Table 1.
Ecological characteristics of the 22 sampling sites.
| Site | Province | Longitude (°) | Latitude (°) | Mean Annual Temperature | Mean Annual Precipitation | Habitat Types |
|---|---|---|---|---|---|---|
| S1 | Tianjin | 116.92 | 38.73 | 506 | 12.96 | Wasteland neighbouring roadside |
| S2 | Tianjin | 117.02 | 38.90 | 515 | 12.92 | Wasteland neighbouring roadside |
| S3 | Tianjin | 116.96 | 39.04 | 520 | 12.84 | Wasteland |
| S4 | Tianjin | 117.16 | 39.15 | 566 | 13.38 | Wasteland |
| S5 | Tianjin | 117.28 | 39.64 | 549 | 11.95 | Wasteland neighbouring roadside |
| S6 | Tianjin | 117.37 | 39.44 | 554 | 12.13 | Wasteland |
| S7 | Tianjin | 117.51 | 39.15 | 551 | 12.43 | Wasteland neighbouring roadside |
| S8 | Tianjin | 117.42 | 38.96 | 555 | 13.03 | Wasteland neighbouring roadside |
| S9 | Tianjin | 116.93 | 39.39 | 535 | 12.39 | Wasteland neighbouring roadside |
| S10 | Tianjin | 116.95 | 39.16 | 532 | 12.69 | Wasteland neighbouring roadside |
| S11 | Tianjin | 117.39 | 40.03 | 564 | 11.73 | Wasteland neighbouring roadside |
| S12 | Tianjin | 117.85 | 39.48 | 588 | 11.79 | Wasteland neighbouring roadside |
| S13 | Hebei | 117.06 | 39.66 | 543 | 11.85 | Wasteland neighbouring roadside |
| S14 | Hebei | 116.92 | 39.88 | 538 | 11.68 | Wasteland neighbouring roadside |
| S15 | Hebei | 116.71 | 39.60 | 546 | 12.16 | Wasteland |
| S16 | Beijing | 116.77 | 39.71 | 545 | 11.92 | Wasteland |
| S17 | Beijing | 116.46 | 39.80 | 570 | 12.31 | Wasteland |
| S18 | Beijing | 116.35 | 39.82 | 571 | 12.40 | Wasteland |
| S19 | Hebei | 116.75 | 39.32 | 535 | 12.39 | Wasteland neighbouring roadside |
| S20 | Hebei | 116.42 | 39.41 | 556 | 12.21 | Wasteland |
| S21 | Hebei | 116.76 | 39.15 | 530 | 12.62 | Wasteland neighbouring roadside |
| S22 | Hebei | 116.45 | 39.09 | 512 | 12.67 | Wasteland neighbouring roadside |