USDA Forest Service, Rocky Mountain Research Station, Moscow, Idaho, 83843, USA.
Division of Natural Science and Mathematics, Snow College, Ephraim, Utah, 84627, USA.
Ecol Appl. 2018 Dec;28(8):2165-2174. doi: 10.1002/eap.1804. Epub 2018 Oct 17.
Genetic resources have to be managed appropriately to mitigate the impact of climate change. For many wildland plants, conservation will require knowledge of the climatic factors affecting intraspecific genetic variation to minimize maladaptation. Knowledge of the interaction between traits and climate can focus management resources on vulnerable populations, provide guidance for seed transfer, and enhance fitness and resilience under changing climates. In this study, traits of big sagebrush (Artemisia tridentata) were examined among common gardens located in different climates. We focus on two subspecies, wyomingensis and tridentata, that occupy the most imperiled warm-dry spectrum of the sagebrush biome. Populations collected across the sagebrush biome were recorded for flower phenology and survival. Mixed-effects models examined each trait to evaluate genetic variation, environmental effects, and adaptive breadth of populations. Climate variables derived from population-source locations were significantly associated with these traits (P < 0.0001), explaining 31% and 11% of the flower phenology and survival variation, respectively. To illustrate our model and assess variability in prediction, we examine fixed and focal point seed transfer approaches to map contemporary and climate model ensemble projections in two different regions of the sagebrush biome. A comparison of seed transfer areas predicts that populations from warmer climates become more prevalent, replacing colder-adapted populations by mid-century. However, these warm-adapted populations are often located along the trailing edge, margins of the species range predicted to be lost due to a contraction of the climatic niche. Management efforts should focus on the collection and conservation of vulnerable populations and prudent seed transfer to colder regions where these populations are projected to occur by mid-century. Our models provide the foundation to develop an empirical, climate-based seed transfer system for current and future restoration of big sagebrush.
遗传资源必须得到妥善管理，以减轻气候变化的影响。对于许多野生植物来说，保护它们需要了解影响种内遗传变异的气候因素，以最小化适应不良的情况。了解性状与气候之间的相互作用，可以将管理资源集中在脆弱的种群上，为种子转移提供指导，并提高在不断变化的气候下的适应性和恢复力。在这项研究中，对不同气候条件下的普通花园中的大 sagebrush（Artemisia tridentata）性状进行了研究。我们关注的是两种亚种，wyomingensis 和 tridentata，它们占据了 sagebrush 生物群落中最危险的温暖干旱范围。在 sagebrush 生物群落中收集的种群被记录下来，用于研究花期和存活率。混合效应模型检查了每个性状，以评估种群的遗传变异、环境影响和适应性广度。从种群来源地得出的气候变量与这些性状显著相关（P < 0.0001），分别解释了花期和存活率变异的 31%和 11%。为了说明我们的模型并评估预测的可变性，我们以两个 sagebrush 生物群落的不同区域为例，检查了固定和焦点种子转移方法，以绘制当代和气候模型集合的预测。对种子转移区域的比较预测表明，来自温暖气候的种群变得更为普遍，到本世纪中叶，取代了适应较冷气候的种群。然而，这些适应温暖气候的种群通常位于物种分布范围的边缘，预计由于气候位的收缩，这些边缘地区的物种将丧失。管理工作应侧重于收集和保护脆弱的种群，并谨慎地将种子转移到较冷的地区，预计这些种群将在本世纪中叶出现在这些地区。我们的模型为开发基于经验和气候的种子转移系统提供了基础，用于当前和未来大 sagebrush 的恢复。
