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

大片热带雨林容易受到人为和自然干扰，必须解决决定其对干扰敏感性的重要问题，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限制的新热带森林的弹性，在这些森林中，植被长期维持在通过降雨、尘埃或雾输入的大气磷。过去的研究人员发现，灰尘和雾的沉积取决于树冠密度(叶面积)。树冠捕获磷，使植被和磷沉积之间实现正反馈。这项研究正在调查控制这些反馈的发生和强度以及它们对气候和土地覆盖变化的敏感性的生态水文学机制。主要目标是：1.量化从沉积到干燥的中热带森林的总磷输入，并调查其在旱季和雨季之间的波动，与火灾有关，以及与砍伐和焚烧的邻近地区。2.管理。量化磷素沉积对冠层特性的依赖，从而量化冠层磷沉积反馈的强度。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。学生将接受培训，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.