本文關(guān)鍵詞： 楊樹人工林 能量分配 表層阻力 Biome-BGC模型 氣候變化 碳水通量　出處：《北京林業(yè)大學(xué)》2016年博士論文　論文類型：學(xué)位論文

【摘要】：在中國(guó)北方地區(qū),楊樹因具有生長(zhǎng)迅速、生產(chǎn)力和生物量高等特點(diǎn)而在碳匯林業(yè)中發(fā)揮著重要的作用,但該高耗水性樹種在固碳的同時(shí)也會(huì)消耗掉大量的水分；在當(dāng)前氣候變化和該地區(qū)水資源短缺的現(xiàn)狀下,進(jìn)一步探究該地區(qū)大面積楊樹人工林的耗水特性和其對(duì)周邊生態(tài)系統(tǒng)可利用水分的潛在影響,評(píng)價(jià)其對(duì)半干旱環(huán)境的適應(yīng)性以及預(yù)測(cè)其碳水通量對(duì)未來(lái)氣候變化的響應(yīng),對(duì)于合理應(yīng)對(duì)氣候變化、制定長(zhǎng)期林業(yè)規(guī)劃和實(shí)行科學(xué)經(jīng)營(yíng)有著十分重要的意義。本研究基于渦度相關(guān)(eddy covariance, EC)系統(tǒng)和微氣象系統(tǒng)對(duì)北京市大興區(qū)楊樹(Populous euramericana cv. "74/76")人工林生態(tài)系統(tǒng)與大氣間碳、水和能量通量長(zhǎng)期連續(xù)地監(jiān)測(cè),研究了該生態(tài)系統(tǒng)在不同氣候條件下能量分配與蒸散發(fā)(ET)的動(dòng)態(tài)變化以及生物物理控制機(jī)制,利用碳水通量觀測(cè)數(shù)據(jù)對(duì)Biome-BGC模型進(jìn)行了參數(shù)敏感性分析、參數(shù)優(yōu)化和模擬結(jié)果的驗(yàn)證和評(píng)價(jià),以及探討了Biome-BGC模型在楊樹人工林碳水通量研究中的適用性。主要研究成果如下：(1)在年際尺度上,楊樹人工林的能量分配與蒸散發(fā)(ET)響應(yīng)于氣候干旱,存在著顯著的濕潤(rùn)與干旱年份間的差異,其中LE/(Rn-G)從濕潤(rùn)年份的0.62下降到干旱年份的0.53,波文比(β)則從0.83上升至1.57；對(duì)應(yīng)地,干早年份中的日平均ET(2.23±1.30 mm/day)低于濕潤(rùn)年份約17%；在季節(jié)尺度上,能量分配和ET的動(dòng)態(tài)變化響應(yīng)于季節(jié)性干旱脅迫,水分供應(yīng)(降水與灌溉之和)則是其主要的影響因素。(2) 表層阻力(Rs)響應(yīng)于氣候干旱,其中干旱年份的Rs:LAI高于濕潤(rùn)年份(71.2sm-1LAI-1)約50%,氣候阻力(R,)和空氣動(dòng)力學(xué)阻力(Ra)并未表現(xiàn)出干濕年份間的差異,均值分別為74.6 s m-1和23.2 s m-1；在季節(jié)尺度上,季節(jié)性干旱脅迫則顯著地影響著Rs和尺i的變化,總體上表現(xiàn)為干旱脅迫時(shí)段的Rs和尺,要高于非脅迫時(shí)段。(3) 冠層分離指數(shù)(Ω)及偏相關(guān)分析結(jié)果表明,Rs是控制楊樹人工林能量分配和ET的主導(dǎo)因素,即使在濕潤(rùn)年份也是如此；β與ET分別與Rs呈正相關(guān)(二階相關(guān)系數(shù)SOCC:0.905～0.965)和負(fù)相關(guān)(SOCC:-0.518～-0.293)關(guān)系,且Rs在干旱年份中對(duì)β和ET的控制作用要顯著強(qiáng)于濕潤(rùn)年份,其中Rs對(duì)ET的控制作用會(huì)隨著土壤水分狀況的改善而增強(qiáng)；β與尺,呈負(fù)相關(guān)關(guān)系(-0.667～-0.614),也表現(xiàn)出類似于其與Rs的干濕年份間差異,Ra只在濕潤(rùn)年份中與β有負(fù)相關(guān)關(guān)系；而Ri和Ra對(duì)ET的影響遠(yuǎn)小于Rs,且在干濕年份中不同的土壤水分條件下有所不同。(4) 楊樹人工林在干旱和濕潤(rùn)年份中的作物干旱系數(shù)(LE/LEeq)分別為0.68和0.81,表明無(wú)論在干旱還是濕潤(rùn)年份,該生態(tài)系統(tǒng)均受限于有限的水資源；由于其ET消耗了所有的自然降水(在干旱和濕潤(rùn)年份中均如此),同時(shí)在干旱年份中還需要灌溉,導(dǎo)致該地區(qū)地下水無(wú)法得到補(bǔ)給；因此,從長(zhǎng)遠(yuǎn)來(lái)看,該地區(qū)大面積栽植的楊樹人工林,會(huì)因其高耗水性而潛在威脅到其周邊生態(tài)系統(tǒng)和生境的用水。(5) Biome-BGC模型中影響楊樹人工林生態(tài)系統(tǒng)碳水通量的主要生理生態(tài)參數(shù)有SLA. k, LWT、LWC:TWC、FLNR、CGPSC:LC、gsmax、wint和LFG；優(yōu)化后模型對(duì)各碳水通量模擬的準(zhǔn)確性方面表現(xiàn)為ET NEE GPP ER,在模擬值與實(shí)測(cè)值的吻合程度上NEE GPP ET ER;而相較于未優(yōu)化的模型,參數(shù)優(yōu)化對(duì)碳水通量模擬準(zhǔn)確性的提升程度上表現(xiàn)為ERGPPETNEE,而對(duì)模擬值與實(shí)測(cè)值的吻合能力的提升程度上則表現(xiàn)為ETERGPPNEE。(6) 在未來(lái)氣候變化條件下,氣溫升高(+2、+4、+6℃C)使楊樹人工林的MR和Tr增強(qiáng),而使GPP、GR、HR、NPP和Es減弱；除了Tr,GPP、MR、 GR、HR、NPP和Es均隨大氣CO2濃度的升高(升至650 ppm、860 ppm)而提高；降水的增加則提高了所有的碳水通量。單獨(dú)大氣CO2濃度上升對(duì)楊樹人工林碳水通量的影響作用要強(qiáng)于單獨(dú)氣溫上升和降水增加各自的作用,碳水通量對(duì)不同氣候變化情景的響應(yīng)則是基于三種作用的疊加；其中在三種因素均上升的未來(lái)氣候變化情景中,楊樹人工林的碳水通量較當(dāng)前氣候下的均有不同程度的提高。
