Sustainability of wood productivity of Pinus taeda based on inventory, export and nutrient cycling

Os impactos do manejo intensivo sobre a sustentabilidade da produção florestal dependem da manutenção da fertilidade dos solos. A contribuição dos resíduos florestais e a ciclagem de nutrientes nesse processo são determinantes. Os objetivos desse trabalho foram: (i) quantificar a biomassa e o estoque de nutrientes na parte aérea e no sistema radicular de um povoamento de Pinus taeda aos 16 anos de idade; (ii) caracterizar o potencial de liberação de nutrientes dos minerais primários e secundários, e o estoque de nutrientes de um Cambissolo Húmico; (iii) quantificar a exportação de nutrientes via colheita de madeira e dos componentes florestais; (iv) avaliar potencial da sustentabilidade da produtividade de madeira com base no balanço de nutrientes, sob diferentes cenários de manejo florestal. Avaliouse uma plantação de Pinus taeda na idade de 16 anos em um Cambissolo Húmico Alumínico léptico de textura argilosa, relevo ondulado no meio-sul catarinense. Amostraram-se dez árvores de cinco classes diamétricas em função da distribuição dos diâmetros à altura do peito. Para cada árvore mensurou-se a biomassa de acículas, galhos, casca, madeira e raízes. Além da biomassa vegetal, amostrou-se serapilheira acumulada e solo nas camadas 0-20, 20-40, 40-60, 60-100, 100-140, 140-180 e 180-190 cm. Equações entre a área seccional a 1,30 m e a biomassa de cada componente foram ajustadas para estimar a biomassa das árvores inventariadas. Equações entre o conteúdo de nutriente e a biomassa do componente também foram ajustadas para estimar a quantidade de cada nutriente em todos os componentes da árvore. As equações permitiram estimar para as demais árvores do talhão a biomassa de cada componente e o seu respectivo estoque de nutrientes. Nas amostras de solo e de serapilheira se determinou a concentração e o estoque de nutrientes, além de no solo realizar-se a caracterização mineralógica. Simularamse três cenários de manejo florestal, retirada da madeira (A), da madeira + casca (B) e da madeira + casca + copa (C) do sistema florestal. A soma de todos os componentes da biomassa foi de 313 Mg ha-1, sendo a madeira o mais representativo (62%). O estoque dos nutrientes na árvore foi N > Ca > K > S > Mg > P. A madeira foi o componente que acumulou as maiores quantidades de nutrientes (210 N, 33 P, 85 K, 91 Ca, 31 Mg e 65 S, kg ha-1). A mineralogia do Cambissolo demonstrou predominância do quartzo nas frações areia, silte e argila, com pequenos traços de vermiculita na fração de silte. A argila é a principal fração que contribui com o intemperismo do solo, devido à transformação da vermiculita-ilita, liberando K. Para os três cenários de manejo, o esgotamento de nutrientes do sistema solo-biomassa foi: P > S > N > K > Mg > Ca. O P e o S permaneceram como mais limitantes no cenário A decorrente de seus baixos estoques disponíveis no solo. No cenário B, o número de rotações florestais se alterou para N, K e S. O cenário C resultou na maior diminuição de produtividade, possibilitando para o P duas rotações e para o Mg 14. Desta forma, evidenciou-se, pelo número potencial de rotações de cultivo, que os diferentes cenários de manejo podem em curto prazo comprometer a sustentabilidade do P. taeda.The impacts of intensive management on the sustainability of forest production depends on the maintenance of soil fertility. The contribution of forest residues and nutrient cycling in this process are crucial. The objectives of this study were: (i) quantify the biomass and nutrient stocks in the shoot above and belowground and root system of a stand of 16-years-old Pinus taeda, (ii) characterize the potential release of nutrients from primary and secondary minerals, and the stock of nutrients in a Humic Cambisol (iii) quantify the export of nutrients through wood harvesting and forest components, (iv) evaluate the potential of sustainability in wood based on the balance of nutrients under different forest management scenarios. We evaluated a 16-years-old plantation of Pinus taeda in a Humic Cambisol, undulating relief in the middle-south of Santa Catarina. Ten trees were sampled from five diameter classes according to the distribution of diameter at breast height. Biomass of the needles, twigs, bark, wood and roots were measured for each tree. Besides the biomass and litter soil samples were collected from the layers 0-20, 20-40, 40-60, 60-100, 100- 140, 140-180 and 180-190 cm. Equations which has the sectional area of 1.30 m as independent variable and the biomass of each component as the dependent variable were adjusted to estimate the biomass of the entire studied forest. Furthermore, equations which has the nutrient content of the component as the dependent variable and the biomass as independent variable were adjusted to estimate the amount of each nutrient in all parts of the tree.The concentration and stock of nutrient were determined from the soil sample collected. In addition, a mineralogical characterization was performed for the soil and litters. Three scenarios simulated forest management, removal of wood (A), the wood and bark (B) and wood + bark + cup (C) of the forest system. The sum of all components of biomass was 313 mg h-1 being the most representative of the wood (62%). The stock of nutrients in the tree was N> Ca> K> S> Mg> P. The wood was the largest exporter of nutrients (210 N, 33 P, 85 K, 91 Ca, 31 Mg and 65 S, kg ha-1). The mineralogy of the Cambisol showed the predominance of quartz sand, silt and clay, with small traces of vermiculite in the silt fraction. Clay is the main fraction which contributes to the weathering of the soil due to the transformation of illite-vermiculite, releasing K. The depletion of nutrients from the soil-biomass was: P> S> N> K> Mg> Ca and S. The P and S remained as the most limiting at the scenario A due to its low inventories in the soil. At the scenario B, the number of rotations forest changed to N, K, S. The scenario C resulted in the greatest reduction in productivity, allowing for P two rotation and for Mg 14. It was evident by the number of potential crop rotations, the different management scenarios in the short term may jeopardize the sustainability of P. taeda

