Table 2 Comparative of main ecosystems in Guyuan County of Hebei Province, China
From: The creation of “Ecosystem Core” hypothesis to explain ecosystem evolution
Ecosystem types | Ecosystems | Emergy investment ratio (EIR) | Emergy self-sufficiency ratio (ESR) (%) | Emergy yield ratio (EYR) | Environmental loading ratio (ELR) | Emergy sustainability index (ESI) |
|---|---|---|---|---|---|---|
Commercial crop | Potatoes | 27.81 | 3.47 | 1.04 | 31.00 | 0.0334 |
Chinese cabbage greenhouse | 27.56 | 3.50 | 1.04 | 30.73 | 0.0337 | |
Spinach greenhouse | 27.56 | 3.50 | 1.04 | 30.73 | 0.0337 | |
Cabbage | 19.03 | 4.99 | 1.05 | 21.25 | 0.0495 | |
Artificial forage | Oats | 2.94 | 25.36 | 1.34 | 3.38 | 0.3963 |
Corn silage | 2.28 | 30.52 | 1.44 | 2.64 | 0.5452 | |
Field crop | Naked oats | 1.31 | 43.34 | 1.76 | 1.56 | 1.1289 |
Flax | 1.30 | 43.51 | 1.77 | 1.55 | 1.1395 | |
Wheat | 1.30 | 43.51 | 1.77 | 1.55 | 1.1398 | |
Grassland | Free grazing | 0.79 | 55.79 | 2.26 | 0.99 | 2.2819 |
Chinese leymus grassland | 0.67 | 60.03 | 2.50 | 0.85 | 2.9418 | |
Natural mowed grassland | 0.66 | 60.07 | 2.50 | 0.85 | 2.9481 |