Application of reference area in US land reclamation assessment system and its implications for China

Compared with developed countries, China's management and evaluation system for mined land reclamation was built late, and the use of reference area is absent.This paper introduces the application of reference area in land reclamation management and evaluation system of US, and its advantages and disadvantages in both theory and practice, aiming to provide a reference for reclamation research and policy making in China.Reference area means a land unit maintained under appropriate management for the purpose of measuring vegetation ground cover, productivity and plant species diversity that are produced naturally or by crop production methods approved by the regulatory authority.Reference areas must be representative of geology, soil, slope, and vegetation in the permit area.According to US federal and state regulations, reference area should be established during baseline survey, and its vegetation information, location and boundaries is required for mining permit applications.During mining and reclamation periods, the reference area should be under proper management, to ensure the usability for measuring success of revegetation.Revegetation standards based on reference area were questioned both theoretically and practically.Conceptually, the reclaimed and reference areas may be different in both succession stage and trajectory, making the comparability doubtable.Practically, vegetation on the small area of reference area could not be representative the vegetation on the reclaimed area, which can be many times larger.And the reference area may suffer from degradation during mining and reclamation periods.However, most of these drawbacks have been solved.As standards based on reference area can automatically adjust temporal variability of vegetation, dispensing with huge data accumulation, it has become the most widely used standards for measuring revegetation success.It has advantages compared with our current revegetation standards of land reclamation, providing an important reference for improving our land reclamation quality standards.