Background Gravity erosion, mass failure on steep slope triggered by self-weight, is an important process controlling the sedimentary structures and growth patterns of the steep slope, and the gravity erosion is also one of the major sources causing large amount of soil loss to the lower reaches. Under the national strategy to promote the high-quality development in the Yellow River Basin, the relationship between the vegetation and gravity erosion in the ecological management on the Loess Plateau has received more and more attentions from China.

Methods Using a comprehensive and selective citation of the references around the world together with an in-depth discussion, this paper discussesd the occurrence mechanisms and research methods of the gravity erosion, as well as the effects of vegetation on soil loss caused by gravity erosion in the small watersheds of the Loess Plateau under the ecological management. The existing problems and future research highlights were also pointed out based on the above analysis.

Results In previous studies, a variety of techniques have been used to estimate the gravity erosion on the Loess Plateau, each with intrinsic limitations and uncertainties. Presently, various methods, including onsite monitoring, onsite survey, field experiment and laboratory experiment, have been used to obtain the original data of gravity erosion on the gully sidewall covered with plants for analyzing the effects of vegetation on gravity erosion. A laboratory or field experiment may show the role of vegetation during the dynamic process of gravity erosion and the experiment is an effective way to study the micro-mechanism of gravity erosion. In contrast, the data of gravity erosion on a large scale can quickly obtained via remote sensing monitoring and the method may provide a reference for macro decision-making on soil and water conservation. Furthermore, the first-hand data observed via onsite monitoring or investigation from the real watershed may be used to testify the realizability of the result from the field or laboratory experiments. The previous studies show that soil erosion from the gully sidewall has not been obviously alleviated due to the serious gravity erosion although the ecological management has been greatly developed and the vegetation have been well restored in the small watersheds of the Loess Plateau.

Conclusions The contribution of gravity erosion to sediment yield under the influence of vegetation and the complex relationship between the vegetation and gravity erosion need to be further explored. In the near future, to propose a new method is necessary in order to obtain the distribution information and development mechanism of gravity erosion and to evaluate the role of vegetation in conserving soil and water in the small watersheds on the Loess Plateau, China. Only has the mechanism of the gravity erosion been thoroughly understood, and then the theoretical framework can be constructed to study the gravity erosion in the area.