Grade evaluation of forest ecological function for Beimandian Forest Farm of Saihanba, Hebei Province of northern China

  Objective   Saihanba Mechanical Forest Farm, Hebei Province of northern China, is the largest plantation forest farm in the world, it has been awarded the “Earth Guardian Award” by the United Nations in 2017. Thus, it is particularly important to scientifically evaluate the contribution of afforestation to the restoration of Saihanba forest ecological function. This study aimed to analyze the current situation of Saihanba forest ecological function from different aspects and provide a theoretical basis for future forest management.

  Method   The ecological function grade of various forests in Beimandian Forest Farm in Saihanba had been evaluated based on Technical Regulations for Inventory for Forest Management Planning and Design (GB/T 26424−2010) with 8 evaluation factors of forest volume, forest naturalness, forest community structure, species structure, total vegetation coverage, canopy density, mean tree height and litter thickness.

  Result   The forest ecological function index of Beimandian Forest Farm of Saihanba was 0.488, in which the stand with good ecological function grade accounted for 3.8%, the stand with medium ecological function grade accounted for 52.7%, the stand with bad ecological function grade accounted for 42.4% and the stand with worse ecological function accounted for 1.1%. The ecological function index of different stand origins was as follows: natural forest (0.545) > planted forest (0.474). The ecological function index of different forest types was as follows: mixed forest of needleleaf and broadleaf species (0.710) > mixed forest of broadleaf species (0.617) >Betula platyphylla natural secondary forest (0.535) > mixed forest of needleleaf species (0.487) > Larix principis-rupprechtii plantation (0.478) > Picea asperata plantation (0.443) > Pinus sylvestris var. mongolica plantation (0.429). The ecological function index of different age groups was as follows: over-mature forest (0.588) > middling forest (0.512) > near-mature forest (0.509) > mature forest (0.504) > young forest (0.434).

  Conclusion   The forest ecological function of Beimandian Forest Farm has significantly improved after nearly 60 years of afforestation projects compared with sandy wasteland. However, the ecological function of artificial forests still has great space for improvement. The artificial forests should be subject to necessary management combined with the concept of near natural management.