[Abstract]:In the Chinese northern region, because of the rapid growth of poplar, the characteristics of higher productivity and biomass in carbon forestry plays an important role, but the high water consumption of tree species in carbon sequestration will also consume large amounts of water; in the current climate change and water resources in this area is short of water. The characteristics and on the surrounding ecological system can utilize the potential effects of water consumption to further explore the area of poplar plantation, evaluate the semi-arid environment adaptability and the prediction of the carbon and water fluxes in response to climate change, to reasonably adapt to climate change, to develop long-term forestry planning and implementation of scientific management is very important the significance of this study. Based on the eddy covariance (eddy covariance EC) system and micro meteorological system in Beijing city of Daxing District poplar (Populous euramericana cv. 74/76) plantation ecosystem and Gas carbon, water and energy fluxes in long-term continuous monitoring of the ecological system with energy distribution and steaming in different climate conditions (ET) and the dynamic changes of biophysical control mechanism of Biome-BGC model parameter sensitivity analysis was conducted using water and carbon flux data, verification and evaluation of parameter optimization and simulation results well, the applicability of Biome-BGC model in water flux of Poplar Plantation in Lin Tan. The main research results are as follows: (1) at the annual scale, energy distribution and evaporation of Poplar Plantation distribution (ET) in response to drought, there are differences between the humid and arid year significantly, the LE/ (Rn-G) decreased from 0.62 to 0.53 years of drought wet years, Povenby (beta) has increased from 0.83 to 1.57; the dry year, the average daily ET (2.23 + 1.30 mm/day) less than about 17% in wet years; season On the scale, seasonal drought stress response dynamic change of energy distribution and ET (precipitation and irrigation, water supply and) is the main influence factors. (2) surface resistance (Rs) in response to drought, the drought year Rs:LAI was higher than that of wet years (71.2sm-1LAI-1) (about 50% climate resistance R) and aerodynamic resistance (Ra) did not show the difference between wet and dry years, the average was 74.6 s M-1 and 23.2 s M-1; in the season scale, seasonal drought stress significantly affects the change of Rs and I scale, the overall performance of the drought stress time and Rs to feet. Higher than that of the non stress period. (3) canopy separation index (q) and partial correlation analysis showed that Rs is a dominant factor to control the energy distribution of Poplar Plantation and ET, even in wet years; beta and ET were positively correlated with Rs (correlation coefficient of two order SOCC:0.905 ~ 