Land uses pose major impacts on river ecosystems, especially their biodiversity. However, how the trophic structure of aquatic communities including fish and macroinvertebrates as well as basal resources within subtropical stream food webs responds to land uses remains unclear. 

The research team from Wuhan Botanical Garden, cooperated  with researchers from Institute of Hydrobiology, studied the response of trophic structure to land uses in subtropical streams using the stable isotope analysis. 

The stable isotope analysis indicated that upland land uses have a significant impact on the δ¹³C discrimination and δ¹⁵N enrichment of macroinvertebrates and fish, and the isotopic compositions of basal aquatic resources in subtropical streams. The contribution of allochthonous resources to higher trophic levels in the subtropical streams was much lower than autochthonous resources regardless of land use in the upland area. Trophic structure alterations in response to land use could possibly result from the combined effects of the availability and variability of basal resources in the river channel and the feeding plasticity of macroinvertebrates and/or fish. 

These findings are useful for watershed management, including land use and land cover programs that facilitate the restoration of biodiversity and function in the riverine ecosystem in subtropical areas.  

The study entitled “Trophic structure in response to land use in subtropical streams” was recently published in the journal Ecological indicators.  

The doctoral student WANG Yang from Wuhan Botanical Garden is the first author, the associate professor TAN Xiang is the corresponding author. The study was supported by the National Natural Science Foundation of China.