辽西低山丘陵区不同年龄荆条冠层截留降雨模拟实验研究

为揭示辽西低山丘陵区不同年龄荆条冠层降雨截留的变化规律，采用人工模拟降雨动态监测荆条冠层降雨截留情况，并建立了经验模型。结果表明：荆条冠层未截留量与降雨量呈线性显著正相关，且随年龄增加，未截留量的增加速率减小；250 min时未截留率趋向稳定为1年生91.87% > 2年生89.75% > 3年生85.08% > 4年生79.00%，未截留率与降雨量显著正相关；荆条截留量随着降雨量的增加而增加，在250 min时4年生为（5.25±0.49）mm > 3年生（3.73±0.65）mm > 2年生（2.60±0.23）mm > 1年生（1.93±0.55）mm，且1、2年生荆条截留量趋向稳定；250 min后冠层截留率逐渐变小并趋向稳定值，4年生21.00% > 3年生14.92% > 2年生10.25% > 1年生8.13%；荆条附加截留量4年生为（0.27±0.03）mm > 3年生（0.17±0.04）mm > 2年生（0.14±0.01）mm > 1年生（0.09±0.02）mm。揭示了不同年龄荆条冠层截留降雨的基本规律，验证了附加截留量，为进一步研究荆条的生态水文效应提供了科学的理论依据，对水土保持树种优选和辽西地区水土流失治理具有一定的指导意义。

Simulated and experimental study on rainfall interception of different aged Vitex negundo var. heterophylla canopies in the low mountains and hills of western Liaoning

Low mountainous and hilly regions of western Liaoning have a semi-arid climate, are located at the southern edge of Horqin sandy land, and are very vulnerable to soil and water loss. Vitex negundo var. heterophylla, a native species, plays an important role in soil and water conservation; thus, research on the principles of rainfall interception based on the distribution of the Vitex negundo var. heterophylla canopy is crucial. To reveal the variation in rainfall interception of different aged Vitex negundo var. heterophylla canopies, rainfall interception of Vitex negundo var. heterophylla canopies were monitored using artificial rainfall simulation. An empirical model was established. The results showed that there was a significantly positive linear correlation between non-interception by canopies and rainfall rate, with the rate of canopy non-interception decreasing with increasing canopy age. The non-interception rate of the canopy tended to be stable for 250 minutes. Non-interception rates are 91.87% for 1-year-old canopy > 89.75% (2-years old) > 85.08% (3-years old) > 79.00% (4-years old). Non-interception rate and rainfall were significantly positively related. The interception amount of different ages canopies increased with increasing rainfall, and were (5.25±0.49) mm (4-years old) > (3.73±0.65) mm (3-years old) > (2.60±0.23) mm (2-years old) > (1.93±0.55) mm (1-year old) for 250 minutes. Additionally, the interception amount of 1-year old and 2-year-old Vitex negundo var. heterophylla canopies tended to be stable. Canopy interception rates gradually decreased and tended to be stable after 250 minutes; they were 21.00% (4-years old) > 14.92% (3-years old) > 10.25% (2-years old) > 8.13% (1-year old). Additional interception amounts by Vitex negundo var. heterophylla canopies were (0.27±0.03) mm (4-years old) > (0.17±0.04) mm (3-years old) > (0.14±0.01) mm (2-years old) > (0.09±0.02) mm (1-year old). The study revealed the basic principles of rainfall interception by different aged Vitex negundo var. heterophylla canopies, verified the additional interception, and provided a scientific theoretical basis for further study. It is of great significance to the selection of tree species for soil and water conservation and soil erosion control in western Liaoning.