Plant Water Requirement For Growth And Its Effects On Space Thermal Environment

At present,China’s natural environment continues to deteriorate and ecological problems are becoming more and more serious.As an important part of the ecological chain,plants play an important role in protecting and improving the natural ecological environment.Therefore,the study of water transport process in plants and its impact on the ecological environment is in line with the objective requirements of China’s current development stage.This paper analyzes the transpiration mechanism of plants and the water transport process of roots and stems,and studies the water transport process of plants and the regulation ability of thermal environment.The calculation models of water demand for plant growth were established,including transpiration rate model,stem water delivery rate model and root water absorption rate model;The calculation methods of average surface temperature of plant canopy leaves were summarized;The stomatal resistance model of plants was optimized.The existing experimental data are investigated,and the water demand model of plant growth is experimentally studied.Based on the transpiration rate model,the spatial thermal environment regulation equation of plants was established.The cooling and humidifying ability of grassland to its surrounding space environment was tested,and the space thermal environment regulation equation of plants was verified.The experimental results show that the calculated values of plant water demand model and thermal environment regulation equation are in good agreement with the measured values,and the relative error ranges are 2.09%-14.13%and 3.13%-23.25% respectively.The effects of climate environment on plant growth water demand and thermal environment regulation were analyzed.The results showed that the growth water demand and thermal environment regulation ability of plants were affected by transpiration rate,stem water delivery rate and root water absorption rate.Moreover,climate and environmental change is the main reason affecting the water demand and thermal environment regulation ability of plants.When the climatic conditions change,the water demand for plant growth has the same change law as the regulation ability of thermal environment.Among them,the change of air temperature has a significant impact on the water demand for plant growth and the regulation ability of thermal environment.When the water demand of plants increases from 17 ℃ to 0.017 ℃under the simulated working condition,the water demand increases from 17 ℃ to0.017 ℃ under the simulated working condition.The changes of water demand and thermal environment regulation ability of plants under different climatic conditions were summarized.The results show that when the transpiration rate is large,the water carrying capacity of the plant stem may not meet its transpiration water demand.It shows that under severe weather conditions,even if soil moisture can meet the transpiration needs of plants,plants may not grow normally because of insufficient water carrying capacity of stems.Taking the climate environment in Lintong and Turpan as an example,the growth water demand and theoretical cooling effect of apple trees were calculated and analyzed.The results show that plants have a good ability to regulate the thermal environment under hot and dry climate conditions.However,due to the limitation of stem water carrying capacity,plants may not grow normally due to water shortage.The research results of this paper can provide some reference for the rational redistribution of water resources and land resources,promote the development of crop irrigation technology to a certain extent,and play a positive role in further exploring the ability of plants to improve the ecological environment.