In the French Alps, some grasslands have been abandoned, others are invaded by scrub whereas they are still used by farmers. What are the relationships between land use changes and other changes at farm level that lead to scrub invasion? We hypothesize that they are linked by two work organization processes: process of changes (changes in the household and farm) leading to less intensive land use; and annual processes (sequences of activities during the year) and their repetition from one year to another, leading to insufficient land maintenance. In this paper, we present a study carried out in the Northern French Alps, based on surveys with livestock farmers. It appears that land use changes are often the consequence of other changes made to address work problems, and land use sequences are defined according to workforce and prioritization of tasks. This highlights the importance of considering farmers as workers in order to evaluate land use changes at the farm level and to link them to the human dimension within farming systems.