Understanding intraspecific variation in plant defense across resource gradients

植物通过把毒药放在叶子上，把刺放在树枝上来保护自己免受饥饿动物的伤害。他们也有很多其他的方法来保护自己。生态学家长期以来一直想知道为什么不同种类的植物采取了非常不同的保护策略。为什么没有一种最好的方法呢？即使是同一物种的不同个体，也会以不同的方式保护自己。因此，生态学的一个主要挑战是弄清楚植物防御差异的原因和后果。一种想法是，在不能快速生长的地方种植植物，可以在国防上投入更多的能量。相比之下，在水分和营养丰富的地方，植物可以快速生长和繁殖--生活很好，所以它们不需要那么多防御。参与该项目的科学家将对这一想法进行测试。他们将研究同一物种的不同个体在生长在压力大的地区和资源丰富的地区时，如何改变他们的防御策略。他们将通过测量植物对昆虫的美味程度来测试防御系统的效果。这一结果可能会为保护农作物免受虫害提供新的策略。研究人员将让高中生和大学生参与这个项目，培训他们如何做科学。此外，公众还将参与各种自然历史和保护计划。该项目包括将在8个高资源和8个低资源环境中复制的种群中的6个共生本地草原植物物种相互移植到每个地区的共同花园中。资源(降雨量)也将在低资源区的一个普通花园中进行操纵，以评估植物生长和防御对非生物因素的反应是可塑性的程度。食草动物的丰度和食草动物对植物适合性的影响(通过昆虫减少实验获得)将在包含两个资源区域的重点物种的种群中进行量化。总的来说，这些实验将评估资源环境如何影响：1)物种内的生长和防御(包括耐性和抗性)进化和可塑性；2)种群间的正相关生长和防御；以及3)昆虫食草动物的丰度和食草动物对植物适合性的影响。最终，所采用的多物种方法将有助于协调经常在物种之间和物种内观察到的不同生长-防御关系。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Plants defend themselves from hungry animals by putting poisons in their leaves and thorns on their branches. There are many other ways they protect themselves, too. Ecologists have wondered for a long time why different species of plants adopt very different strategies of protection. Why wouldn't there be one best way? Even different individuals of the same species defend themselves differently. Thus, a major challenge in ecology is to figure out the causes and consequences of differences in plant defense. One idea is that plants in places where they can't grow fast, can invest more energy in defense. In contrast, plants in places with lots of water and nutrients can grow and reproduce quickly -- life is good, so they don't need as much defense. Scientists with this project will test that idea. They will look at how different individuals of the same species may change their strategies of defense when grown in stressful areas and areas of plenty. They will test how well the defenses work by measuring how tasty the plants are to insects. Results may reveal new strategies for protection of farm crops from insect pests. The researchers will involve high school and college students in the project, training them how to do science. Also, the public will be engaged through various natural history and conservation programs.This project involves reciprocally transplanting six co-occurring native grassland plant species from populations replicated within eight high- and eight low-resource environments into common gardens located in each region. Resources (rainfall) will also be manipulated in a common garden located in the low-resource region to evaluate the extent to which responses of plant growth and defense to abiotic factors are plastic. Herbivore abundance and the impacts of herbivores on plant fitness (accessed via insect-reduction experiments) will be quantified within populations containing the focal species across the two resource regions. Collectively, these experiments will evaluate how the resource environment influences: 1) growth and defense (both tolerance and resistance) evolution and plasticity within species; 2) positive growth and defense correlations across populations, and 3) insect herbivore abundance and the impacts of herbivory on plant fitness. Ultimately, the multispecies approach employed will help to reconcile the different growth-defense relationships often observed among vs. within species.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.