Abstract Detail

The Hills are Alive: Ecology and Evolution of the Intermountain West Flora

Caughlin, T. Trevor [1], Zaiats, Andril [1], Germino, Matthew J. [2], Delparte, Donna M. [3], Richardson, Bryce A. [4], Forbey, Jennifer S. [1], Olsoy, Peter [1], Cattau, Megan [5].

Consequences of intraspecific variation in big sagebrush for ecological pattern and process in the Great Basin.

Big sagebrush (Artemisia tridentata Nutt.) is a keystone plant species throughout much of the western North America. The once-extensive sagebrush steppe biome, dominated by sagebrush species that are foundational to ecosystem structure and function, is increasingly degraded by invasive annual grasses and anthropogenic wildfires. In the context of these ongoing changes, understanding the ecology and evolution of big sagebrush is a critical research need. A defining characteristic of big sagebrush is high intraspecific diversity, including variable morphology, genome size, and genetic adaptation to local environments. Using replicated common garden experiments, our team is disentangling the contributions of intraspecific variation to ecological function in big sagebrush. We established a common garden experiment in 2010 with seeds collected across the Great Basin representing three subspecies (Basin/tridentata, Wyoming/wyomingensis, and mountain/vaseyana) and two ploidy levels (2x and 4x). Subspecies and ploidy levels demonstrate demographic differences, including growth, survival, and competitive tolerance. Isotope addition experiments reveal that demographic variation is paralleled by functional differences in root zone of influence between sagebrush subspecies and ploidy levels. In addition to belowground differences, we have quantified thermal differences between sagebrush plants, using an unoccupied aerial system (UAS) with an infrared camera to quantify leaf-level variability in thermal environments. Thermal imagery reveals that divergent morphology between sagebrush subspecies can explain variable within-canopy temperatures. Our results have implications for restoration and conservation of sagebrush steppe, where accounting for intraspecific variation in big sagebrush plants will be essential for effective land management. An overarching future goal will be to address how high levels of intraspecific diversity are maintained within big sagebrush, including ecological and evolutionary mechanisms of coexistence.

1 - Boise State University, Department of Biological Sciences, Boise, ID
2 - US Geological Survey, Forest and Rangeland Ecosystem Science Center, Boise, ID
3 - Idaho State University, Geosciences Department, Boise , ID
4 - Forest Sciences Laboratory, US Forest Service, Moscow, ID
5 - Boise State University, Human Environmental Systems, Boise, ID

Keywords:
polyploidy
sagebrush steppe
thermal ecology
root zone of influence
spatial model.

Presentation Type: Symposium Presentation
Session: SY5, The Hills are Alive: Ecology and Evolution of the Intermountain West Flora
Location: /
Date: Thursday, July 22nd, 2021
Time: 11:15 AM(EDT)
Number: SY5004
Abstract ID:1186
Candidate for Awards:None