森林郁闭度和凋落物对延胡索生长和土壤酶化学计量的影响  

Effects of Forest Canopy Density and Litter Manipulation on Corydalis yanhusuo Growth and Soil Enzyme Stoichiometry

作　　者：张文卓 张前前 俞叶飞 迟晓立 何安国 王雨齐 吕强锋 李永春[1] ZHANG Wen-Zhuo;ZHANG Qian-Qian;YU Ye-Fei;CHI Xiao-Li;HE An-Guo;WANG Yu-Qi;LYU Qiang-Feng;LI Yong-Chun(College of Environmental and Resource Sciences/State Key Laboratory of Subtropical Silviculture,Zhejiang A&F University,Hangzhou 311300,China;Dapanshan National Nature Reserve Administration of Zhejiang Province,Panan 322300,China)

机构地区：[1]浙江农林大学环境与资源学院/亚热带森林培育国家重点实验室,杭州311300 [2]浙江省大盘山国家级自然保护区管理局,磐安322300

出　　处：《农业生物技术学报》2024年第2期322-333,共12页Journal of Agricultural Biotechnology

基　　金：国家自然科学基金(32071742);浙江省金华市科学技术研究计划重点项目(2021-2-004);浙江省磐安县科技计划重点项目(磐科农202102,磐科农202203)。

摘　　要：森林较高的郁闭度致使光照不足,以及林下较厚的凋落物层产生的化感作用,是影响杉木(Cunninghamia lanceolata)林下草本植物种子萌发和幼苗生长的主要因素。本研究以人工杉木林下药用植物野生延胡索(Corydalis yanhusuo)为研究对象,采用两因素裂区试验设计探究郁闭度(低,中和高)和凋落物(去除和保留)对林下土壤酶化学计量限制和延胡索生长特性的影响。结果表明,杉木林郁闭度降低,光强增加,显著增加了延胡索株高(24%~27%)、叶绿素相对含量SPAD(soil and plant analyzer development)值(11%~33%)、净光合速率(28%~39%)、气孔导度(28%~35%)、胞间二氧化碳浓度(10%~24%)等植物生理指标,但凋落物处理对延胡索生长参数无显著影响。但是,在低郁闭度下,凋落物保留处理提高了土壤可溶性有机氮(11%~21%)的含量,且提高了土壤β-1,4-葡萄糖苷酶(β-1,4-glucosidase,BG)、β-1,4-N-乙酰氨基葡萄糖苷酶(β-1,4-N-acetylglucosaminidase,NAG)和亮氨酸氨基肽酶(leucine aminopeptidase,LAP)酶活性。郁闭度与凋落物的交互作用对延胡索株高、SPAD值有显著影响(P<0.01),对土壤碳氮磷含量有显著影响,对土壤BG、NAG、LAP、酸性磷酸酶(acid phosphatase,AP)活性有显著影响(P<0.01)。进一步分析表明,土壤酶化学计量比BG/(LAP+NAG)和(LAP+NAG)/AP均小于1,说明土壤缺乏微生物可利用的磷,表现为磷营养限制。在凋落物保留处理下,随着郁闭度增加,土壤BG/AP比例降低,表明降低郁闭度和保留凋落物能缓解土壤磷营养限制。回归分析表明,土壤BG/AP与延胡索株高、SPAD值、净光合速率、气孔导度、蒸腾速率呈显著正相关,表明较低的郁闭度和凋落物保留处理可缓解土壤微生物磷营养限制,促进植物生长。本研究可为延胡索及其他濒危野生植物种群的回归生境适宜性探索提供理论依据。Canopy density is the main factor affecting herbaceous plant growth because it leads to insufficient light,thick litter layer,and gives allelopathy effect.The main objective of this study was to explore the canopy density(low,medium,and high)and litter effects on the growth of C.yanhusuo with the restriction of soil enzyme stoichiometry.Results revealed that low canopy density of Cunninghamia lanceolata significantly increased height(24% to 27%),SPAD(soil and plant analyzer development)value(11% to 33%),net photosynthetic rate(28% to 39%),stomatal conductance(28% to 35%)of C.yanhusuo.Also,low canopy density increased the intercellular carbon dioxide concentration(10% to 24%)in C.yanhusuo plants.Although,litter manipulation had no significant impacts on growth of C.yanhusuo.With low canopy density,litter retention significantly increased the content of soil-soluble organic nitrogen(N)(11% to 21%),and enzyme activity of β-1,4-glucosidase(BG),β-1,4-n-acetylglucosaminidase(NAG)and leucine aminopeptidase(LAP).Canopy density,litter manipulation and their interaction showed significant effects on values of SPAD,soil C,N,phosphorus(P)content and related enzymes.The interaction between canopy density and litter had significant effects on plant height and SPAD value(P<0.01),which had a significant effect on the soil C,N and P content,and had a significant effect on the soil BG,NAG,LAP,and acid phosphatase(AP)activity(P<0.01).Microbial P limitation was demonstrated among all treatments via BG/(LAP+NAG)and(LAP+NAG)/AP,which indicated that the soil lacked P for microorganisms availability.In litter retention treatment,the soil BG/AP ratio decreased with increasing canopy density,and suggested that reducing canopy density and retaining litter could alleviate the restriction of soil phosphorus.It was evident that there was significant positive correlation between soil BG/AP and plants growth parameters.The low canopy density with litter retention significantly improved the soil enzyme activities and phosphorus supply that inc

关 键 词：凋落物 郁闭度 延胡索 土壤酶活性 酶化学计量 磷营养限制 

分 类 号：S718.5[农业科学—林学]