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Pinheiro R.C.,Sao Paulo State University | de Deus J.C.,Sao Paulo State University | Nouvellon Y.,CIRAD - Agricultural Research for Development | Nouvellon Y.,University of Sao Paulo | And 7 more authors.
Forest Ecology and Management

Although pioneer studies showed several decades ago that deep rooting is common in tropical forests, direct measurements of fine root distributions over the entire soil profile explored by the roots are still scarce. Our study aimed to compare, 2 years after planting, fine root traits of Eucalyptus trees planted from cuttings and from seedlings in order to assess whether the propagation mode has an influence on the capacity of the trees to explore very deep soils. Soils cores were sampled down to a depth of 13.5 m at the peak of leaf area index (LAI), 2 years after planting, under three Eucalyptus clones (belonging to species E. saligna, E. grandis × E. urophylla, E. grandis × E. camaldulensis) and under E. grandis seedlings in the same Ferralsol soil. LAI was estimated using allometric equations based on destructive sampling of eight trees per genotype.All the genotypes exhibited fine root densities roughly constant between the depths of 0.25 and 6.00 m. Changes in fine root traits (diameter, specific root length and specific root area) were low between the topsoil and the root front. The ratios between mean tree height and root front depth ranged from 0.8 to 1.2 for the four genotypes. Although tree vertical extension was roughly symmetric above and belowground for all the genotypes, the depth of the root front ranged from 8.0 m for the seedlings and the E. grandis × E. urophylla clone to 11.5 m for the E. saligna clone. Soil water content profiles suggested that the four genotypes had the capacity to withdraw water down to a depth of 8-10 m over the first 2 years after planting. Total fine root length ranged from 3.3 to 6.0 km per m2 of soil depending on the genotype. The root area/leaf area ratio ranged from 1.3 to 3.2 and was negatively correlated with LAI across the four genotypes. This pattern suggests that the genotypes more conservative for water use (with a low LAI) invest more in fine root area relative to leaf area than genotypes adapted to wet regions (with a high LAI). The velocity of downward movement of the root front might be a relevant criterion in the last stage of the breeding programs to select clones with a fast exploration of deep soil layers in drought prone regions. © 2016 Elsevier B.V. Source

de Melo E.A.S.C.,Forestry Science and Research Institute IPEF | Bazani J.H.,4tree Agroflorestal | Arthur J.C.,Forestry Science and Research Institute IPEF | Borges J.S.,Duratex | And 2 more authors.

Eucalypt plantations in Brazil have the highest mean productivity when compared to other producing countries, and fertilizer application is one of the main factors responsible for these productivities. Our aim was to identify appropriate rates of N, P and K in eucalypt plantations and their interactions with edaphoclimatic factors. Four trials with four rates and three nutrients (N, P and K) were set up. Each nutrient was studied separately, and the trees received sufficient rates of all of the other nutrients through fertilization, to avoid limitations not related to the desired nutrient. We assessed solid wood volume (SV), productivity gains (PG), leaf nutrient content and leaf area index (LAI) to determine the responses to fertilization. PG, regarding N, rates ranged from 104% to 127% at 60 months after planting. P fertilizer application led to gains in productivity in soils with levels of P-resin up to 5 mg· kg-1, but decreased with stand age. K fertilizer application responses increased within age in three sites. In Paulistania, responses to K application were close to zero. N and K responses were climate related. Leaf nutrient content and LAI were not able to predict the highest yields obtained. © 2016 by the authors. Source

Alvares C.A.,Forestry Science and Research Institute IPEF | Stape J.L.,Forest Productivity Cooperative FPC | Stape J.L.,North Carolina State University | Stape J.L.,University of Sao Paulo | And 3 more authors.
Meteorologische Zeitschrift

Köppen's climate classification remains the most widely used system by geographical and climatological societies across the world, with well recognized simple rules and climate symbol letters. In Brazil, climatology has been studied for more than 140 years, and among the many proposed methods Köppen0s system remains as the most utilized. Considering Köppen's climate classification importance for Brazil (geography, biology, ecology, meteorology, hydrology, agronomy, forestry and environmental sciences), we developed a geographical information system to identify Köppen's climate types based on monthly temperature and rainfall data from 2,950 weather stations. Temperature maps were spatially described using multivariate equations that took into account the geographical coordinates and altitude; and the map resolution (100 m) was similar to the digital elevation model derived from Shuttle Radar Topography Mission. Patterns of rainfall were interpolated using kriging, with the same resolution of temperature maps. The final climate map obtained for Brazil (851,487,700 ha) has a high spatial resolution (1 ha) which allows to observe the climatic variations at the landscape level. The results are presented as maps, graphs, diagrams and tables, allowing users to interpret the occurrence of climate types in Brazil. The zones and climate types are referenced to the most important mountains, plateaus and depressions, geographical landmarks, rivers and watersheds and major cities across the country making the information accessible to all levels of users. The climate map not only showed that the A, B and C zones represent approximately 81%, 5% and 14% of the country but also allowed the identification of Köppen's climates types never reported before in Brazil. © Gebrüder Borntraeger, Stuttgart 2013. Source

