Assessing the influence of lithology on the temporal-spatial variability of sediment transport and its relation to primary production in mountain streams

初级生产为地球上大多数生命提供了基本的能量来源，因此了解控制初级生产的因素是理解生态系统的关键。在溪流中，相关研究主要集中在光和营养的影响上。下伏地质和沉积物运输的作用还没有得到很好的探索。在源头溪流中占主导地位的初级生产者的藻类生活在岩石上。移动这些岩石的流动事件可以刮走藻类，并将系统重置为低产量水平。因此，了解河流中沉积物冲刷和磨损频率的控制是理解初级生产动力学的基础。这个研究项目将有助于更好地理解生态系统和景观的共同进化。这个跨学科的研究项目将河流地貌学和河流生态学联系起来。目标是确定：(a)速度和剪切应力的空间变异性如何影响砾石层状溪流中的沉积物输运，(b)它们如何影响河段和斑块尺度上的初级生产力，以及(c)下垫基岩岩性对这些过程的控制。该项目将结合使用二维模型和俄勒冈海岸山脉四个地点的现场测量数据。这些地点的选择是基于相似的气候、光照、营养物质和温度，但不同的岩性，以隔离其施加的控制。该项目由一位早期职业生涯的西班牙裔女性调查员领导。与当地一所高中的合作将为教师提供研究经验，并让美国原住民高中生参与其中。

Primary production provides the fundamental source of energy for most life on earth, and therefore understanding what controls primary production is key to understanding ecosystems. In streams, relevant research has focused mainly on the influence of light and nutrients. The role of underlying geology and sediment transport has not been as well explored. The algae that dominate primary producers in headwater streams live on rocks. Flow events that mobilize those rocks can scrape algae away and reset the system to low production levels. Understanding controls on the frequency of sediment scour and abrasion in a stream is therefore fundamental to understanding the dynamics of primary production. This research project will contribute to a better understanding of the coevolution of ecosystems and landscapes.This interdisciplinary research project links fluvial geomorphology and stream ecology. The goal is to determine: (a) how spatial variability in velocity and shear stress affect sediment transport in gravel-bedded streams, (b) how these affect primary productivity at reach and patch scale, and (c) what control underlying bedrock lithology exerts on these processes. This project will couple the use of a 2D model and the collection of field measurements in four sites in the Oregon Coast Range. The sites have been selected based on similar climate, light, nutrients, and temperature, but different lithology to isolate the controls it exerts. The project is led by an early career Hispanic female investigator. Collaboration with a local high school will provide a research experience for teachers and involve Native American high school students.