Land Transport Infrastructures (LTIs) generate multiple impacts on biodiversity, from the first landscape transformations, to the effects of the green areas management throughout their operational phase. Scientific work in road ecology helped spatialize most impacts of ITT on natural environments and biodiversity. In the French territorial context, the 1976 law on Environmental Impact Assessment (EIA) and the Grenelle laws in the 2000s established an increasingly demanding framework for studies. This framework has fostered new engineering practices aiming to ecological transparency of ITT under the doctrine of Avoidance-Reduction-Compensation. Now, developers and researchers also question the continuity of impacts throughout the life phases of ITT, as well as cumulative impacts (combining direct, indirect and/or induced impacts) on biodiversity. The limitations of impact studies and models raise questions on the role of residents in the observation of environmental impacts. This article provides an overview of the impact models and their limitations, with the example of French High Speed Lines (HSL) interrogates these impacts through the prism of the "enlightened catastrophism" and proposes some key-clues for diffuse impacts (cumulative plus unnoticed impacts) on biodiversity. It concludes on the interest of the notion of diffusion to think the spatial scale in a plurality of time frames.