Impact of Salix oritrepha shrub encroachment on characteristics of herbaceous plant communities in the alpine meadows of the Eastern Qilian Mountains

doi:10.11686/cyxb2025113

Abstract

Abstract:

Exploring the impacts of shrub encroachment on the characteristics of herbaceous plant communities in the alpine meadows of the Eastern Qilian Mountains is important both for understanding local ecological equilibrium and for the development of animal husbandry. This study was carried out in alpine meadows dominated by Salix oritrepha in Tianzhu， Gansu Province. Using a space-for-time substitution method， we assessed differences in plant height， coverage， and aboveground biomass across various functional groups， and species diversity indexes， under light， moderate， and heavy levels of shrub encroachment in both shrub and grass patches. As shrub encroachment intensified， herbaceous plant height increased in both patch types， whereas the cover of sedges declined and the aboveground biomass of grasses remained stable. The composition of forbs shifted significantly， with Equisetum arvense becoming dominant under severe shrub encroachment. Species richness， Shannon-Wiener diversity， Simpson’s dominance， and Pielou’s evenness indexes all decreased in shrub patches as shrub encroachment intensified. Correlation analysis revealed a significant negative relationship between herbaceous species diversity and the plant height and canopy size of S. oritrepha. Overall， the results of this study show that S. oritrepha expansion has both suppressive and facilitative effects on herbaceous communities， with the extent of these effects varying depending on the plant functional group and the degree of shrub encroachment.

Key words: alpine shrub meadow, shrub encroachment, herbaceous plant functional groups, species diversity

Yang LIU, Hong XIAO, Chang-lin XU, Ming-yue DENG, Wen-qiang WEI, Ao HAN, Kai MA, Yun WANG. Impact of Salix oritrepha shrub encroachment on characteristics of herbaceous plant communities in the alpine meadows of the Eastern Qilian Mountains[J]. Acta Prataculturae Sinica, 2026, 35(3): 13-25.

Figures/Tables 10

References 39

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灌丛特征Shrub characteristics	灌丛化程度Degree of shrub encroachment
灌丛特征Shrub characteristics	轻度Light	中度Moderate	重度Heavy
高度Height （cm）	45.67±1.20c	71.67±1.20b	127.67±1.45a
冠幅面积Crown area （m²）	0.19±0.05c	0.48±0.10b	1.44±0.41a
地上生物量Aboveground biomass （g·clump^-1）	194.61±22.69c	587.28±85.84b	2395.89±101.44a
茎粗Stem diameter （mm）	5.12±0.81c	6.75±0.33b	12.38±0.14a
分蘖株数Tillering number （No.）	24.00±1.15c	45.00±2.31a	29.67±0.67b

灌丛特征Shrub characteristics	灌丛化程度Degree of shrub encroachment
灌丛特征Shrub characteristics	轻度Light	中度Moderate	重度Heavy
高度Height （cm）	45.67±1.20c	71.67±1.20b	127.67±1.45a
冠幅面积Crown area （m²）	0.19±0.05c	0.48±0.10b	1.44±0.41a
地上生物量Aboveground biomass （g·clump^-1）	194.61±22.69c	587.28±85.84b	2395.89±101.44a
茎粗Stem diameter （mm）	5.12±0.81c	6.75±0.33b	12.38±0.14a
分蘖株数Tillering number （No.）	24.00±1.15c	45.00±2.31a	29.67±0.67b

物种名 Species name	科 Family	灌丛斑块Shrub patch			草地斑块Grass patch
物种名 Species name	科 Family	轻度Light	中度Moderate	重度Heavy	轻度Light	中度Moderate	重度Heavy
铃铃香青A. hancockii	菊科Asteraceae	4.00	1.67	1.33	15.67	9.67	—
钝苞雪莲Saussurea nigrescens	菊科Asteraceae	—	20.33	4.00	—	—	—
球花蒿A. smithii	菊科Asteraceae	1.00	—	—	12.00	—	—
黄帚橐吾Ligularia virgaurea	菊科Asteraceae	—	—	—	—	—	12.33
翻白草P. discolor	蔷薇科Rosaceae	9.67	8.33	—	13.00	18.33	0.67
鹅绒委陵菜Potentilla anserina	蔷薇科Rosaceae	—	—	—	—	24.00	8.33
北方獐牙菜S. diluta	龙胆科Gentianaceae	4.00	0.67	—	6.33	—	—
珠芽蓼B. vivipara	蓼科Polygonaceae	18.00	7.00	11.67	46.33	51.33	17.67
银莲花Anemone cathayensis	毛茛科Ranunculaceae	5.33	6.67	8.67	13.00	13.33	9.00
肉果草L. tibetica	通泉草科Primulaceae	1.33	3.33	—	—	0.33	1.67
问荆E. arvense	木贼科Equisetaceae	—	2.33	40.67	—	5.67	57.00
小米草Euphrasia pectinata	玄参科Scrophulariaceae	—	—	—	1.67	8.67	15.00

物种名 Species name	科 Family	灌丛斑块Shrub patch			草地斑块Grass patch
物种名 Species name	科 Family	轻度Light	中度Moderate	重度Heavy	轻度Light	中度Moderate	重度Heavy
铃铃香青A. hancockii	菊科Asteraceae	4.00	1.67	1.33	15.67	9.67	—
钝苞雪莲Saussurea nigrescens	菊科Asteraceae	—	20.33	4.00	—	—	—
球花蒿A. smithii	菊科Asteraceae	1.00	—	—	12.00	—	—
黄帚橐吾Ligularia virgaurea	菊科Asteraceae	—	—	—	—	—	12.33
翻白草P. discolor	蔷薇科Rosaceae	9.67	8.33	—	13.00	18.33	0.67
鹅绒委陵菜Potentilla anserina	蔷薇科Rosaceae	—	—	—	—	24.00	8.33
北方獐牙菜S. diluta	龙胆科Gentianaceae	4.00	0.67	—	6.33	—	—
珠芽蓼B. vivipara	蓼科Polygonaceae	18.00	7.00	11.67	46.33	51.33	17.67
银莲花Anemone cathayensis	毛茛科Ranunculaceae	5.33	6.67	8.67	13.00	13.33	9.00
肉果草L. tibetica	通泉草科Primulaceae	1.33	3.33	—	—	0.33	1.67
问荆E. arvense	木贼科Equisetaceae	—	2.33	40.67	—	5.67	57.00
小米草Euphrasia pectinata	玄参科Scrophulariaceae	—	—	—	1.67	8.67	15.00