caa a22 4500 445383968 CHVBK 20180317143026.0 cr unu---uuuuu 170323e20110601xx s 000 0 eng 10.1007/s10021-011-9436-8 doi (NATIONALLICENCE)springer-10.1007/s10021-011-9436-8 Carbon, Water, and Energy Exchanges of a Hybrid Poplar Plantation During the First Five Years Following Planting [Elektronische Daten] [Tiebo Cai, David Price, Alberto Orchansky, Barb Thomas] Eddy covariance was used to measure above-canopy exchanges of CO2 and water vapor at an operational plantation of hybrid poplar (variety "Walker”) established on marginal agricultural land in east central Alberta, Canada. Winter ecosystem respiration (R e) rates were inferred from seasonal changes in the normalized respiration rate at 10°C (R 10) for the growing season and observations of soil CO2 concentration measured with solid-state probes. Over five consecutive growing seasons following planting, gross ecosystem production (GEP) increased each year, ranging from 21gCm−2y−1 in year 1 to 469gCm−2y−1 in year 5. During this period, the annual carbon balance shifted from a net source of greater than 330gCm−2 in year 1 to approximately C-neutral in year 5. Total carbon (C) release over 5years likely exceeded 630gCm−2. Intra- and interannual variations in temperature and soil water availability greatly affected annual C balance each year. GEP and R e were particularly sensitive to temperature during spring and to soil water availability in summer: year 5 was notable because a cold spring and accumulating drought caused growth and carbon uptake to fall well below their potential. Annual evapotranspiration (ET) increased slightly with leaf area, from 281mm in year 1 to 323mm in year 4, but in year 5 it declined, while exceeding total precipitation (P). This trend of increasing annual ET/P suggests that annual GEP could become increasingly water-limited in years with below normal precipitation, as the plantation achieves maximum leaf area. Measured canopy albedos did not change appreciably over three winters, suggesting that estimates of increased radiative forcing resulting from afforestation in high latitudes could be exaggerated in regions where fast-growing deciduous plantations are managed on short (~20-year) rotations. Her Majesty the Queen in right of Canada, 2011 plantation nationallicence hybrid poplar nationallicence net ecosystem exchange nationallicence chronosequence nationallicence carbon sequestration nationallicence drought nationallicence land-use change nationallicence Cai Tiebo Natural Resources Canada, Northern Forestry Centre, 5320-122 Street NW, T6H 3S5, Edmonton, Alberta, Canada aut Price David Natural Resources Canada, Northern Forestry Centre, 5320-122 Street NW, T6H 3S5, Edmonton, Alberta, Canada aut Orchansky Alberto Micrometeorology Consultant, Edmonton, Alberta, Canada aut Thomas Barb Alberta-Pacific Forest Industries Inc, T0A 0M0, Boyle, Alberta, Canada aut Ecosystems Springer-Verlag 14/4(2011-06-01), 658-671 1432-9840 14:4<658 2011 14 10021 https://doi.org/10.1007/s10021-011-9436-8 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10021-011-9436-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Cai Tiebo Natural Resources Canada, Northern Forestry Centre, 5320-122 Street NW, T6H 3S5, Edmonton, Alberta, Canada aut NATIONALLICENCE 700 1- Price David Natural Resources Canada, Northern Forestry Centre, 5320-122 Street NW, T6H 3S5, Edmonton, Alberta, Canada aut NATIONALLICENCE 700 1- Orchansky Alberto Micrometeorology Consultant, Edmonton, Alberta, Canada aut NATIONALLICENCE 700 1- Thomas Barb Alberta-Pacific Forest Industries Inc, T0A 0M0, Boyle, Alberta, Canada aut NATIONALLICENCE 773 0- Ecosystems Springer-Verlag 14/4(2011-06-01), 658-671 1432-9840 14:4<658 2011 14 10021 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer