A Complete Assessment of Carbon Stocks in Above and Belowground Biomass Components of a Hybrid Eucalyptus Plantation in Southern Brazil

Hybrid eucalypt clones are grown for fiber production worldwide and to provide an ecosystem service that can store atmospheric carbon at a very fast rate. This study assessed the carbon stocks in the soil and various tree fractions in a 10-year-old plantation of Eucalyptus urophylla S.T. Blake × Eucalyptus globulus Labill. in Southern Brazil. Four experimental plots were established, and an inventory of Eucalyptus trees was conducted by considering five diametric classes. Three trees in each diametric class were harvested for biomass and carbon quantification. The understory biomass of native trees was quantified in five subplots and the litter was quantified in 16 subplots. Organic C was quantified in the soil (SOC) and roots (diameter ≤ 0.5 cm) to a depth of 100 cm. The C concentration in the different biomass fractions of the eucalyptus trees were 55.7% (±0.6), 50.4% (±0.4), 49.5% (±0.6) and 45.4 % (±0.9) for leaves, branches, wood and bark, respectively. The C concentrations in the understory fractions were 51.4% (±1.0) for the canopy and 50.0% (±0.9) for the stem. The carbon concentration in the fine root biomass was 45.7% (±1.4). Soil C concentrations were 1.23% (±0.32), 0.97% (±0.10), 0.45% (±0.14), and 0.24% (±0.10) for depths of 0–25, 25–50, 50–75, and 75–100 cm. C was allocated in: (a) the trees (aboveground fraction = 118.45 Mg ha−1 and belowground fraction = 30.06 Mg ha−1 ), (b) the understory = 1.44 Mg ha−1 , (c) the litter = 8.34 Mg ha−1 , and (d) the soil (without roots) = 99.7 Mg ha−1 . The share of total C stock (a + b + c + d = 258.0 Mg ha−1 ) was similar in the aboveground (49.7%) and belowground (50.3%) fractions, thus indicating a very high rate of C sequestration in the biomass. Eucalyptus plantations in Brazil are fast growing (for this study = 36.7 m3 ha−1 year−1 ) and contribute to intense carbon sequestration in above and belowground biomass (14.8 Mg ha−1 year−1 ).The National Council of Technological and Scientific Development (CNPq—Brazil) awarded the first author with a research grant (Award Number 200589/2014-8) for a one-year stay at the USC in SpainS

Nutritional prescriptions for Eucalyptus plantations: lessons learned from Spain

Eucalyptus globulus Labill is the main exotic broadleaf species planted and managed for pulp and energy production in Spain, where it covers an area of more than 0.6 million ha. The climatic and soil conditions of the planting areas range from the predominantly acidic or fertile soils developed over limestone in Atlantic areas of the north and northwest of the Iberian Peninsula to the less weathered soils developed from slates, sandy deposits or limestone in the drier southwest. The widely varying conditions explain the large differences in proposed fertilizer prescriptions. This review paper provides an analysis of the proposed practices and prescriptions by considering trial results and the need to develop site specific prescriptions for seedling standards and fertilization at planting establishment. Analysis of nutritional studies and of nutrient balances over a whole rotation is presented in order to provide basic information for defining maintenance fertilization, identified as the main bottleneck for sustainable wood production in these stands. Different fertilization practices are used by non industrial owners and Spanish pulp companies, with the last one applying a more intense management relying in more fertilization. A complete consideration of nutrition-related operation and decisions is shown to be essential for maintaining potential productivity, reduce biotic and abiotic damages and reduce mineral fertilization needsWe thank the National Council of Technological and Scientific Development (CNPq-Brazil) for a scholarship awarded to the first authorS

Concentração e retranslocação de nutrientes em acículas de Pinus taeda L.

