Réalisées par des traducteurs professionnels, des entreprises, des pages web ou traductions disponibles gratuitement.
epekto overgrazing
epekto overgrazing
Dernière mise à jour : 2020-09-14
Fréquence d'utilisation : 1
Qualité :
Référence:
the causes of soil alkalinization in the songnen plain of northeast china were mainly analyzed from two aspects, natural and anthropogenic. natural factors of alkalinization are parent materials, topographic positions, freeze-thaw action, wind conveyance, water properties and semi-arid/sub-humid climate. some of them were always being neglected, such as freeze-thaw action and wind conveyance. anthropogenic causes are mainly population pressure, overgrazing and improper agricultural and economic policies. in recent decades, overgrazing played a main role in secondary soil alkalinization, which led to the decline of leymus chinensis grasslands. now, the alkalinization is very severe, and more than 3.2 × 106 ha area has been affected by salt, which becomes one of the three largest sodic–saline areas in the world.
alkalinizing effect
Dernière mise à jour : 2016-10-18
Fréquence d'utilisation : 1
Qualité :
Référence: