气候变化对三江平原沼泽湿地NPP的影响研究

发布时间：2018-07-05 10:08

本文选题：气候变化 + BIOME-BGC　；参考：《中国科学院研究生院(东北地理与农业生态研究所)》2016年博士论文

【摘要】：湿地生态系统是地球上的主要碳库,其对全球气候变化影响巨大;同时,湿地生态系统又是对气候变化异常敏感的生态系统。本文选择我国气候变化最为剧烈的东北三江平原沼泽湿地为研究对象,分析过去50年和未来40年该区域气候变化情况,并模拟沼泽湿地植被净初级生产力(NPP)对气候变化的响应情况,评估气候变化对沼泽湿地NPP的主要影响,通过对过去50年的NPP变化,预估未来40年气候变化对三江平原沼泽湿地系统的可能影响及风险。具体研究结论如下:1、1961~2010年三江平原地区气候变化总体趋势表现为气温持续升高,降水量略有增加,蒸发量微弱增加,呈现出暖化的气候变化趋势。水热指标中温暖指数和寒冷指数均呈增加趋势,而湿度指数和干燥指数未见明显变化,但波动十分剧烈,连续干旱日数呈现下降趋势,而夏天日数增加。最高和最低年平均气温出现年份和东北区域的情况相同,但三江平原地区的增温幅度高于东北平均值。未来40年(2011~2050)气候将持续暖化趋势。RCP2.6,RCP4.5,RCP6.0和RCP8.5情景下气温均值分别为3.84,3.89,3.72和4.12℃,均高于过去50年的平均气温(3.21℃),增温速率分别为0.35,0.47,0.32和0.63℃/10a,RCP6.0情景下增温速率最慢,RCP4.5和RCP8.5情景气温增幅最大,气温波动也最为剧烈。4种气候情景下降水量、蒸发量均呈略微增加趋势,温暖指数、寒冷指数持续上升,夏天日数更长,生长季长度也更长,湿度指数均值虽略高于基准期,但却呈现出下降趋势,连续干旱日数低于过去50年。三江平原地区气候基本上延续了过去的气候变化趋势,4种气候情景下,以RCP8.5情景下气候变化最为剧烈,而RCP2.6情景下气候变化最为平缓。2、通过模型参数本地化和优化调整,BIOME-BGC模型对小叶章湿地和苔草湿地NPP的模拟值与实测值决定系数(R2)分别达到0.87和0.72,说明BIOME-BGC模型适用于三江平原沼泽湿地NPP的模拟。1961~2010年三江平原沼泽湿地npp年平均值为326.8gcm-2a-1,波动幅度在281.2~365.6gcm-2a-1之间,总体上呈微弱的增加趋势,说明过去50年气候变化趋势促进了沼泽湿地npp的增加;在区域分布上,随着时间的变化npp区域差异变大,npp偏高的区域呈现出增加趋势,而npp偏低的区域则表现为下降趋势,而这意味着气候变化会对湿地npp较低的地区产生较大威胁;4种沼泽湿地植被类型npp差异明显,其中以芦苇湿地npp最高(395.0gcm-2a-1),其次为小叶章-芦苇湿地(352.2gcm-2a-1)和小叶章苔草湿地(304.1gcm-2a-1),苔草湿地npp最低(255.9gcm-2a-1),但波动却最为剧烈,其npp波动范围在194.1~297.7gcm-2a-1之间,说明气候变化对苔草湿地npp的影响最大。未来气候情景下,2011~2050年三江平原沼泽湿地npp模拟均值为329.4gcm-2a-1,与基准期(1981~2010)沼泽湿地npp均值(330.4gcm-2a-1)基本相同,但npp的年际波动加剧。在rcp8.5情景下,沼泽湿地npp变化最为剧烈,波动范围在283.7~379.4gcm-2a-1之间,标准差达25.6;rcp2.6情景次之,npp波动范围在293.4~378.2gcm-2a-1之间,标准差为20.8;在rcp4.5和rcp6.0情景下,沼泽湿地npp较为稳定,波动幅度和基准期较为接近。未来气候情景下,三江平原沼泽湿地npp空间分布格局与过去50年基本一致,表现为东部、中部和西部地区npp偏低,而中部区域东西两侧的npp值相对较高。大部分地区npp呈增加趋势,rcp2.6和rcp6.0情景下,全区npp变化较小,主要表现为北部地区npp增加;而rcp4.5和rcp8.5情景下,则是全区大部分地区npp都有增加趋势。四种类型沼泽湿地中,以苔草湿地波动最为剧烈,其在rcp8.5情景下波动范围201.8~330.2gcm-2a-1,标准差高达32.8,超过所有其他情景及沼泽湿地类型;其次为芦苇湿地,标准差29.7;而小叶章-苔草湿地和小叶章-芦苇湿地的npp则相对较为稳定。与过去50年相比,苔草湿地和芦苇湿地npp呈增加趋势。3、未来气候情景下三江平原沼泽湿地npp均值较基准期变化不大,但年际间波动剧烈,部分年份风险等级较高。rcp2.6情景下沼泽湿地npp风险最低,rcp8.5情景下沼泽湿地npp风险最高,未来40年有9年面临较高风险,高风险年份主要出现在2040年以后;在区域分布上,高风险主要发生在三江平原中部偏北的外七星河两侧和兴凯湖东部地区。RCP8.5情景下存在风险的区域最大,其次为RCP4.5,而RCP2.6情景下仅兴凯湖东部区域存在风险;各气候情景下,以小叶章-苔草湿地和小叶章-芦苇湿地风险较高,芦苇湿地和苔草湿地风险相对较低。4、多项分析均表明未来沼泽湿地NPP变化主要受到水分因素变化的影响,而温度相关的气候因素则对沼泽湿地变化影响微弱。逐步回归分析表明影响沼泽湿地NPP变化的气候因素以蒸发量和干燥度指数最为显著,二者合计对NPP影响的贡献率(R2)可达0.62,此外,降水量和湿度指数也对NPP有较大影响,而温度相关的气候因素并不是影响沼泽湿地NPP的主要因素。随着国家湿地保护条例的颁布实施,以及三江平原湿地保护红线的严格执行,未来气候将会是影响三江平原沼泽湿地系统变化的主导因素。
[Abstract]:The wetland ecosystem is the main carbon pool on the earth, which has great influence on the global climate change. At the same time, the wetland ecosystem is also an ecological system sensitive to climate change. This paper chooses the most intense northeast Sanjiang plain swamps in China as the research object, and analyzes the climate change in the past 50 years and the next 40 years. The response of the net primary productivity of marsh vegetation (NPP) to climate change was simulated and the main effects of climate change on the swamp wetland NPP were evaluated. The possible effects and risks of climate change on the marsh wetland system in Sanjiang plain in the next 40 years were estimated by the NPP changes of the past 50 years. The conclusions are as follows: 11961~2010 The general trend of climate change in Sanjiang plain area is that the temperature continues to rise, the precipitation is slightly increased, the evaporation is slightly increased, and