Pine root exploration of standing dead tree trunks: a short-cut biocycling process

Aim of study: To characterize the colonization of Pinus herrerae roots in trunks of dead standing trees and to evaluate the composition of roots and decomposing tissues of standing dead trees. Area of study. Jaguariaíva, Paraná state, Southern Brazil. Material and methods: This study evaluated root attributes in the soil, litter, and trunks of dead standing trees and the composition of wood and bark of trees. Root traits (length, mass mycorrhizal colonization, and mean nutrient concentrations), soil and organic layers, and mean nutrient concentrations of wood and bark for were analyzed by non-parametric test. Main results: Approximately 2 to 3.5 years after tree death, roots of adjacent trees in F and H horizon litter migrate into the wood/bark interface. Eight and a half years after tree death, roots of adjacent trees reached up to 3.3 m above the litter surface. At the wood/bark interface, a root mantle formed (length greater than 1 km m-2) with ~5% ectomycorrhizal colonization. Root presence in the wood/bark interface reduced P, K, and Fe concentration of dead wood and Zn concentration in bark. Research highlights: Our results indicate that roots of P. herrerae are capable of colonizing dead tree trunks as a nutrient resource pool. This nutrient acquisition mechanism may function as a shortcut in the biogeochemical cycling of nutrients in forest systems

Cellulosic industrial waste to enhance Pinus taeda nutrition and growth: a study in subtropical Brazil.

Os objetivos deste trabalho foram avaliar a influência de um composto (70% de lodo e 30% de cinza de caldeira) no desenvolvimento de árvores de Pinus taeda em locais de baixo crescimento no Brasil subtropical que apresentavam sintomas de deficiência em ciclos anteriores, e avaliar como o composto influencia as características químicas do solo. Seis meses após o transplante das mudas, foram aplicadas manualmente cinco doses do composto (controle, 14, 25, 49 e 60 Mg ha-1). Nos três anos seguintes, amostras de solo e acículas foram coletadas para análise de nutrientes, juntamente com as medidas dendrométricas das plantas. A análise do solo indicou pequeno aumento na disponibilidade de K e diminuição do Al trocável. Grandes melhorias no crescimento foram observadas em termos de altura e diâmetro na altura do peito, e a clorose da acícula desapareceu quando o composto foi aplicado. Após três anos de aplicação do composto, o volume de tronco aumentou de 13 m3 ha-1do controle para 37 m3 ha-1 no tratamento com 49 Mg ha-1. O crescimento de P. taeda foi inversamente relacionado ao Mn e diretamente relacionado à concentração foliar de K e B. Os resultados sugerem que a aplicação de composto deve ser realizada, uma vez que aumenta o crescimento inicial de P. taeda, sendo uma maneira importante de utilizar resíduos da indústria de polpa celulósica e contribuir para um manejo mais sustentável de solos de baixa fertilidade

Piling secondary subtropical forest residue: long-term impacts on soil, trees, and weeds.

Abstract. The objective of this study was to evaluate the long-term effects of piling secondary forest residue (after 3 decades) on soil chemical properties, growth, and nutrition of Pinus taeda and weeds at three locations. After secondary forest removal and residue piling, areas were cultivated with P. taeda (22 years), followed by eucalyptus (7 years), and returned to P. taeda. At 2 years of age, tree height and needle-nutrient levels of ongoing P. taeda from areas influenced by residue piling and areas outside the piling zone were evaluated. Biomass and nutrient levels of herbaceous and shrub weeds, NDVI indices (via a drone), and soil chemistry were also evaluated. Residue-piled areas displayed a decrease in soil pH and an increase in available soil P and K. Although herbaceous and shrub-weed biomass increased 2.5 to 10 times in residue-piling areas, this did not compromise pine growth. While residue piling had little impact on the nutritional status of pine and weeds, NDVI values indicated greater plant growth in piling areas. In general, the long-term effect of residue piling was an important factor associated with the large variation in tree growth and weed incidence after 3 decades