An F-Ratio Model for Pelagic Marine Ecosystem

远洋海洋生态系统的 F 比模型

• 批准号: 9725966
• 负责人: Edward Laws
• 金额: $ 19.61万
• 依托单位: University of Hawaii
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-01-01 至 2001-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9725966&HistoricalAwards=false
• 关键词: Ratio; Model; Pelagic; Marine; Ecosystem

This research will develop a simple ecosystem model which will account for observed f ratios in pelagic marine ecosystems during both steady state and non steady state conditions. The central hypotheses of the model are as follows: (1) Production is controlled by a single nutrient, the identity of which is determined by the nutritional requirements of the phytoplankton community and the ratio of allochthonous nutrient inputs to the system. (2) The size spectrum of the phytoplankton community is a critical determinant of the f ratio. Large cells are associated with a high f ratio, and small cells are associated with a low f ratio. (3) Marine pelagic ecosystems naturally evolve toward a condition in which stability is maximized. Work carried out to date indicates that maximum stability is associated with low f ratios, i.e. in the range 0.05 0.1. Nutrient pulses are expected to shift the f ratio to larger values because under steady state conditions the large celled phytoplankton are always growing at a low relative growth rate, and the small celled phytoplankton are growing at a high relative growth rate. The principal long term goal of this research is the development of a simple model of the f ratio which can be embedded into much larger ocean-atmosphere models to explain the production and export of organic carbon from the euphotic zone. A secondary goal of this work is the development of a theoretical framework with which to reconcile various measures of the productivity and turnover of pelagic marine ecosystems, i.e., differences between gross photosynthesis and net photosynthetic production of particulate carbon.

本研究将建立一个简单的生态系统模型，该模型将解释在稳态和非稳态条件下在远洋海洋生态系统中观察到的f比。该模型的核心假设如下：（1）生产力是由一个单一的营养控制，其身份是由浮游植物群落的营养需求和外来营养输入系统的比例。(2)浮游植物群落的大小谱是f比的关键决定因素。大小区与高f比相关联，并且小小区与低f比相关联。(3)海洋水层生态系统自然会朝着稳定性最大化的方向发展。迄今为止进行的工作表明，最大的稳定性与低的f比，即在0.05 - 0.1的范围内。营养脉冲预计将转移的f比更大的值，因为在稳态条件下，大细胞浮游植物总是在一个低的相对增长率，和小细胞浮游植物生长在一个高的相对增长率。本研究的主要长期目标是发展一个简单的f比模型，该模型可以嵌入到更大的海洋-大气模型中，以解释真光层有机碳的产生和输出。这项工作的第二个目标是建立一个理论框架，用以协调对中上层海洋生态系统生产力和周转的各种衡量，即：总光合作用和净光合作用产生的颗粒碳之间的差异。