不同生态恢复措施对紫色土活性有机碳的影响

研究不同生态恢复措施—"参考林分"(C0)、"林果草+水平沟"(C1)、"乔灌草+竹节沟"(C2)、"油茶+等高草带"(C3)和"未治理地"(CK)对土壤总有机碳和活性有机碳的影响。结果表明:生态恢复后,其中C1和C2措施总有机碳含量分别比未治理地CK增加了51.87%和52.90%(P0.05),达到C0措施的48.42%和48.75%。然而,C3措施未显著影响总有机碳含量,仅为C0措施的29.32%。C1和C2措施的微生物量碳、冷水和热水浸提的可溶性有机碳含量均显著提高,分别比CK措施增加了49.91%~78.77%、43.15%~91.11%和28.17%~108.36%,达到C0措施的67.01%~89.47%、35.65%~57.95%和32.88%~39.21%,而C3措施的微生物量碳和冷水浸提的可溶性有机碳略为减少,而热水浸提的可溶性有机碳增加了29.87%。土壤总有机碳与各活性碳之间以及各活性碳之间相关性均达到极显著水平。微生物量碳、冷水和热水浸提的可溶性有机碳占总有机碳的比例分别介于1.91%~4.73%、0.76%~2.49%和4.11%~8.16%之间。

Effect of Different Ecological Restoration Measures on Active Organic Carbon in Purple Soil

Effects of different ecological restoration measures on total soil organic carbon (SOC) and active soil organic carbon are studied. The measures include reference forest (C0), forest-garden-grass+horizontal ditch (C1), arbor- shrub- grass + bamboo knot ditch (C2), Camellia oleifera + equal height grass strip (C3) and unrestored area (CK). The results showed that the SOC of C1 and C2 significantly increased by 51.87% and 52.90% compared with that of CK after ecological restoration, and reached 48.42% and 48.75% of that of C0. Microbial biomass carbon, soluble organic carbon extracted by cold water and hot water under C1 and C2 increased by 49.91%-78.77%, 43.15%-91.11% and 28.17%-108.36% compared with those of CK, and they were 67.01%-89.47%, 35.65%-57.95% and 32.88%-39.21% of that of C0, while biomass carbon, soluble organic carbon extracted by cold water under C3 slightly decreased, soluble organic carbon extracted by hot water increased by 29.87%. There were extremely significant relationships between the SOC and different labile organic carbon components and among the components. The proportion of microbial biomass carbon, soluble organic carbon extracted by cold water and hot water to the total organic carbon ranged from 1.91% to 4.73%, 0.76% to 2.49% and 4.11% to 8.16%, respectively.