Aiming at evaluating nutrients concentration and retranslocation in the Pinus taeda L. needles, this study was developed in two stands, in native grass area and in second rotation area, with same species and same age (7.5 years old) in Cambará do Sul, RS. The needles were collected in plants in four orthogonal points (South, North, East and West), sampled new needles, mature needles and old needles. The material was dried in a stove, milled and chemically analyzed (macro and micronutrients). The concentrations of N, P, K, B, Cu and Zn had decreased, of Ca, Fe and Mn increased, and the Mg and S have remained constant with the age of the needles. The retranslocation rate (old-new needles) was more than 50% for most nutrients, except for Mn and Fe, showed that cumulative effect and the Ca reference element.Objetivou-se avaliar a concentração e retranslocação de nutrientes em acículas de Pinus taeda L.. O estudo foi realizado em dois povoamentos, um implantado em área de campo nativo e outro em área de segunda rotação, com mesma espécie e mesma idade (7,5 anos) no município de Cambará do Sul, RS. As acículas foram coletadas nas plantas nos quatro pontos ortogonais (sul, norte, leste e oeste), amostrando-se acículas jovens, maduras e senescentes. O material foi seco em estufa, moído e analisado quimicamente (macro e micronutrientes). As concentrações de N, P, K, B, Cu e Zn diminuíram, de Ca, Fe e Mn aumentaram e o Mg e S mantiveram-se constantes com o aumento da idade das acículas. A taxa de retranslocação (acícula senescente-nova) foi superior a 50% para a maioria dos nutrientes, com exceção ao Mn e Fe, que apresentaram efeito cumulativo e o Ca, usado como elemento referência pela sua baixa mobilidade

Chemical composition of soil solution under eucalyptus plantation in Southern Brazil

This study focuses on changes in the chemical composition of solutions during their transfer in the soil cultivated with hybrid of Eucalyptus urophylla x Eucalyptus globulus stand in southern Brazil. The chemical composition of soil solution was evaluated from January to December in 2010, when the plant was from 8.5 to 9.5 years-old. Ceramic lysimeters was installed in order to measure the chemical composition of the soil solution in two different depths (30 and 80 cm) with six repetitions. The lysimeters were connected to a vacuum pump, where in each four hours, during ten minutes, the solution was suctioned. The soil solutions were collected in glass bottles with 0.5 liters of capacity. Fortnightly the samples were collected and each replicate of soil solution was analyzed separately. The solutions were filtered (0.45 μm) and the nutrients concentrations were measured. The concentration of N – NO3-, K+, Ca2+, Mg2+, Na+, S – SO42- and pH were variable during the year, but without significant difference (p > 0.05) in both depth (30 and 80 cm in depth). However, N - NH4+ concentration of soil solution was high, for both depths, in the months November and December. The concentrations of soil solution N – NO3-, N - NH4+, K+ and Mg2+ are not different in the soil profile (30 and 80 cm depth). S – SO42- (2.67 and 2.17 mg L-1, respectively in 30 and 80 cm depth) and Ca2+ (1.17 and 0.64 mg L-1, respectively in 30 and 80 cm depth) decrease in soil profile (p < 0.05), whilst, Na+ (2.10 and 2.60 mg L-1, respectively in 30 and 80 cm depth) and pH (4.78 and 5.11, respectively in 30 and 80 cm depth) increase in soil profile (p < 0.05). Pearson’s correlation between cations and anions in the soil solution was significant (p < 0.01). In both depths, N – NO3- was directly correlated with Ca2+ and Mg2+, whilst S – SO42- was inversely correlated with Mg2+. This change in chemical composition of soil solution indicated different patterns of nutrients were taken up by roots

Produção de serapilheira e transferência de nutrientes em área de segunda rotação com floresta de Pinus taeda L. no município de Cambará do Sul, RS.

This study had the objective of evaluating the litter and nutrients transfer to the soil in a second rotation area with Pinus taeda L. forest, during three years (5th to 7th year) in Cambará do Sul, RS. Three plots (48 m x 50 m) were allocated, each one with 5 collectors (1 m2). All the material deposited was collected monthly between April, 2004 and March, 2007. After each collection, the material was identified and sent to the Forest Ecology Laboratory at Universidade Federal de Santa Maria, where it was dried in a stove, weighed, milled and analyzed considering macro and micronutrient amounts. The litter annual average deposition was 4.519,1 kg ha-1, showing to be variable during the three years of study. The total  return of macronutrients to the soil (kg ha-1 year-1) was 28,7 of Ca; 27,3 of N; 4,8 of Mg; 4,6 of K; 2,4 of S and 1,8 of P and the total of micronutrients (g ha-1 year-1) was 6.689,7 of Mn; 1.092,9 of Fe; 142,8 of Zn; 60,0 of B and16,7 of Cu.Objetivou-se avaliar a transferência de serapilheira e nutrientes das copas ao solo em área de segunda rotação com floresta de Pinus taeda L. num período de 3 anos (5o ao 7o ano de idade) no município de Cambará do Sul, RS. Para tanto, foram alocadas três parcelas de 48 m x 50 m, cada uma com cinco coletores de 1 m2. Todo material depositado foi coletado mensalmente entre abril de 2004 e março de 2007. Após cada coleta, o material foi identificado e levado para o laboratório de Ecologia Florestal da Universidade Federal de Santa Maria onde posteriormente foi seco em estufa, pesado, moído e analisado quimicamente quanto aos teores de macro e micronutrientes. A deposição média anual de serapilheira foi de 4.519,1 kg ha-1, mostrando-se variável no decorrer dos três anos de estudos. O aporte total de macronutrientes ao solo, em kg ha-1 ano-1, foi de: 28,7 de Ca; 27,3 de N; 4,8 de Mg; 4,6 de K; 2,4 de S e 1,8 de P e o aporte de micronutrientes, em g ha-1 ano-1, foi de: 6.689,7 de Mn; 1.092,9 de Fe; 142,8 de Zn; 60,0 de B e 16,7 de Cu

