Micronutrientes na serapilheira depositada em florestas secundárias no litoral do Paraná

Abstract

Os micronutrientes são muito importantes na manutenção da fertilidade do solo, sendo sua deposição via serapilheira em Floresta Atlântica ainda pouco estudada. Esse trabalho objetivou avaliar a concentração e o aporte de micronutrientes na serapilheira depositada em áreas secundárias da Floresta Ombrófila Densa Submontana em Antonina, PR. A serapilheira foi coletada em três parcelas em diferentes estágios de sucessão secundária, separada em frações e folhas de espécies conhecidas, seca e pesada para realização das análises químicas de Cu, Mn, Fe e Zn. A ordem de concentração dos micronutrientes foi Mn > Fe > Cu > Zn, com teores de Mn e Fe relativamente altos. Entre as frações, houve grande variação nos teores de micronutrientes, sendo que a concentração de Cu foi maior nos ramos e miscelânea, o teor de Fe foi maior nas folhas e na miscelânea, o Mn foi superior nos ramos e o Zn foi maior nos ramos e folhas. Houve grande variação nos teores nas estações do ano, sem tendência definida. Os teores de Cu e Fe foram menores na FS-2, enquanto o Zn não apresentou tendência definida. O teor de Mn aumentou com o avanço da sucessão secundária, o que indica bioacumulação deste elemento no solo florestal. Palavras-chave: ciclagem de micronutrientes, Floresta Atlântica, serapilheira, sucessão florestal. Micronutrients in litter deposited in a successional gradient of Atlantic Rain Forest in Paraná state, Brazil ABSTRACT: Micronutrients are very important in the maintenance of soil fertility, and their deposition through litter in the Atlantic Forest is still little studied. This study aimed to evaluate the concentration and input of micronutrients by litterfall in secondary areas of Submontane Atlantic Rain Forest in Antonina, PR. The litter was collected in three plots at different stages of secondary succession, separated into fractions and leaves of selected species, dried and weighed to perform the chemical analysis of Cu, Mn, Fe and Zn. The concentration order of the micronutrients was Mn > Fe > Cu > Zn, with relatively high Mn and Fe contents. Among of litter fractions, there was a great variation in the micronutrient contents, where the concentration of Cu was higher in the branches and miscellaneous, the Fe content was higher in the leaves and in the miscellaneous, the Mn was superior in the branches and the Zn was higher in the branches and leaves. There was a great variation in the contents of the seasons of the year, with no defined trend. Cu and Fe contents were lower in FS-2, while Zn showed no particular trend. Mn content increased with forest sucession suggesting bioaccumulation of Mn in the forest soil.

Patterns of litter and nutrient return to the soil during passive restoration in Cerrado, Brazil

“…(Rengel 2007). The micronutrient order in the litter (Fe > Mn > B > Zn > Cu) was similar for passive restoration sites, and have been corroborated by other tropical forests (Bianchin et al 2017;Klippel et al 2016;Lopez Hernandez et al 2014). After aluminum, iron is the second most abundant metal in the Earth's crust, possessing extremely low mobility (Broadley et al 2012).…”

“…There are few studies on micronutrient potential return. However, this study verifies that, the potential return of iron and manganese were lower than Dense Mountain Ombrophilous Forest (Freitas et al 2015), as well as Ombrophilous Dense Forest (Caldeira et al 2008) and Submontane Atlantic Rain Forest (advanced) (Bianchin et al 2017). Boron had shown to be lower than the values observed in Lowland (Sayer et al 2020) and Dense Mountain Ombrophilous Forest (Freitas et al 2015) but higher than Ombrophilous Dense Forest (Caldeira et al 2008).…”

Contribution of Pseudobombax aff. petropolitanum to Nutrient Cycling in Woody Vegetation from a Neotropical Inselberg

“…The descending order of macronutrient (N > Ca > K > Mg > P > S) and micronutrient (Mn > Fe > B > Zn > Cu) concentration observed in the inselberg litterfall was the same for a fragment of Seasonal Deciduous Forest in the municipality of Itaara, Rio Grande do Sul state (Schumacher et al, 2018), and closed to that observed in litterfall from two sites of Alluvial Dense Ombrophilous Forest at different successional stages (Ca > N > K > Mg > P; Mn > Fe > Zn > Cu) in Salto Morato Natural Reserve, Paraná state (Scheer et al, 2011); the concentration of S and B were not determined in the referred study. Regarding specifically the concentration of micronutrients, the decreasing order was also very similar in comparison with the litterfall of areas of Submontane Dense Ombrophilous Forest (Mn > Fe > Cu > Zn), regardless of the successional stage (initial, intermediate, advanced), in the Guaricica Natural Reserve, Paraná state (Bianchin et al, 2017).…”

“…The data were individualized in seasons (spring: September, October, and November; summer: December, January, and February; autumn: March, April, and May; winter: June, July, and August), following the methodology of other studies (Bianchin et al, 2017). The interaction effects between season (spring, summer, autumn, winter) and litterfall fraction (PP, OS) were investigated within five pseudo-replicates for both litterfall and C content, and three pseudo-replicates for nutrient concentration.…”

“…Nutrient cycling is an important soil entry route for nutrients derived from senescent plant material, and studies have focused on litterfall and its nutrient concentration in forest ecosystems, such as Ombrophilous Forest (Bianchin et al, 2017;Camara et al, 2018a;2018b), Semideciduous Forest (Scheer et al, 2011;Machado et al, 2018;Carvalho et al, 2019;Dick & Schumacher, 2020;Menezes et al, 2020;Câmara et al, 2021;Lagemann et al, 2022), and Deciduous Forest (Schumacher et al, 2018;Araújo et al, 2020). Regardless of the forest typology being subject to greater or lesser seasonality, climate conditions influence nutrient cycling (Scheer et al, 2011;Bianchin et al, 2017;Dick & Schumacher, 2020).…”