Mineral nitrogen and phosphorus pools affected by water table lowering and warming in a boreal forested peatland

Abstract

Changes in atmospheric temperature and lowering in water‐table (WT) are expected to affect peatland nutrient dynamics. To understand the response of peatland nitrogen (N) and phosphorus (P) dynamics to warming and drainage in a continental wooded‐bog of hummock–hollow microtopography, we compared three sites: (a) control, (b) recently drained (2–3 years; experimental), and (c) older drained (12–13 years; drained), during 2013. The WT was lowered at experimental and drained sites to 74 and 120 cm, respectively, whereas a warming of ~1 °C was created at one half of the microforms using open‐top chambers. Responses of peat total inorganic nitrogen (TIN = nitrate nitrogen [NO3−‐N] + ammonium nitrogen [NH4+‐N]) and phosphate‐P (PO43−‐P) pools and vegetation C:N ratio, δ13C and δ15N to the experimental treatments were investigated across sites/microforms and over time. Peat TIN available and extractable pools increased with deepening of WT and over time and were greater at hummocks relative to hollows. In contrast, the PO4 pools increased with short‐term drainage but reverted to very close to their original (control) nutrient values in the longer term. The WT and warming driven change in the peat TIN pool was strongly reflected in the vascular vegetation C:N ratio and shrub δ13C and δ15N, whereas moss nutrient dynamics did not vary between sites. Therefore, we suggest that atmospheric warming combined with WT deepening can increase availability of mineral N and P, which then can be reflected in vascular vegetation and hence modify the productivity and ecosystem functioning of the northern midlatitude continental wooded bogs in the long term.

Elevated nutrient concentrations in headwaters affected by drained peatland

“…The main processes behind these elevated concentrations are suggested to be increasing decomposition of peat layers caused by artificial drainage, a relative rise in watertable as the peat layer compresses and thus increased leaching of elements from decomposed peat layers. Elevated concentrations of nutrients have also been reported in pore waters from old peatland forestry drainage areas (Memberu et al 2017) and manipulated peatland (Munic et al 2017). The results from the present study support these findings.…”

“…This shows that anthropogenic effects are the dominant factor affecting leaching in general, but leaching intensity will probably be highly sensitive to future changes in local climate and especially fluctuations in soil moisture, temperature, and precipitation conditions. Fluctuations in the watertable within peat layers at drained sites promotes oxidization of peat and increases pore water nutrient concentrations (Memberu et al 2017, Munic et al 2017, and thus increases the risk of leaching of dissolved nutrients to watercourses. In summary, the combined effect of changing climate (temperature, precipitation), increasing peat decomposition level due to drainage, and fluctuating watertables creates a high risk of nutrient leaching from drained peatland, which may explain the increasing loads from old drained peatlands reported by e.g.…”

Mango Fruit Yield and Critical Quality Parameters Respond to Foliar and Soil Applications of Zinc and Boron

“…A repeated measure analysis of variance (ANOVA) was used to test the effects of foliar and soil B and Zn treatments on leaf mineral contents, fruit retention, fruit yield, and fruit quality variables. Since the same variables were quantified for 2013–15, the year was taken as fixed as well as a repeated measurement following Munir et al [33]. Difference between treatment means was compared by Tukey’s significance difference test at p ≤ 0.05.…”

ACC Deaminase Producing PGPR Bacillus amyloliquefaciens and Agrobacterium fabrum along with Biochar Improve Wheat Productivity under Drought Stress

“…Consistent and prolonged warming and drought conditions combined with associated abiotic and biotic changes [12] may drastically retard crop productivity and risk food security [13,14]. Drought stress reduces nutrient uptake, which can cause poor development of roots, low transpiration and photosynthetic rates, closure of leaf stomata and desiccation resulting in wilting of plants [15][16][17]. Like other abiotic stresses, the drought also stimulates stress ethylene synthesis through an elevated level of 1-Aminocyclopropane-1-carboxylic acid (ACC; an ethylene precursor) via the methionine pathway, in higher plants [18,19].…”