The current degradation crisis in arid and semiarid lands is creating severe economic and social difficulties, aggravating the food situation and greatly affecting the least developed countries and small farmers around the world. However, little attention has been given to the wealth of knowledge held by rural livestock farmers on this phenomenon, particularly those linked to environmental indicators. The objective of this work was to investigate plant attributes used by smallholders as ethnoindicators of short- and long-term environmental change. Using an ethnoecological approach, the study was carried out along with rural livestock smallholders who inhabit the central-northern Patagonian plateau. Open and semistructured interviews were carried out with 35 informants who were strongly associated with subsistence livestock farming. A total of 23 plant species were registered as being involved in detection of environmental change. The types of environmental change recorded were short term (such as droughts) and long term (such as desertification). These plants presented 14 different indicators, involving various life forms: gramineous or graminoid plants (65%), woody species (30%), and plants that are not gramineous or graminoid (5%). The plant community attributes that functioned as indicators were presence/absence of species, species abundance, and visible plant characteristics such as exposed roots, changes in plant architecture, and/or changes in phenology. The traits used as indicators provide complex information that is essential to the understanding of plant development and the structure and functioning of the managed ecosystem. Key lessons from this work include the following: The integration of plant ethnoindicators is important for the successful diagnosis and permanent monitoring of arid lands; and development plans incorporating indicators constructed with the involvement of the local people, as well as the rangeland professionals, must help to mobilize knowledge and practice on an equal basis.