Biosaline production of seedlings of native species from the Caatinga dry forest/Producao biossalina de mudas de especies florestais nativas da Caatinga

The Caatinga dry forest species are well adapted and resilient to the climatic conditions of the Brazilian semiarid region. However, this is one of the more vulnerable ecosystems to climate change, due to increasing deforestation and drought in the last years. Water shortage in this region has prompted studies into the possibility of safe brackish water use/reuse for forage and forest seedling production. We tested, in this study, alternative sources to potable water to irrigate forest seedlings in nurseries, which have high water expenditure. The trail was performed in a completely randomized design with three irrigation water sources and four replications with five seedlings. Biosaline fish cropping water; brackish groundwater and tap water were used for irrigation of seedlings of Anadenanthera colubrina, Erythrina velutina and Aspidosperma pyrifolium, grown in a screened nursery greenhouse in polyethylene bags filled with sand and soil (1:1 v/v). Seed germination and seedlings growth were evaluated for up to 80 days. Results showed that irrigation with biosaline fish farming waste water with electrical conductivity values > 6 dS.[m.sup.-1] did not compromise the seed germination nor the seedlings growth in nursery. Brackish ground water, however, slowed the development of seedlings. Faced with the possibility of water shortages due to climate change, the use of non-potable sources of water, can therefore, be an alternative and low input technique for the production of seedlings of native species from Caatinga. Keywords: Brackish water; Seedling production; Irrigation; Nursery As espécies florestais da Caatinga estão adaptadas e são resilientes às condições climáticas da região semiárida brasileira. No entanto, este é um dos ecossistemas mais vulneráveis às mudanças climáticas, devido ao aumento do desmatamento e à seca dos últimos anos. A escassez de água nessa região induziu estudos sobre a possibilidade de utilização/reutilização segura da água salobra para a produção de forragem e de mudas florestais. Testaram-se, nesse estudo, fontes alternativas à água potável para irrigação de mudas florestais em viveiros, que apresentam elevado gasto de água. O ensaio foi realizado em delineamento inteiramente casualizado com três fontes de água para irrigação e quatro repetições de cinco plântulas. Água biossalina, provinda de cultivo de peixe; água subterrânea salobra e água de abastecimento foram utilizadas para irrigar mudas de Anadenanthera colubrina, Erythr