**2.4 The application of LCA on ecological research**

In the environmental ecology research, LCA has been widely used in plant nursery, forestry management, and agricultural production. *Lazzerini* assessed the carbon emissions of two types of nursery plant cultivation (in-pot and on-field) in Tuscany (Italy). Guided by LCA, this study summarized the carbon emissions of farm structure, aboveground structure, input of cultivation, and packaging in nursery cultivation. He pointed out the GHG emission of in-pot cultivation was 7.4– 26.5 kg CO2/m<sup>2</sup> /y�<sup>1</sup> , which was much higher than that of 0.6–1.0 kg CO2/m<sup>2</sup> /y�<sup>1</sup> of on-field cultivation [34]. *Berg* summarized the energy consumption and carbon emissions in Sweden's forestry management process by LCA. The forestry life cycle includes seedling production, silviculture, logging, and haulage to the wood processing plant. In Sweden forestry, the energy consumption (in m<sup>3</sup> wood unit) is about 150–200 MJ/m<sup>3</sup> /y�<sup>1</sup> , and the carbon emissions (CO2-eq) is about 12.5–17.1 kg/ m3 /y�<sup>1</sup> . The energy consumption and carbon emissions in logging and transportation are the most obvious, accounting for more than 60% of the total amount [35]. *Ingram* used LCA method to study the management carbon footprint of red maple forest during planting. The life cycle of the study included 1-year seedling production and 4-year seedling field management. It was found that the carbon emission (CO2-eq) footprints were 2.9 kg/plant for tube feeding materials and the consumption of fuel and energy was 10.3 kg/plant during production, at a distance. In 386 km of transportation, 4.0 kg/plant and 3.3 kg/plant in planting and landscape sites, the most carbon emissions were from production to planting, accounting for 17.7 kg/plant and accounting for 86% of the total greenhouse gas emissions [36]. Haas et al. assessed the environmental impacts of intensive, extensive, and organic forage management in 18 grasslands in Allgau, Bavaria, and southwestern Germany by LCA. The energy consumption of tube feeding was 19.1, 8.7, and 5.9 GJ/ha/y<sup>1</sup> , respectively, while the greenhouse gas emissions were 9.4, 7.0, and 6.3 t/ha/y<sup>1</sup> , respectively. It was concluded that organic animal husbandry was more environmentally friendly and intensive animal husbandry had a stronger environmental impact [37].

landscapes that meet the design requirements can be regarded as the "product" of maintenance work. Therefore, the environmental impact of the maintenance tasks

The maintenance of green space has long-term and repetitive characteristics. After the completion of the green space, the management work is continuously carried out. Although the content of the maintenance work will change with the growth of plants, the change is not obvious reflected in the annual period. Jiang Shipping divides the green space into three stages: initial age (≤3 years), middle age (4–10 years), and mature age (>10 years). It is considered that the annual management content of each stage is repeated [40]. Therefore, in the urban green space LCA evaluation, the life cycle of each stage green space can be carried out annually.

The system boundary is the evaluation scope of the LCA, and the material consumption and waste discharge within the system boundary are the substance list. When conducting LCA evaluation of products or behaviors, the related upstream and downstream processes are very intensive. Some process factors participate in system construction, but the environmental impact on the system is limited, or the environmental impact data is not clear. In order to avoid interference with the accuracy of the evaluation results, these processes are generally excluded from the system boundary. **Figure 4** is a systematic flowchart of urban green space maintenance. The plant combinations of green space are divided into four layer

can be defined as the goal of the green space maintenance LCA.

**3.2 System boundary and LCI data collection**

*Sustainable Design in Urban Green Space DOI: http://dx.doi.org/10.5772/intechopen.90026*

**Figure 5.**

**227**

*The plant combinations in urban green space.*

At present, there are few studies on the environmental impact of urban green space using LCA. In 2015, Dr. Ji Yuan-yuan summarized the carbon emission inventory of landscape sites in the production, construction, maintenance, and abandonment stage. She believed that the main consumption material in maintenance stage includes fossil energy, irrigation water, fertilizer, and pesticides [38]. Strohbach and Haase believe that the total carbon emissions per hectare of urban green space in Leipzig (Germany) are about 2.6–4.7 t/CO2 in 50 years after its construction [39].
