The geographical distribution of organisms and their assembly in habitats were central problems for early scientific ecology at the turn of the 20th century. However, it was difficult to study these phenomena without collecting an enormous amount of local data. A particular group within the scientific community thus became essential for the observation-laden ecological research: lay observers. In the second half of the 19th century, skilled amateurs who were organized in local societies of national history accumulated large quantities of data on the nature and culture of regional environments across Europe. The practice of mapping became a particularly popular method through which to link the network of observers with its objects. In Germany these surveys on regional environments involved a claim for a conservation of landscapes, and were thereby influenced by a specific concept of regionality: "Heimat" (roughly translated as "homeland"). My paper will focus on the concept and practice of "Heimat" in ecological data-gathering in Germany by 1900. As I will show, "Heimat" became a link between academic and amateur science while simultaneously impacting the emerging discipline of ecology on both conceptual and material levels. My paper focuses on the mapping activities of Dresden's society of natural history Isis as well as on private exchange organizations for natural specimens in the states of Saxony and Thuringia. Analysing the social make-up of the observational networks – consisting of a typical mixture of amateur and professional scientists –, my paper highlights the conceptual and material consequences of such collecting activities. The practices of collecting, mapping and preserving local nature and culture, I argue, created a specific emotional tie to landscapes: a particular feeling for "Heimat". Simultaneously, it allowed ecological observations to circulate beyond academic discourses. With its spill-over to the nature conservation movement, the interactions of amateur and professional observers with local environments had long-lasting political and cultural consequences beyond the field of ecology.