NUTRITIONAL BALANCE, ESSENTIAL OIL AND WOOD PRODUCTION FROM Corymbia citriodora Hill & Johnson WITH SEWAGE SLUDGE AND MINERAL FERTILIZER APPLICATIONS

The Corymbia citriodora is one of the most important forest species in Brazil and the reason is the diversity of its use, because it produces good quality wood and the leaves may be used for essential oil production. Although, there are not many studies about species and the handling effect in the nutritional balance. This study aimed to evaluate the biomass production and nutrient balance in the conventional production of essential oil and wood of Corymbia citriodora with sewage sludge application. The experiment design established was the randomized blocks, with four replicates and two treatments: 1 - fertilization with 10 tons ha(-1) (dry mass) of sewage sludge, supplemented with K and B, and 2 - mineral fertilization. It was evaluated the aerial biomass production, the nutrient export of the leaves, the essential oil and wood production at four years old. The trees that received application of sewage sludge produced 20 % more leaves biomass than the trees with mineral fertilization, resulting in larger oil production. Besides, the trees with sewage sludge application produced 14.2 tons ha(-1) yr(-1) of woody biomass that was 27 % higher than the treatment with mineral fertilization. For both treatments the N balance was negative, but treatment with sewage sludge application (-45 kg ha(-1)) was four times lower than the observed on mineral fertilization treatment (-185 kg ha(-1)). It may be concluded in this paper that the application of sewage sludge benefits the production of leaves biomass, essential oil and wood, besides result better nutritional balance of the Corymbia citriodora production system

Balanço nutricional, produção de óleo essencial e madeira de Corymbia citriodora Hill & Johnson com aplicação de lodo de esgoto e fertilizante mineral