the climate change trend is warm. The warm index and the cold index in the water and heat index are all increasing, but the humidity index and the drying index are not obviously changed, but the fluctuation is very intense and continuous drought. The number of days showed a downward trend, while the number of summer days increased. The highest and lowest annual average temperatures were the same as those in the northeast region, but the increase in temperature in the Sanjiang plain was higher than that in the northeast. The climate will continue to be.RCP2.6 in the next 40 years (2011~2050), and the mean temperature under the scenarios of RCP4.5, RCP6.0 and RCP8.5 is 3.84,3.89,3., respectively. 72 and 4.12 C were higher than the average temperature of the past 50 years (3.21 degrees C). The temperature increasing rate was 0.35,0.47,0.32 and 0.63 /10a respectively. The temperature increasing rate was the slowest under the RCP6.0 situation. The temperature increase of RCP4.5 and RCP8.5 was the largest, the temperature fluctuation was also the most severe.4 climate scenario, and the evaporation amount showed a slight increase trend, the warm index, the cold index. Continuous rise, the number of days longer in summer, growing Ji Changdu longer, the average humidity index is slightly higher than the baseline period, but presents a downward trend, the number of consecutive dry days is lower than the past 50 years. The climate of Sanjiang plain has basically continued the trend of the past climate change, under the 4 climate scenarios, under the RCP8.5 scenario, the climate change is the most intense, and RC Under the P2.6 scenario, the climate change is the most gentle.2. Through the localization and optimization of the model parameters, the BIOME-BGC model has reached 0.87 and 0.72, respectively, of the simulated values and the measured values (R2) of the NPP in small leaf and Carex wetland, indicating that the BIOME-BGC model is suitable for the simulated.1961~2010 year of the marsh wet of Sanjiang plain in Sanjiang plain. The average value of the NPP year is 326.8gcm-2a-1, and the fluctuation range is between 281.2~365.6gcm-2a-1, and the trend of the climate change in the past 50 years has promoted the increase of NPP in the marsh wetland. In the regional distribution, the regional difference in the NPP region becomes larger with the change of time, and the region of the higher NPP is increasing, while the region of the NPP is low. The region showed a downward trend, which meant that climate change would have a greater threat to the lower NPP areas of the wetland, and the vegetation types of the 4 marshes were significantly different, including the highest (395.0gcm-2a-1) in reed wetland NPP, followed by the leaflet reed wetland (352.2gcm-2a-1) and the lolia lolia wetland (304.1gcm-2a-1), and the most NPP in the moss wetland NPP. Low (255.9gcm-2a-1), but the volatility is the most intense, its NPP fluctuation range between 194.1~297.7gcm-2a-1, indicating that climate change has the greatest impact on the NPP of the moss wetland. Under the future climate scenario, the mean of NPP simulation of the Sanjiang plain marsh wetland is 329.4gcm-2a-1, and the NPP mean (330.4gcm-2a-1) of the base period (1981~2010) marsh wetland is basic. The same, but the interannual fluctuation of NPP intensifies. In the rcp8.5 scenario, the