Ash content, carbon and C/N ratio in paricá in function of NPK fertilization

ABSTRACT Fertilization in areas of forest plantations is needed to supplement plants´ nutritional needs until harvest. An experiment was performed to check the influence of fertilization on levels of ash, carbon and C/N relation in Schizolobium amazonicum. Soil liming was performed and fertilization occurred after 15 days of incubation. S. amazonicum seedlings were produced and submitted to fertilization with N, P and K: N = 0, 40, 80 and 120 kg ha-1; P2O5 = 0, 50, 100 and 200 kg ha-1; K2O = 0, 50, 100 and 200 kg ha-1. The plants were measured after 180 days. The seedlings of 20 treatments with the highest increase in height and diameter were transplanted to the field. Soil was fertilized and limestone was spread; seedlings were distributed into randomized blocks, with six replications. After 12 months, the plants were removed to determine ash, organic carbon, C/N relation contents. The ashes were submitted to digestion to determine nutrient concentrations. Fertilization influenced the levels of ash and organic carbon and C/N relation in S. amazonicum. Results indicate that the species has a potential for energy production.

Nutrition facts and limits for micronutrients in tree species used in urban forestry

ABSTRACT There is a huge lack of researches that evaluate the nutritional limits in tree species used in urban forestry, especially in terms of micronutrients. This study aimed to establish limits and range of micronutrients levels for the proper development of tree species utilized in urban forestry. The study was conducted in the city of Santa Maria-RS-Brazil. Through forest inventory, 23 forest species present in urban forest were selected, and 05 vegetative branches of each tree were collected, in which the contents of B, Cu, Fe, Mn and Zn were analyzed. Ranges of micronutrients' contents were developed for class limits criteria. Nutritional problems were detected for B, Cu and Zn in G. robusta and S. cumini, indicating a need of fertilization and management of these trees. The levels of Mn were within an adequate range only for the species C. illinoensis and H. chrysotrichus. The contents of B were higher than the level considered adequate for H. chrysotrichusand M. nigra. The rates of Fe showed high levels for E. japonica, H. chrysotrichusand S. babylonica. The estimated nutritional limits enable a greater control in the classification of the results for each tree species utilized in urban forestry.

Nutrient composition of mature and litter leaves and nutrient mobilization in leaves of tree species from secondary rainforests in the South of Brazil

The aim of this work was to analyze the concentration of N, P, K, Ca and Mg in mature and litter leaves and nutrient mobilization in leaves of different tree species from secondary forests of the Atlantic Forest. At the study site, located in Floresta do Palmito (Paranaguá, PR), three different forest typologies namely Initial, Intermediary and Advanced were selected. The predominant sequence of nutrients in litter leaves was: N > Ca > Mg > K > P. This sequence was very similar to that found for mature leaves, the difference being only the change in order between Mg and K. Nutrients mobilized in leaves were higher in the typology Advanced compared to the typology Initial, mainly N, P and K. The majority of the species studied did not mobilize Ca to other parts of the plant, except Clusia criuva (typology Intermediary) and Ocotea pulchella (typology Advanced).

O objetivo do presente trabalho foi analisar a concentração de N, P, K, Ca e Mg nas folhas maduras e folhas de serapilheira e mobilização destes elementos nas folhas de diferentes espécies arbóreas de florestas secundárias da Mata Atlântica. A área de estudo localiza-se na Floresta do Palmito (Paranaguá, PR), onde foram selecionadas três tipologias florestais, com diferentes idades e estruturas, denominadas tipologia Inicial, tipologia Intermediária e tipologia Avançada. A seqüência predominante de nutrientes nas folhas de serapilheira foi: N > Ca > Mg > K > P. Esta seqüência foi muito similar nas folhas maduras, sendo a única diferença a mudança de ordem entre o Mg e o K. Os nutrientes mobilizados foram maiores na tipologia Avançada em relação à tipologia Inicial, principalmente no caso do N, P e K. A maioria das espécies estudadas não mobilizou Ca para outras partes da planta, exceto no caso das espécies Clusia criuva (tipologia Intermediária) e Ocotea pulchella (tipologia Avançada).