The Corymbia citriodora is one of the most important forest species in Brazil and the reason is the diversity of its use, because it produces good quality wood and the leaves may be used for essential oil production. Although, there are not many studies about species and the handling effect in the nutritional balance. This study aimed to evaluate the biomass production and nutrient balance in the conventional production of essential oil and wood of Corymbia citriodora with sewage sludge application. The experiment design established was the randomized blocks, with four replicates and two treatments: 1 – fertilization with 10 tons ha-1 (dry mass) of sewage sludge, supplemented with K and B, and 2 - mineral fertilization. It was evaluated the aerial biomass production, the nutrient export of the leaves, the essential oil and wood production at four years old. The trees that received application of sewage sludge produced 20 % more leaves biomass than the trees with mineral fertilization, resulting in larger oil production. Besides, the trees with sewage sludge application produced 14.2 tons ha-1/yr-1 of woody biomass that was 27 % higher than the treatment with mineral fertilization. For both treatments the N balance was negative, but treatment with sewage sludge application (-45 kg ha-1) was four times lower than the observed on mineral fertilization treatment (-185 kg ha-1). It may be concluded in this paper that the application of sewage sludge benefits the production of leaves biomass, essential oil and wood, besides result better nutritional balance of the Corymbia citriodora production system.O Corymbia citriodora é uma das espécies florestais mais difundidas no Brasil, sendo um dos motivos a diversidade de uso da espécie, pois produz madeira de qualidade e as folhas podem ser utilizadas para produção de óleo essencial. Entretanto, é uma espécie que não tem muitos estudos relacionados ao efeito do manejo no balanço nutricional. O objetivo deste trabalho foi avaliar a produção de biomassa e o balanço nutricional no sistema convencional de produção de óleo essencial e madeira de Corymbia citriodora com a aplicação de lodo de esgoto. O delineamento experimental utilizado foi em blocos casualizados, com quatro repetições e dois tratamentos, sendo eles: 1 - Fertilização com 10 t ha-1 (base seca) de lodo de esgoto, complementado com K+B, e 2 - Fertilização mineral. Foi avaliada a produção de biomassa aérea das árvores e dos respectivos componentes (folha, galho, casca e lenho), a exportação de nutrientes via colheita da folhas, a produção de óleo essencial e da madeira aos quatro anos de idade. Observou-se que as árvores fertilizadas com lodo produziram 20 % mais folhas durante o ciclo de produção, o que resultou em maior produção de óleo essencial. Além disso, o tratamento com a aplicação do lodo produziu 14,2 t ha-1 ano-1 de biomassa lenhosa, que foi 27 % superior ao tratamento com fertilização mineral. Para ambos os tratamentos o balanço do N foi negativo, sendo que a exportação de N no tratamento com aplicação de lodo de esgoto (-45 kg h-1) foi 4 vezes menor que a observada no tratamento com fertilização mineral (-185 kg ha-1). Com o presente estudo pode-se concluir que a aplicação de lodo de esgoto em plantios de Corymbia citriodora beneficia a produção de biomassa foliar, óleo essencial e madeira, além de propiciar melhor balanço nutricional

Balan\ue7o nutricional, produ\ue7\ue3o de \uf3leo essencial e madeira de Corymbia citriodora Hill & Johnson com aplica\ue7\ue3o de lodo de esgoto e fertilizante mineral

