The Role of the Canopy Subsystem in Tropical Forest NutrientCycles: Mechanisms and Models

纳德卡尼博士将在热带山地原始云雾林中研究树冠附生植物群落在营养循环中的功能作用。她假设附生物质通过促进大气养分补充和系统内养分保持而发挥“基石成分”的作用。Nadkarni结合了几种研究方法，包括：1)实验室和田间以过程为导向的实验方法，以测试关于附生植物如何增加冠层内的养分吸收和养分保持的具体假设，以及2)量化营养库和通量的小区方法，包括估计生态系统水平的植物生物量、凋落物、穿透雨，以及某些气态通量。这些信息将被整合到一个养分循环模型中，该模型将通过对邻近几乎没有附生植物的次生林中的营养库和通量的测量来进行测试和验证。这项工作将把树冠过程与热带森林生态系统生态的其他方面联系起来，并将有助于不断增长对鲜为人知的热带树木树冠的认识。更广泛地说，这可以被视为任何包含“基石生态系统元素”的复杂生态系统的案例研究，这些元素中的某些成分可能具有比其生物量或外观所显示的更大的功能重要性。纳德卡尼博士是热带附生植物群落领域的杰出研究人员。玛丽·塞尔比植物园在这一关键研究领域为纳德卡尼博士提供了模范支持。

Dr. Nadkarni will investigate the functional role of the canopy- dwelling epiphyte community in nutrient cycling in a primary tropical montane cloud forest. She hypothesizes that epiphytic matter functions as a "keystone component" by contributing to atmospheric nutrient recruitment and within-system nutrient retention. Nadkarni combines several research approaches including: 1) a process-oriented experimental approach in the lab and field to test specific hypotheses on how epiphytes increase nutrient recruitment and nutrient retention within the canopy and, 2) a plot approach to quantify nutrient pools and fluxes, including an estimation of ecosystem-level ephiphyte biomass, litterfall, throughfall, and certain gaseous fluxes. This information will be integrated into a nutrient cycling model that will be tested and validated with measurements of nutrient pools and fluxes in an adjacent secondary forest which has virtually no epiphytes. This work will relate canopy processes to other aspects of ecosystem ecology in tropical forests and will contribute to the growing body of knowledge of the poorly known tropical tree canopy. More generally, this can be viewed as a case study for any complex ecosystem that contains "keystone ecosystem elements", certain components that may have greater functional importance than their biomass or appearance suggests. Dr. Nadkarni is an outstanding researcher in the area of tropical epiphytic communities. The Marie Selby Botanical Gardens provides exemplary support for Dr. Nadkarni in this critical area of research.