0.965) and Negative correlation (SOCC:-0.518 ~ -0.293), and Rs in dry year in control effect on beta and ET is significantly stronger than the wet year, the control effect of Rs on ET will be enhanced with the improvement of soil moisture; beta and feet, negative correlation (-0.667 ~ -0.614), also showed differences dry and wet year is similar to the Rs, Ra only in wet years and beta has negative correlation; and the effects of Ri and Ra on ET far less than Rs, and different soil moisture conditions in dry and wet years under different. (4) crop drought coefficient of Poplar Plantation in arid and humid year the (LE/LEeq) were 0.68 and 0.81, showed that both in dry or wet years, the ecological systems are subject to limited water resources; because the ET consumed all the natural precipitation (both in arid and humid year), while in drought years also need irrigation, resulting in The groundwater can not get supplies; therefore, in the long run, poplar plantation area planted in the area, because of its high water consumption and the potential threat to the surrounding ecosystem and habitat water. (5) the Biome-BGC model in the influence of carbon and water fluxes of main physiological and ecological parameters of Poplar Plantation Ecosystem SLA. K, LWT, LWC:TWC, FLNR, CGPSC:LC, gsmax, wint and LFG; the accuracy of the simulation model of carbon and water fluxes after optimizing the performance for the ET NEE GPP in ER, the simulation results fit the degree of NEE GPP ET ER with the measured values; and compared to the non optimized model, parameter optimization to improve the degree of simulation the accuracy of carbon and water fluxes on the performance of ERGPPETNEE, and the simulation value is consistent performance for the ETERGPPNEE. to improve the degree of the ability and the measured value (6) in the future climate change conditions, temperatures (+2, +4, +6 C C) made of poplar plantation MR And the GPP, enhanced Tr, GR, HR, NPP and Es decreased; in addition to Tr, GPP, MR, GR, HR, NPP and Es decreased with the increasing atmospheric CO2 concentrations (up to 650 ppm, 860 ppm) increased; the increase of precipitation increased carbon and water fluxes all alone. Atmospheric CO2 concentration rose a stronger effect on Yang Shuren forest carbon and water fluxes increase their effect on individual temperature rise and precipitation, carbon and water fluxes response to different climate change scenarios is the superposition of three effects which are based on; a rise in three factors of future climate change scenarios, improve the carbon and water fluxes of Poplar Plantation than under the current climate in varying degrees.

【學(xué)位授予單位】：北京林業(yè)大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2016
【分類號(hào)】：S792.11
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本文編號(hào)：1542214