also take more nutrients away stored in the snowpack before plants need them [ 27 , 28 ]. Supplement snowfall stimulates NEP and GEP simultaneously in the mixed prairie [ 29 , 30 ], but has no effect on ecosystem respiration in an alpine bog [ 31 ]. However, few studies have focused on the effect of snowfall on WUE in recent years.…”

Long‐term enhanced winter soil frost alters growing season CO2 fluxes through its impact on vegetation development in a boreal peatland

“…For instance, studies in both a boreal peatland and a boreal forest found that winter soil frost could influence the soil dissolved organic carbon concentration during the subsequent growing season (Haei et al, 2010(Haei et al, , 2013Agren et al, 2012), which may affect the amount of C substrates available for heterotrophic respiration. In addition, C decomposer communities are sensitive to soil frost (Sulkava & Huhta, 2003;Haei et al, 2011;Bombonato & Gerdol, 2012;Aanderud et al, 2013) and any change in such communities may substantially influence CO 2 production and, thus, emissions during the growing season.…”

Southern Appalachian Peatlands Support High Archaeal Diversity

“…Because methane released from these wetland areas is of microbial origin [9][10][11][12][13], it is important to increase our understanding of the associated microbial communities. The southern region of the United States is of special interest as mid-latitude wetlands are predicted to dramatically increase methane gas release as climate warming occurs [14][15][16].…”