Respostas estruturais foliares de Eremanthus incanus (Less.) Less.(Asteraceae) ocorrentes em área de deposição de rejeito de mineração de quartzito

Abstract

Currently, the regeneration of degraded areas is a global concern, but soil impoverishment caused by rock removal makes such action difficult. However, it is possible to find individuals of Eremanthus incanus, also known as “candeia”, growing and establishing themselves naturally in piles of quartzite extraction waste. The literature describes their ease of establishing themselves in adverse environments, but little is known about the anatomical and nutritional strategies that may favor their survival in these environments. Therefore, the objective of this study was to analyze the structural characteristics of E. incanus leaves present in soils with deposition of quartzite destruction waste and compare them with plants naturally occurring in Campo rupestre. The study was carried out in the municipality of Luminárias (MG) in two distinct areas: a region occupied by quartzite waste piles and a native formation of Campo rupestre. In which five plots were delimited per area, and three individuals were sampled per plot. For this purpose, morphometric characteristics were measured in each sampled tree. In addition, leaf anatomy, specific leaf area (SLA), chlorophyll estimation (SPAD), leaf chemistry and soil chemistry were analyzed. The data were submitted to the Welch Two Sample or Wilcox test, at 5% probability. Anatomical and morphometric parameters such as xylem vessel area and trichome thickness and DBH and CAP showed statistical difference between the study areas. The xylem vessel area was larger in the area with waste deposition, being an adaptation to avoid embolism in the vessels. The amount of organic matter was statistically higher in the Campo rupestre area. Foliar chemical compounds such as K, Ca, Mg, Mn, Zn, and Fe had higher concentrations in plants collected on rock waste, while S, B, and Cu were higher in the Campo rupestre area. Thus, E. incanus performs well in the use of nutrients available in the waste, without the need for major structural adjustments (among those analyzed) in the leaves, and has potential for revegetation of these areas.