swamp wetland NPP changes most violently, the fluctuation range is between 283.7~379.4gcm-2a-1, the standard difference is 25.6; the rcp2.6 scenario is second, the NPP fluctuation range is between 293.4~378.2gcm-2a-1, the standard deviation is 20.8; in the rcp4.5 and rcp6.0 scenarios, the swamp wetland NPP is more stable, undulation amplitude and The datum period is relatively close. Under the future climate scenario, the spatial distribution pattern of NPP in the Sanjiang plain marsh is basically consistent with the past 50 years, showing the low NPP in the East, the middle and western regions, while the NPP value of the eastern and western regions is relatively high. Most of the region NPP shows an increasing trend, and the NPP changes in the whole region under the rcp2.6 and rcp6.0 scenarios are smaller. The NPP increased in the northern region, while in the rcp4.5 and rcp8.5 scenarios, the NPP in most areas of the whole region increased. In the four types of swamps, the fluctuation of the moss wetland was the most intense, and its fluctuation range under the rcp8.5 scenario was 201.8~330.2gcm-2a-1, the standard deviation was up to 32.8, more than all the other scenarios and marshland types; secondly, The standard deviation of the reed wetland is 29.7, while the NPP of the small leaf seal and the small leaf and reed wetland is relatively stable. Compared with the past 50 years, the NPP of the moss and reed wetland is increasing.3, and the NPP mean of the marsh wetland in Sanjiang plain is less than the reference period under the future climate situation, but the interannual fluctuation and part of the year risk are more severe. Under the situation of higher.Rcp2.6, the NPP risk of marsh wetland is the lowest, and the NPP risk of marsh wetland is the highest under rcp8.5 scenario. The risk of high risk is higher in the next 40 years. The high risk year is mainly after 2040, and the high risk occurs mainly in the outer Qixinghe River and the eastern region of Xingkai Lake in the north of Sanjiang plain. The risk area is the largest, followed by RCP4.5, and the risk is only in the eastern region of the Xingkai Lake under the RCP2.6 scenario. Under the climate scenario, the risk of the small leaf chapter moss wetland and the lobule reed wetland is higher, the risk of reed wetland and the Carex wetland is relatively low.4. Many analysis all show that the changes of NPP in the future marsh are mainly water. The influence of the variation of the factors on the change of the climate is weak. The stepwise regression analysis shows that the climatic factors that affect the NPP change of the marsh wetland are the most significant with the evaporation and the dryness index, and the contribution rate of the two to the NPP (R2) can be up to 0.62. In addition, the precipitation and humidity index also have a better effect on the NPP. The temperature related climatic factors are not the main factors affecting the marsh wetland NPP. With the promulgation and implementation of the national wetland protection regulations and the strict implementation of the Sanjiang plain wetland protection red line, the future climate will be the leading factor affecting the change of the marsh wetland system in Sanjiang plain.
【学位授予单位】：中国科学院研究生院(东北地理与农业生态研究所)
【学位级别】：博士
【学位授予年份】：2016
【分类号】：P467;X171.1

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