Effects of transformation processes in 'jubraka' agroforestry systems of the Nuba Mountains, Sudan, on plant diversity and nutrient fluxes

在苏丹中部的努巴山，一场旷日持久的内战最近结束，引发了大规模的变革进程，除其他外，影响了这一以前与世隔绝的地区的传统农业生态系统。努巴族农民主要依靠两种耕作方式，一种是种植高粱的“远农场”，另一种是混合种植蔬菜和果树的“家庭农场”，称为“jubraka”。尽管朱布拉卡对农民的生计和当地农业生物多样性的保护非常重要，但朱布拉卡在很大程度上被科学家忽视了。最近未经证实的报告表明，传统的枣树正在迅速转变，往往变成了商业菜园，其特点是外部投入水平很高，如矿物质肥料。朱布拉卡作为高度多样化的农林的特殊结构和努巴山的实际情况，为利用朱布拉卡作为研究(亚)热带农业生态系统现代化动态的模式系统提供了独特的机会。计划进行的调查的主要目标是确定朱布拉卡转型的过程和后果。在包括“传统”和“转化”(商业化)的60个Jubraka中，将结合农学、形态和分子方法，对植物物种多样性、营养通量和管理进行定量评估。将使用多变量统计分析来确定转型进程的驱动因素对植物物种多样性和当地人口粮食安全的相对重要性。

In the Nuba Mountains, Central Sudan, the recent end of a long-lasting civil war initiated large-scale transformation processes that, among others, affected the traditional agro-ecosystems of this formerly isolated region. Nuba farmers mainly rely on two farming plot types, the ‘far farm’ for sorghum cultivation and the ‘house farm’ or homegarden, called ‘jubraka’, for mixed cultivation of vegetables and fruit trees. Despite their importance for farmers’ livelihoods and conservation of local agrobiodiversity, jubrakas have been largely neglected by scientists. Unconfirmed recent reports indicate a rapid transformation of traditional jubrakas, often into commercial vegetable gardens that are characterized by high levels of external inputs such as mineral fertilizers. The particular structure of jubrakas as highly diverse agroforests and the actual situation in the Nuba Mountains provide a unique opportunity to use jubrakas as model systems for studying modernization dynamics of (sub)tropical agroecosystems. Main objective of the planned investigation is to determine the processes and consequences of jubraka transformation. In 60 jubrakas, including ‘traditional’ and ‘transformed’ (commercialized) ones, plant species diversity, nutrient fluxes, and management will be quantitatively assessed, combining agronomical, morphological, and molecular approaches. Multivariate statistical analysis will be used to determine the relative importance of drivers of transformation processes on plant species diversity and on food security of the local population.