Effects of grazing on vegetation diversity and soil multifunctionality in coconut plantations

Qianwen Duan; An Hu; Weibo Yang; Ruoyun Yu; Guodao Liu; Hengfu Huan; Rongshu Dong; Xinyong Li

doi:10.3389/fpls.2022.1109877

Effects of grazing on vegetation diversity and soil multifunctionality in coconut plantations

Front Plant Sci. 2023 Jan 11:13:1109877. doi: 10.3389/fpls.2022.1109877. eCollection 2022.

Authors

Qianwen Duan^{1

2

3}, An Hu^{1

2

3}, Weibo Yang⁴, Ruoyun Yu⁴, Guodao Liu^{1

2

3}, Hengfu Huan^{1

2

3}, Rongshu Dong^{1

2

3}, Xinyong Li^{1

2

3}

Affiliations

¹ Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, China.
² Key Laboratory of Crop Gene Resources and Germplasm Enhancement in Southern China, Ministry of Agriculture & Rural Affairs, Haikou, China.
³ Key Laboratory of Tropical Crops Germplasm Resources Genetic Improvement and Innovation of Hainan Province, Haikou, China.
⁴ Coconut Research Institute of Chinese Academy of Tropical Agricultural Sciences, Wenchang, China.

Abstract

Grazing is the main way of utilizing understory vegetation in the tropics. However, the effects of grazing on vegetation diversity and soil functions in coconut plantations remain unclear. Therefore, this study was conducted in a young coconut plantation that was grazed by geese in Wenchang, China. We identified four grazing intensities according to the aboveground biomass, namely, no grazing (CK), light grazing (LG), moderate grazing (MG), and heavy grazing (HG). In April 2022, we used the quadrat method to investigate the composition and traits of vegetation, collected and analyzed 0-40-cm soil samples in each grazing intensity. The results showed that grazing changed the composition of understory species. The predominant species changed from Bidens pilosa to Praxelis clematidea + Paspalum thunbergii and then to P. clematidea with increasing grazing intensity. The richness, Shannon-Wiener index, evenness, modified functional attribute diversity (MFAD), functional divergence (Fdiv), and functional evenness (Feve) of CK were 4.5, 1.0, 0.29, 0.20, 0.84, and 0.80, respectively. Taxonomic diversity did not respond to LG, but responded significantly to MG and HG. Compared with CK, MG and HG increased richness by 96% and 200%, respectively, and Shannon-Wiener index increased by 40% and 98%, respectively. HG increased evenness by 95%. For functional diversity, MG and HG increased MFAD by 164% and 560%, respectively, but Fdiv and Feve did not respond to grazing intensity. The carbon (C) functioning, nitrogen (N) functioning, phosphorus (P) functioning, and multifunctionality in the 0-10-cm topsoil of CK were -0.03, 0.37, -0.06, 0.20, and 0.14, respectively. Grazing increased C functioning, P functioning, and multifunctionality in the 0-10-cm topsoil but decreased N functioning. Multiple linear regression showed that the taxonomic diversity and functional diversity could be used to estimate soil functions, but these vary among soil layers. In general, MG and HG can increase vegetation diversity and soil function. It may be possible to promote even distribution of geese by adding water sources or zoning grazing. Furthermore, quantitative grazing experiments are needed to determine the efficient use pattern of the understory in coconut plantations in tropics.

Keywords: functional diversity; geese grazing; soil functions; taxonomic diversity; tropics.

Associated data

figshare/10.6084/m9.figshare.21590607.v1

Grants and funding

This work was supported by the earmarked fund for CARS (CARS-34), Hainan Province Natural Science Foundation of China (322QN394), the Central Public-interest Scientific Institution Basal Research Fund for Chinese Academy of Tropical Agricultural Science (No. 1630032022025, 1630032022011) and the Specific Research Fund of The Innovation Platform for Academicians of Hainan Province (YSPTZX202020).