中图分类号：S153.6：Q948 文献标识号：A 文章编号：1001-4942（2025）06-0111-10

AbstractGlobal changes and human activities induce great shrub encroachments in coastal wetland ecosystems，altering their structures and functions.Taking the typical shrub-encroached wetland in the Yellow River Delta as a case and based on the GIS platform，we quantified the spatial pattern heterogeneity of soil particle composition （ 0～80cm， ）by lacunarity analysis and analyzed the effects of different shrub encroachment types on soil particles by the cold（hot）spot analysis.The results were as folows.（1） The contents of different size soil particles in shrub-encroached wetland showed as silt gt; sand gt; clay. The content of clay and silt increased with the increase of soil layer depth while that of sand decreased.（2）The lacunarityof clay was higher than that of silt and sand in 0～20 -cm layer，and they were similar in 20～30 -cm layer. But below ，the lacunarity of clay decreased gradually utill lower than that of silt and sand.（3） The hot-spot area of sand in 0～50 -cm layer occupied the largest in shrub patches，while that of clay in 0～40 -cm layer and silt in 0～50 -cm layer （except 1O＼～2O-cm layer）occupied the largest in tidal flat without shrubs.The hot-spot areas of soils in Tamarix chinensis cluster patches and bare land were moderated.These results could provide scientific references for accurate assessment of wetland shrub-encroached efect and wetland protection and res

toration.

KeywordsWetland shrub encroachment； Soil particle size; Spatial heterogeneity；Lacunarity analysis;Cold-hot spot analysis； Yellow River Delta

由于全球气候变化和人类活动，天然草本生态系统逐渐被灌木等木本植物侵占，即发生灌丛化现象[1-2]。当前对干旱和半干旱草原地区草原灌丛化的研究较多[2-3]，而对滨海湿地灌丛化的研究有限[4-5]。目前已有报道怪柳、红树林、桉树等木本植物入侵海岸带湿地生态系统，引起滨海湿地生态系统结构和功能的变化。比如，灌丛化改变了植被间隙的资源流动模式，使风和水输送的各种物质在灌层下累积以及灌木间隙受到的侵蚀增加等，这些过程使得灌丛的“肥岛效应”增强[。灌木人侵也会引起生态系统生产力的复杂变化，例如弗吉尼亚杜松（Juniperusvirginia）对美国西部低海拔草原的侵占已被证明可以提高净生态系统生产力，并引起土壤和植物碳氮库含量和空间格局改变[7]。红树林入侵可能会使盐沼湿地营养物质储存增加，从而增强其抵御风暴的能力，但同时也会导致原有滨海湿地生物栖息地减少[8] O

粒径组成是最基本的土壤物理参数，代表不同粒径的土壤颗粒在土壤固相中所占的比例[9]它与土壤结构、土地利用、植被覆盖等密切相关，显著影响土壤水分和养分特征，进而影响土壤侵蚀过程和生态恢复过程[10-11]。一般认为，土壤粒径组成相对稳定，在小的尺度范围变化不大。但是由于土壤内部物理、化学和生物过程的相互作用，以及各种自然和人类活动的相互干扰，土壤粒径在局地尺度上也可能具有较大变异[12]。……