Larix gmelinii is a zonal community in the Greater Khingan Range, accounting for more than 70% of the entire Greater Khingan Range area. Its timber production accounts for about 30% of the country's total wood production. At present, with the global climate warming significantly, the zonal permafrost partially disappears or shrinks, seriously affecting the survival and distribution of the Larix gmelinii forest, which has caused widespread concern in the forestry and ecology communities. This study has changed the previous method of using models to predict the response of forests to climate change, using operability experiments, and using water potential as an indicator to analyze the water index of the Larix gmelini under climate warming conditions, to understand the warming of larch The response of the environment has a certain guiding significance. The plant water potential pressure chamber can effectively measure the plant water potential. Scan WeChat, we met with hate: Intelligent Basketball Machine, Basketball Pitching Machine, Basketball Launcher Yi He Technology (Shenzhen) Co.,Ltd , https://www.ball-shootingmachine.com
While measuring the water potential, time domain reflectometry TDR was used to select probes of 10 cm and 20 cm. Eight points were randomly selected in each provenance plot to determine the soil moisture content of 5, 10, and 20 cm. For the different provenances of Larix gmelinii, under the same drought stress conditions, the water potential of the shoots declined more in the early morning, which indicates that the more serious the water deficit in the trees is, the more the physiological function is disturbed, and the higher the rise, indicating that The stronger the recovery ability, the stronger the anti-interference ability. The average water potential of branches in Tahe, Songling, Heihe, and Taling Mountains in the growing season was -030, - 0135, -0737, and -1399 MPa, respectively. Generally speaking, in the indicator of early morning water potential in the entire growing season, Tahe is the strongest recovering ability, that is, the higher the latitude of the provenance is, the faster the moisture recovery is.
The determination of the plant water potential pressure chamber found that the water potential at noon can reflect the maximum value of water deficit; the difference between the midday water potential and the early morning water potential of the tree branches represents the drought resistance of the plant. The greater the absolute value, the stronger the drought resistance of the plant. It has been confirmed in the experiment that seasonal changes in the early morning water potential of the trees are good indicators of seasonal changes in soil moisture on the site. 