COLLABORATIVE RESEARCH: Do lianas alter community and ecosystem dynamics in tropical forests? A large-scale experimental test

热带森林最近最显著的变化之一是木本藤本植物(藤本植物)丰度和生物量的增加。这一变化很重要，因为最近的证据表明，藤本植物是生态系统过程和树木群落共存的主要贡献者。增加藤本植物可能会减少树木的生长，增加树木的死亡率，并改变土壤养分动态--从而改变热带森林的碳、水和养分通量。藤本植物对高密度树种的生长和更新的阻碍作用也大于低密度树种，这将进一步减少森林的碳储量和碳通量。在巴拿马共和国，私人投资机构将建立长期的试验性林地，在这些林地中，他们从一半的地块中移除藤本植物。PIs将测量碳动态、土壤养分和水分有效性以及树木对藤本植物的响应的长期变化。拟议的项目将是第一个大规模、长期的实验研究，以量化藤本植物在社区和生态系统层面的过程中的作用，并将为预测未来热带森林随藤本植物丰度变化而发生的变化提供基准。该项目将促进各种更广泛的影响，包括国际能力建设、学生辅导和实地教育。PI将积极指导来自美国和拉丁美洲的博士后、研究生和本科生，并将现有的实验基础设施用于美国的留学项目。该项目还为热带森林生态的其他合作研究提供了实验基础设施。

One of the most notable recent changes in tropical forests is the increase in woody vine (liana) abundance and biomass. This change is important because recent evidence suggests that lianas are major contributors to ecosystem processes and tree community coexistence. Increasing lianas will likely reduce tree growth, increase tree mortality, and change soil nutrient dynamics - thus changing tropical forest carbon, water, and nutrient fluxes. Lianas also may impede growth and regeneration of tree species with high wood density more than species with lower wood density, which would further reduce forest carbon stocks and fluxes. In the Republic of Panama, PIs will establish long-term experimental forest plots in which they remove lianas from half of the plots. The PIs will measure long-term changes in carbon dynamics, soil nutrient and water availability, and tree responses to lianas.The proposed project will be the first large-scale, long-term experimental study to quantify the role of lianas in both community- and ecosystem-level processes, and it will provide a benchmark for predicting future tropical forest changes with changing liana abundance. The project will facilitate a variety of broader impacts, including international capacity building, student mentoring, and field-based education. The PIs will actively mentor post-docs and graduate and undergraduate students from the US and Latin America, as well as use the established experimental infrastructure for US-based study-abroad programs. The project also provides experimental infrastructure for additional collaborative research on tropical forest ecology.