Ciclagem De Nutrientes De Um Plantio De Eucalipto Em Regeneração De Espécies Nativas No Sub-Bosque

Abstract

ResumoO processo de ciclagem de nutrientes é importante para a sustentabilidade das formações florestais naturais e implantadas. Buscando contribuir com um melhor entendimento sobre esse processo, o objetivo deste estudo foi avaliar a ciclagem de nutrientes em um plantio puro de eucalipto com regeneração de espécies nativas em seu sub-bosque. Para o aporte e decomposição da serapilheira foram utilizados, respectivamente, coletores cônicos e litter bags. Posteriormente foram separadas as frações foliares de eucalipto (Corymbia citriodora) (EUC), regeneração nativa do sub-bosque (REG) e da fração controle com espécies de uma Floresta Estacional Semidecidual (FES). A seqüência do retorno de macronutrientes pelas folhas seguiu a mesma ordem para todas as frações foliares: N>K>P. As folhas de FES aportaram mais macronutrientes ao solo, enquanto EUC e REG aportaram a mesma quantidade. A degradação foliar foi mais elevada para FES, seguida da REG e do EUC. A velocidade de liberação de macronutrientes das folhas do EUC obedeceu a seguinte ordem: K>P>N. Enquanto para a FES e REG, o retorno foi na sequência: N>K>P e K>P>N, respectivamente. Esses resultados demonstram a importância da conservação da serapilheira nos ambientes estudados, principalmente na proteção e retorno de nutrientes para esses solos. Palavras-chave: Plantios homogêneos; material orgânica; serapilheira; aporte e decomposição de biomassa; conservação do solo. Abstract Nutrient cycling in the eucalyptus plantation with a regeneration of native species in understory.The nutrient cycling process is important for the sustainability of natural and planted forest formations. Therefore, the aim of this study was to evaluate the contribution of Nutrient cycling in the eucalyptus plantation with a regeneration of native species in understory. For deposition and decomposition of litter were used conical collectors and litter bags respectively. Subsequently were separated the foliar fractions of eucalyptus (Corymbia citriodora) (EUC), the native understory regeneration (REG) and a control with fraction of Semideciduous Forest species (FES). The sequence of the return of nutrients through the leaves followed the same order for all foliar fractions: N> K>P. The leaves of FES deposited more macronutrients on the ground, while EUC and REG contributed the same amount. The leaf degradation was higher for FES, then the REG and EUC. The rate of nutrients release from the EUC leaves followed the order K>P>N, while FES and REG this return following order N>K>P and K>P>N respectively. These results demonstrate the importance of litter conservation in the study site, especially in the protection and nutrient return of these soils. Keywords: Homogeneous plantations; organic material; litter input and decomposition of biomass; soil conservation. INTRODUÇÃOO aporte e a transformação da serapilheira são fundamentais para manutenção das propriedades dos solos tanto para florestas nativas quanto para os plantios de espécies exóticas comerciais (PINTO et al., 2008;SCHUMACHER et al., ...

INITIAL DEVELOPMENT OF EUCALYPTUS CLONE I144 (Eucalyptus grandis x Eucalyptus urophylla) IN RESPONSE TO FOLIAR AND SOIL FERTILIZATION

“…Nitrogen-N was between low and adequate levels, Ca between suitable and deficient and Mg between low and deficient. According to Carvalho et al (2017) in Eucalyptus forests the rate of nutrients release from leaves followed the K>P>N order, which matches with the results of Abreu-Junior et al (2017), that also reported P and N increases in Eucalyptus leafs during the initial growth of the specie.…”

“…The plant height growth was higher than that observed by Magalhães (2013) for clone I144, in Vitória da Conquista, Bahia. They also presented superior growth in relation to data obtained by Cipriani et al (2013) in Porto Velho, Rondônia. …”

Litter Dynamics in Eucalyptus and Native Forest in the Brazilian Cerrado

“…In the case of planted forest systems, changes in litterfall and litter layer can be influenced by characteristics of the species, particularly of the chemical composition (Ferreira et al, 2016), management, plant density (Hakamada, Hubbard, Ferraz, Stape, & Lemos, 2017), age of trees (Corrêa, Schumacher, & Momolli, 2016), type of clone (Conti-Junior, Silva, & Couto, 2017) and climatic conditions (temperature and precipitation) (Binkley et al, 2017;Carvalho et al, 2017).…”

Temporal Variability of Granulometric Fractions of the Organic Matter of an Ultisol in a Transition Area

“…Its largest share is present in the oceans with 38,000 Pg, followed by geological formations with 5000 Pg, and finally the soil carbon compartment (2500 Pg), which consists of mineral (1000 Pg) and organic carbon (1500 Pg) [1], the latter compartment being the most susceptible to modifications. The changes in carbon stocks in the organic compartment of the soil can be influenced by several factors, such as climatic, geographic and physiological [2]. In addition, anthropic activities, especially agriculture can significantly influence their changes.…”