More is not always better: responses of the endemic plant Vellozia nanuzae to additional nutrients

ABSTRACT

Soil nutrients are one of the main drivers of plant species composition and distribution, mainly due to the role they play in plant survival and reproductive success. However, the nutritional requirements of plants inhabiting their native ecosystems are still poorly known. This is the case for most species of campo rupestre vegetation, which are found on infertile soils of quartzitic and ferruginous origin. The present study evaluated the effects of macronutrients and substrates on survival and growth of the micro-endemic Vellozia nanuzae (Velloziaceae). Plant mortality was about 95 % higher in soil enriched with macronutrients and almost 100 % in soils with added manure in the first 30 days. Individual plants from treatments with added nutrients had lower growth (53 % less) compared to individuals on natural substrates. In conclusion, Vellozia nanuzaesurvived and developed better on soil of its original habitat even though it is acidic and poor in nutrients. Our results show that more nutrients are not always better for the survival and development of native species that inhabit harsh ecosystems.

Keywords: campo rupestre; plant nutrition; rupestrian grasslands; soil nutrients; Velloziaceae