A range of social and economic factors impact tree species, such as Sclerocarya birrea subsp. caffra (marula), which provide livelihood sustenance for local communities in the savanna woodlands of southern Africa. As an ecologically important savanna species, valued both culturally and economically, it is imperative to understand if resource use is sustainable. Population stability can be understood by comparing tree density and size-class distribution (SCD) profiles across land-use types (homestead yards, fields and rangelands) in non-conservation savanna social-ecological systems. Marula tree population data were gathered in rangeland transects and randomly selected fields and yards from four human settlements in the Bushbuckridge municipality of north-eastern South Africa. Total density was lowest in fields (mean ± SE = 7.4 ± 0.7 trees/ha) and highest in homestead yards (mean ± SE = 25.7 ± 4.1 trees/ha). Social data revealed that elevated seedling and sapling population densities in yards is linked to discarded kernels from marula beer making. Total densities increased in yards over a 15-year period but declined in rangelands, with female densities remaining almost constant across land-use types over this period. This is an important finding as it is a strong indication of socially-mediated population structure changes, confirming that combined cultural and economic value can lead to examples of species conservation. In this case, the prioritization of female trees as the distinguished fruit producers. SCD revealed weak recruitment in fields and rangelands. Diminished regeneration, combined with overharvesting for fuelwood in rangelands and felling trees in yards, is likely to negatively impact population stability in the long-term. Understanding resource conservation and degradation in the context of important non-timber forest products (NTFPs) is a key knowledge challenge, with this study serving as an updated inventory benchmark for marula populations in the area. Important lessons learned here can be applied to other social-ecological contexts where a key natural resource is responsible for sustaining livelihoods.

一系列社会和经济因素会影响树木，例如Sclerocarya birrea亚种。卡夫拉（marula），为南部非洲大草原林地的当地社区提供生计。作为一种具有生态重要性的热带稀树草原物种，无论是在文化上还是在经济上都受到重视，因此必须了解资源的使用是否可持续。通过比较非保护性热带稀树草原社会生态系统中各种土地利用类型（宅基地，田地和牧场）的树木密度和大小分类分布（SCD）剖面，可以了解种群的稳定性。南非东北部的布什巴克里奇市的四个人类住区的牧场样地和随机选择的田地和庭院中收集了马拉拉树的种群数据。总密度在田间最低（平均±SE = 7.4±0.7棵树/公顷），而在宅基地中最高（平均±SE = 25.7±4.1棵树/公顷）。社会数据显示，院子里幼苗和树苗种群密度的提高与马拉鲁啤酒生产中丢弃的籽粒有关。在15年的时间里，院子里的总密度增加了，但是牧场上的总密度下降了，在此期间，女性的密度在各种土地利用类型中几乎保持不变。这是一个重要发现，因为它强烈表明了社会介导的人口结构的变化，证实了文化和经济价值的结合可以带来物种保护的实例。在这种情况下，将雌性树优先作为杰出的水果生产者。SCD揭示了田间和牧场的招聘疲软。长期而言，再生能力下降，牧场过度采伐和院子里砍伐树木的过度组合，可能会对人口稳定产生负面影响。在重要的非木材林产品（NTFP）的背景下，了解资源保护和退化是一项关键的知识挑战，这项研究可作为该地区重要种群的最新存量基准。在此学习的重要经验教训可以应用于其他社会生态环境，在这些环境中，关键的自然资源负责维持生计。