| 黄土丘陵区次生林演替过程土壤酶活性响应特征及影响机制 |
| 摘要点击 261 全文点击 11 投稿时间：2024-05-07 修订日期：2024-06-25 |
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| 中文关键词 黄土丘陵区 次生林演替 酶活性 植被群落多样性 土壤理化性质 |
| 英文关键词 Loess Hilly Region secondary forest succession enzyme activity vegetation community diversity soil physico-chemical properties |
| 作者 | 单位 | E-mail | | 刘剑剑 | 西北农林科技大学农学院, 杨凌 712100
陕西省循环农业工程技术研究中心, 杨凌 712100 | 491433929@qq.com | | 刘涵宇 | 西北农林科技大学农学院, 杨凌 712100
陕西省循环农业工程技术研究中心, 杨凌 712100 | | | 李向阳 | 西北农林科技大学农学院, 杨凌 712100
陕西省循环农业工程技术研究中心, 杨凌 712100 | | | 张琦 | 西北农林科技大学农学院, 杨凌 712100
陕西省循环农业工程技术研究中心, 杨凌 712100 | | | 曾嘉 | 西北农林科技大学农学院, 杨凌 712100
陕西省循环农业工程技术研究中心, 杨凌 712100 | | | 李桂兴 | 西北农林科技大学农学院, 杨凌 712100
陕西省循环农业工程技术研究中心, 杨凌 712100 | | | 何梦凡 | 西北农林科技大学农学院, 杨凌 712100
陕西省循环农业工程技术研究中心, 杨凌 712100 | | | 任成杰 | 西北农林科技大学农学院, 杨凌 712100
陕西省循环农业工程技术研究中心, 杨凌 712100 | | | 杨改河 | 西北农林科技大学农学院, 杨凌 712100
陕西省循环农业工程技术研究中心, 杨凌 712100 | | | 韩新辉 | 西北农林科技大学农学院, 杨凌 712100
陕西省循环农业工程技术研究中心, 杨凌 712100 | hanxinhui@nwsuaf.edu.cn |
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| 中文摘要 |
| 土壤胞外酶受到土壤水分、养分等一系列生物和非生物因素的调控.在植被恢复中,因生态系统和土壤垂直空间环境的异质性,土壤表层和底层酶活性对不同演替阶段的响应差异和驱动机制还不明确.因此,采用“空间代替时间”的方法,以黄土丘陵区次生林演替不同阶段为研究对象,分析了次生林演替过程中土壤表层和底层4种胞外酶的变化特征及影响因子.结果表明：①与0~20 cm土层相比,土壤底层（40~100 cm） β-1,4-葡萄糖苷酶（BG）、β-D-纤维二糖水解酶（CBH）和β-1,4-N-乙酰氨基葡萄糖苷酶（NAG）活性显著降低,但在演替后期0~20 cm土层碱性磷酸酶（ALP）活性显著低于20~40 cm和40~60 cm土层.与演替初期和后期相比,土壤酶活性在演替中期达到最大值.②次生林演替改变了植物群落和土壤养分剖面分布特征.在演替中期Gleason丰富度指数（G）、Shannon-Wiener多样性指数（H）和Pielou均匀度指数（E）最低.与演替初期相比,演替中期表土层（0~40 cm）硝态氮含量显著增加,而与演替中期相比,演替后期底土层（40~100 cm）土壤含水量和有机碳含量显著增加.③冗余分析和最小偏二乘路径模型表明,土壤养分是影响次生林土壤表层（0~40 cm）酶活性的最主要因素,其中硝态氮对土壤酶活性的变化解释率最高,土壤含水量是调控土壤底层（40~100 cm）酶活性的关键因子.研究还表明,次生林中随着土层深度的增加,土壤酶活性显著降低,演替中期土壤酶活性含量最高,在土壤表层,酶活性主要受到硝态氮含量的影响,在土壤底层,酶活性主要受到土壤含水率的调控.该结果明确了不同演替阶段土壤酶活性的剖面特征及表土层和底土层的驱动因素,可为制定科学的森林土壤保护政策提供依据. |
| 英文摘要 |
| Soil extracellular enzymes are regulated by a range of biotic and abiotic factors, such as soil moisture and nutrients. In vegetation restoration, due to the heterogeneity of ecosystems and vertical spatial environments of soils, the differences in the response of soil surface and substrate enzyme activities to different stages of succession and the driving mechanisms are unclear. Therefore, using the method of “space instead of time,” we analyzed the characteristics of four extracellular enzymes and their influencing factors in the soil surface and bottom layers during the succession of secondary forests in loess hilly areas. The results showed that： ① The activities of β-1,4-glucosidase （BG）； β-D-cellobiose hydrolase （CBH）； and β-1,4-N-acetamido-glucosidase （NAG） were significantly lower in the soil subsoil layer （40-100 cm） compared with those in the 0-20 cm soil layer； however, the activities of alkaline phosphatase （ALP） in the late successional period in the 0-20 cm soil layer were significantly lower than those in the 20-40 cm and 40-60 cm soil layers. Compared with the early and late successional stages, the soil enzyme activities reached the maximum value in the middle stage of succession. ② The succession of secondary forest changed the distribution characteristics of plant community and soil nutrient profile. In the middle stage of succession, the Gleason （G） richness index, Shannon-Wiener diversity index （H）, and Pielou evenness index （E） were the lowest. Compared with that in the early succession stage, the nitrate nitrogen content in the topsoil （0-40 cm） increased significantly in the middle succession stage. Compared with that in the middle succession stage, the soil water content and organic carbon content in the bottom soil layer （40-100 cm） increased significantly in the late succession stage. ③ Redundancy analysis and the least squares path model showed that soil nutrients were the most important factor affecting the soil enzyme activity in the surface layer （0-40 cm） of secondary forest, among which nitrate nitrogen had the highest explanation rate for the change of soil enzyme activity, and soil water content was the key factor to regulate the soil enzyme activity in the bottom layer （40-100 cm）. The results showed that the soil enzyme activity decreased significantly with the increase in soil depth in secondary forest, and the soil enzyme activity was the highest in the middle stage of succession. In the surface layer of soil, the enzyme activity was mainly affected by the content of nitrate nitrogen, and in the bottom layer of soil, and the enzyme activity was mainly regulated by soil water content. The results clarified the profile characteristics of soil enzyme activities at different succession stages and the driving factors of topsoil and subsoil, which provided a basis for formulating scientific forest soil protection policies. |
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