Distribution pattern and factors affecting litter stocks at the slope-scale in a karst forest in subtropical China
Distribution pattern and factors affecting litter stocks at the slope-scale in a karst forest in subtropical China
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DOI：
10.1016/j.gecco.2023.e02683
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发表时间：
2023-10-16
影响因子：
4
通讯作者：
Liu，Zhanfeng
中科院分区：
文献类型：
--
作者：
Hou，Manfu;Yu，Huaming;Liu，Zhanfeng
凋落物分布显著影响养分循环、能量转移和各种生态系统服务。然而，很少有人知道微地形如何影响凋落物的积累和分布在森林地面上。通过对中国亚热带典型喀斯特森林凋落物量和岩石暴露率（RER）在10 × 120 m的石灰岩山地上的300个1 × 1 m网格的测定，研究了凋落物量在坡面尺度上的分布特征及其与地形和RER的关系。结果表明：（1）喀斯特森林凋落物平均蓄积量为691.54 ± 332.60 g·m-2，其中未分解凋落物占65.81%，（2）凋落物蓄积量空间分布不均匀，变化中等，在整个坡面上呈现5个聚集区和4个稀疏区;（3）粗面内质网与枯落物蓄积量呈显著负相关（R =-0.37，P < 0.01），随坡度和坡位的增加而增加;喀斯特地区粗面内质网与地形的耦合作用，通过再分配过程直接影响凋落物的积累，并通过改变微环境间接影响凋落物的分解速率，从而改变了凋落物在坡面尺度上的分布格局。我们的研究强调了喀斯特生态系统复杂的坡度尺度形态在通过调节凋落物再分配改变养分循环和能量转移方面的重要性，为喀斯特生境高环境异质性的形成提供了新的见解。
Litter distribution significantly affects nutrient cycling, energy transfer, and various ecosystem services. However, little is known about how microtopography affects litter accumulation and distribution on the forest floor. Distribution characteristics of litter stocks at the slope-scale and their relationship with topography and rock exposure rate (RER) in a typical subtropical karst forest in China were determined by measuring the litter stock and RER of 300 grids of1 × 1 m in a 10 × 120 m square on a limestone hill. The results showed that (1) the average litter stock of karst forest was 691.54 ± 332.60 g∙m-2, among which 65.81% was undecomposed litter; (2) the spatial distribution of litter stocks was uneven with moderate variation, presenting five aggregated areas and four sparse areas on the entire slope; (3) there was a significant negative correlation between RER and litter stock (R = −0.37, P < 0.01), which increased with increasing slope gradient and slope position; and (4) the RER coupled with topography in karst areas directly affected litter accumulation via the redistribution process and indirectly affected the decomposition rate by altering the microenvironment, which reshaped the slope-scale distribution pattern of litter stocks. Our research highlights the importance of the complex slope-scale morphology of karst ecosystems in altering nutrient cycling and energy transfer by mediating litter redistribution, providing new insights into the formation of the high environmental heterogeneity in karst habitats.