RUI: Testing Optimal Partitioning and Plant Strategy Theories: Do Conclusions Differ When Functional Adjustments are Explicitly Distinguished from Ontogenetic Drift?

9408120麦康纳海在植物生态学研究中，不同遗传特性的植物(例如物种)或生长在不同环境中的植物之间的差异通常是通过比较单个、通常是任意的时间点上的植物来评估的。这种植物反应的静态观点没有认识到植物发展的动态和不确定性。植物的大多数特征在生长和发育过程中都会发生变化；例如，幼苗的根冠生物量比率通常很高，然后随着植株大小的增长而下降。此外，不同遗传特性或在不同环境中的植物的生长和发育速度可能会有所不同。因此，在任何一个时间点观察到的差异可能不代表对特定环境的适应性反应，而可能至少部分归因于植物发育阶段或大小的差异。在过去的几年里，人们普遍认识到，要广泛地了解植物之间的环境和遗传差异，就需要对植物的生长和发育进行动态表征。我们必须将我们的重点从植物在发育过程中的某一时刻的快照转移到发展本身的动态。生物量分配模式(即投入到不同植物结构中的相对生物量)受到植物生态学家和植物进化生物学家的极大关注。例如，这些特征被用来描述对环境限制的功能适应。由于分配模式在植物生长和发育过程中可能会发生变化，不同的分配模式可能源于分配本身的灵活性(分配可塑性)或植物整体生长(生长或发育速度的可塑性)。在分配可塑性严格归因于生长或发育速率变化的情况下，我们目前关于植物最优生长模式和植物对不同环境的功能适应的许多理论可能需要修订。我们建议将资源可获得性对植物生长速度和生物量分配的影响分开。我们将在具有不同资源可获得性水平(二氧化碳、光、养分和水)的环境中种植植物，以确定生物量分配的差异是由于生长速度的差异、分配的差异，还是两者都有。这些实验将提供有关植物对资源可获得性不同环境的功能适应方面亟需的信息。***

9408120 McConnaughay In plant ecological research, differences among plants of different genetic identity (e.g., species) or among plants grown in different environments are usually assessed by comparing plants at a single, often arbitrary, point in time. This static view of plant responses does not recognize the dynamic and indeterminate nature of plant development. Most characteristics of plants change during growth and development; the ratio of root: shoot biomass, for example, is usually high in seedlings ald then declines as the plant grows in size. Furthermore, plants of different genetic identity or in different environments may differ in rates of growth and development. Thus differences observed at any one point in time may not represent an adapative response to a given environment, but rather may be due, at least in part to differences in the developmental stage or size of the plant. In the last several years, there has been a widespread recognition that a broad understanding of environmental and genetic differences among plants requires a dynamic characterization of plant growth and development. We must shift our focus from snapshots of plants at one point in development to the dynamics of development itself. Biomass allocation patterns (i.e., relative amounts of biomass put in to varying plant structures) have received considerable attention from plant ecologists and plant evolutionary biologists. For example, these traits have been used to describe functional adaptations to environmental constraints. Since allocation patterns may change during plant growth and development, different allocation patterns may result from flexibility in allocation per se (allocation plasticity) or in overall plant growth (plasticity in growth or developmental rates). In cases where allocational plasticity is strictly due to alterations in growth or developmental rates, much of our current theory concerning optimal growth patterns and functional adaptations of plants to variable environments may need to be revised. We propose to separate the effects of resource availability on plant growth rate and biomass partitioning. We will grow plants in environments with different levels of resource availability (CO2, light, nutrients and water) in order to determine if differences in biomass allocation result from differences in growth rates, partitioning, or both. These experiments will provide much needed information concerning plant functional adaptations to environments differing in resource availability. ***