Ecosystem stability is multidimensional and includes resistance, resilience, invariance, and persistence. However, recent empirical studies have mainly focused on the temporal stability of ecosystem functions. In the face of global climate change and biodiversity loss, ensuring the temporal stability of terrestrial ecosystem productivity is essential for sustaining ecosystem functions and services.
Previous manipulative experiments have shown that biotic factors, particularly plant diversity, are important for maintaining ecosystem stability. However, different aspects of plant diversity can have inconsistent effects on ecosystem stability. The diversity hypothesis suggests that communities with high diversity tend to contain species that respond differently to environmental changes, which can enhance community stability through compensatory dynamics. On the other hand, the mass ratio hypothesis suggests that dominant species have a strong influence on ecosystem stability, particularly in communities with low evenness. This suggests that exploring different aspects of biodiversity may help explain the contribution of biotic factors to ecosystem stability.
Recent studies have also highlighted the importance of abiotic factors such as climate variability and water supply in ecosystem stability. However, biodiversity and ecosystem stability vary widely across climate regimes, geographic regions, and ecosystem types, and this environmental context-dependence hinders our understanding of how various drivers affect ecosystem stability.
The Tibetan Plateau is a region that is ecologically fragile and highly sensitive to climate change. At present, there are limited studies on the stability of the ecosystem here, particularly in ecosystems other than the alpine grasslands. Therefore, our understanding of the drivers of ecosystem stability on the Tibetan Plateau remains incomplete.
To address this gap, our study aimed to explore the effects of multiple biotic and abiotic factors on ecosystem stability using biodiversity data from field surveys and satellite remote sensing at 143 sites across different ecosystems on the Tibetan Plateau (Fig. 1). We conducted field surveys and plant community sampling during the 2019-2021 growing seasons, and obtained environmental factors from public databases. To measure long-term stability, we used the annual maximum Normalized Difference Vegetation Index (NDVI) from 2000-2020 as a proxy for aboveground vegetation productivity.
The integrated analysis of multi-source data enables us to have a more comprehensive understanding of the mechanism of maintaining stability of the terrestrial ecosystem on the Tibetan Plateau. In particular, spectral indices of vegetation from remote sensing can be a good substitute foraboveground biomass monitoring, which allows easy access to data on large spatial and temporal scales, and with the development of high-resolution satellites, such monitoring can better reflect conditions on the ground.
In summary, this study found that abiotic factors such as climate and soil conditions play a more significant role in ecosystem stability than biotic factors, with direct impacts on stability. This knowledge can guide targeted conservation efforts for specific ecosystems, which is critical for managing and protecting ecosystems sustainably in the face of climate change and biodiversity loss.
To learn more about our work, visit https://doi.org/10.1038/s43247-023-00849-8
The work was supported by the second Tibetan Plateau Scientific Expedition and Research Program (STEP), China (Grant No. 2019QZKK0306), and the National Science Foundation of China (Grant No. 41730854). We thank the National Ecosystem Science Data Center, National Science & Technology Infrastructure of China for providing the NDVI dataset (http://www.nesdc.org.cn). In addition, our field work was aided by many scientists involved in the second Tibetan Plateau Scientific Expedition and Research Program, whose contributions were invaluable (Fig. 2).