Hydrological feedbacks between phosphorous deposition and canopy cover in dry seasonal forests

大面积的热带森林容易受到人为和自然干扰的影响，必须解决决定其对破坏的敏感性的重要问题，以改进管理做法。其中之一是土地利用或热带风暴模式的变化如何影响磷有限的新热带森林的恢复能力，在这些森林中，植被通过降雨、灰尘或雾等大气磷输入得以长期维持。过去的研究人员发现，尘埃和雾的沉积取决于冠层密度（叶面积）。冠层捕获磷，使植被和磷沉积之间形成正反馈。本研究旨在探讨控制这些反馈发生和强度的生态水文机制及其对气候和土地覆盖变化的敏感性。主要目标是：1。量化从沉积到干燥的新热带森林的总磷输入，并调查其在干湿季节之间的波动，与火灾有关，并靠近？刀耕火种？management.2。量化磷沉降对冠层特性的依赖，从而量化冠层-磷沉降反馈的强度。确定降雨、沙尘和冠层凝结在总磷输入中的相对大小和作用。这三个过程受到气候和土地覆盖变化的不同影响。将对学生进行培训，并开发用于保护这些敏感生态系统的教材。

Large areas of tropical forests are vulnerable to both anthropogenic and natural disturbances, and important issues determining their sensitivity to disruption must be addressed to gain improved management practices. One of these is how changes in land-use or tropical storm patterns affect the resiliency of phosphorus-limited Neotropical forests where vegetation is sustained in the long term by atmospheric phosphorus inputs through rainfall, dust, or fog. Past researchers have found that dust and fog deposition depend on canopy density (leaf area). Canopy traps phosphorus enabling a positive feedback between vegetation and phosphorus deposition. This study is investigating the ecohydrological mechanism controlling the occurrence and strength of these feedbacks and their susceptibility to changes in climate and land cover. The principle objectives are:1. To quantify the total phosphorus input from deposition to a dry neotropical forest and to investigate its fluctuations between dry and wet seasons, associated with fires, and proximity to ?slash and burn? management.2. To quantify the dependence of phosphorus deposition on canopy properties and thus the strength of the canopy-phosphorus deposition feedback.3. To determine the relative magnitudes and roles of rainfall, dust, and canopy condensation in total phosphorus input. These three processes are differently affected by changes in climate and land cover.Students will be trained and teaching materials developed for use in protecting these sensitive ecosystems.