To reveal the net ecosystem of Elymus nutans artificial grassland ecosystem (100 ° 26′–100 ° 41 ′ E, 34 ° 17′–34 ° 25 ′ N, elevation 3 980 m) CO2 exchange (NEE), this study uses the data of 2006 vorticity-related system observations to analyze the NEE, total primary productivity (GPP), ecosystem respiration (Reco) and Reco / GPP changes in the artificial grassland and their impact factors . The so-called PP Bag is made with polypropylene as the material of plastic bags, its general use of color printing, offset printing process, bright colors, generally do more woven bags, in addition, PP bag is tensile polypropylene plastic, belongs to a thermoplastic.It is non-toxic, tasteless and transparent.Easy to burn, flame for melting dripping, yellow under blue, from the fire smoke less, continue to burn, more used for cosmetics, food, toys, clothing, stationery, electronics, hardware products and other industries packaging.The color is transparent, good quality, good toughness, because of its hard brittle material decided that it is only suitable for packaging is not suitable for load-bearing. Pp Plastic Bag,Pp Handbag,Pp Shopping Bag,Polypropylene Packaging Bags Wenzhou Shandao Electronic Commerce Co., Ltd. , https://www.reusablebaglife.com