CRB: Research Toward Sustainable Land Use and Biodiversity in Mosaic of Agriculture and Tropical Forest

9424606海恩斯这项研究将分三个阶段进行。这三个阶段的长期目标是确定在不同土壤质量和地形的热带地区各种自然或半自然土地使用的可持续性。可持续性被定义为土地利用的养分和土壤质量损失率低于养分输入和土壤形成率。这一点很重要，因为在整个太平洋地区，物种丰富的森林越来越多地转化为农业用地。在许多热带地区，农业通常是短命的，然后田地就被遗弃了。弃耕地和热带潮湿森林分别倾向于具有负的和正的净土壤质量和养分平衡。因此，在景观尺度上，森林可以抵消邻近田地的损失。因此，景观尺度的可持续性要求恢复和再生天然森林植被。该项目的近期目标是记录废弃牧场的演替模式，并确定可能限制森林再生速度的因素。为此，将对不同土壤类型和条件下的演替速度进行量化，并将测量种子雨、种子库、种子发芽、幼苗建立和树苗生长。这些因素将结合起来，以了解限制殖民化和物种的增长，恢复热带森林社区。 鉴于许多热带地区的森林砍伐率和人口增长率迅速增加，快速恢复废弃农田植被的能力变得越来越重要。这项研究将提供有价值的人口水平的数据，在景观尺度上，以指导实验方法，大规模恢复废弃的农业用地在热带地区。

9424606 Haines This research will be conducted in three phases. The long-term goal for the three phases is to determine the sustainability of various natural or semi-natural land uses on tropical sites of differing soil quality and topography. Sustainability is defined as land use in which rates of nutrient and soil mass loss are less than rates of nutrient input and soil formation. This is important because of increasing conversion of species rich forests to agricultural land throughout the tpopics. in many tropical areas, agriculture is typically short-lived, and fields are then abandoned. Abandoned fields and tropical moist forest tend to have negative and positive net soil mass and nutrient balances, respectively. Thus, at the landscape scale, forests can offset losses from adjacent fields. Therefore, landscape scale sustainability requires restoration and regeneration of natural forest vegetation. The near-term goal of this project is to document patterns of abandoned pasture succession, and identify factors potentially limiting the rate of forest regeneration. To do so, rates of succession on different soil types and conditions will be quantified, and seed rain, seed bank, seed germination, seedling establishment and sapling growth will be measured. These factors will be combined to understand limitations to colonization and growth of species for the restoration of tropical forest communities. Given the rapidly increasing rates of deforestation and population growth in many tropical areas, the ability to rapidly restore vegetation to abandoned cropland becomes increasingly important. This study will provide valuable population-level data at the landscape scale to guide experimental approaches to large-scale restoration of abandoned agricultural land in the tropics.