Nodules biomass density in mixed and monospecific stands of Eucalyptus grandis x Eucalyptus urophylla and Acacia mearnsii

We aimed to evaluate the distribution of the nodules biomass density in Acacia mearnsii at monospecific and mixed planting with Eucalyptus grandis x E. urophylla in southern region of Brazil. The nodules biomass quantification was performed at the stand 18th month of age. The collecting was made using a cylindrical steel extractor tube with 7.0 cm of inside diameter in four depths: 0 – 5; 5 – 10; 10 – 20 and 20 – 30 cm. Due to the great variability, the nodules biomass, although being much higher in the monospecific planting of Acacia mearnsii when comparing to mixed planting, did not show significant differences (p > 0.05). The greater nodules density was found in the layers 5 to 10 cm of depth, near to thetree trunk and at the planting line followed by the planting diagonal and row. The nodules biomass density found for the black-wattle (up to 2.4 g dm-3) demonstrates the importance of the use of this atmospheric nitrogen-fixing species in mixed plantings with eucalyptus. DOI: http://dx.doi.org/10.13086/2316-980x.v01n03a0

Ecological and Environmental Aspects of Nutrient Cycling in the Atlantic Forest, Brazil

In developing countries, where population growth is on the rise, intense anthropogenic actions in natural forests are observed usually in the form of burnings and shallow cuts. With aiming to deploy crops or even promote irrational exploitation of forest products. In this context, preservation of natural forests (tropical and subtropical forests) depends on the knowledge of their dynamics. This information is important to allow exploration of natural forests sustainably or to subsidize conservation actions. In planted and native forests, the biogeochemical cycling of nutrients predominantly occurs through production and decomposition of litterfall. The information provided in this chapter, in particular with regard to nutrient cycling, is an important basis for understanding the structure and dynamics of nutrients in the ecosystem. We characterized nutrient stocks and elucidate some aspects of forest growth and productivity. This information is important to enhance biodiversity conservation and generate ecosystem goods and services in the Atlantic Forest Biome. Even with the intense change of land use (from forest to agricultural, pasture and urbanization), the region has high diversity of endemic species, and is considered a priority area for biodiversity conservation

Estoque de nutrientes em consórcios de Eucalyptus urograndis, Acacia mearnsii e Zea mays

