N enrichment, increased precipitation, and the effect of shrubs collectively shape the plant community in a desert ecosystem in northern China

Yuxuan Bai; Weiwei She; Yuqing Zhang; Yangui Qiao; Jie Fu; Shugao Qin

doi:10.1016/j.scitotenv.2019.135379

N enrichment, increased precipitation, and the effect of shrubs collectively shape the plant community in a desert ecosystem in northern China

Sci Total Environ. 2020 May 10:716:135379. doi: 10.1016/j.scitotenv.2019.135379. Epub 2019 Nov 21.

Authors

Yuxuan Bai¹, Weiwei She¹, Yuqing Zhang², Yangui Qiao¹, Jie Fu¹, Shugao Qin³

Affiliations

¹ Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China.
² Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China; Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Forestry University, Beijing, China. Electronic address: zhangyqbjfu@gmail.com.
³ Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China; Engineering Research Centre of Forestry Ecological Engineering, Ministry of Education, Beijing Forestry University, Beijing, China.

PMID: 31839302
DOI: 10.1016/j.scitotenv.2019.135379

Abstract

Understanding the responses of biological communities to global climate change is pivotal to accurately forecasting future dynamics and developing effective strategies for the adaptive ecological management of desert ecosystems. Although direct demographic responses of plant species to climatic factors have been widely acknowledged, they are also regulated by interspecific interactions (i.e., the effects of shrubs on herbaceous plants). The magnitude and direction of regulation of such interspecific interactions remain unclear. To address this knowledge gap, a full factorial field experiment simulating three levels of N enrichment (ambient, 10 kg N ha^-1 yr^-1, and 60 kg N ha^-1 yr^-1) and three levels of precipitation (ambient, 20% increase, and 40% increase) were conducted in the Mu Us Desert, northern China. N enrichment and increased precipitation significantly increased herbaceous productivity by improving the soil water content and nutrient availability (e.g., soil DIN:SAP) when shrubs were not present. Taller species responded to N enrichment, whereas those with a greater specific leaf area responded to increased precipitation. When shrubs were present, they acted as a 'buffer islands' that moderated the responses of herbaceous species to N enrichment and increased precipitation by weakening the effect of the improved soil water status. The magnitude of the effect of shrubs on herbaceous biomass and richness was comparable to that of N enrichment and increased precipitation. Our results highlight the importance and complexity of both large-scale environmental changes and small-scale interspecific interactions in structuring plant communities in desert ecosystems. Moreover, abiotic environmental factors and biotic interactions should be integrated in efforts to predict the responses of plant communities to future global change in desert ecosystems.

Keywords: Artemisia ordosica; Buffer island; Desert ecosystem; Increased precipitation; Interspecific interactions; Mu Us Desert; N enrichment.

MeSH terms

China
Desert Climate
Ecosystem*
Plants
Soil

Substances

Soil