海北高寒草甸碳密度的空间异质性分布

NWIPB OpenIR

	海北高寒草甸碳密度的空间异质性分布
	孙建文
学位类型	硕士
导师	李英年
	2010-05
学位授予单位	中国科学院研究生院
学位授予地点	北京
学位专业	生态学
关键词	高寒草甸生产力空间异质性季节动态年际变化放牧强度碳密度土壤容重地统计地下地上生物量比
摘要	本研究通过分析中国科学院海北高寒草甸生态系统定位站（海北站）周边的高寒草甸的生产力和气象观测数据，利用数学回归模拟了高寒草甸的碳密度时间差异分布，并分别利用数理统计和地统计探讨了不同地形、不同植被类型情况下高寒草甸植被生物量及植被和土壤碳的空间分布规律。主要结论有： 1．利用数学回归方法得到海北高寒矮嵩草草甸植被群落地上生物量的季节动态的Logistic回归模型为(5.3180.03 349.72026 1 t N e   )；LAI季节动态回归模型可表示为(LAI=305.296-4.951t+0.0266t2-4.689E-5t3)；LAI与地上生物量（AB）的二次多项式关系模型（LAI=0.54+0.027AB-7.05E-5AB2）。 2．海北高寒矮嵩草草甸植被枯落物季节动态变化可用三次函数表达：L＝-13.469 + 0.042M3。地下地上生物量比季节动态变化可用二次函数RS＝206.128-44.956M+2.488M2表达，地下地上生物量比最低值出现在8月底。地下地上生物量比与地上生物量有很强的相关关系（RS＝1.944+1.572×103/AB）。利用其回归方程及其植被地下地上比，对海北高寒矮嵩草草甸自1980年以来的30年植被净初级生产力和植被碳密度进行插补，得到海站近30年植被地上净初级生产力平均为360.872g/m2、地下净初级生产力平均为782.380g/m2，平均植被碳密度为457.3gC/m2。分析发现，海北高寒矮嵩草草甸植被地上和地下生物量有相同的变化规律，有些年份地上净初级生产力变化表现出比地下净初级生产力滞后一年的特点。 3．分析2001～2009年恢复后矮嵩草草甸、阴坡金露梅灌丛草甸、原生矮嵩草草甸、藏嵩草沼泽化草甸、阳坡矮嵩草草甸和滩地夏季放牧金露梅灌丛草甸的植被净初级生产力和植被碳密度发现，6种不同区域植被碳密度分别为433.2gC/m2、700.9gC/m2、397.0gC/m2、2900.0gC/m2、501.3gC/m2、644.3gC/m2，每年输入土壤的碳量分别为365.9gC/m2、646.7gC/m2、320.2gC/m2、2833.2gC/m2、432.5gC/m2、553.9gC/m2。植被总碳密度表现出藏嵩草沼泽化草甸阴坡金露梅灌丛草甸>滩地金露梅灌丛草甸阳坡矮嵩草草甸恢复后矮嵩草草甸原生矮嵩草草甸。海北站地区放牧利用使每年归入土壤的地上生物量碳素量减少了43.5%。恢复后矮嵩草草甸、阴坡金露梅灌丛草甸、原生矮嵩草草甸、阳坡矮嵩草草甸0～40cm土层的土壤碳密度分别为14.90kgC/m2、17.13kgC/m2、11.22kgC/m2、17.21kgC/m2，表现出恢复后矮嵩草草甸、阴坡金露梅灌丛草甸、阳坡矮嵩草草甸>原生矮嵩草草甸。 4．通过克里格插值的衍生法KED生成的海北站附近植被碳密度分布图显示，此地区最大值和最小值分别为744.649gC/m2和4463.730gC/m2；海北站东部的藏嵩草草甸生物量碳密度非常集中。 5．假设放牧围栏由出入口到草场深处放牧强度是逐渐减小的。通过设计采样点并集植被净初级生产力和土壤样品分析发现，放牧围栏内放牧强度对植被碳和土壤碳的分布影响较为复杂。出入口附近羊群践踏频度大，土壤容重大（1.054g/cm3），形成重牧效应，土壤碳密度较小（13.87kg/m2）。植被碳密度因草场退化杂类草居多，植物根系发达表现出较高的水平（1.497kg/m2）。远离出入口的草场深处，由于放牧强度不断下降，植被碳密度下降（在离出入口的140m为0.746kgC/m2），但更远距离处反而有所升高（如离出入口的240m为1.417gC/m2）。其土壤碳密度变化复杂，随离出入口距离拉长，土壤碳密度表现出升高（如离出入口的130m为17.19kgC/m2）—下降（如离出入口的170m为12.62kgC/m2）—再升高（如离出入口的240m为14.39kgC/m2）的趋势。
其他摘要	According to the NPP and climate data of alpine meadow around Haibei Alpine Meadow Ecosystem Research Station, CAS (Haibei Station), we analyzed the temporal variation of the Alpine Meadow productivity with the regression analysis method, and explored the carbon density special of the Alpine Meadow in different terrain, different vegetation types and different land use types with the methods of statistic and geostatistics. The preliminary conclusions as following: 1. With the mathematical regression method, we build the following functions: Logistic regression model of Alpine Kobresia meadow vegetation biomass seasonal dynamics as (5.3180.03 349.72026 1 t Ne   ); regression model of LAI seasonal dynamic as (LAI = 305.296-4.951t +0.0266t2-4.689E-5t3); the quadratic polynomial function of LAI and above-ground biomass (AB) is (LAI = 0.54 +0.027 AB-7.05E-5AB2). 2. The monthly dynamics of Alpine Kobresia meadow litter could be expressed as: L =- 13.469 + 0.042M3. The monthly dynamics of root- shoot biomass ratio could be expressed as a quadratic function: RS = 206.128-44.956M +2.488 M2, and the time of the minimum root- shoot biomass ration is in the end of August. Aboveground- and underground biomass has a strong relationship, as: RS = 1.944 + 1.572 × 103/AB. The interpolation biomass dynamics figure showed that alpine meadows above ground biomass has the same variation character as the below biomass during the last 3 decades. And they got a cycle of 2 to 3 years approximately. Specially, the below-ground biomass got a hysteretic period of 1 year compared to aboveground biomass. 