Hygroscopic particulate salts on leaf surfaces may facilitate the formation of microscopic leaf wetness, wax degradation, and enhanced of trace gas exchange in forest environments. In order to investigate the interaction of microscopic leaf wetness and dry-deposited inorganic compounds, a field campaign that combined measurements using electrical conductance sensors and leaf washing techniques was carried out in a coniferous forest in Germany during the summer period. Within the canopy, electrical conductivity was directly and continuously measured across a needle surface exposed to the air and covered with branches. Inorganic ion concentrations of washed samples at the top and middle of the canopy were measured and used to estimate leaf-level dry deposition rates of inorganic compounds. The results of both electric conductance and washed ion concentrations indicated the presence of deposited salts on needles within the canopy. Sulfate (SO₄²⁻) and nitrate ions (NO₃⁻) were dominant among soluble mass compounds in washed samples. A higher deposition rate of oxidized nitrogen (measured as NO₃⁻) was estimated at the top of the canopy (0.59 μmol m⁻² h⁻¹) than in the middle (0.15 μmol m⁻² h⁻¹), indicating that dry deposition of oxidized nitrogen mainly occurs near the canopy top. The deliquescent behavior of deposited hygroscopic salts was suggested by a hysteresis effect depending on increasing or decreasing relative humidity in our leaf wetness measurements. The results indicate that deposition of atmospheric inorganic compounds on needles and leaves can facilitate the formation of leaf wetness on the vegetation surface.

叶片表面的吸湿性颗粒盐可能有助于在森林环境中形成微观叶片湿润，蜡降解并增强痕量气体交换。为了研究微观叶片湿度和干燥沉积的无机化合物之间的相互作用，在夏季，在德国的针叶林中开展了野外活动，该活动使用电导率传感器和叶片洗涤技术进行了测量。在顶篷内，直接和连续地测量暴露于空气并覆盖有分支的针头表面的电导率。测量冠层顶部和中间的洗涤样品的无机离子浓度，并将其用于估算无机化合物的叶面干沉降速率。电导率和洗涤的离子浓度的结果均表明在冠层内的针上存在沉积的盐。硫酸盐在洗涤样品中，可溶性物质中₄ ²⁻）和硝酸根离子（NO ₃ ⁻）占主导地位。氧化的氮的较高的沉积速率（如测得的NO ₃ ^- ）（0.59微摩尔米估计为篷的顶部^-2  ħ ^-1）中比在中间（0.15微摩尔米^-2  ħ ^-1），表明氧化氮的干沉降主要发生在冠层顶部附近。滞后效应表明了沉积的吸湿盐的潮解行为，这取决于在我们的叶片湿度测量中相对湿度的增加或减少。结果表明，大气无机化合物在针叶上的沉积可促进植被表面叶片湿润的形成。