http://dx.doi.org/10.5902/1980509810543This study aimed to determine the nutrient pool in monospecific and mixed stands of Eucalyptus urograndis and Acacia mearnsii in a consortium with Zea mays.The amount determination of nutrients of forest species was carried out in the treatments: 100E (100% of eucalyptus); 100A (100% of black wattle) and 50E:50A (50% of eucalyptus + 50% of black-wattle). On the other hand, for corn, it was carried out in all treatments (100E; 100A, 50E:50A; 75E:25A – 75% of eucalyptus + 25% black-wattle and 25E:75A – 25% of eucalyptus + 75% of black wattle). The delimitation adopted was the one of a randomized block with three replications. The magnitude of the nutrient pool in the agrossilvicultural systems biomass was: N> K > Ca > Mg > P > S, for macronutrients, and Mn > Fe > Zn > B > Cu, for micronutrients. Due to the great export of nutrients through the corn harvest, residues should be kept and it is necessary to make a nutritional reposition, mainly with P, N, K, S and Zn in the following crops, because of the higher amount that are exported with the extraction of the corn tang, which reaches 75.3; 60.6; 59.9; 55.8 e 53.8%, respectively, in relation to the total stocked in the biomass. http://dx.doi.org/10.5902/1980509810543Este estudo teve como objetivo determinar o estoque de nutrientes em povoamentos monoespecíficos e mistos de Eucalyptus urograndis e Acacia mearnsii em consórcio com Zea mays. A determinação da quantidade de nutrientes das espécies florestais foi realizada nos tratamentos: 100E (100% de eucalipto); 100A (100% de acácia-negra) e 50E:50A (50% de eucalipto + 50% de acácia-negra). Já, para o milho foi realizada em todos os tratamentos (100E; 100A; 50E:50A; 75E:25A - 75% de eucalipto + 25% de acácia-negra e 25E:75A - 25% de eucalipto + 75% de acácia-negra). O delineamento adotado foi de blocos ao acaso com três repetições. A magnitude do estoque de nutrientes na biomassa total do sistema agrossilvicultural foi: N > K > Ca > Mg > P > S, para os macronutrientes, e Mn > Fe > Zn > B > Cu, para os micronutrientes. Devido à grande exportação de nutrientes pela colheita da espiga do milho, devem-se manter os resíduos culturais nos sistemas agrossilviculturais e fazer reposição nutricional, principalmente de P, N, K, S e Zn, em cultivos seguintes, em decorrência da grande quantidade que é exportada pela extração da espiga, a qual chega a 75,3; 60,6; 59,9; 55,8 e 53,8%, respectivamente, em relação ao total estocado na biomassa agrícola

Efeito da fragmentação florestal sobre o acúmulo de serapilheira em Floresta Estacional Decidual

The objective of this study was to evaluate the effect of forest fragmentation on the accumulation of litter in Deciduous Forest in Silveira Martins, RS. Fifteen sampling points were established along the fragment, marked with the aid of Google Earth program and covered with the use of GPS during data collection, and measure tape to identify the distance established point-to-point: eight points were marked in the north-south direction; points in the east-west; and the central point equidistant 25m each of them. For each point, five samples of litter accumulated were collected using wooden frame with size 0.25 m x 0.25 m, after collecting them, the material was stored in paper-bags. In the laboratory, the samples were separated into the following fractions: leaves, twigs (diameter ≤1.0 cm) and miscellaneous (other waste), putting them to drying at a temperature of 70°C, and weighted on a precision scale (0, 01g). There were variations in the litter disposition from from east to south directions in relation to other averageof deposition, confirming that this fragmentation influenced in the accumulation of the litter, because there was not found less concentration in streme points and more in the central points of the forest fragmentation. In the Chemical analisis, higher concentration of N (20.42 g kg-1) and Ca (13.82 g kg-1) were verified, however in relation to macronutrients, there was a large concentration of Mn (815.29 g kg-1).Objetivou-se com o presente estudo avaliar o efeito da fragmentação florestal sobre o acúmulo de serapilheira em Floresta Estacional Decidual em Silveira Martins, RS. Foram estabelecidos 15 pontos amostrais ao longo do fragmento, demarcados com auxílio do programa Google Earth e percorridos com utilização de GPS durante as coletas, e fita métrica para medir a distância estabelecida ponto a ponto, sendo demarcados oito pontos no sentido norte-sul, seis pontos no sentido leste-oeste e mais o ponto central equidistantes 25m cada. Para cada ponto foram coletadas cinco amostras de serapilheira acumulada utilizando moldura de madeira com tamanho de 0,25 m x 0,25 m, após a coleta o material foi armazenado em sacos de papel-pardo. Em laboratório, as amostras foram separadas nas seguintes frações: folhas, galhos finos (diâmetro ≤1,0 cm) e miscelâneas (demais resíduos) e postas para secagem a uma temperatura de 70 °C, e pesadas em balança de precisão (0,01g). Ocorreu variação na deposição de serapilheira nos sentidos leste e sul em relação as demais médias de deposição do fragmento, sendo o material de miscelânea que gerou esta variação. Nas análises químicas verificou-se em relação aos macronutrientes, maior concentração de N (20,42 g kg-1) e de Ca (13,82 g kg-1), já em relação aos micronutrientes há uma grande concentração de Mn (815,29 g kg-1)