# Effects of Harvesting Disturbance on Soil Nematode Diversity and Soil Properties in Ophiocordyceps sinensis Excavation Areas of the Qinghai–Tibet Plateau

## TL;DR

This study examines how harvesting Ophiocordyceps sinensis affects soil nematode diversity and soil properties in the Qinghai–Tibet Plateau, finding limited immediate impacts but potential long-term risks.

## Contribution

The study provides a multi-regional analysis of soil and nematode responses to O. sinensis excavation, revealing spatial heterogeneity and altered soil-nematode relationships.

## Key findings

- Excavation significantly reduced soil available potassium across all regions.
- Nematode diversity remained largely stable, with only minor declines in some areas.
- Soil-nematode relationships were altered, with stronger potassium-nematode correlations in disturbed sites.

## Abstract

Ophiocordyceps sinensis is a valuable medicinal resource distributed in the Qinghai–Tibet Plateau and the adjacent alpine regions, and seasonal excavation poses potential risks to fragile alpine soil ecosystems. As sensitive indicators of soil ecological change, soil nematodes can effectively evaluate such disturbances. This study compared the soil physicochemical properties and nematode diversity in excavated and non-excavated sites across multiple regions. Excavation significantly reduced soil available potassium (p < 0.01), while changes in other nutrients showed strong spatial heterogeneity. Nematode community diversity was generally stable, with only regional declines in evenness (Shannon index decreased from 2.91 to 2.46 in HeN), and more than 70% of nematode genera and species were shared between sites with consistent dominant taxa. Correlation analysis revealed that excavation altered soil–nematode relationships. The positive association between available potassium and nematode diversity was significantly strengthened (p < 0.05), while correlations of soil pH and organic matter with nematode diversity were weakened or shifted. These findings indicate that impacts under current excavation intensity are relatively limited. However, widespread available potassium reduction and localized shifts in soil–nematode relationships imply potential long-term risks, which require attention for the sustainable management of alpine soils.

Ophiocordyceps sinensis (O. sinensis) is a valuable medicinal fungus distributed in the Qinghai–Tibet Plateau and adjacent high-altitude regions. Wild excavation has raised increasing concerns about its impact on fragile alpine soil ecosystems. Soil nematodes are sensitive indicators of soil environmental change and can effectively reflect disturbance-induced shifts in soil biotic communities. Understanding the effects of O. sinensis excavation on soil nematode diversity is essential for assessing soil biological health and supporting sustainable management of alpine ecosystems. However, most existing studies are limited to single regions, and few have simultaneously analyzed changes in soil properties, nematode diversity, and soil–nematode relationships across heterogeneous landscapes. The goal of this study was to reveal the impacts of O. sinensis excavation on soil physicochemical properties, nematode diversity and community composition, as well as soil–nematode relationships in typical producing areas, and to assess the ecological risks of current harvesting practices. We investigated five typical O. sinensis-producing regions in Qinghai Province (Henan, Hualong, Maqin, Yushu, Zaduo) and compared excavated and non-excavated sites to evaluate disturbance effects. The results showed strong regional heterogeneity in soil responses to excavation. Soil available potassium (AK) was significantly and consistently lower in all excavated sites (p < 0.01), whereas changes in other soil nutrients varied by region. Nematode α-diversity was generally stable, with a significant decrease in the Shannon index only in Henan (from 2.91 to 2.46). Soil nematode community composition was highly similar between treatments, with more than 70% of shared genera and species remaining largely unchanged and dominant taxa unchanged. Correlation analysis indicated that excavation reshaped soil–nematode relationships, and AK may act as a potential influencing factor associated with nematode diversity in disturbed sites. Overall, under current excavation intensity, the impacts of O. sinensis harvesting on total soil nematode diversity are relatively limited. However, the widespread reduction in AK and localized diversity decline suggest potential long-term ecological risks under intensive or prolonged disturbance.