Campoe O.C.,Forestry Science and Research Institute IPEF | Stape J.L.,North Carolina State University | Albaugh T.J.,North Carolina State University | Lee Allen H.,North Carolina State University | And 3 more authors.
Forest Ecology and Management

Fertilization and irrigation may substantially increase productivity of forests by increasing stand leaf area index and the efficiency of converting intercepted light into wood biomass. This stand-level growth response is the summation of individual tree responses, and these tree-level responses are often non-linear, resulting from shifting in the intensity of competition and dominance. We examined tree-level responses of aboveground net primary production (ANPP), absorbed photosynthetically active radiation (APAR) and (light use efficiency) LUE in relation to tree size class to explore how stand-level outcomes depend on shifting patterns among trees. We evaluated the production ecology of a nine-year-old loblolly pine (Pinus taeda L.) plantation, 2years after the initiation of treatments: control, irrigation, fertilization and irrigation+fertilization. We measured tree level ANPP, simulated APAR for individual tree crowns using the MAESTRA process-based model and calculated LUE (ANPP/APAR) in relation to tree size to explore the influence of tree dominance on both light capture and light use efficiency. Fertilization and irrigation+fertilization strongly increased both APAR and LUE, in contrast to little effect of irrigation alone. Tree size had a strong influence on APAR and LUE across all treatments; the largest 20% trees showed 3.4 times greater ANPP when compared to the smallest 20% trees, with 66% resulting from higher APAR, and 34% from higher LUE, than the smallest 20% of trees. Fertilization increased the growth of the largest 20% trees 2-fold (8.6kg tree-1year-1), with 29% of the increase resulting from higher APAR (13.7GJ tree-1year-1), and 71% from higher LUE (0.63gMJ-1), relative to the largest trees in the control treatment (4.3kg tree-1year-1, 11GJ tree-1year-1 and 0.39gMJ-1, respectively). Irrigation and fertilization tripled production (13.2kg tree-1year-1) of the largest trees with an even greater proportional contribution from increased LUE (15.1GJ tree-1year-1, 85% response contribution; APAR 0.87gMJ-1, 15% response contribution). Overall, large trees grow faster than smaller trees because of greater light capture, whereas the greater response of large trees to treatments resulted more from increased efficiency of using light. © 2012 Elsevier B.V. Source

Campoe O.C.,Forestry Science and Research Institute IPEF | Stape J.L.,North Carolina State University | Nouvellon Y.,CIRAD - Agricultural Research for Development | Nouvellon Y.,University of Sao Paulo | And 5 more authors.
Forest Ecology and Management

Brazilian Eucalyptus plantations are some of the most productive forest plantations in the world, sustaining mean growth rates of 25Mgha-1year-1 (50m3ha-1year-1) over the 4.7 million hectares planted across the country. To better understand forest productivity, studies at the stand scale need to be coupled with tree level evaluations of the production ecology (the assessment of wood production as a function of crown light absorption and light use efficiency). The soil clay content (≈20% to ≈40%), topography and historical land use of the experimental site generated a natural gradient in productivity. We measured (from 6 to 7years after planting) stem wood dry biomass growth and estimated light absorption and light use efficiency at the tree level with a three-dimensional array model (MAESTRA) in 12 plots within a seed-origin Eucalyptus grandis plantation. We investigated the hypothesis that dominant trees (the 20% largest) are more productive than non-dominant trees (the 20% smallest) as a result of greater light absorption and light use efficiency; and that with increasing productivity across plots, dominant trees would show larger increases in light use and light use efficiency in comparison to non-dominant trees. The 20% smallest of the trees averaged 10.6kg of stem wood dry biomass (1.6kg of stem wood growth during the last year of the rotation), compared with 185kg per stem wood in the 20% largest of trees (34kg of stem wood growth over the same period). The smallest trees contained 7.2% of the leaf area as compared to the largest trees (3.0m2 versus 41.7m2), and they absorbed only 6.7% as much light (2.2 versus 32.8GJyear-1). The smallest trees grew at about 4.7% of the rate of the largest trees, which is a smaller percentage than the difference in absorbed photosynthetically active radiation; therefore the light use efficiency was lower for the smallest trees (0.75kgGJ-1 versus 1.03kgGJ-1). Our results show the significant contribution of dominant trees to stand productivity and the importance of evaluating production ecology at the individual tree scale. © 2012 Elsevier B.V. Source

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