Collaborative Research: Changes in ecosystem production and benthic biodiversity following the widespread loss of an ecosystem engineer

合作研究：生态系统工程师广泛流失后生态系统生产和底栖生物多样性的变化

• 批准号: 1435194
• 负责人: Matthew Edwards
• 金额: $ 35.6万
• 依托单位: San Diego State University Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1435194&HistoricalAwards=false
• 关键词: Collaborative; Research; Changes; ecosystem; production

In many ecosystems the presence of a single dominant species can modify the physical conditions of the environment and alter patterns of biodiversity, nutrient cycling, and primary production. Losses of these "ecosystem engineers" can have profound impacts to how ecosystems function. Coastal kelps provide excellent examples of organisms whose structure modifies the physical characteristics of their habitats (light, nutrients, water motion) and supports enhanced biodiversity. The kelp forests in the coastal waters of the Aleutian Archipelago have suffered large-scale declines over the past several decades. This project will examine how these losses impact patterns of ecosystem production and biodiversity using a combination of techniques ranging from in situ benthic chambers and shipboard incubations to remote sensing using satellite imagery. The results will provide an understanding of how such events may impact this and other ecosystems. This project will support graduate students and will introduce the public to the Aleutian ecosystems in a series of videos. The investigators will also work with a San Diego high school teacher to integrate project findings into classroom activities, and they expect to involve a teacher in their field program. The investigators will ask two highly integrated questions: 1) How do the widespread losses of kelp forests impact benthic productivity across the Aleutian Archipelago? 2) How do the widespread losses of kelp forests impact benthic biodiversity and community structure across the archipelago? To address these, the investigators will estimate changes to productivity at ten islands where they have historic data on seaweed community composition and estimates of kelp canopy cover. They will use in situ benthic chambers placed in both kelp forests and urchin barrens to measure plot-scale patterns of net ecosystem productivity (NEP), and shipboard incubations to examine net primary productivity (NPP) for the dominant macroalgae. Data for individual species rates of NPP will be scaled by their biomass and combined with in situ plot-scale benthic chamber experiments of whole communities to estimate NEP at the islands visited. These estimates will be scaled up to calculate NEP across the entire archipelago by first extrapolating results from the study sites to entire islands, and then across the archipelago. They will also estimate broad-scale patterns in production by characterizing water column irradiances across the archipelago and modeling NPP using species-level relationships between irradiance and photosynthesis. Coupling these with estimates of water column irradiance and community respiration will allow modeling of NEP across this region. Benthic biodiversity will be assessed using diver surveys and shipboard benthic trawls. Following these activities, satellite remote sensing of the kelp canopies dating back to the 1980s and the investigators' own historical data on benthic macroalgal abundances at these and other islands will be used to estimate the temporal and spatial patterns of change across the archipelago.

在许多生态系统中，单个主要物种的存在可以改变环境的物理状况，并改变生物多样性，营养循环和初级生产的模式。这些“生态系统工程师”的损失可能会对生态系统的运作产生深远的影响。沿海海带提供了有机体的极好例子，其结构可修饰其栖息地的物理特征（轻，营养，水运动），并支持增强的生物多样性。 在过去的几十年中，阿留申群岛沿海地区的海带森林遭受了大规模下降。该项目将研究这些损失如何使用从原位底栖腔室和船上孵化到使用卫星图像的遥感的技术组合影响生态系统生产和生物多样性的模式。 结果将对此类事件可能如何影响该生态系统产生理解。该项目将支持研究生，并将在一系列视频中向公众介绍Aleteian生态系统。调查人员还将与一位圣地亚哥高中老师合作，​​将项目调查结果整合到课堂活动中，他们希望将一名老师参与其现场计划。调查人员将提出两个高度综合的问题：1）海带森林的广泛损失如何影响整个阿留申群岛的底栖生产力？ 2）海带森林的广泛损失如何影响整个群岛的底栖生物多样性和社区结构？为了解决这些问题，调查人员将估计十个岛上生产率的变化，在那里他们拥有有关海藻社区组成的历史数据以及海带冠层覆盖的估计。他们将使用放置在海带森林和顽童贫瘠的原位底栖腔室来测量净生态系统生产力（NEP）的情节尺度模式，并孵化船舶孵化来检查主要宏观藻类的净初级生产力（NPP）。 NPP单个物种速率的数据将通过其生物量来缩放，并与整个社区的原位情节尺度底栖腔室实验相结合，以估算所见岛屿的NEP。这些估计将进行扩展以计算整个群岛的NEP，首先将研究地点的结果推到整个岛屿，然后再推断整个群岛。他们还将通过表征整个群岛的水柱辐照以及使用辐照度和光合作用之间的物种水平关系来对生产中的广泛模式进行估算。将它们与水柱辐照度和社区呼吸的估计结合在一起，将允许在该地区对NEP进行建模。底栖生物多样性将使用潜水员调查和船上底栖拖网进行评估。在这些活动之后，可以追溯到1980年代的海带檐篷的卫星遥感以及研究人员对这些岛屿和其他岛屿上底栖大型宏观藻类丰度的历史数据将用于估计整个群岛整个群岛变化的时间和空间模式。