Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : Effects of Simulated Precipitation on Nutrient Resorption of Most Common Plants in Desert Steppe

Auteur : 白柳

Grade : Master 2022

Université : Inner Mongolia Agricultural University

Résumé partiel
Global climate warming changes the precipitation pattern,which will affect the nutrients cycle of grassland ecosystem.Nutrient resorption is a crucial part of the nutrients cycle between plant and soil since it is one of the ways that plant nutrients are recycled.Inner Mongolia’s desert steppe is located in an arid and semi-arid region that is sensitive to temperature and precipitation variations.The study on the effect of precipitation change on plant nutrients resorption in desert steppe is helpful to predict the plant adaptation mechanism of desert steppe to precipitation change.Based on a 6-year field experiment platform of simulated precipitation,which used a completely randomized block design to build up four different precipitation treatments,decrease precipitation by 50%,natural precipitation,increase precipitation by 50% and increase precipitation by 100%.Stipa breviflora,Cleistogenes songorica,Convolvulus ammannii,Artemisia frigida,and Kochia prostrata were chosen as the main species in the research region,and the amounts of nitrogen（N）and phosphorus（P）in their mature green leaves and senescent dead leaves were measured,and calculated the nutrient resorption efficiency ;We also measured the soil physical and chemical indexes in the different treatments.The main research results are shown as followings :（1）In 2020,decrease precipitation by 50%,soil moisture and microbial biomass nitrogen were significantly reduced,whereas soil inorganic nitrogen and total phosphorus were significantly enhanced（P＜0.05）,increase precipitation by 50% significantly increased soil moisture and p H value（P＜0.05）,and increase precipitation by 100% significantly increased soil moisture,p H value and organic carbon（P＜0.05）.In 2021,decrease precipitation by 50% significantly reduced soil moisture（P＜0.05）,increased soil inorganic nitrogen and available phosphorus（P＜0.05）,and increase precipitation by 100%significantly increased soil moisture and soil p H value（P＜0.05）.（2）Simulated precipitation changed aboveground biomass.In 2020,decrease precipitation by 50%,the aboveground biomass of S.breviflora were significantly reduced（P＜0.05）,and increase precipitation by 100% significantly increased the aboveground biomass of S.breviflora,C.songorica and K.prostrata（P＜0.05）.In 2021,increase precipitation by 100% significantly increased the aboveground biomass of K.prostrata（P＜0.05）.The aboveground biomass wasunaffested by increasing precipitation by 50%（P＞0.05）

Mots clés : Simulated precipitation ;Desert steppe ;Nutrient resorption ;Leaf nutrient content ;

Présentation (CNKI)