Comparison On Capability Of Water Holding And Nutrition Preserving In Artificial Hybrid Forest And Second Shrub-forest

For comparing capability of water holding and nutrition preserving in artificial Pinus tabulaeformis and Pinus armandi Franch hybrid forest and the second shrub forest, this study adopt hydrology method to monitor two location ecological system which is Pinus tabulaeformis and Pinus armandi F. hybrid forest system and the second shrub forest system in the upper reaches of Minjiang River. The experiments have supervised the change of nutrition in water of re-contribution/contribution in process of onetime rainfall event. Measurement indexes include rainfall, throughfall, stemflow, evaporation, surface runoff,soil-penetration and the consistence of P, K, Na, Ca, Mg and the value of pH in water; and have simulated the relation-curve of throughfall, stemfiow, evaporation and rainfall; and have analyzed the correlation of throughfall, stemfiow, evaporation and rainfall; and compared the components of conserving water by comparing the change of input/output of water; and compared the components of preserving nutrition by comparing the change of input/output of nutrition. The study shows that:1. The throughfall of the hybrid forest and the second shrub forest with the rainfall have linear relationship. They will increase with rainfall gradually. The stemflows of the hybrid forest have a significant linear relationship with rainfall, while the shrub forests have exponent function relationship with it. The arbor stemfiow will increase with the arbor DB (the abbreviation of Diameter of Breast) scale/level in hybrid forests, while the shrub-forests have not.The evaporation of the hybrid forest is 15.2% of the amount of total rainfall, while the second shrub-forest is 7.8%. Both the evaporations of two ecosystems are linear relationship with rainfall, the strength of rainfall and the time of rainfall. The evaporations are significant relationship with the time of rainingfall.Both the surface runoffs of the two sampling fields are small and their penetrations are little difference. The hybrid forest has supervised 11 times surface runoff, and its soil-penetration water is 14.3% of the amount of raining-fall while the second shrub-forest has 6 times and its soil-penetration water is 14.6% of the amount.2. The difference of the two ecosystem conservations is not significant in onetime rainfall event.3. The average pH of penetrating rainfall of the hybrid ecosystem is 6.40, while the second shrub-forest is 7.02. The nutrition factors of throughfall (including P, K, Na, Ca, Mg etc) are not relation with rainfall characters in the two ecosystems. The average pH of stemflow in the hybrid ecosystem is 5.97, while the second shrub-forest is 6.48. The consistence of Ca, Mg, K have rising tendency from August to October in the water samplings of the two ecosystems, while P, Na and the value of PH is not. The average PH of stemflow and soil-penetration water in the hybrid ecosystem are 7.82 and 7.72 respectively, and are 8.48 and 7.92 in shrub-forest ecosystem.4. During the observation, the total input of nutrition in the hybrid ecosystem is 130.421 kg.ha^-2, and its output is 75.872 kg. ha^-2. So its preservation is 54.548 kg.ha^-2. The total input of nutrition in the second shrub-forest ecosystem is 121.743 kg.ha^-2, and its output is 58.275 kg. ha^-2. And its preservation is 63.468 kg.ha^-2. Obviously, the conservation of nutrition in the second shrub-forest ecosystem is more than the hybrid ecosystem. The two ecosystems are not significant difference in conservation components of nutrition by comparing the input/output of P, K, Na, Ca, Mg in throughfall, stemflow, surface runoff and soil-penetration.