河南典型暖(热)性草地固碳特征及区域差异

通过野外调查取样与室内分析,研究了河南两种气候区内分布的典型草地(豫西北的暖性草丛和暖性灌草丛,豫南的暖性草丛、暖性灌草丛、热性草丛和热性灌草丛)植被与土壤碳密度特征及碳分布差异.结果表明: 豫西北与豫南地区草地植被地上平均生物量分别为327.4和221.4 g·m^-2,呈北高南低趋势,差异显著;而根系平均生物量分别为1.58×10³和1.94×10³ g·m^-2,呈南高北低趋势,且差异显著.豫西北和豫南地区地上平均碳密度分别为113.75和77.35 g C·m^-2.豫西北地区暖性草丛植被地上碳密度大于暖性灌草丛,但差异不显著;而豫南地区热性草丛活体碳密度显著低于其他3种类型草地.豫西北与豫南地区地下平均碳密度分别为6.35×10³和5.14×10³ g C·m^-2.豫西北地区2种类型草地根系碳密度和土壤碳密度差异均不显著;豫南地区热性灌草丛根系碳密度显著低于其他3种类型草地,而热性草丛土壤碳密度显著大于其他3种类型草地.豫西北和豫南地区草地生态系统平均碳密度分别为6.46×10³和5.22×10³ g C·m^-2,呈北高南低趋势,且土壤贡献最大(78%～90%).豫西北地区2种类型草地生态系统碳密度差异不显著;豫南地区热性草丛生态系统碳密度最高为9.70×10³ g C·m^-2,显著大于其他3种类型草地.本研究结果为准确计算河南不同类型草地生态系统碳储量及评估其固碳潜力提供基础数据.

Carbon sequestration characteristics and regional differences of typical warm and tropical grasslands in Henan Province,China.

In this study, we examined the vegetation and soil carbon density characteristics and carbon distribution differences of four typical grasslands in two climatic zones, including warm-tempe-rate tussock (WT), warm-temperate shrub tussock (WS), tropical tussock (TT), and tropical shrub tussock (TS) in Henan Province. The results showed that the average aboveground biomass of grasslands was significantly higher in Northwest Henan (327.4 g·m^-2) than that in South Henan (221.4 g·m^-2), whereas the average root biomass in Northwest Henan (1.58×10³ g·m^-2) was significantly lower than that in South Henan (1.94×10³ g·m^-2). The average aboveground carbon density of grasslands in Northwest and South Henan was 113.75 and 77.35 g C·m^-2, respectively. The aboveground carbon density of WT in Northwest Henan was higher than that of WS, though not statistically significant. The living biomass carbon density of TT was significantly lower than that of other grasslands in Southwest Henan. The average underground carbon density of grasslands in Northwest and South Henan were 6.35×10³ and 5.14×10³ g C·m^-2, respectively. In Northwest Henan, there was no difference between WT and WS for both the root and soil carbon density. In South Henan, the root carbon density of TS was significantly lower than other grasslands, while the soil carbon density of TT was significantly higher than other grasslands. The average carbon density of grassland ecosystem in Northwest and South Henan was 6.46×10³ and 5.22×10³ g C·m^-2, respectively. Soil was the main contributor of ecosystem carbon storage and accounted for about 78%-90% of total grassland ecosystem carbon density. In addition, there were no significant differences in the ecosystem carbon density between WT and WS in Northwest Henan, while TT possessed significantly higher ecosystem carbon density (9.70×10³ g C·m^-2) compared with other grasslands in Southern Henan. Our results provide basic data for accurately calculating ecosystem carbon storage and assessing carbon sequestration potential of different grasslands in Henan Province.