The Study On Comparation Of Soil Respiration Of Tropical Seasonal Rainforest And Rubber Plantation In Xishuangbanna

In the metabolism process of soil,CO₂ was produced and released into the atmosphere through a process called soil respiration.Soil respiration is an important part in the global carbon cycle.Further research on soil respiration of the forest ecosystem is helpful for people to understand and evaluate the function of carbon source and carbon sink and it has important scientifically function to understand and study the carbon cycle of the terrestrial ecosystem.The soil respiration of the forest ecosystem is closely related to the change of environmental factors.What’s more,the temporal and spatial dynamics of soil respiration can have a profound impact on the carbon storage and carbon emission of the forest ecosystem.Studing the temporal and spatial variations of the forest ecosystem’s soil respiration is an necessary step to correctly understand the carbon cycle of the forest ecosystem,and it is significant to accurately assess the dynamic changes of soil carbon of the forest ecosystem.In this paper,we selected the typical tropical seasonal rainforest and artificial rubber（Hevea brasiliensis）plantation as the research objects,from the Nabanhe National Nature Reserve in Xishuangbanna,China.The purpose of this research was understand the spatial and temporal differences of soil respiration between tropical seasonal rainforest and artificial rubber plantation.We used the soil carbon flux automatic monitoring system（LI-8100A）,to determine the soil respiration from the selected plots.on November 2014 to November 2015.At the same time,the related environmental factors were monitored.According to the monitoring results,the similarities and differences of two kinds of forest soil respiration were compared and analyzed from two perspectives of time and space.Moreover,the relationship between soil respiration and environmental factors of two kinds of forest types was studied.The research results mainly show that:（1）With the changes of time,the soil respiration of seasonal rainforest,old rubber plantation and young rubber plantation have significant variation characteristics.The average rate of soil respiration sorts as: Seasonal rainforest > Old rubber plantation >Young rubber plantation.（2）In the foggy and cool season,the dry and hot season and the rainy season,seasonal rainforest and rubber plantation forest soil respiration rate on average showed:Seasonal rainforest > artificial rubber plantation;Between the three different seasons,average rate of seasonal rainforest and rubber plantation forest soil respiration wererainy season > dry season > fog cool season,soil respiration rate of the minimum and maximum values were respectively in fog cool season and rainy season.（3）In down,middle and upper slope,the average soil respiration rate of the seasonal rainforest,the old rubber plantation and the young rubber plantation,Respectively show as: down slope > upper slope > middle slope;middle slope > upper slope > down slope;down slope > upper slope > middle slope.（4）In the period of a year,the variations of seasonal rain forest,old rubber plantation and young rubber plantation’s soil respiration rate were mainly effected by air temperature and soil temperature,but with little effect of air humidity and soil moisture.（5）In the fog cool season,the soil respiration rate of seasonal rainforest,old rubber plantation and young rubber plantation was mainly effected by air temperature and soil temperature;In the dry season,the soil respiration rate of seasonal rainforest was mainly effected by air humidity,while old rubber plantation soil respiration rate was mainly influenced by air humidity,soil temperature and soil moisture in the shallow soil.Young rubber forest soil respiration rates was effected by soil temperature;During the rainy season,the main driving factors of soil respiration rate of the old rubber plantation wre soil temperature,but driving factors in seasonal rain forest were complex,among which moisture was particularly obvious.（6）In old rubber plantation sensitivity of soil respiration to soil temperature was strongest,followed by the young rubber plantation,and seasonal rainforest was weakest.In the soil layer range of 0⁷0cm,with the increase of soil depth,the Q10 value of the three forest types increased,the sensitivity of soil respiration of three kinds forests to deep soil temperature is higher than that of shallow layer soil temperature.