Study On The Relations Between Water Consumption Haracteristics And Growth Of The Main Afforestation Seedling In Loess Plateau

In order to understand the characteristics of forest transpiration, water consumption growth and the relationship between growth and water consumption, selected ten trees which commonly used in the Arid-semiarid of the Loess Plateau as the research object,used TRIME-EZ Soil Moisture Tester, SR6400precision electronic balance, the rule, tap measure, vernier caliper and other instruments to test seedings. By excel2007office software for data analysis,got conclusions as following.1) The diurnal changes of transpiration rate display signal-peak curve or double-peak curve which high in the noon and low in the morning and evening. The peak time appear between10:00to14:00, many of which appear in between12:00to14:00. The peak of diurnal changes of transpiration is closely related with environment. With the change of environmental conditions, the peak shape can change with each other.2) Transpiration rate increase with the increase of soil water content and reduce with the decrease of soil water content. The bigger transpiration rate, the faster change with soil water content. As climatic conditions change toward to increase transpiration rate direction, the broad-leaved trees reach the peak time in advance, the conifer species postponed.3) Transpiration water consumption becomes large with the increase of soil water, little with the reduce of soil water. The larger transpiration water consumption, the faster change with soil water content.4) Broad-leaf trees and conifer species ground diameter growth are maximum in July, followed by August, minimum in June and broad-leaved species and coniferous species almost no differences.5) Broad-leaves species tree height growth is maximum in July, followed by August, minimum in June. Conifer species tree height growth is maximum in July, followed by June, minimum in August. Broad-leaved species is more than conifer species in tree height growth.6) Separately take the transpiration water consumption and tree height and ground diameter growth in different water condition to make water and growth function.