多因子变化对中国主要作物产量和温室气体排放的影响研究

发布时间：2018-01-04 01:02

本文关键词：多因子变化对中国主要作物产量和温室气体排放的影响研究　出处：《中国农业大学》2017年博士论文　论文类型：学位论文

【摘要】：全球气候和人类活动引起的环境变化已成为农业生态系统可持续发展面临的重大挑战。而农业生态系统不仅是气候变化的承受者,也是导致N_2O和CH_4增加的重要排放源。如何在确保粮食安全的同时,减少温室气体排放,是当前我国应对全球变化的当务之急。认识气候变化和人类活动造成的多因子环境变化对中国主要农作物产量和温室气体排放的影响,对制定"气候智慧型农业"策略,促进国家粮食安全和可持续发展具有极其重要的理论与现实意义。而多因子协同作用、大区域尺度人类活动和管理措施的数据库建立和参数化以及陆地生态系统模型与基于过程的农业机理模型的有机结合,是当前农业生态系统增产和减排的研究热点与难点。本文基于历史实验和观测数据,对陆地生态系统动态模型的农业模块(DLEM-Ag)进行改进升级,得到基于作物生长过程的DLEM-AG2.0模型,并应用该模型模拟分析多因子环境变化(气候、大气C0_2、对流层0_3、氮沉降、氮肥施用量以及土地覆盖和利用)对1980-2012年中国主要农作物(小麦、玉米和水稻)产量以及温室气体(N0_2、CH_4)排放的影响,为制定未来适宜的农业生产和管理措施提供理论依据。主要结果如下:(1)改进的DLEM-AG2.0模型可以模拟中国不同气候条件和管理措施下小麦、玉米和水稻的叶面积增长、干物质积累、产量形成以及温室气体(N_20和CH_4)排放的动态过程,模拟误差均小于20%。DLEM-AG2.0能够用来模拟中国多种环境因子变化对作物产量和温室气体排放的影响。(2)1980～2012年间,中国平均温度、大气C0_2浓度、0_3浓度、大气氮沉降和氮肥施用量增长趋势都非常显著;降水年际间变化较大;玉米种植面积显著增加,增加速率为0.05×108hayr-1;小麦和水稻面积均以0.02×108hayr-1的趋势下降。(3)在多种环境因子变化的情况下,1980～2012年间中国小麦、玉米和水稻的产量均有所增加,但相对于80年代,增产趋势在2000年代下降了 52.6～99.5%。1980～2012年间中国小麦、玉米和水稻田的N_2O、CH_4排放分别增加了 27.2～54.3%和20.1～34.7%,但在2000年代下降趋势显著。中国小麦、玉米和水稻的产量、N_20以及CH_4排放都存在显著的时空差异。1980～2012年间,气候变化和0_3浓度增加使三种作物产量分别降低了产量变化的39.8%～64.9%和4.5%～13.8%,该负面影响逐渐增大。氮肥施用量增加对作物产量升高的贡献CO_2浓度急速增加土地利用和覆盖变化大气氮沉降,氮肥施用量增加和土地利用变化的贡献作用在2000年代有所降低,C0_2浓度增加和大气氮沉降的贡献不断增强。(4)1980～2012年间,气候变化使中国小麦、玉米和水稻田N_20排放量降低了排放变量的13.7%～29.7%,且负效应增加趋势显著(p＜0.01)。氮肥施用量增加对中国作物田N_20排放量增加的贡献土地利用和覆盖变化CO_2浓度变化大气氮沉降0_3浓度变化。而土地利用和覆盖变化对水稻田CH_4排放量升高的贡献CO_2浓度增加气候变化＞氮肥施用量增加＞大气氮沉降。大气0_3浓度抑制水稻CH_4排放量增加。
[Abstract]:The environmental changes caused by global climate and human activities has become a major challenge for the sustainable development of the agricultural ecosystem. And agricultural ecosystem is not only climate change bear, which is also the important source of N_2O and CH_4 increase. How to ensure food security and reduce greenhouse gas emissions, is currently China's response to global change the effects of multiple factors. A pressing matter of the moment to understand climate change and environmental changes caused by human activities on the China main crop yield and greenhouse gas emissions, to develop "climate smart agriculture" strategy, has extremely important theoretical and practical significance to promote the national food security and sustainable development. The multi factor synergy, large scale database human activities and management measures and the establishment of parametric and terrestrial ecosystem model and based on the process mechanism model of the agricultural machine. That is the research hotspot and difficulty of the agricultural ecosystem production and emission reduction. The history of experimental and observational data based on agricultural module of terrestrial ecosystem dynamic model (DLEM-Ag) to upgrade, the DLEM-AG2.0 model of crop growth process based on multi factor analysis and environmental change by using this model (climate, atmosphere C0_2, the 0_3, nitrogen deposition, nitrogen fertilizer and land cover and use of 1980-2012 Chinese) main crops (wheat, maize and rice yield) and greenhouse gases (N0_2, CH_4) the effect of discharge, provide a theoretical basis for the future development of appropriate agricultural production and management measures. The main results are as follows: (1) the improved DLEM-AG2.0 model can simulate the wheat China different climate conditions and management measures, the leaf area of maize and rice growth, dry matter accumulation and yield formation of greenhouse gases (N_20 CH_4) and the dynamic process of emissions, simulation error is less than 20%.DLEM-AG2.0 can be used to simulate the Chinese various environmental factors on crop yield and greenhouse gas emissions. (2) from 1980 to 2012 years, China average temperature, atmospheric C0_2 concentration, 0_3 concentration, atmospheric nitrogen deposition and nitrogen growth trend is very significant; annual variation of precipitation; corn acreage increased significantly, the increase rate of 0.05 * 108hayr-1; wheat and rice area decreased to 0.02 * 108hayr-1 (3). The trend of changes in various environmental factors under the condition of 1980 ~ 2012 years China wheat, maize and rice yield were increased, but compared to 80s. The trend of yield decreased by 52.6 ~ 99.5%.1980 ~ 2012 Chinese wheat in 2000s, maize and paddy field N_2O, CH_4 emissions were increased by 27.2 ~ 54.3% and 20.1 ~ 34.7%, but decreased in 2000s A significant trend. Chinese wheat, maize and rice yield, N_20 and CH_4 emissions are remarkable temporal and spatial difference of.1980 ~ 2012 years, climate change and the increase in 0_3 concentration in three kinds of crop yield were decreased by 39.8% ~ 64.9% and the yield change from 4.5% to 13.8%, the negative effect gradually increases. The increase of nitrogen on crop the yield increased the contribution of CO_2 concentration increased rapidly in land use and land cover changes in atmospheric nitrogen deposition, the increase of nitrogen and land use change contribution decreased in 2000s, the increase of C0_2 concentration and the contribution of atmospheric nitrogen deposition increased. (4) from 1980 to 2012 years, climate change makes China wheat, corn and rice fields N_20 emissions reducing emissions from 13.7% to 29.7% variables, and the negative effect of increased significantly (P < 0.01). The amount of nitrogen fertilizer increased with increase of crop field land China N_20 emissions With the change of CO_2 concentration and cover change of atmospheric nitrogen deposition 0_3 concentration. The land use and cover change on paddy field increased CH_4 emissions with the increase of CO_2 concentration, the amount of nitrogen fertilizer increased climate change, atmospheric nitrogen deposition of atmospheric 0_3 concentration. The inhibition of rice CH_4 emissions increased.

【学位授予单位】：中国农业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：S181

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