VARIATIONS IN LEAF FUNCTIONAL TRAITS OF SIX SPECIES ALONG A NITROGEN ADDITION GRADIENT IN LEYMUS CHINENSIS STEPPE IN INNER MONGOLIA Nitrogen deposition and Leymus chinensis leaf chlorophyll content in Inner Mongolian grassland Comparative analysis of leaf gas exchange and chlorophyll fluorescence of Euonymus japonicus Thunb by field experiment in the typical urban and suburban areas in Beijing Effect of Strong Light on Net Photosynthetic Rate between Two Rice Subspecies du ring Leaf Aging Epistatic and QTL × Environment Interaction Effects of QTLs for Leaf Traits and Leaf Chlorophyll Content in Soybean