Collaborative Research: Fern Biogeochemistry and Ecosystem Stoichiometry

蕨类植物是许多生态系统的重要组成部分，它们的化学成分与与它们一起生长的植物有很大的不同。这种对比在攀缘蕨类和树蕨中尤为明显；这些古老的血统含有非常低浓度的钙，可能支持不同的有机化合物。许多夏威夷雨林由一棵树和一种基生蕨类植物共同主导，这些系统中的蕨类植物可以贡献50%的地上净初级产量和氮、磷循环。拟议的研究将结合观察、实验和建模来了解Ca和其他元素的动力学，以及在这些相对简单的系统中的顽固性有机化合物。单细胞x射线微分析将用于确定树木和蕨类植物以及真菌和细菌之间的化学差异，有机化合物将通过热解GC-MS和同步加速器FTIR，沿着从凋落物到土壤有机质的衰变连续体进行分析。本研究将整合系统发育、生物化学、生态学和有机地球化学的信息和方法，以确定蕨类植物和树木之间的差异如何影响分解者群落和分解过程。在这个模型系统中获得的对基本过程的理解将扩大我们对陆地生态系统的理解。它还将把从高中到博士阶段的学生纳入研究，将教育与基础研究联系起来。通过我们与卡美哈美哈学校和夏威夷大学希洛夏威夷实习项目的互动，其中一些学生将是夏威夷原住民。此外，该研究将通过将几种现代分析技术应用于生态问题来建立科学能力。

Ferns are abundant components of many ecosystems, and they differ substantially in chemistry from the plants with which they occur. These contrasts are particularly strong in the climbing ferns and tree ferns; these ancient lineages contain remarkably low concentrations of Ca and may support a different set of organic compounds. Many Hawaiian rainforests are co-dominated by a tree and a basal fern, and the fern in these systems can contribute 50% of aboveground net primary production and N and P cycling. The proposed research will apply a combination of observations, experiments, and modeling to understand the dynamics of Ca and other elements, and of recalcitrant organic compounds, in these relatively simple systems. Single-cell x-ray microanalysis will be used to determine differences in chemistry between trees and ferns on the one hand, and fungi and bacteria on the other, and organic compounds will be analyzed via pyrolysis GC-MS and synchrotron FTIR, along the decay continuum from litter to soil organic matter. This proposed research will integrate information and approaches from phylogeny, biochemistry, ecology, and organic geochemistry to determine how differences between ferns and trees affect the decomposer community and the decomposition process. The understanding of fundamental processes gained in this model system will broaden our understanding of terrestrial ecosystems. It will also link education to basic research by incorporating students at levels from high school to Ph.D. into the research. Some of these students will be Native Hawaiians, through our interactions with Kamehameha Schools and the University of Hawaii - Hilo Hawaiian Internship Program. In addition, the research will build scientific capacity by applying several modern analytical techniques to ecological questions.