נגישות
menu      
חיפוש מתקדם
Forest Ecology and Management
Schiller, G., Department of Agronomy and Natural Resources, Institute of Plant Sciences, Agricultural Research Organization - The Volcani Center, P.O. Box 6, Bet Dagan, 50250, Israel
Ungar, E.D., Department of Agronomy and Natural Resources, Institute of Plant Sciences, Agricultural Research Organization - The Volcani Center, P.O. Box 6, Bet Dagan, 50250, Israel
Cohen, S., Department of Environmental Physics and Irrigation, Institute of Soil, Water and Environmental Sciences, Agricultural Research Organization - The Volcani Center, P.O. Box 6, Bet Dagan, 50250, Israel
Herr, N., The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot, 76100, Israel
We estimated water use by the two main oak species of the Lower Galilee region of Israel-Tabor (Quercus ithaburensis) and Kermes (Quercus calliprinos)-to develop management options for climate-change scenarios. The trees were studied in their typical phytosociological associations on different bedrock formations at two sites with the same climatic conditions. Using the heat-pulse method, sap flow velocity was measured in eight trunks (trees) of each species during a number of periods in 2001, 2002 and 2003. Hourly sap flux was integrated to daily transpiration per tree and up-scaled to transpiration at the forest canopy level. The annual courses of daytime transpiration rate were estimated using fitted functions, and annual totals were calculated. Sap flow velocity was higher in Tabor than in Kermes oak, and it was highest in the youngest xylem, declining with depth into the older xylem. Average daytime transpiration rate was 67.9 ± 4.9 l tree-1 d-1, or 0.95 ± 0.07 mm d-1, for Tabor oak, and 22.0 ± 1.7 l tree-1d-1, or 0.73 ± 0.05 mm d-1, for Kermes oak. Differences between the two oak species in their forest canopy transpiration rates occurred mainly between the end of April and the beginning of October. Annual daytime transpiration was estimated to be 244 mm year-1 for Tabor oak and 213 mm year-1 for Kermes oak. Adding nocturnal water fluxes, estimated to be 20% of the daytime transpiration, resulted in total annual transpiration of 293 and 256 mm year-1 by Tabor and Kermes oaks, respectively. These amounts constituted 51% and 44%, respectively, of the 578 mm year-1 average annual rainfall in the region. The two species differed in their root morphology. Tabor oak roots did not penetrate the bedrock but were concentrated along the soil-rock interface within soil pockets. In contrast, the root system of Kermes oak grew deeper via fissures and crevices in the bedrock system and achieved direct contact with the deeper bedrock layers. Despite differences between the two sites in soil-bedrock lithological properties, and differences in the woody structure, annual water use by the two forest types was fairly similar. Because stocking density of the Tabor oak forests is strongly related to bedrock characteristics, thinning as a management tool will not change partitioning of the rainfall between different soil pockets, and hence soil water availability to the trees. In contrast, thinning of Kermes oak forests is expected to raise water availability to the remaining trees. © 2010 Elsevier B.V. All rights reserved.
פותח על ידי קלירמאש פתרונות בע"מ -
הספר "אוצר וולקני"
אודות
תנאי שימוש
Water use by Tabor and Kermes oaks growing in their respective habitats in the Lower Galilee region of Israel
259
Schiller, G., Department of Agronomy and Natural Resources, Institute of Plant Sciences, Agricultural Research Organization - The Volcani Center, P.O. Box 6, Bet Dagan, 50250, Israel
Ungar, E.D., Department of Agronomy and Natural Resources, Institute of Plant Sciences, Agricultural Research Organization - The Volcani Center, P.O. Box 6, Bet Dagan, 50250, Israel
Cohen, S., Department of Environmental Physics and Irrigation, Institute of Soil, Water and Environmental Sciences, Agricultural Research Organization - The Volcani Center, P.O. Box 6, Bet Dagan, 50250, Israel
Herr, N., The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot, 76100, Israel
Water use by Tabor and Kermes oaks growing in their respective habitats in the Lower Galilee region of Israel
We estimated water use by the two main oak species of the Lower Galilee region of Israel-Tabor (Quercus ithaburensis) and Kermes (Quercus calliprinos)-to develop management options for climate-change scenarios. The trees were studied in their typical phytosociological associations on different bedrock formations at two sites with the same climatic conditions. Using the heat-pulse method, sap flow velocity was measured in eight trunks (trees) of each species during a number of periods in 2001, 2002 and 2003. Hourly sap flux was integrated to daily transpiration per tree and up-scaled to transpiration at the forest canopy level. The annual courses of daytime transpiration rate were estimated using fitted functions, and annual totals were calculated. Sap flow velocity was higher in Tabor than in Kermes oak, and it was highest in the youngest xylem, declining with depth into the older xylem. Average daytime transpiration rate was 67.9 ± 4.9 l tree-1 d-1, or 0.95 ± 0.07 mm d-1, for Tabor oak, and 22.0 ± 1.7 l tree-1d-1, or 0.73 ± 0.05 mm d-1, for Kermes oak. Differences between the two oak species in their forest canopy transpiration rates occurred mainly between the end of April and the beginning of October. Annual daytime transpiration was estimated to be 244 mm year-1 for Tabor oak and 213 mm year-1 for Kermes oak. Adding nocturnal water fluxes, estimated to be 20% of the daytime transpiration, resulted in total annual transpiration of 293 and 256 mm year-1 by Tabor and Kermes oaks, respectively. These amounts constituted 51% and 44%, respectively, of the 578 mm year-1 average annual rainfall in the region. The two species differed in their root morphology. Tabor oak roots did not penetrate the bedrock but were concentrated along the soil-rock interface within soil pockets. In contrast, the root system of Kermes oak grew deeper via fissures and crevices in the bedrock system and achieved direct contact with the deeper bedrock layers. Despite differences between the two sites in soil-bedrock lithological properties, and differences in the woody structure, annual water use by the two forest types was fairly similar. Because stocking density of the Tabor oak forests is strongly related to bedrock characteristics, thinning as a management tool will not change partitioning of the rainfall between different soil pockets, and hence soil water availability to the trees. In contrast, thinning of Kermes oak forests is expected to raise water availability to the remaining trees. © 2010 Elsevier B.V. All rights reserved.
Scientific Publication
You may also be interested in