干旱胁迫下江南油杉幼苗生长与耗水特性OACSTPCD

In order to investigate growths and water consumption characteristics of Keteleeria fortunei var.cyclo-lepis seedlings under drought stress,and provide theoretical basis for water management of K.fortunei var.cyclo-lepis at seedling stage and exploration of drought restoration technology,taking 2-year-old K.fortunei var.cyclo-lepis seedlings as materials,appropriate water(CK)and mild(T1),moderate(T2)and severe(T3)drought treat-ments by potted water control method were set,with 75%-80%,55%-60%,35%-40%and 15%-20%of maxi-mum field capacity respectively.Growth changes and water consumption characteristics of K.fortunei var.cyclo-lepis seedlings under different drought degrees were studied.Results showed that growth of seedling height de-creased with deepening of drought degrees from 30 to 40 days.Under mild drought treatment,growth of ground diameter was the best from 30 to 40 days,and growth rate of ground diameter was significantly higher than those of other treatments.Mild drought treatment was beneficial to accumulations of stem and root biomass.From 30 to 40 days,root-shoot ratio increased with deepening of drought degrees.Average daily and weekly water con-sumptions and total water consumption decreased with deepening of drought degrees.Under mild drought treat-ment,daily water consumption reached the highest at later stage of stress,and after the highest value,daily wa-ter consumptions were similar to daily water consumptions under moderate and severe drought treatments,which were at lower levels.Under mild drought environment,K.fortunei var.cyclolepis seedlings had highly effi-cient utilization for soil moisture,which indicated that K.fortunei var.cyclolepis seedlings had certain drought tolerance ability.Considering growths and water consumption characteristics of seedlings,controlling soil mois-ture content at 55%-60%of maximum field capacity could maintain normal growths of K.fortunei var.cyclole-pis seedlings,facilitate accumulations of stem and root biomass,realize highly efficient utilization for soil mois-ture,and achieve goal of water-saving seedling and dry land ecological restoration.