LI-6400 portable photosynthesis system

LI-COR的便携式气体交换系统使人们可以测量叶片在光照条件下的光合作用速率，以及在黑暗条件下叶片和其他器官的呼吸速率。它还可以测量蒸腾速率，这在研究植物对干旱的反应时是至关重要的。根据措施的类型和正在研究的植物类型，有许多实验室可用。我们将使用这台设备来确定春季短暂的鲑鱼百合的年生长在多大程度上受到其鳞茎生长能力的限制。要做到这一点，我们需要测量树叶固定碳的能力，并估计球茎利用这些碳进行自身生长或将其储存为淀粉的能力。虽然许多经济用途植物的生长受到它们固定碳的能力的限制，但许多野生物种在利用它们的叶子固定的碳方面表现出一些限制。更好地描述这种限制是很重要的，因为它对植物利用与全球变暖相关的大气二氧化碳增加的能力有重大影响。这些研究还可以为这类植物开发生长模型。该设备还将用于测量和比较黑云杉林下(灌木和乔木)北方物种的光合作用速率和氮素利用效率，作为评估砍伐或部分收获后生理驯化研究的一部分。对不同树种的养分和水分利用效率的估计有助于我们理解收获干扰后树种之间的竞争关系。这场竞争最终影响了黑云杉的展位动态和商业革命。

The portable gas exchange system from LI-COR allows one to measure both the photosynthetic rate of leaves under light conditions and the respiratory rate of leaves and other organs in the dark. It also allows the measurement of transpiration rates, which are of primary importance when studying the response of plants to drought. Many chambers are available, depending on the type of measures and the type of plants under study. We will use this equipment to determine to which extent the annual growth of a spring ephemeral, the trout lily, is limited by the growth capacity of its bulb. To do so, we need to measure the capacity of the leaves to fix carbon and estimate the capacity of the bulb to use this carbon for its own growth or to stock it as starch. Although growth of many plants of economical use is limited by their capacity to fix carbon, many wild species exhibit some limits to use the carbon fixed by their foliage. It is important to better characterise this limitation because it has major impact on the capacity of the plants to take advantage of the atmospheric CO2 increase associated with global warming. These studies could also allow growth models to be developed for such type of plants. The equipment will also be used to measure and compare rates of photosynthesis and nitrogen use efficiency among boreal species in the understory (shrubs and trees) of black spruce stands, as part of a study evaluating physiological acclimation following clearcut or partial harvest. The estimation of nutrient and water use efficiency of the different species may contribute to our understanding of the competitive relationships between species after disturbance by harvest. This competition ultimately influences the stand dynamics and the commercial revolution of black spruce.