Linking nutrient flux in a desert food web to the allocation dynamics in lizards: Combining stable isotopes and ecological stoichiometry

植物-动物群落中的营养动态是捕食者繁殖和种群动态的关键驱动因素，但人们对其了解甚少。这是第一个试图将食虫蜥蜴的营养分配与昆虫猎物质量的变化联系起来的研究，这些变化是由季节和雨水驱动的植物营养质量变化引起的。在新墨西哥州的塞维莱塔LTER，夏季季风推动植物利用C4光合作用进行生产。对于昆虫来说，这些C4植物的营养价值低于冬季雨水驱动的春季C3植物。本研究将测量并利用这些植物和昆虫的稳定同位素、脂质蛋白含量和季节丰度的自然差异，并结合实验室实验，探索C3和C4资源在季节和年际时间尺度上的营养变化对蜥蜴繁殖的重要性。更广泛的影响：通过将降水和植物生长与昆虫和脊椎动物的营养生态学和生殖生理学联系起来，该项目将扩大当前生态学调查的范围。这些数据还将有助于深入了解气候变化如何影响动植物群落的生态。最后，本研究将通过塞维莱塔LTER研究人员与GK-12教育工作者的合作，丰富中学科学教育。

Nutrient dynamics within plant-animal communities are critical, yet poorly understood, drivers of the reproductive and population dynamics of predators. This is the first study that attempts to link nutrient allocation in insectivorous lizards to variation in insect prey quality resulting from seasonal and rain-driven variation in plant nutritional quality. At the Sevilleta LTER in New Mexico, summer monsoons drive the production of plants using C4 photosynthesis. These C4 plants are less nutritious for insect consumers than winter-rain-driven, spring dominant C3 plants. This study will measure and use a remarkable combination of naturally occurring differences in stable isotopes, lipid-protein content and seasonal abundance of these plants and insects, interlinked with a laboratory-based experiment, to explore the importance of nutritional variation in C3 and C4 resources for lizard reproduction at seasonal and inter-annual timescales. Broader impacts: This project will broaden the scope of current ecology investigations by linking precipitation and plant growth to the nutritional ecology and reproductive physiology of insect and vertebrate consumers. These data will also provide insight into how climate change may impact the ecology of plant-animal communities. Lastly, this study will enrich middle school science education through collaborations between Sevilleta LTER researchers and GK-12 educators.