Response of Pinus massoniana Leaf Area Index (LAI) to Climate Indicators in Fujian Province Multi-Scale Comparisons of Particulate Matter and Its Size Fractions Deposited on Leaf Surfaces of Major Greening Tree Species Quantitative Assessment of Vegetation Cover and Management Factor Based on Leaf Area Index and Remote Sensing Canopy Structure and Photosynthesis Traits of Summer Maize under Different Planting Densities