1 材料与方法
1.1 材料
1.2 方法
1.3 数据处理
2 结果与分析
2.1 秋冬季土壤含水量的日变化特征
2.2 PAR、RH和Ta的日变化特征
2.3 秋冬季气体交换参数的日变化特征
表1 光合特征参数日变化的秋冬动态Tab. 1 Diurnal changes of leaf photosynthetic parameters of P. glauca McClure |
| 时间Time | Pn / (μmol·m-2·s-1) | Gs / (mmol·m-2·s-1) | Ci / (μmol·mol-1) | Tr / (mmol·m-2·s-1) | Vpdl / kPa | WUE /(mmol·mol-1) | |
|---|---|---|---|---|---|---|---|
| 2018-10 | 8:00 | 2.110±0.260ab | 0.034±0.002a | 297.484±9.686a | 0.723±0.048ab | 2.129±0.010c | 2.917±0.316a |
| 10:00 | 2.466±0.460a | 0.031±0.004ab | 259.095±20.294b | 0.850±0.101a | 2.732±0.027a | 2.888±0.433a | |
| 12:00 | 1.201±0.396abc | 0.026±0.003abc | 317.006±20.733b | 0.702±0.079ab | 2.659±0.037a | 1.666±0.477a | |
| 14:00 | 0.910±0.262bc | 0.021±0.003bcd | 323.770±18.466b | 0.490±0.061bc | 2.293±0.033b | 1.769±0.520a | |
| 16:00 | 0.490±0.253cd | 0.015±0.001cd | 338.112±33.060b | 0.260±0.013c | 1.722±0.038d | 0.925±0.034a | |
| 18:00 | -0.083±0.059d | 0.011±0.001d | 539.833±40.542b | 0.135±0.016c | 1.176±0.035e | -4.464±0.863b | |
| 2019-01 | 8:00 | 0.437±0.087b | 0.016±0.003 b | 243.188±10.351b | 0.343±0.051c | 2.142±0.009a | 1.461±0.307a |
| 10:00 | 4.427±0.572a | 0.064±0.006a | 288.085±18.490ab | 0.962±0.069a | 1.532±0.014bc | 4.717±0.651a | |
| 12:00 | 5.490±0.810a | 0.049±0.002a | 221.202±25.371b | 0.773±0.038b | 1.591±0.024b | 7.058±0.977a | |
| 14:00 | 4.821±1.168a | 0.047±0.008a | 241.485±21.398b | 0.675±0.095b | 1.465±0.013c | 6.706±0.916a | |
| 16:00 | 1.579±0.250b | 0.026±0.002b | 303.290±12.623ab | 0.232±0.019c | 0.903±0.006d | 6.815±0.915a | |
| 18:00 | 0.303±0.127b | 0.012±0.002b | 341.628±39.370a | 0.081±0.014d | 0.695±0.006e | 5.641±1.367a | |
注:同一时期同列不同小写字母者表示差异显著(P<0.05)。 | |
Note: Different lowercase letters in the same column in the same period mean significant difference (P<0.05). |
2.4 秋冬季枝条Ψw的日变化特征
2.5 光合水分参数与环境因子相关性分析
表2 光合水分参数与环境因子相关性分析Tab. 2 Correlation analysis of leaf photosynthetic parameters and environmental factors of P. glauca McClure |
| 时间 Time | 参数 Factors | Pn | Gs | Ci | Tr | Vpdl | WUE | RH | Ta | PAR | Ψw | 土壤含水量 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2018-10 | Pn | 1 | ||||||||||
| Gs | 0.948** | 1 | ||||||||||
| Ci | -0.913* | -0.791 | 1 | |||||||||
| Tr | 0.946** | 0.957** | -0.828* | 1 | ||||||||
| Vpdl | 0.836* | 0.783 | -0.866* | 0.914* | 1 | |||||||
| WUE | 0.838* | 0.713 | -0.980** | 0.722 | 0.780 | 1 | ||||||
| RH | -0.903* | -0.832* | 0.921** | -0.936** | -0.988** | -0.839* | 1 | |||||
| Ta | 0.841* | 0.742 | -0.851* | 0.896* | 0.976** | 0.743 | -0.975** | 1 | ||||
| PAR | 0.296 | 0.368 | -0.356 | 0.538 | 0.690 | 0.296 | -0.582 | 0.612 | 1 | |||
| Ψw | -0.128 | 0.091 | 0.280 | -0.059 | -0.202 | -0.273 | 0.202 | -0.321 | -0.249 | 1 | ||
| 土壤含水量 | 0.731 | 0.785 | -0.558 | 0.585 | 0.284 | 0.561 | -0.396 | 0.250 | -0.183 | 0.194 | 1 | |
| 2019-01 | Pn | 1 | ||||||||||
| Gs | 0.917* | 1 | ||||||||||
| Ci | -0.594 | -0.416 | 1 | |||||||||
| Tr | 0.893* | 0.966** | -0.572 | 1 | ||||||||
| Vpdl | 0.244 | 0.266 | -0.805 | 0.49 | 1 | |||||||
| WUE | 0.524 | 0.336 | 0.082 | 0.138 | -0.632 | 1 | ||||||
| RH | 0.986** | 0.956** | -0.612 | 0.954** | 0.347 | 0.397 | 1 | |||||
| Ta | -0.571 | -0.614 | 0.839* | -0.781 | -0.923** | 0.366 | -0.668 | 1 | ||||
| PAR | 0.872* | 0.733 | -0.619 | 0.763 | 0.279 | 0.440 | 0.865* | -0.523 | 1 | |||
| Ψw | -0.313 | -0.499 | 0.494 | -0.669 | -0.806 | 0.572 | -0.459 | 0.842* | -0.408 | 1 | ||
| 土壤含水量 | -0.169 | 0.053 | -0.225 | 0.244 | 0.709 | -0.839* | -0.013 | -0.581 | 0.020 | -0.882* | 1 |
注:样本数n=6;* 和 ** 分别代表在0.05和0.01水平上显著。 | |
Note: Sample size n = 6; * and ** mean significance at 0.05 and 0.01 level, respectively. |
2.6 秋冬季净光合速率对气象因子的响应
表3 淡竹光合作用的气象因子响应特性Tab. 3 Response characteristics of meteorological factors to photosynthesis in P. glauca McClure |
| 气象因子 Meteorological factor | 季节 Season | 回归方程 Regression equation | 最适点 Optimum point | 光补偿点 Light compensation point /(μmol·m-2·s-1) | 光饱和点 Light saturation point /(μmol·m-2·s-1) |
|---|---|---|---|---|---|
| Ta | 秋季 | y=-0.0483x2+3.0438x-46.237 | 31.509 ℃ | ||
| 冬季 | y=-0.1887x2+8.725x-96.097 | 23.119 ℃ | |||
| RH | 秋季 | y=-0.0049x2+0.3533x-4.5501 | 36.051% | ||
| 冬季 | y=-0.0297x2+3.1086x-76.563 | 52.333% | |||
| PAR | 秋季 | y=-1E-05x2+0.015x-1.1128 | 78.271 | 750.000 | |
| 冬季 | y=-2E-05x2+0.0201x-0.0208 | 1.036 | 502.500 |
