**Table 15 Statistical analysis for fluctuated concentration rate of shrub structure type**

a. Group statistics(winter) |

Classification | Number of samples (N) | Mean value (%) | Std. deviation (%) | Std. error (%) | Min (%) | Max (%) |

Single layer | 32 | 88.788 | 19.4664 | 3.4412 | 49.2 | 116.7 |

Double layer | 192 | 81.160 | 19.4769 | 1.4056 | 44.3 | 132.0 |

Multi layer | 32 | 68.925 | 24.5723 | 4.3438 | 35.6 | 116.7 |

Total/mean | 256 | 80.584 | 20.7211 | 1.2951 | 35.6 | 132.0 |

b. Levene's test for equality of variances (winter) |

Levene's statistics | df1 | df2 | Sig. |

2.258 | 2 | 253 | 0.107 |

c. Analysis of variance (ANOVA) (winter) |

Classification | Sum of squares | df | Mean squares | F | Sig. |

Between groups | 6,567.143 | 2 | 3,283.572 | 8.072 | 0.000 |

Within groups | 102,920.434 | 253 | 406.800 | | |

Total | 109,487.578 | 255 | | | |