Using the Southwest Experimental Garden Array to enhance riparian restoration in response to global environmental change: Identifying and deploying genotypes and populations for current and future environments [Chapter 4]

Abstract

The role of genetics in ecosystem restoration has largely revolved around the policy of using local genotypes (i.e., those sourced from areas near the restoration site), based on the logic that local plants are best adapted to local conditions (Johnson et al. 2004; Meffe and Carroll 1977). In a relatively stable environment, this is a sound practice; however, global environmental change impacts on the landscape are increasingly rendering this policy as inadequate at best and damaging at worst (Whitham et al. 2010). Here we define “global change” as ongoing changes in temperature, moisture, interactions with invasive plants and pathogens, increases in the frequency and severity of environmental extremes (e.g., fires, droughts), and other challenges (Cayan et al. 2010; Gutschick and BassiriRad 2003; Jones and Monaco 2009). Because of rapid environmental change, plants that are locally adapted to current environmental conditions are likely to become increasingly maladapted to their changing native environments. For example, in Arizona, Grady et al. (2011, 2015) found that Fremont cottonwoods (Populus fremontii) were currently locally adapted along an elevational gradient, and that tree genotypes from lower elevations transplanted to higher elevations were predicted to outperform the local genotypes at higher elevations under climate change conditions. In regions of especially rapid change such as the American Southwest (Garfin et al. 2013; Seager et al. 2007), local populations are likely to lack sufficient genetic variation to adapt to these new environments (Aitken et al. 2008; O’Neill et al. 2008a). Similarly, with the rapid velocity of climate change coupled with fragmented landscapes (Loarie et al. 2009), many species cannot migrate fast enough to reach favorable environments (Aitken et al. 2008; Davis and Shaw 2001).

Parent Publication

• Riparian research and management: Past, present, future: Volume 2

Citation

Whitham, Thomas G.; Gehring, Catherine A.; Bothwell, Helen M.; Cooper, Hillary F.; Hull, Julia B.; Allan, Gerard J.; Grady, Kevin C.; Markovchick, Lisa; Shuster, Stephen M.; Parker, Jackie; Cadmus, Abraham E.; Ikeda, Dana H.; Bangert, Randy K.; Hultine, Kevin R.; Blasini, Davis E. 2020. Using the Southwest Experimental Garden Array to enhance riparian restoration in response to global environmental change: Identifying and deploying genotypes and populations for current and future environments [Chapter 4]. In: Carothers, Steven W.; Johnson, R. Roy; Finch, Deborah M.; Kingsley, Kenneth J.; Hamre, Robert H., tech. eds. Riparian research and management: Past, present, future. Volume 2. Gen. Tech. Rep. RMRS-GTR-411. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. p. 63-79.