Coarse woody debris( CWD) has an important role in hydrological function and water and soil conservation function of forest ecosystem especially mountain forest ecosystem. To understand water holding capacity of CWD i...Coarse woody debris( CWD) has an important role in hydrological function and water and soil conservation function of forest ecosystem especially mountain forest ecosystem. To understand water holding capacity of CWD in subalpine forest of southeast Tibet,CWD reserve of primitive A. fabri forest in Sygera Mountain was investigated by sample plot method,and water absorption and storage capacity of CWD was studied by using soaking method. The results showed that decay grade was positively related to water storage potential,that is to say,the higher the decay grade,the larger the water storage potential. Saturated water holding capacity,saturated water holding rate,effective water holding capacity and effective water holding rate of A. fabri CWD all rose with decay grade increased,and the order was Ⅴ>Ⅳ>Ⅲ>Ⅱ>Ⅰ. CWD reserve was 51.555 t/hm^2,and the maximum water storage capacity was 71.601 t/hm^2,while effective water storage capacity was 60.861 t/hm2,which was equivalent to 6.086 mm of rainfall.展开更多
The impact on seedling recruitment by fallen wood of A. fabri forest in Tibet Sygera Mountain was studied. The results showed that regenerated seedlings on fallen wood roughly showed normal distribution,and there were...The impact on seedling recruitment by fallen wood of A. fabri forest in Tibet Sygera Mountain was studied. The results showed that regenerated seedlings on fallen wood roughly showed normal distribution,and there were more regenerated seedlings in the middle of fallen wood,while regenerated seedlings were fewer at two ends. Fallen wood at level IV had the most regenerated seedlings,followed by level-III fallen wood,and regenerated seedlings were the fewest on fallen wood at level V. The number and species of regenerated seedling on and around fallen wood on the west slope were more than that on the east slope. With the improvement of decomposition level,regenerated seedling per unit area firstly increased and then decreased,but the number of regenerated seedling on and around fallen wood was far more than that in woodland.展开更多
The hydrological character parameters of the litter amount, the maximum water capacity and water absorption speed of the litter on the forest land under four type of \%Abies fabri\% forest (young, half_mature,mature a...The hydrological character parameters of the litter amount, the maximum water capacity and water absorption speed of the litter on the forest land under four type of \%Abies fabri\% forest (young, half_mature,mature and overmature stand)on the Gongga Mountain were studied in this paper. The result showed that the litter amount under the overmature stand was the maximum(67 8?t·hm -2 ), the second was the mature stand(53 4 t·hm -2 ), the third was the half mature stand(40 4 t·hm -2 ), the fourth was the young stand(32 6?t·hm -2 ). The maximum water capacity of the undecomposed litter under the mature stand was 428 8% of the litter’s dry weight, that of the litter under the overmature stand was 411 6%, that of the litter under the half_mature stand was 378 8%, that of the litter under the young stand was 296 7%. The maximum water capacity of the half_decomposed litter under the mature stand was 234 5% of the litter’s dry weight, that of the litter under the overmature stand was 175 6%, that of the litter under the half mature stand was 160 3%, that of the litter under the young stand was 132 5%. The equation between the water absorption speed of the litter and the soaked time is S=kt n. The result also shows that the litter’s variation with the time has no relation to forest age, while its decomposition degree is positively related to stand age.展开更多
A field experiment was carried out to examine the soil respiration rate in Abies fabri forests in Gongga Mountain National Nature Reserve using LI-6400-09 portable soil respiration chamber.The results showed that the ...A field experiment was carried out to examine the soil respiration rate in Abies fabri forests in Gongga Mountain National Nature Reserve using LI-6400-09 portable soil respiration chamber.The results showed that the soil respiration rate and soil temperature of mature and middle-aged A.fabri forests were different in each month.The soil CO2 emission rates of the two stands had obvious seasonal variation characteristics,which were arranged: summer > autumn > spring > winter;the monthly average soil CO2 emission rate of the mature aged forest ranged from 0.82 to 5.88 μmol/(s·m^2),with the coefficient of seasonal variation of 50.6%;and the average monthly soil respiration rate of middle-aged forest was in the range of 0.52-3.52 μmol/(s·m^2),with the coefficient of seasonal variation of 48.5%.The seasonal variation of soil CO2 emission rate was positively correlated with the 5 cm soil temperature.And the Q10 values of the soil CO2 emission rates in the mature and middle-aged A.fabri forests were 3.2 and 2.6,respectively,and the sensitivity index of CO2 emission to temperature in the mature A.fabri forest was higher than that in the middle-aged forest.展开更多
基金Supported by the National Natural Science Foundation of China(31460122,31360119)
文摘Coarse woody debris( CWD) has an important role in hydrological function and water and soil conservation function of forest ecosystem especially mountain forest ecosystem. To understand water holding capacity of CWD in subalpine forest of southeast Tibet,CWD reserve of primitive A. fabri forest in Sygera Mountain was investigated by sample plot method,and water absorption and storage capacity of CWD was studied by using soaking method. The results showed that decay grade was positively related to water storage potential,that is to say,the higher the decay grade,the larger the water storage potential. Saturated water holding capacity,saturated water holding rate,effective water holding capacity and effective water holding rate of A. fabri CWD all rose with decay grade increased,and the order was Ⅴ>Ⅳ>Ⅲ>Ⅱ>Ⅰ. CWD reserve was 51.555 t/hm^2,and the maximum water storage capacity was 71.601 t/hm^2,while effective water storage capacity was 60.861 t/hm2,which was equivalent to 6.086 mm of rainfall.
