Relationship between Leaf Surface Characteristics and Particle Capturing Capacities of Different Tree Species in Beijing

Abstract

Leaf surface is a multifunctional interface between a plant and its environment, which affects both ecological and biological processes. Leaf surface topography directly affects microhabitat availability and ability for deposition. In this study, atomic force microscopy (AFM) and the resuspended particulate matter method were applied to evaluate the adsorptive capacity of the leaf surface. Patterns of particulate-capturing capacities in different tree species and the effect of leaf surface features on these capacities were explored. Results indicated the following: (1) more total suspended particles (TSP) per unit leaf area were captured by coniferous tree species than by broad-leaved tree species in a particular order-i.e., Pinus tabuliformis > Pinus bungeana > Salix matsudana > Acer truncatum > Ginkgo biloba > Populus tomentosa; (2) Significant seasonal variation in particulate-capturing capacities were determined. During the observation period, the broad-leaved tree species capturing TSP and coarse particulate matter (PM 10 ) clearly exhibited a ∩-shape pattern-that is, increasing initially and later on decreasing; meanwhile, the ∩-shape pattern was not clearly shown in P. tabuliformis and P. bungeana. However, no obvious patterns in the absorption of fine particulate matter (PM 2.5 ) were found in the tested tree species; (3) The leaf surface topography, as observed by AFM and scanning electron microscopy, revealed that the broad-leaved tree exhibits a good correlation between micro-roughness of leaf surfaces and density of particles settling on leaf surfaces over time. However, the main factors affecting the adsorptive capacities of the leaves in coniferous trees are the number of stomata as well as the amount of epicuticular wax and the properties of the cuticle in different seasons.

Effects of Particle Matters on Plant: A Review

“…Different techniques has been used to study the mechanisms of PM capturing and filtering behavior of different types of plants [48,49].…”

“…Then the surface roughness and other microscopic characteristics of leaves could be characterized. And the resuspended matter method was applied to evaluate the adsorptive capacity of the leaf surface [16].…”

“…Zhang found that the number of stomata was one of the main factors for coniferous trees to capture particle matters, which was different from Chen. Also, the properties of the cuticle in different seasons will affect the ability to capture particle matters in some plants [16]. Leonard found lanceolate leaves possess higher PM tolerance compared to needle-like or linear leaves due to the epicuti cular wax and leaf hairs [15] .…”

“…were observed mostly by means of scanning electron microscopy (SEM) [14]. Atomic force microscopy (AFM), confocal laser scanning microscopy (CLSM), gas chromatograph and image analysis method such as image J were also used to analyze the microstructure of leaves and the PM leaves adsorbed [15][16][17][18].…”

Effects of Urban Greenspace Patterns on Particulate Matter Pollution in Metropolitan Zhengzhou in Henan, China

“…During the last 30 years, air pollution in China has become a major environmental issue, especially particulate matter (PM) pollution [1] due to rapid urbanization and dramatic growth in energy consumption [2]. Particulate matter refers to a solid and liquid mixture consisting of organic and inorganic substances in air [3].…”