Grazing Intensity Shapes Vegetation Structure and Soil Characteristics in High-Elevation Rangelands of Nepal

Area of Science:

• Rangeland ecology
• Sustainable land management
• Himalayan ecosystem studies

Background:

• Ecological impacts of livestock grazing on rangelands are critical for sustainable management.
• There is limited experimental data on grazing impacts in the Himalayan region.
• Rangeland health requires balancing livestock production with ecosystem preservation.

Purpose of the Study:

• To assess the effects of varying grazing intensities (non-grazed, light, moderate, high) on sub-alpine rangelands in Nepal.
• To analyze impacts on plant diversity, community composition, biomass, and soil properties.
• To provide evidence for sustainable rangeland management in high-altitude areas.

Main Methods:

• Field experiment across three sub-alpine rangelands in Jumla district, Nepal.
• Evaluated four grazing intensities: non-grazed (NG), lightly grazed (LG), moderately grazed (MG), and highly grazed (HG).
• Measured plant species diversity, community composition (NMDS), plant height, biomass, and soil physicochemical properties.

Main Results:

• Species richness increased from highly grazed to non-grazed conditions.
• Moderate grazing (MG) plots showed high diversity and productivity.
• Plant height and biomass decreased with increased grazing intensity; elevation had a negative effect.
• Soil organic carbon and nitrogen were generally higher under non-grazed and moderately grazed conditions, with site-specific variations.

Conclusions:

• Results support the intermediate disturbance hypothesis, indicating ecological benefits of moderate grazing.
• Grazing impacts are site-specific, necessitating adaptive and localized management strategies.
• Findings inform evidence-based rangeland management for Nepal and similar high-altitude regions.