Negative effects of river control include altered sediment and biotic processes, leading to channel incision and discordance between water delivery and the evolved physiology of seed dispersal. In forests where tree regeneration is inhibited due to such altered processes, tree mortality is of utmost importance guiding forest management. I compared cottonwood ring-widths between adjacent live and dead forest patches in a nested plot design along the regulated Rio Grande, New Mexico. Particle size in the associated sediments, competition, and age were analyzed as contributing factors. The entire stand had declining growth between 2002 and 2015. Tree growth correlated strongest with August and September streamflow and the trees that died grew similarly to their surviving neighbors until 2010. Surviving trees differ from adjacent dead trees in that they are larger and rooted in finer sediments. The die-off associated with coarser underlying sediments implies that water-holding capacity is important to tree health.
cottonwood, Rio Grande, tree growth
Varani, Hannah A.. "Factors Affecting a Riparian Cottonwood Stand Die-off Along the Rio Grande Pueblo of Santa Ana New Mexico, USA." (2020). https://digitalrepository.unm.edu/wr_sp/185