3. With the field survey data from 2001 to 2008, we estimated the vegetation carbon density of 6 types of alpine meadow in Haibei Research Station. Preliminary results from our calculation showed that, for the reinstated Kobresia humilis meadow, shady Potentilla fruticosa shrub meadow, native Kobresia meadow, Kobresia tibetica, sunny Kobresia humilis meadow and summer grazing Potentilla fruticosa shrub meadow, the vegetation carbon density were 433.2gC/m2,700.9gC/m2, 397.0gC/m2, 2900.0gC/m2, 501.3gC/m2 and 644.3gC/m2 respectively, and the annual soil carbon inputs were 365.9gC/m2, 646.7gC/m2, 320.2gC/m2, 2833.2gC/m2, 432.5gC/m2 and 553.9gC/m2 respectively. By grazing, livestock product outputs and other factors, the aboveground biomass which would enter soil and translate into carbon content decreased 43.5% per year. For the reinstated Kobresia meadow, shady Potentilla fruticosa shrub meadow, native Kobresia meadow, Kobresia meadow, the soil carbon density of 40cm layer under gound was 14.90gC/m2, 17.13gC/cm2, 11.22gC/cm2, 17.21gC/cm2 respectively, as the carbon density in Kobresia meadow, shady Potentilla fruticosa shrub meadow and sunny Kobresia meadow higher than in native Kobresia meadow. 4. With the method of KED, we build the vegetation carbon density distribution map of the station. The map showed that the maximum and minimum values were 744.649gC/m2 and 4463.730gC/m2 respectively. And the biomass carbon density was very concentrated in the east of Haibei station where the Tibetan swamp meadow of plateau Kobresia was. 5. Based on the hypothesis that the grazing intensity was increasing as approaching the by the entrance of fence form the rangeland depths, we designed the grazing intensity experiment. With skillfully set sampling points and scientific analysis of the survey data, we found that soil carbon variation were very complex under different grazing intensity. Because of the heavy trampling by the sheep near the entrance, soil have large SBD(1.054g/cm3), large SOC(13.87kg/m2) and large vegetation carbon density(1.497kg/m2). With the farther away from the entrance, the grazing are declining, and the vegetation carbon density decreasing(0.746kgC/m2 at 140m), but until a distance, the vegetation carbon density are increasing(1.417gC/m2 at 240m). With the farther away from the entrance, the change of soil carbon density is complex. It is increasing firstly (17.19kgC/m2 at 130m) – then decreasing (12.62kgC/m2 at 170m) – increasing again (14.39kgC/m2 at 240m).
学科领域	生物科学
语种	中文
文献类型	学位论文
条目标识符	http://210.75.249.4/handle/363003/3395
专题	中国科学院西北高原生物研究所
推荐引用方式 GB/T 7714	孙建文. 海北高寒草甸碳密度的空间异质性分布[D]. 北京. 中国科学院研究生院,2010.

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