若尔盖高原受到全球气候变化和不合理人类活动的双重影响,发生了不同程度的沙化,其沙化草地的生态恢复和固碳功能受到国内外的广泛关注。通过采集治理区的植物和土壤样本,对若尔盖草地沙化治理区的生态系统恢复过程进行了实地考察和实验分析,以空间结构代替时间序列,运用多种方法分析了碳含量、碳储量和碳密度的变化。结果表明:在5 a的管护期间,(1)样本碳含量、碳密度和碳储量分别在36.67 ~44.41 g · kg~(-1),8.87 ~ 57.62 kg · m~(-2)和(10.61 ~ 36.56) * 10~4 t · hm~(-2)之间,且碳密度和碳储量随着治理年限的增长呈现出逐渐增加的趋势;(2)植物生物量与碳含量具有很好的线性关系,植物生物量的累积有利于碳储量的增加。(3)随着生态恢复的进行,土壤理化性质得到不断改善,固碳能力得到恢复,通过相关分析发现,土壤有机碳与土壤有机质、质地和含水量呈显著正相关,与PH值和容重呈显著负相关;(4)对若尔盖的气象数据进行分析发现,若尔盖近年来气温总体偏高,加快了碳的分解,不利于草地的碳汇一碳源平衡调节。固碳研究为全球气候变化下的若尔盖草地沙化治理提供了基础数据,也为若尔盖草地沙化治理建设工程进一步完善和生态恢复研究提供了现实依据。
英文摘要:
Zoige plateau has been affected by the global climate change,especially the effects of some unreasonable human activities. The ecological restoration and carbon fixation function of the desertified grassland are widely concerned at home and abroad. The plant samples and soil samples were collected from treatment area,and field investigation and experiment analysis of ecosystem restoration process of the treatment area were carried out. Taking spatial structure instead of times series,a lot of method was used to analyze the change of carbon content,carbon storage and carbon density. The results show that during the 5 years of management and protection: (1) Carbon content of the samples changes between 36.67 -44.41 g · kg~(-1), carbon density changes between 8.87 -57.62 kg · m~(-2); carbon storage changes between(10.61 - 36.56) * 10~4 t · hm~(-2) and with the increase of treatment years, carbon density and carbon storage show a gradually increasing trend; (2) Plant biomass and carbon content has a good linear relationship, the accumulation of plant biomass is beneficial to increasement of carbon storage. (3) Physicochemical properties of soil are improved and carbon fixation ability is recovered with the ecological restoration. Founded on correlation analysis,soil organic carbon,soil organic matter and texture show a significant positive correlation with water content,and a negtive correlation with, pH value; (4) By the analysis of meteorological data, the temperature of Zoige area in recent years is higher than its average temperature,the status accelerates the carbon decomposition,and is unfavorable to the grassland carbon sequestration and the adjustment of carbon balance. Based on the above results,the research of carbon fixation provides basic data for the treatment of grassland desertification under the background of global climate change, and will also provide a realistic basis for the further improvement of Zoige desertified grassland management and the study of ecological restoration.