基金Supported by the National Natural Science Foundation of China(31460122)Excellent Teaching Team Project in Tibet Colleges and Universities:Plateau Forest Cultivation and Management Team(2017)
文摘The impact on seedling recruitment by fallen wood of A. fabri forest in Tibet Sygera Mountain was studied. The results showed that regenerated seedlings on fallen wood roughly showed normal distribution,and there were more regenerated seedlings in the middle of fallen wood,while regenerated seedlings were fewer at two ends. Fallen wood at level IV had the most regenerated seedlings,followed by level-III fallen wood,and regenerated seedlings were the fewest on fallen wood at level V. The number and species of regenerated seedling on and around fallen wood on the west slope were more than that on the east slope. With the improvement of decomposition level,regenerated seedling per unit area firstly increased and then decreased,but the number of regenerated seedling on and around fallen wood was far more than that in woodland.
文摘The hydrological character parameters of the litter amount, the maximum water capacity and water absorption speed of the litter on the forest land under four type of \%Abies fabri\% forest (young, half_mature,mature and overmature stand)on the Gongga Mountain were studied in this paper. The result showed that the litter amount under the overmature stand was the maximum(67 8?t·hm -2 ), the second was the mature stand(53 4 t·hm -2 ), the third was the half mature stand(40 4 t·hm -2 ), the fourth was the young stand(32 6?t·hm -2 ). The maximum water capacity of the undecomposed litter under the mature stand was 428 8% of the litter’s dry weight, that of the litter under the overmature stand was 411 6%, that of the litter under the half_mature stand was 378 8%, that of the litter under the young stand was 296 7%. The maximum water capacity of the half_decomposed litter under the mature stand was 234 5% of the litter’s dry weight, that of the litter under the overmature stand was 175 6%, that of the litter under the half mature stand was 160 3%, that of the litter under the young stand was 132 5%. The equation between the water absorption speed of the litter and the soaked time is S=kt n. The result also shows that the litter’s variation with the time has no relation to forest age, while its decomposition degree is positively related to stand age.
基金Supported by National Key Research and Development Program of China(2017YFC0504903 2016YFC0503305)+1 种基金National Natural Science Foundation of China(41771062)CAS Key Technology Talent Program(CAS201665)
文摘A field experiment was carried out to examine the soil respiration rate in Abies fabri forests in Gongga Mountain National Nature Reserve using LI-6400-09 portable soil respiration chamber.The results showed that the soil respiration rate and soil temperature of mature and middle-aged A.fabri forests were different in each month.The soil CO2 emission rates of the two stands had obvious seasonal variation characteristics,which were arranged: summer > autumn > spring > winter;the monthly average soil CO2 emission rate of the mature aged forest ranged from 0.82 to 5.88 μmol/(s·m^2),with the coefficient of seasonal variation of 50.6%;and the average monthly soil respiration rate of middle-aged forest was in the range of 0.52-3.52 μmol/(s·m^2),with the coefficient of seasonal variation of 48.5%.The seasonal variation of soil CO2 emission rate was positively correlated with the 5 cm soil temperature.And the Q10 values of the soil CO2 emission rates in the mature and middle-aged A.fabri forests were 3.2 and 2.6,respectively,and the sensitivity index of CO2 emission to temperature in the mature A.fabri forest was higher than that in the middle-aged forest.
