基于Biome-BGC模型的千烟洲森林水分利用效率研究

温永斌; 韩海荣; 程小琴; 李祖政

doi:10.13332/j.1000-1522.20190001

摘要:

目的为了探究全球气候变化背景下森林生态系统水分利用效率的影响因子及其对气候变化的响应。

方法本文利用经PEST模型参数优化后的Biome-BGC模型，对千烟洲森林生态系统2000—2014（CK）年以及不同气候情景变化模式下的水分利用效率及其影响因子进行了探究。

结果（1）千烟洲的年均温和最大叶面积指数同水分利用效率呈显著正相关关系（P < 0.01），降水同水分利用效率间的相关性不显著（P > 0.05）。（2）千烟洲不同情景模式水分利用效率的取值区间是2.09 ~ 3.71 g/kg、均值2.90 g/kg。（3）同CK（2.18 ~ 2.57 g/kg、均值2.38 g/kg）相比，千烟洲各情景模式下大气CO₂浓度增加情景（2.38 ~ 3.41 g/kg、均值2.90 g/kg）、降水和大气CO₂浓度同时增加情景（2.38 ~ 3.33 g/kg、均值2.86 g/kg）、气温和大气CO₂浓度同时增加情景（2.58 ~ 3.71 g/kg、均值3.15 g/kg）、降水和气温同时增加（2.30 ~ 2.84 g/kg、均值2.57 g/kg）及降水、气温和大气CO₂浓度同时增加情景（2.70 ~ 3.60 g/kg、均值3.15 g/kg）的水分利用效率差异显著。但是，降水增加情景（2.09 ~ 2.68 g/kg、均值2.39 g/kg）和气温增加情景（2.13 ~ 2.81 g/kg、均值2.47 g/kg）对水分利用效率的影响不显著。（4）降水和大气CO₂浓度同时增加情景与大气CO₂浓度增加情景的水分利用效率差异不显著，气温和大气CO₂浓度同时增加情景与大气CO₂浓度增加情景的水分利用效率差异显著。

结论（1）千烟洲森林生态系统的水分利用效率受到气温和叶面积指数的影响，情景分析表明水分利用效率能很好的对气候变化做出响应。（2）降水、气温和大气CO₂浓度对水分利用效率的影响存在耦合效应。（3）增温对水分利用效率的影响要大于降水。

Abstract:

ObjectiveThe objectives of this study are to explore the impact factors of forest ecosystem water use efficiency and its response to climate change in the context of global climate change.

MethodWe used the Biome-BGC model optimized by PEST model parameters to explore the water use efficiency and its influencing factors of the Qianyanzhou forest ecosystem in different climate scenarios, Jiangxi Province of eastern China.

Result(1) The annual average temperature and maximum leaf area index of Qianyanzhou were significantly positively correlated with water use efficiency (P < 0.01). The correlation between precipitation and water use efficiency was not significant (P > 0.05). (2) The water use efficiency of different scenarios in Qianyanzhou was in the range of 2.09−3.71 g/kg and the mean was 2.90 g/kg. (3) Compared with CK (2.18−2.57 g/kg, mean 2.38 g/kg), double the concentration of atmospheric carbon dioxide scenario (C scenario, 2.38−3.41 g/kg, mean 2.90 g/kg), annual precipitation increased by 15% and double the concentration of atmospheric carbon dioxide scenario (PC scenario, 2.38−3.33 g/kg, mean 2.86 g/kg), temperature increased by 4 ℃ and double the concentration of atmospheric carbon dioxide scenario (TC scenario, 2.58−3.71 g/kg, mean 3.15 g/kg), annual precipitation increased by 15% and temperature increased by 4 ℃ scenario (PT scenario, 2.30−2.84 g/kg, mean 2.57 g/kg) and annual precipitation increased by 15%, temperature increased by 4 ℃ and double the concentration of atmospheric carbon dioxide scenario (PTC scenario, 2.70−3.60 g/kg, mean 3.15 g/kg) were significantly different. However, the annual precipitation increased by 15% scenario (P scenarion, 2.09−2.68 g/kg, mean 2.39 g/kg) and the temperature rised by 4 ℃ scenario (T scenario, 2.13−2.81 g/kg, mean 2.47 g/kg) had no significant effect on water use efficiency. (4) The water use efficiency between the PC scenario and the C scenario was not significant, and the TC scenario was significantly different from the water use efficiency of the C scenario.

Conclusion(1) The water use efficiency of Qianyanzhou forest ecosystem was affected by temperature and leaf area index. Scenario simulations showed that water use efficiency of Qianyanzhou can respond well to climate change. (2) There existed coupling effects of precipitation, temperature and atmospheric carbon dioxide concentration on water use efficiency. (3) The effect of warming on water use efficiency was greater than precipitation.

基于Biome-BGC模型的千烟洲森林水分利用效率研究

Forest water use efficiency in Qianyanzhou based on Biome-BGC model, Jiangxi Province of eastern China