Responses of restinga plant species to pollution from an iron pelletization factory

Abstract

shape Byrsonima sericea DC. (Malpighiaceae), shape Cordia verbenacea DC. (Boraginaceae) and shape Psidium guineense SW. (Myrtaceae) were studied in two experimental sites: a restinga forest fragment, near an iron pelletization factory (mining area) and a restinga conservation unit “Paulo Cesar Vinha State Park”. The aims were verify the effects of emissions from a pelletization factory on some anatomical and physiological parameters and on absorption and accumulation of particulate iron by the leaves. A protocol was adjusted using Prussian blue reaction to histochemical detection of iron. Comparing the same species in two locals, shape C. verbenacea was the greatest accumulator of metallic iron, whereas shape B. sericea presented greater content of sulphur in mining area. The greater leaf contents of metallic iron may be related to the adhesion of the particles deposited on the leaves and to the characteristics of the covering tissue and the leaf. The foliar parameters evaluated in addition to soil analysis and atmospheric precipitation data indicated that the effects of particulate deposition occurred due foliar uptake. Structural characteristics such as peltate trichomes of leaf abaxial surface in shape B. sericea and hypodermis observed in shape B. sericea (one layer) and shape P. guineense (3--4 layers), probably formed a barrier lessening the penetration of metallic iron into the mesophyll as evidenced by the lower iron leaf content and iron accumulation in trichomes observed in these two species. In leaves of shape C. verbenacea occurred a positive reaction for iron in trichomes, epidermic cells at both faces, stomata, some xylem cells, collenchyma and endodermis at the midrib, and mesophyll tissues. The obtained data indicated that the unit conservation is also under pollution impact.