Sept. 16, 2019<\/p>\n\n\n\n
Scientists\nwith the Merriam-Powell Center for Environmental Research have received a four-year,\n$859,000 grant from the National Science Foundation to assess how cottonwood\ntrees have evolved to tolerate environmental stresses, including changing\ntemperature and insect herbivory. The results will aid ongoing river\nrestoration projects across the Southwest by helping identify which trees will continue\nto support healthy ecosystems in a changing world.<\/p>\n\n\n\n
Along rivers in the\nsouthwestern United States, cottonwood trees provide shade, habitat and food\nfor a wide range of species. As such, cottonwoods influence a much larger\ncommunity of understory plants, insects, microbes, birds and mammals. <\/p>\n\n\n\n
Previous research at NAU has shown that the genetic makeup of a cottonwood tree can impact traits such as leaf size and chemistry, and these traits affect all of the species that depend on the tree. However, in a changing environment, the tree\u2019s genetics are only part of the equation for predicting tree health and ecological effects. Genes may be expressed differently when a tree is exposed to new environmental cues, leading to leaves that are thicker or thinner or more or less protected from insect herbivory. Known as phenotypic plasticity, this change in trait expression might be higher in trees that have evolved to deal with constantly changing climates than in trees from very stable environments. <\/p>\n\n\n\n
\u201cA tree\u2019s genes\nprobably set it up not just to do the same thing all the time, but to respond\nto environmental stresses like hot or dry conditions or insect outbreaks in\nparticular ways that will help it survive. Without ways to predict these\nresponses or their effects on ecosystems, our ability to understand the\nconsequences of climate change is really limited,\u201d said Rebecca Best<\/strong>, the project\u2019s principal investigator and assistant professor\nin NAU\u2019s School of Earth and Sustainability. \u201cOur hope is that by understanding\nthe stresses this species has experienced in the past, we can better predict\nwhat these trees will be able to do in the rapidly changing landscape of the\nfuture.\u201d <\/p>\n\n\n\n To investigate these stresses and responses, the researchers will use\ntrees of the same genetic identity planted in three common gardens distributed\nacross a steep environmental gradient from Yuma to Utah. <\/p>\n\n\n\n \u201cNAU is recognized as a world leader in the field of community and\necosystem genetics, and this effort continues an important tradition of\nexcellence in this area,\u201d said David\nSchultz<\/strong>, NAU vice president of research. \u201cAdditionally, this project will\nuse three existing common gardens and build on research initiated by a previous\nNSF grant.\u201d <\/p>\n\n\n\n The\nexperimental gardens, Emerging Frontiers Macrosystem Biology grant\n#1340852, were\ndesigned by Gery Allan<\/strong>, Thomas Whitham<\/strong>, Kitty Gehring<\/strong>, Kevin Grady<\/strong>\nand Samuel Cushman<\/strong> at NAU and Kevin\nHultine at the Desert Botanical Garden.<\/p>\n\n\n\n Co-principal investigators on the new grant are Whitham, Allan and\nRichard Lindroth, University of Wisconsin-Madison. Other collaborators include Christopher Doughty<\/strong> and postdoctoral\nresearcher Hillary Cooper<\/strong>. The\nproject is funded by the National Science Foundation under Grant No. 1914433. <\/p>\n","protected":false},"excerpt":{"rendered":"