凋落物作为生态系统重要的组成部分,对土壤碳氮输入以及土壤呼吸过程有重要影响。以中国中部温带丘陵地区南太行焦作龙翔山为研究区域,沿海拔148~827 m的阴阳两坡向设置样点,研究地表凋落物现存量及其碳氮化学计量特征,并分析其养分潜在归还能力及关键影响因子。结果表明:1)龙翔山地表凋落物现存量平均值为(540.81±388.00)g/m²,海拔800 m以下,凋落物现存量在不同海拔梯度间无显著差异;海拔800 m以上,凋落物现存量显著增加(P<0.05)。2)龙翔山4种植被类型中,温带常绿针叶林主要分布在海拔800 m以上,其地表凋落物现存量[(1 038.95±289.31)g/m²]最高,极显著高于温带落叶阔叶林、灌丛和草甸(P<0.01);同时地表凋落物现存量与凋落物最大氮回归量之间存在极显著正相关关系(r=0.96,P<0.01)。3)凋落物最大氮回归量、凋落物最大碳回归量、土壤氮含量和海拔是影响地表凋落物现存量的主要影响因子;此外,植被类型对其也具有重要影响。焦作龙翔山植物群落的凋落物现存量较大,植被类型在其调控过程中发挥着重要作用。

The litter is a vital component of ecosystems and its decomposition process profoundly affects soil carbon input and the soil respiration process.In this experiment,Longxiang Mountain in Jiaozuo was selected as the study area,which is located in the southern Taihang Mountains and belongs to the temperate hilly region of central China.Sample sites were established along altitudes ranging from 148 to 827 m and on both sunny and shady slopes.The study focused on the existing quantity of surface litter,carbon and nitrogen stoichiometric characteristics,and analyzed its potential nutrient return capacity and key influencing factors.The results showed that:1)The average value of the existing litter biomass on the surface of Longxiang Mountain is 540.81±388.00 g/m²,and there is no significant difference in the existing litter biomass among different altitude gradients below an altitude of 800m.Also,the existing litter biomass increased significantly above 800m(P<0.05).2)Among the four vegetation types in Longxiang Mountain,temperate evergreen coniferous forests were mainly distributed above an altitude of 800 m,and their surface litter biomass was the highest[(1 038.95±289.31 g/m²)],which was the significantly higher than that of deciduous broad-leaved forests,scrubs and meadows(P<0.01).Additionally,there is a highly significant positive correlation(r=0.96,P<0.01)between surface litter biomass and the maximum nitrogen return from litter.3)The litter's maximum nitrogen and carbon return capacity,soil N content,and altitude were the main driving factors affecting the existing quantity of surface litter.In addition,vegetation type also has an important direct effect on the existing quantity of surface litter.In conclusion,the litter of the plant community in Longxiang Mountain in Jiaozuo is a critical factor,and the vegetation type plays an important role in its regulation process.