[Effects of long-term nitrogen addition on the nitrogen pools in a meadow steppe ecosystem]. / é¿æ氮添å 对èç¸èåçæç³»ç»æ°®åºçå½±å.
Ying Yong Sheng Tai Xue Bao
; 32(8): 2783-2790, 2021 Aug.
Article
en Zh
| MEDLINE
| ID: mdl-34664451
ABSTRACT
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. There were six levels of N addition (i.e., 0, 2, 5, 10, 20 and 50 g·m-2·a-1) and two levels of mowing (i.e., mowing and unmown). Samples of aboveground tissues of dominant plant, root, aboveground litter, and soil to the depth of 100 cm were collected in the seventh year after treatments. The N content was measured and the N pool was calculated. The results showed that N addition significantly increased the N content of aboveground plant tissues and litter, as well as N pools of Leymus chinensis, plant community, litter and ecosystem. Mowing significantly increased the N content of L. chinensis leaf and litter, but reduced N pools of L. chinensis, plant community and litter, and did not affect their responses to N addition. There was a significant interactive effect between mowing and N addition on plant community N pool. High levels of N addition in the unmown treatment led to more N stored in the litter pool, with the saturation threshold for the plant community N pool occurred at 10 g·m-2·a-1. Under mowing treatment, the plant community N pool increased with the increasing N addition, and more N stored in plant community N pool after mowing. Mowing could alleviate the negative impacts of increasing N deposition on biodiversity and ecosystem stability, and extended postponing the occurrence of ecosystem N saturation induced by increasing N deposition.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Ecosistema
/
Nitrógeno
Idioma:
Zh
Revista:
Ying Yong Sheng Tai Xue Bao
Asunto de la revista:
SAUDE AMBIENTAL
Año:
2021
Tipo del documento:
Article
País de afiliación:
China