Nitrogen fixation associated with two cohabiting moss species expresses different patterns under Cu and Zn contamination.

Nitrogen (N) fixation by moss-associated cyanobacteria is an important N source in pristine ecosystems. Previous studies have shown that moss-associated N fixation is sensitive to anthropogenic N pollution. However, we still lack understanding of the effects of other factors derived from anthropogenic sources, such as heavy metal pollution on N fixation.

Enhanced foliar N enrichment with increasing nitrogen addition rates: Role of plant species and nitrogen compounds.

Determining the abundance of N isotope (δ N) in natural environments is a simple but powerful method for providing integrated information on the N cycling dynamics and status in an ecosystem under exogenous N inputs. However, whether the input of different N compounds could differently impact plant growth and their N signatures remains unclear. Here, the response of N signatures and growth of three dominant plants (Leymus chinensis, Carex duriuscula, and Thermopsis lanceolata) to the addition of three N compounds (NH HCO , urea, and NH NO ) at multiple N addition rates were assessed in a meadow steppe in Inner Mongolia.

Effects of 12-Year Nitrogen Addition and Mowing on Plant-Soil Micronutrients in a Typical Steppe.

Changes in soil micronutrient availability may have adverse consequences on grassland productivity, yet it’s still largely unclear how concurrent human practices, such as fertilization and mowing, affect micronutrient cycling in the plant-soil systems. Here, we measured six essential micronutrient (Fe, Mn, Cu, Zn, Co and Mo) contents in both plant pool (separated as aboveground plant parts, litter, and belowground roots) at the community level and soil pool (0−10 cm depth) after 12-year consecutive nitrogen (N) addition (0, 2, 10, and 50 g N m−2 year−1) and mowing in a typical steppe of the Mongolian Plateau. The results show that (i) medium-N (10 g m−2 year−1) and high-N (50 g m−2 year−1) addition rates significantly increased contents of soil-available Fe (+310.

[Effects of long-term nitrogen addition on the nitrogen pools in a meadow steppe ecosystem].

Increasing atmospheric nitrogen (N) deposition greatly affects species diversity, productivity, and stability of ecosystems. It is thus of the great importance to understand how grassland N pools respond to the increased atmospheric N deposition. This study was conducted in a meadow steppe in Erguna, Inner Mongolia, China.