Analysis On The Effects Of Rainfall Characteristics On Larix Gmelinii Of Interception Loss And Water Chemistry In Daxing’anling Mountains

The Daxing’anling Mountains is located in the cold temperate zone of China.The zonal vegetation is a bright coniferous forest dominated by Larix gmelinii.It is not only the most representative forest ecosystem in the Daxing’anling Mountains,but also the natural barrier of the Songnen Plain and the Hulunbeier Grassland,It Maintains the ecological balance of the Northeast.In this paper,it is necessary to study the effect of rainfall on the canopy interception and water chemistry of Larix gmelinii forest in Daxing’anling Mountains area.we selected the larch forest in the northern part of Daxing’anling Mountains as the object of study,observed the rainfall redistribution process,the collection and determination of water samples.The effects of rainfall characteristics on the canopy interception and water chemistry of Larix gmelinii forest were analyzed.The results were as follows:（1）During the whole growing season,the total amount of canopy interception was 64.92mm,accounting for 24.41%of the total rainfall,Forest characteristics and rainfall,rainfall duration,rainfall intensity and rainfall interval will have a influence on canopy interception.When the rainfall is 0.4 mm and 0.8 mm,the canopy interception is not affected by any factors.100%interception.The canopy interception increased with the increase of rainfall.When the precipitation is more than 12 mm,which indicates that the canopy interception increases with precipitation increase but the increase rate was decreasing.With the increase of rainfall intensity,canopy interception was also increased but this increase was not endless.When the rainfall intensity was more than 0.058 mm·min^-1,the canopy interception decreased.With the increase of inter-events interval and LAI,the canopy interception and the canopy interception rate also showed an increasing trend,and the interception effect was obvious.（2）During the observation period,indicating that the air quality the contents of K⁺,Ca²⁺,Mg²⁺,CL^-,SO₄^2-were lower in the forest.The content of Ca²⁺and Mg²⁺increased greatly and the content of each element in the rain was increased after the redistribution of larch forest.The contents of Ca²⁺,Mg²⁺,CL^-and SO₄^2-in the runoff of the trunk were significantly correlated with the rainfall outside the forest（P<0.01）.Compared with the rain outside the forest,the water content of each element is much higher,these nutrients ldissolves into the land after the redistribution of rainfall.（3）The amount of K⁺in rainfall redistribution and rainfall was positively correlated with the increase of rainfall and rainfall duration.The increase rate of K⁺content increased with the increase of rainfall and rainfall duration.The increase rate of K⁺content in rainfall intensity and rainfall interval.However,when the rainfall intensity is more than 0.041 mm·min^-1,the increase rate of K⁺content begins to change,the increase rate of K⁺content tends to stable when the rainfall interval increases to 233.28 h.The main factor influencing the K⁺content in the rain outside the forestis the inter-events interval,the dominant factors affecting the K⁺content in the penetrating rain,the shrub and the runoff are the rainfall,the K⁺content in the dry water for rainfall intensity.（4）The effect of rainfall on the increase of Ca²⁺content in litter at different levels of Larix gmelinii was that when the rainfall was less than 11.0 mm,the variation range of Ca²⁺content also increased with the increase of rainfall,The increase of Ca²⁺content in the inter-events interval,the variation of Ca²⁺content in the shrubs and the runoff of the shrubs showed the increase with the interval,and the Ca²⁺The effect of rainfall characteristics on the change of Ca²⁺content was in the order of inter-events interval>rainfall intensity>precipitation.The results showed that the increase of Ca²⁺content in the water permeated water was the same.（5）When the rainfall is less than 14.0 mm,the increase of Mg²⁺content increases with the increase of rainfall,when the rainfall is>14.0 mm,the effect of rainfall intensity on the increase of Mg²⁺content is related to rainfall In addition.with the increase of rainfall intensity,the increase of Mg²⁺content in all levels of rainfall showed a decreasing trend.The inter-events interval was positively correlated with the increase of Mg²⁺content in penetrating rain,trunk runoff and dry water and the increase of Mg²⁺content in the rain was not correlated.The importance of rainfall characteristics was the order of inter-events interval>precipitation>rainfall intensity in the process of rainfall redistribution during the redistribution of Larix gmelinii forest.（6）The increase of Cl^-content in shrub layer of Larix gmelinii forest was affected by precipitation,decreased with the increase of precipitation.The increase of SO₄^2-content in rainfall and shrimp,shrub and tree runoff.The results showed that there was a negative correlation with the variation range of SO₄^2-content in dry water.The rainfall intensity showed only positive correlation with the change of SO4^2-content in trunk runoff.The variation range of Cl^-content in shrubs was negatively correlated with the variation of SO₄^2-content in penetrating rain,shrubs and rainwater.there was a positive correlation between the variation of Cl^-.There has no significant correlation between the variation range of Cl^-and SO₄^2-in runoff.