"Carbon and water balances of hybrid poplar plantations, and lodgepole pine and Douglas-fir stands"

我的研究目的是为了更好地了解杂交杨树（HP）人工林、从山松甲虫（MPB）攻击中恢复的黑松林和管理的沿海道格拉斯冷杉（DF）林分的碳(C)、水和能量平衡。将使用一种微气象方法，即涡旋相关方差（EC），对净生态系统生产力（即碳的封存或损失）和蒸散（即水的利用）进行全年测量。我的HP研究的一个目的是确定草原地区不同年龄的HP人工林将C作为植物生物量（用于纤维或生物能源生产）和土壤有机质的能力。由于HP人工林对水的需求量很大，一个关键目标将是通过比较水的利用和降水来确定广泛人工林的可持续性。将确定对地下水位排水速率的影响，并评估对区域水平衡的影响。在我的MPB研究中，一个重要的目标是测量在未采伐的林分中，当被砍伐的树木开始倒下，分解率可能会增加时，碳平衡的恢复速度。此外，采用部分回收采伐（只采伐松树）而不是完全回收采伐（导致大量碳损失）的可行性将通过评估前者的风损和碳封存来确定。基于过程的森林生产模型（3PG）将与几种管理方案一起使用，以估计我们的MPB研究地点附近近期碳平衡的可能变化。我的DF研究将集中于测量2007年施肥的23岁林分的强烈生长反应，因为它开始排挤竞争的林下植被。此外，在2013年之前，将使用EC测量最近施肥的61年树龄林分收获（2011年1月）造成的净砍伐造成的碳损失。控制过程将通过测量土壤和木材采伐碎屑的呼吸作用、土壤表面甲烷和氧化亚氮通量、溪流中碳转运速率以及采伐后土壤水分状况的变化来研究。

The goal of my research is to better understand the carbon (C), water and energy balances of hybrid poplar (HP) plantations, lodgepole pine stands recovering from mountain pine beetle (MPB) attack, and managed coastal Douglas-fir (DF) stands. A micrometeorological method, eddy covariance (EC), will be used to make year-round measurements of net ecosystem productivity (i.e., C sequestration or loss) and evapotranspiration (i.e., water use). One aim of my HP research is to determine the capacity of different-aged HP plantations in the Prairie region to sequester C as plant biomass (for fibre or bioenergy production) and soil organic matter. Because of the high water requirements of HP plantations, a key objective will be to determine the sustainability of extensive plantations by comparing water use and precipitation. Effects on the rate of water drainage to the water table will be determined and the implications for the regional water balance assessed. In my MPB research, an important objective is to measure the rate of recovery of the C balance in non-harvested stands when killed trees are starting to fall with the possibility of increasing decomposition rates. In addition, the feasibility of using partial salvage harvesting (removing only pine trees) rather than clearcut salvage harvesting (which results in large C losses) will be determined by assessing wind damage and C sequestration in the former. A process-based forest production model (3PG) will be used with several management scenarios to estimate likely near-future changes in the C balance in the vicinity of our MPB research sites. My DF research will focus on measuring the strong growth response of a 23-year-old stand fertilized in 2007 as it begins to crowd out competing understory vegetation. In addition, the losses of C from a clearcut resulting from the harvesting (in Jan 2011) of a recently-fertilized 61-year-old stand will be measured using EC until 2013. Controlling processes will be studied using measurements of respiration by soil and woody harvesting debris, soil-surface methane and nitrous oxide fluxes, rates of C transport in stream water, and post-harvesting changes in the soil water regime.