气溶胶对陆生植物生长的影响研究进展

陆生植物生长过程受太阳辐射、热量、水分、土壤等多重因素的影响,气溶胶粒子通过对太阳辐射的散射和吸收,并作为云凝结核和冰核,改变云的物理特性及生命期对上述环境因子产生影响,进而影响植物的生长。气溶胶的直接影响主要表现为气溶胶覆盖植物叶片,影响植物的呼吸作用、气孔导度及对阳光的利用率等;间接影响主要表现在气溶胶可降低入射太阳辐射量并降低光合作用及净初级生产力,但同时又会增加散射辐射量,增加植物可利用光合有效辐射,产生相互矛盾的结果;气溶胶还通过影响降水和气温,进一步影响植物对光、水、热的利用等方面。气溶胶对植物的生长影响以间接影响为主,直接影响较少。其次,各种大气气溶胶对植物的伤害作用超过大气气溶胶对植物生长促进作用。在人为气溶胶中,硫酸盐、黑碳及粉尘对植物生长以抑制作用为主,而氮化物中氮沉降既可以促进植物生长,含氮气溶胶形成的酸雨及光化学烟雾又会抑制植物生长。自然气溶胶中,火山气溶胶对植物生长产生的影响差异较大,沙尘总体对植物产生不利影响,而生物气溶胶及宇宙尘埃的影响研究还较少。

Research Progress on Growth Effect of Atmospheric Aerosols on Land Plants

The growth process of land plant is affected by multiple factors, such as solar radiation, heat, water, soil and so on. Aerosol particles can scatter and absorb the solar radiation, and change the physical properties and lifetime of clouds as cloud condensation nuclei and ice nuclei, and have an impact on the above mentioned environmental factors, then affect the plants growth. Direct effects of aerosols are mainly manifested as overspreading leaves, affecting plant respiration, stomatal conductance and utilization of the solar radiation. Indirect effects of aerosols are mainly manifested as reducing the amount of solar radiation, then photosynthesis rate and net primary productivity, but increasing the amount of scattered radiation at the same time, and increasing the effective photosynthetic radiation of plants, which produce a mutual conflicting result. Aerosols also affect the precipitation and temperature, and further affect the light, water and heat utilization of plant. The growth effects of aerosols on plants are mainly indirect effects, and less direct effects. The adverse effects of various atmospheric aerosols surpass profitable effect on plant growth. The sulfate, black carbon and dust aerosols in anthropogenic aerosols can inhibit the plant growth, while the nitrogen deposition can promote plant growth, acid rain and photochemical smog formed by nitrides will inhibit plant growth. In natural aerosol, the influence of volcanic aerosol on plant growth is quite different, dust generally have adverse effects on plants, while the effects of biological aerosol and cosmic dust are less researched.