本文選題：森林-草原交錯(cuò)帶　切入點(diǎn)：CENTURY模型　出處：《內(nèi)蒙古農(nóng)業(yè)大學(xué)》2017年博士論文　論文類型：學(xué)位論文

【摘要】：草地生態(tài)系統(tǒng)的碳動(dòng)態(tài)研究在全球變化研究領(lǐng)域中具有非常重要的地位。準(zhǔn)確評(píng)估草地生態(tài)系統(tǒng)碳源/匯關(guān)系及其對(duì)氣候變化和人類干擾的響應(yīng)和反饋?zhàn)饔檬且粋�(gè)重大的科學(xué)問題。森林-草原交錯(cuò)帶是生態(tài)交錯(cuò)帶中受人類活動(dòng)干擾最為敏感的區(qū)域之一,具有對(duì)氣候變化的潛在指示作用。本研究以賽罕烏拉自然保護(hù)區(qū)這一典型森林-草原交錯(cuò)帶為研究對(duì)象,針對(duì)該區(qū)域的草地生態(tài)系統(tǒng),利用生物地球化學(xué)循環(huán)模型(CENTURY模型和DNDC模型),將樣地實(shí)測(cè)數(shù)據(jù)、站點(diǎn)觀測(cè)數(shù)據(jù)、遙感影像和模型模擬耦合在一起,進(jìn)行了一系列的參數(shù)本地化、模型驗(yàn)證和分析,將驗(yàn)證好的模型進(jìn)一步分析森林-草原交錯(cuò)帶草地生態(tài)系統(tǒng)在氣候變化和自然保護(hù)條件下的碳動(dòng)態(tài)情況。主要結(jié)論如下:(1)經(jīng)過大量參數(shù)本地化后的CENTURY模型、DNDC模型能夠很好地反映研究區(qū)的碳動(dòng)態(tài),都通過了實(shí)測(cè)數(shù)據(jù)、文獻(xiàn)數(shù)據(jù)的多方位檢驗(yàn)和驗(yàn)證。在模擬精度方面,以日為時(shí)間步長(zhǎng)的DNDC模型要比以月為時(shí)間步長(zhǎng)的CENTURY模型精度高,在一些動(dòng)態(tài)分析上更具有優(yōu)勢(shì)。(2)在過去的55年中,研究區(qū)地上生物量為71.01gC/m2,地下生物量為601.96gC/m2,總生物量為672.97gC/m2。研究區(qū)地上生物量和總生物量的變化趨勢(shì)與年降水量一致,與年平均氣溫關(guān)系不明顯。降水是影響地上生物量和總生物量的重要?dú)庀笠蜃印?3)自1961年以來,研究區(qū)單位面積碳儲(chǔ)量總體呈上升趨勢(shì),1968年、1988年和2006年出現(xiàn)急劇下降,隨后持續(xù)上升�？偺純�(chǔ)量密度為73295.41kgC/hm2,其中,植被碳密度為6729.69kgC/hm2,土壤碳密度(0-50cm)為66565.73kgC//hm2,總碳儲(chǔ)量為 0.22TgC。(4)研究區(qū)55年當(dāng)中,共有17年為碳源,其余均為碳匯。1961-2015年共增加碳蓄積22108.24kgC/hm2,平均每年增匯量為401.96kgC/hm2。研究發(fā)現(xiàn),碳匯與地上生物量、降水量、總生物量、地下生物量、相對(duì)濕度為極顯著正相關(guān)(p0.01),與地上生物量和降水量的相關(guān)系統(tǒng)分別達(dá)到0.785和0.756;碳匯與潛在蒸散量和日平均氣溫為極顯著負(fù)相關(guān)(p0.01),相關(guān)系數(shù)分別為-0.637和-0.395。(5)基于CENTURY模型預(yù)測(cè)未來30-50年,研究區(qū)地上、地下生物量和單位面積土壤碳儲(chǔ)量呈略增態(tài)勢(shì)。
[Abstract]:The carbon dynamics of grassland ecosystem plays a very important role in the field of global change. It is important to evaluate accurately the carbon source / sink relationship of grassland ecosystem and its response and feedback to climate change and human disturbance. The forest-grassland ecotone is one of the most sensitive areas of the ecotone affected by human activity. This study focused on the typical forest- grassland ecotone of the Sahanula Nature Reserve, and aimed at the grassland ecosystem of the region. By using biogeochemical cycle model (CENTURY) and DNDC model, a series of parameter localization, model verification and analysis have been carried out by coupling the measured data, station observation data, remote sensing image and model simulation. The verified model will be used to further analyze the carbon dynamics of grassland ecosystems in the forest- grassland ecotone under the conditions of climate change and natural conservation. The main conclusions are as follows: (1) the CENTURY model with a large number of localized parameters is a DNDC model. Can well reflect the carbon dynamics of the study area, In terms of simulation accuracy, the DNDC model with day as time step is more accurate than CENTURY model with month as time step. In the past 55 years, the aboveground biomass was 71.01 g C / m ~ (2), the underground biomass was 601.96 g C / m ~ (2), the total biomass was 672.97 g C / m ~ (2). The variation trend of aboveground biomass and total biomass was consistent with the annual precipitation. Precipitation is an important meteorological factor affecting aboveground biomass and total biomass. Since 1961, carbon storage per unit area in the study area has been on the rise, and decreased sharply in 1968, 1988 and 1988. The total carbon storage density was 73295.41 kg C / hm 2, in which the vegetation carbon density was 6729.69 kg C / hm 2, the soil carbon density was 0-50 cm) and the total carbon storage was 66565.73 kg C / r 路hm 2, and the total carbon storage was 0.22 TgC.4) in the study area, there were 17 years of carbon sources in the study area. The rest were carbon sinks. 1961-2015. The total increase in carbon stock was 22108.24kgC / hm ~ (2), and the average annual increase was 401.96 kg C / hm ~ (2). The study found that carbon sink and aboveground biomass, precipitation, total biomass, underground biomass, The correlation system between relative humidity and aboveground biomass and precipitation was 0.785 and 0.756, respectively, and the correlation coefficient between carbon sink and potential evapotranspiration and daily mean temperature was extremely significant negative correlation, the correlation coefficient was -0.637 and -0.395.55) based on CENTURY model. For the next 30-50 years, Aboveground biomass and soil carbon storage per unit area in the study area increased slightly.
【學(xué)位授予單位】：內(nèi)蒙古農(nóng)業(yè)大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2017
【分類號(hào)】：Q948

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