Spatial variation of herbaceous cover species community in Cu-contaminated vineyards in Pampa biome.

ABSTRACT

Study's objective was to evaluate spatial variability of herbaceous cover species community in vineyards cultivated in soil with increasing Cu levels in Pampa biome. Three vineyards, with increasing soil Cu available contents and a natural field area (NF), were selected. In each experimental area, soil Cu content, botanical composition, cumulative aerial biomass, and aerial part Cu concentration, in most frequent species, were evaluated. In total, 39 vascular plant species were identified, including four exotic species. Biodiversity indicators did not significantly correlate with soil Cu. However, botanical composition variation could be observed. In NF, Poaceae and Asteraceae families presented greater dry mass contribution, while this contribution decreased in higher soil Cu concentration areas. The Cu concentration and accumulation in plant aerial part were higher in older vineyards, as plant aerial part accumulated, in average, 13.8 mg Cu m-2. Among species found in experimental fields, Ageratum conyzoides, a species known to form Cu-tolerant populations, occurred in most areas, especially in vineyards, presenting higher aerial Cu concentrations, with a mean of 126.47 mg kg-1. Soil enrichment with Cu did not alter the vegetation's biodiversity, but may have contributed to the botanical composition modification. The native species, P. plicatulum and A. conyzoides, presented a high bio-accumulation factor and are potential candidates for phytoremediation techniques.