Influencia de los defecaderos de camélidos sobre el desarrollo vegetal y riqueza de especies en morrenas glaciales, Tierra del Fuego

Abstract

The few studies of herbivore-plant interaction in severe environments have concluded that the herbivores have a minor role on the process of colonization in the early states of the succession. This paper describes the effects of camelid (Lamma guanicoe) dung heaps on vegetation patterns on a recent glacial moraine. Floristic composition, diversity, abundance and dispersion syndrome spectra of the vegetation growing on dung heaps was compared with that of control sites unaffected by camelid defecation. Soil parameters of both substrates were analyzed. Vascular species riches and diversity were significantly higher on dung heaps. Anemochory was the dominant dispersion syndrome on both substrate types. Dung heaps had higher levels of organic matter, nitrogen and phosphorus, suggesting more favorable substrate conditions. Thus, dung heaps appear to offer favorable sites for seedling establishment in an otherwise resource-poor environment, and their role as seed sources could accelerate the process of colonisation of glacial moraines.