A Tale of Two Land - The True Economic Costs of Land Use Projects
Authors: Wul Maoguo , Jiang Fan , Xu Shiyan , Chen Jun , Liu Kaika 
Published: December 2021

Land use is an important part of the human-land system, which can provide huge ecosystem services. Land use changes also lead to changes in the value of ecosystem services. Considering primary production, maintaining carbon dioxide and oxygen balance, nutrient cycling, water conservation,
soil erosion and other main services functions, this study establishes a land use ecosystem services value (ESV) estimation method based on the terrestrial ecosystem simulator (TESim) implemented for regional scales (TESim-R model) coupled with the Land Use and Land Cover Change (LUCC) model
(the TES-LUC model). This ESV estimation model facilitates understanding the true economic costs of land use projects as it considers ecosystem services. This model can be utilized to calculate the ecosystem data of different types of land use by substituting in data of meteorology, vegetation,
soil, and control attribute, and then evaluate the ESVs of land use according to different ecosystems. Following Constanza et al. (2007), this study classifies the ESV of an area into five categories: primary production, climate regulation, nutrient cycling, water conservation, and erosion
control. Using the net primary productivity (NPP) output value simulated by the TES-LUC model as the basis, the ESVs of five categories can be calculated, respectively. The sum of the five ESVs yields the total ESV. This study introduces the model through the example of China. To test the
model, two cost benefit analysis, one on a land use development project of a small community, and the other one on a large national project, are conducted. The effectiveness of the model is evaluated for both projects.

This study first investigates the “Grain-for-Green”
Project in Long County, Sha’anxi Province, China based on the remote sensing image of the county and the data published by the local bureau of statistics from 2000 to 2015. Using the model, this study calculates and analyzes the change of ESV in Long County during the study period. The
results demonstrate that the area of woodland, construction land, and grassland increased in different proportion, among which the area of grassland increased the most at 15.15%. The increase in land area mainly came from the decrease in farmland, the reduced area of which is up to 6,055.40hm2.
During the study period, the total ESV increased by 1.670×107 yuan, an increase of 0.52%. This is mainly attributed to the increase in the ESV of woodland and grassland. However, due to the sharp decrease in the area of farmland and water body, the NPP and the nutrient cycling function
of Long County were affected, exhibiting decreasing ESVs during the period. Therefore, based on the model and results, this study puts forward policy implications for land use projects from perspectives of water resources.

The model is further tested by evaluating the environmental
costs of a large national land use project, the “Rapid Urbanization” Project of Yangtze River Delta, which is in the Outline of China’s National Land Planning. Using data of land use gathered from six terms of remote sensing image interpretation data of Resource and Environmental
Science Data Center of the Chinese Academy of Sciences from 1990 to 2015, the results derived from the model find that rapid urbanization leaded to unbalanced transition among different types of land, which caused a significant loss of ESV. From 1990 to 2015, the ESV of Yangtze River Delta
decreased from 171.701 billion yuan to 168.267 billion yuan. Moreover,among five E5V components, the loss in the ESV of soil erosion was the highest, which decreased by 1.518 billion yuan due to the violent transformation between farmland and construction land. As a concluding remark, this
study proposes a series of implications for large land use projects from the perspective of planning, implementation, and management.