Department of Biology, 208 Mueller Laboratory, The Pennsylvania State University, University Park, PA 16802, USA.
Plant Biol (Stuttg). 2012 Jan;14(1):249-52. doi: 10.1111/j.1438-8677.2011.00459.x. Epub 2011 Mar 2.
Plant structural defences play a key role in preventing fitness loss due to herbivory. However, how structural defences are affected by potential climate change is rarely examined. We examined how leaf morphological traits that relate to the structural defence of an invasive thistle, Carduus nutans, change in a warmer climate. We manipulated warming using open-top chambers (OTCs) and examined the morphology of leaves at three different positions (the 5th, 10th and 15th leaves, counted from the top of the plant) in two destructive summer censuses. We found that structural defence traits were different under ambient versus warmed conditions. Prickle densities (both the number of prickles per leaf area and the number of prickles per leaf mass) were significantly lower in plants grown in a warmer climate. Our results suggest that plant structural defences may be reduced under warming, and therefore should be considered when examining species' responses to climate change.
植物结构防御在防止因食草而导致的适应度下降方面起着关键作用。然而，结构防御受潜在气候变化影响的情况却很少被研究。我们研究了与入侵蓟 Carduus nutans 的结构防御相关的叶片形态特征在更温暖的气候下如何发生变化。我们使用开顶式气室（OTC）来操纵升温，并在两个破坏性的夏季普查中，在植物顶部算起的第 5、10 和 15 片叶的三个不同位置上检查叶片的形态。我们发现，在环境条件和升温条件下，结构防御特征不同。在温暖气候下生长的植物的刺密度（每叶面积的刺数和每叶质量的刺数）显著降低。我们的研究结果表明，在升温下植物的结构防御可能会减弱，因此在研究物种对气候变化的响应时应该考虑这一点。
