Campo García, ADD.; Gualberto Fernandes, TJ.; Molina Herrera, A. (2014). Hydrologyoriented (adaptive) silviculture in a semiarid pine plantation: How much can be modified the water cycle through forest management?. European Journal of Forest Research. 133(55):879-894. doi:10.1007//s10342-014-0805-7. European Journal of Forest ResearchHydrology-oriented (adaptive) silviculture in a semiarid pine plantation: how much can be modified the water cycle through forest management?--Manuscript Draft-- Order of Authors Secondary Information:Abstract: Hydrology-oriented silviculture might adapt Mediterranean forests to climatic changes, although its implementation demands a better understanding and quantification on the water fluxes. The influence of thinning intensity (high, medium, low and a control) and its effect on the mid-term (thinned plots in 1998 and 2008) on the water cycle (transpiration, soil water and interception) and growth (Basal Area Increment, BAI) were investigated in 55-year-old Aleppo pine trees. Thinning enhanced a lower dependence of growth on climate fluctuations. The high intensity treatment showed significant increases in the mean annual BAI (from 4.1 to 17.3 cm2) that were maintained in the mid-term. Thinning intensity progressively increased the sap flow velocity (vs) in all cases with respect the control. In the mid-term, an increased functionality of the inner sapwood was also observed. Mean daily tree water use ranged from 5 (control) to 18 (high intensity) l tree-1. However, when expressed on an area basis, daily transpiration ranged from 0.18 (medium) to 0.30 mm (control), meaning that, in spite of the higher transpiration rates in the remaining trees, stand transpiration was reduced with thinning. Deep infiltration of water was also enhanced with thinning (about 30% of rainfall) and did no compete with transpiration, as both presented opposite seasonal patterns. The changes in the stand water relationships after ten years were well explained by the forest cover metric. The blue to green water ratio changed from 0.15 in the control to 0.72 in the high intensity treatment, with the remaining treatments in the 0. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 2 velocity (v s ) in all cases with respect the control. In the mid-term, an increased functionality of the inner sapwood was also observed. Mean daily tree water use ranged from 5 (control) to 18 (high intensity) l tree -1 . However, when expressed on an area basis, daily transpiration ranged from 0.18 (medium) to 0.30 mm (control), meaning that, in spite of the higher transpiration rates in the remaining trees, stand transpiration was reduced with thinning. Deep infiltration of water was also enhanced with thinning (about 30% of rainfall) and did no compete with transpiration, as both presented opposite seasonal patterns. The changes ...
ElsevierGualberto-Fernandes, TJ.; Campo García, ADD.; Herrera Fernandez, R.; Molina Herrera, A. (2016). Simultaneous assessment, through sap flow and stable isotopes, of water use efficiency (WUE) In water-limited regions, adaptive management of forest and water relationships has been put 17 forward, to implement hydrology-oriented silviculture to reduce stand evapotranspiration and, 18 at the tree level, to improve growth and water use efficiency (WUE). The main goal of this 19 study was to evaluate the effect of thinning in the short and medium term on tree growth, 20 climate (drought) sensitivity, WUE performed using growth and sap flow measurements and 21WUEi performed using δ increased growth, but also changed the tree growth-precipitation relationships, with C trees 27 depending more on precipitation than thinned trees did. WUEi after thinning was significantly 28 affected only in the medium term, with C trees being more efficient (94.4 μmolCO2/molH2O) 29 than H98 trees (88.7), especially in dry spells (100.7). WUEi was found to increase when 30 precipitation decreased, regardless of the treatment. However, WUE increased sharply from C 31 was not consistent with our experimental data. Thus, the question of whether stable isotopes 37 can be used as a tool for addressing the ecophysiological impacts of thinning remains open. 38
Estimating forest transpiration is of great importance for Adaptive Forest Management (AFM) in the scope of climate change prediction. AFM in the Mediterranean region usually generates a mosaic of different canopy covers within the same forest. Several models and methods are available to estimate forest transpiration, but most require a homogeneous forest cover, or an individual calibration/validation process for each cover stand. Hence, a model capable of reproducing accurately the transpiration of the whole canopy-cover mosaic is necessary. In this paper, the use of Artificial Neural Network (ANN) is proposed as a flexible tool for estimating forest transpiration using the forest cover as an input variable. To that end, sap flow, soil water content and other environmental variables were experimentally collected under five Aleppo pine stands of different canopy covers for two years. These sets of inputs were then used for the ANN training. Stand transpiration was accurately estimated using climate data, soil water content and forest cover through the ANN approach (correlation coefficient R = 0.95; Nash-Sutcliffe coefficient E = 0.90; root-meansquare error RMSE = 0.078 mm day -1 ). Finally, the input value for soil water content (when not available) was computed using the process-based model Gotilwa+. Then, this computed soil water content was used as input in the proposed ANN. This combination predicted the forest transpiration with values of R = 0.90, E = 0.63, and RMSE = 0.068 mm day -1 . Artificial Neural Network proved to be a useful and flexible tool to predict the transpiration dynamics of an Aleppo pine stand regardless of the heterogeneity of the forest cover produced by adaptive forest management.
657RESUMO -Este trabalho foi desenvolvido com o objetivo de quantificar o carbono estocado nos diferentes componentes das árvores de Hevea sp., na fazenda experimental da Empresa de Pesquisa Agropecuária de Minas Gerais (EPAMIG), no Município de Oratórios, Minas Gerais, servindo como base para verificar a importância da cultura no seqüestro de carbono e, conseqüentemente, na mitigação do efeito-estufa. Após as análises, verificouse que: a) os galhos contribuíram com a maior quantidade de carbono armazenado, seguido por troncos, raízes e folhas; b) existe relação exponencial positiva entre a quantidade de carbono na árvore e nos seus componentes e o seu diâmetro medido a 1,30 m do solo (dap); c) a variável dap foi significativa, a 95% de probabilidade em todas as equações ajustadas. No entanto, a variável altura total foi significativa apenas nas equações de tronco e galhos. Complementarmente com base nos dados das parcelas, verificou-se que ao final de 12 anos o plantio de Hevea sp. consegue seqüestrar, em média, 62,10 toneladas de carbono por hectare em sua biomassa viva, considerando um espaçamento de 7 x 3 m, ou seja, uma densidade média de 476 árvores por hectare.Palavras-chave: Hevea sp., seqüestro de carbono e equações. QUANTIFICATION OF CARBON STORED IN THE AERIAL PART AND ROOTS OF 12-YEAR-OLD
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