The Corymbia citriodora is one of the most important forest species in Brazil and the reason is the diversity of its use, because it produces good quality wood and the leaves may be used for essential oil production. Although, there are not many studies about species and the handling effect in the nutritional balance. This study aimed to evaluate the biomass production and nutrient balance in the conventional production of essential oil and wood of Corymbia citriodora with sewage sludge application. The experiment design established was the randomized blocks, with four replicates and two treatments: 1 \u2013 fertilization with 10 tons ha-1 (dry mass) of sewage sludge, supplemented with K and B, and 2 - mineral fertilization. It was evaluated the aerial biomass production, the nutrient export of the leaves, the essential oil and wood production at four years old. The trees that received application of sewage sludge produced 20 % more leaves biomass than the trees with mineral fertilization, resulting in larger oil production. Besides, the trees with sewage sludge application produced 14.2 tons ha-1/yr-1 of woody biomass that was 27 % higher than the treatment with mineral fertilization. For both treatments the N balance was negative, but treatment with sewage sludge application (-45 kg ha-1) was four times lower than the observed on mineral fertilization treatment (-185 kg ha-1). It may be concluded in this paper that the application of sewage sludge benefits the production of leaves biomass, essential oil and wood, besides result better nutritional balance of the Corymbia citriodora production system.O Corymbia citriodora \ue9 uma das esp\ue9cies florestais mais difundidas no Brasil, sendo um dos motivos a diversidade de uso da esp\ue9cie, pois produz madeira de qualidade e as folhas podem ser utilizadas para produ\ue7\ue3o de \uf3leo essencial. Entretanto, \ue9 uma esp\ue9cie que n\ue3o tem muitos estudos relacionados ao efeito do manejo no balan\ue7o nutricional. O objetivo deste trabalho foi avaliar a produ\ue7\ue3o de biomassa e o balan\ue7o nutricional no sistema convencional de produ\ue7\ue3o de \uf3leo essencial e madeira de Corymbia citriodora com a aplica\ue7\ue3o de lodo de esgoto. O delineamento experimental utilizado foi em blocos casualizados, com quatro repeti\ue7\uf5es e dois tratamentos, sendo eles: 1 - Fertiliza\ue7\ue3o com 10 t ha-1 (base seca) de lodo de esgoto, complementado com K+B, e 2 - Fertiliza\ue7\ue3o mineral. Foi avaliada a produ\ue7\ue3o de biomassa a\ue9rea das \ue1rvores e dos respectivos componentes (folha, galho, casca e lenho), a exporta\ue7\ue3o de nutrientes via colheita da folhas, a produ\ue7\ue3o de \uf3leo essencial e da madeira aos quatro anos de idade. Observou-se que as \ue1rvores fertilizadas com lodo produziram 20 % mais folhas durante o ciclo de produ\ue7\ue3o, o que resultou em maior produ\ue7\ue3o de \uf3leo essencial. Al\ue9m disso, o tratamento com a aplica\ue7\ue3o do lodo produziu 14,2 t ha-1 ano-1 de biomassa lenhosa, que foi 27 % superior ao tratamento com fertiliza\ue7\ue3o mineral. Para ambos os tratamentos o balan\ue7o do N foi negativo, sendo que a exporta\ue7\ue3o de N no tratamento com aplica\ue7\ue3o de lodo de esgoto (-45 kg h-1) foi 4 vezes menor que a observada no tratamento com fertiliza\ue7\ue3o mineral (-185 kg ha-1). Com o presente estudo pode-se concluir que a aplica\ue7\ue3o de lodo de esgoto em plantios de Corymbia citriodora beneficia a produ\ue7\ue3o de biomassa foliar, \uf3leo essencial e madeira, al\ue9m de propiciar melhor balan\ue7o nutricional

Sustainability of Wood Productivity of Pinus TaedaBased on Nutrient Export and Stocks in the Biomass and in the Soil

ABSTRACT The impact of intensive management practices on the sustainability of forest production depends on maintenance of soil fertility. The contribution of forest residues and nutrient cycling in this process is critical. A 16-year-old stand of Pinus taeda in a Cambissolo Húmico Alumínico léptico (Humic Endo-lithic Dystrudept) in the south of Brazil was studied. A total of 10 trees were sampled distributed in five diameter classes according to diameter at breast height. The biomass of the needles, twigs, bark, wood, and roots was measured for each tree. In addition to plant biomass, accumulated plant litter was sampled, and soil samples were taken at three increments based on sampling depth: 0.00-0.20, 0.20-0.40, 0.40-0.60, 0.60-1.00, 1.00-1.40, 1.40-1.80, and 1.80-1.90 m. The quantity and concentration of nutrients, as well as mineralogical characteristics, were determined for each soil sample. Three scenarios of harvesting intensities were simulated: wood removal (A), wood and bark removal (B), and wood + bark + canopy removal (C). The sum of all biomass components was 313 Mg ha-1.The stocks of nutrients in the trees decreased in the order N>Ca>K>S>Mg>P. The mineralogy of the Cambissolo Húmico Alumínico léptico showed the predominance of quartz sand and small traces of vermiculite in the silt fraction. Clay is the main fraction that contributes to soil weathering, due to the transformation of illite-vermiculite, releasing K. The depletion of nutrients from the soil biomass was in the order: P>S>N>K>Mg>Ca. Phosphorus and S were the most limiting in scenario A due to their low stock in the soil. In scenario B, the number of forest rotations was limited by N, K, and S. Scenario C showed the greatest reduction in productivity, allowing only two rotations before P limitation. It is therefore apparent that there may be a difference of up to 30 years in the capacity of the soil to support a scenario such as A, with a low nutrient removal, compared to scenario C, with a high nutrient removal. Hence, the effect of different harvesting intensities on nutrient availability may jeopardize the sustainability of P. taeda in the short-term