Abstract: With the continuous development of society, CO₂-based greenhouse gas emissions are increasing, triggering a series of environmental problems, how to effectively reduce emissions and carbon sequestration has become a current hot topic. In the past, people tend to pay attention to the carbon sink function of plants, but little attention has been paid to the carbon emissions generated during their production in nurseries.Therefore, we take three types of garden nurseries in Tianjin, namely, flower nursery, grass nursery and forest nursery, as the research object, construct their life cycle evaluation system, and use the carbon emission coefficient method to calculate the carbon emissions during the life cycle of the three types of garden nurseries by selecting the carbon source indexes such as transportation, electricity, water and horticultural materials. The calculation results show that the carbon emissions during the life cycle are mainly concentrated in the maintenance stage of the nursery, and from the overall point of view, the carbon emissions generated in the maintenance stage of the grass nursery are the largest at 601890 kg, followed by the carbon emissions generated in the maintenance stage of the flower nursery at 390180 kg, and the carbon emissions generated in the maintenance stage of the forest nursery are the smallest at 90080 kg. From the point of view of carbon emission per unit area of production area, the flower nursery produces the largest emission per unit area in the maintenance stage, followed by the grass nursery, and the forest nursery produces the smallest emission, which is 11.54 kg, 1.35 kg and 0.13 kg, respectively. Plants in the production of garden nurseries produce a large amount of carbon emissions during the production lifecycle, and the main sources of carbon are related to the use of electricity, water, fertilizers, and horticultural materials. Therefore, greenhouse flowers, turf and other plant materials should be used reasonably and appropriately in plant utilization practices.

Key words: landscape nursery, whole life cycle, carbon emission factor, carbon emission quantification