College of Forestry, Henan Agricultural University, Zhengzhou, 450002, China.
Faculty of Science and Marine Environment, University Malaysia Terengganu, 21300, Kuala Terengganu, Malaysia.
Environ Pollut. 2020 Oct;265(Pt A):114951. doi: 10.1016/j.envpol.2020.114951. Epub 2020 Jun 6.
Greenhouse gases (GHGs) carbon dioxide (CO) and nitrous oxide (NO), contribute significantly to global warming, and they have increased substantially over the years. Reforestation is considered as an important forestry application for carbon sequestration and GHGs emission reduction, however, it remains unknown whether reforestation may instead produce too much CO and NO contibuting to GHGs pollution. This study was performed to characterize and examine the CO and NO emissions and their controlling factors in different species and types of pure and mixture forest used for reforestation. Five soil layers from pure forest Platycladus orientalis (PO), Robinia pseudoacacia (RP), and their mixed forest P-R in the Taihang mountains of central China were sampled and incubated aerobically for 11 days. The P-R soil showed lower CO and NO production potentials than those of the PO soils (P < 0.01). The average reduction rate of cumulative CO and NO was 31.63% and 14.07%, respectively. If the mixed planting pattern is implemented for reforestation, the annual CO reduction amounts of China's plantation can be achieved at 8.79 million tonnes. With the increase of soil depths, cumulative CO production in PO and RP soils decreased, whereas CO and NO production in P-R soil did not show similar pattern. Soil particle size fraction was the main factor influencing GHGs emissions, and the clay fraction showed negative correlation with cumulative CO and NO production. In summary, compared with PO pure artificial forests, the mixture plantation mode can not only reduce GHGs pollution but also improve soil fertility, which is conducive to sustainable management of artificial forests.
温室气体（GHGs）二氧化碳（CO）和氧化亚氮（NO）对全球变暖有重大贡献，多年来它们的含量大幅增加。造林被认为是固碳和减少 GHGs 排放的重要林业应用，但造林是否会产生过多的 CO 和 NO 而导致 GHGs 污染仍不清楚。本研究旨在描述和研究不同造林纯林和混交林物种和类型中 CO 和 NO 的排放及其控制因素。从中国中部太行山的纯林侧柏（PO）、刺槐（RP）及其混交林 P-R 中采集了 5 个土层并进行了 11 天的有氧培养。与 PO 土壤相比，P-R 土壤的 CO 和 NO 产生潜力较低（P<0.01）。累积 CO 和 NO 的平均减少率分别为 31.63%和 14.07%。如果实施混合种植模式进行造林，中国人工林的年 CO 减排量可达到 879 万吨。随着土壤深度的增加，PO 和 RP 土壤中累积 CO 的产生减少，而 P-R 土壤中 CO 和 NO 的产生没有表现出类似的模式。土壤颗粒大小分数是影响 GHGs 排放的主要因素，粘粒分数与累积 CO 和 NO 的产生呈负相关。总之，与 PO 纯人工林相比，混交林模式不仅可以减少 GHGs 污染，还可以提高土壤肥力，有利于人工林的可持续管理。
