Effects of Temperature on Phytoplankton Growth Rates

温度是控制极地系统中许多过程的基本变量，但令人惊讶的是，很少有人尝试合成温度对称为浮游植物的单细胞生物生长的影响。因为浮游植物是所有海洋食物网的基础，它们在海洋生态中扮演着重要的角色。许多全球模型使用一个简单的关系来推断温度对浮游植物生长的影响，这种影响源于较暖的水域到极地的温度，但这给模型的结果带来了很大的不确定性。这个项目将研究在极地系统中遇到的低温下温度对生长的影响。此外，考虑到未来可能发生的海洋变化，它将使人们能够更准确地预测未来对这种变化的反应。该项目还将推动NSF培养新一代科学家和向公众提供科学发现的目标。该项目将有一名研究生参与实地工作，本科生参与国内机构的研究活动。这项工作的成果将被纳入新的本科课程，研究人员将通过一般讲座和其他外展活动让公众参与进来。温度是所有生态系统中的一个基本变量，也是极地系统唯一最重要的划界特征。它也可能受到气候变化的影响；事实上，在过去的半个世纪里，南极的一些(但不是所有)地区经历了显著的大气变暖。尽管温度对生物系统有明显而深远的影响，但几乎所有的模型都使用从变暖的温度推导出的温度增长率公式。如果这种温度-浮游植物生长关系低估了生长速度，对浮游植物光合作用的模型估计可能会低估这些速率高达60%。如果是这样的话，这可能会对温度变化对海洋生产力影响的区域和全球模型产生深远影响。为了解决这一不确定性，该项目将量化南极(低于4摄氏度)温度下浮游植物的最大生长速度-温度关系。从南极水域分离的浮游植物将被用于实验，以评估出现在南极的多种浮游植物的最大生长速度。将进行温度扰动实验，以评估南极浮游植物在适应生长过程中温度上升后对一系列温度的反应。

Temperature is a fundamental variable controlling many processes in polar systems, but surprisingly few attempts to synthesize the effects of temperature on the growth of single-celled organisms called phytoplankton have been made. Because phytoplankton are the base of all marine food webs, they play an essential role in the ocean's ecology. Many global models use a simple relationship that extrapolate the effects of temperature on phytoplankton growth derived from warmer waters to polar temperatures, but this introduces substantial uncertainties in the models' results. This project will investigate the effects of temperature on growth at the low temperatures encountered in polar systems. Furthermore, given the potential oceanic changes expected in the future, it will allow much more accurate predictions of future responses to this change. The project will also further the NSF goals of training new generations of scientists and of making scientific discoveries available to the general public. The project will involve a graduate student in the fieldwork and undergraduates in research activities at the home institution. Results from the work will be incorporated into a new undergraduate course and the researchers will involve the public through general lectures and other outreach activities. Temperature is a fundamental variable in all ecosystems, and is the single most important delimiting feature of polar systems. It is also likely to be influenced by climate change; indeed, some (but not all) regions in the Antarctic have experienced significant atmospheric warming in the past half century. Despite the clear and profound influence of temperature of biological systems, nearly all models use a temperature-growth rate formulation derived from warmer temperatures. Modeled estimates of phytoplankton photosynthesis may underestimate these rates by up to 60% if the growth rate is underestimated by this temperature-phytoplankton growth relationship. If so, this could have profound impacts on regional and global models of the impacts of temperature change on oceanic productivity. To address this uncertainty, this project will quantify the phytoplankton maximum growth rate-temperature relationship at temperatures encountered in the Antarctic (less than 4 degrees C). Phytoplankton isolated from Antarctic waters will be used in experiments designed to assess the maximum growth rates of a number of types of phytoplankton that occur in the Antarctic. Temperature perturbation experiments will be performed to assess the response of Antarctic phytoplankton to a range of temperatures after having been acclimated to increased temperatures during growth.