Seabirds are typical biovectors, delivering both nutrients and metals across ecosystem boundaries. However, seabird transfer of Ag and Co has not been well documented. Using an ornithogenic sediment core collected from the remote Zhaoshu Island, South China Sea, we investigated potential impacts of seabirds on Ag and Co transportation. These two elements exhibited peak abundance in a guano layer in the sediment profile. Via statistical analyses, Ag, Co, and previously identified avian bio‐elements (Cn, Zn, Cd, P, As, and Se) had a common source, that is, guano. Guano input was also partly responsible for the distribution of Y, Ce, La, Sc, and U in the bulk sediments. The concentration‐versus‐depth profiles of Mn, Mo, Bi, Rb, and W were possibly associated with organic matter.

Land is a finite and non‐renewable natural resource. The competitive decisions of local governments will have a profound impact on the green and efficient use of land resources. This paper examines the nonlinear effect of local government competition on green land use total factor productivity (GLTFP) using data from 171 Chinese cities from 2006 to 2019. The results show that (1) there is an inverted U‐shaped relationship between the local government competition and GLTFP, and this conclusion holds after addressing a series of endogeneity concerns. (2) Local government competition can affect the inverted U‐shaped relationship between GLTFP through the misallocation of land resources. (3) The impact of local government competition on GLTFP is more prominent in first‐tier and new first‐tier cities in China and cities in western China.