ABSTRACT Robinia pseudoacacia L. (black locust) is an invasive deciduous, broad-leaved tree that has the potential to be widely distributed across South Africa. It has invaded all nine South African provinces. The potential economic impact of R. pseudoacacia on agricultural production stems from the tree’s ability to reduce the carrying capacity for livestock. This study estimated the potential economic implications of R. pseudoacacia on agricultural production in South Africa, specifically the livestock sector. R. pseudoacacia’s potential distribution was calculated by using a maximum-entropy predictive habitat model, MaxEnt. The distribution of livestock, based on grazing capacity (ha/large stock unit) in South Africa, was then determined. The potential direct economic impacts were estimated by assessing the impact of the potential distribution of R. pseudoacacia on the carrying capacity for livestock. The results showed that an infestation of R. pseudoacacia has the potential to reduce the total gross margin in the livestock sector by between approximately R135 million and R674 million, dependent on the level of invasion. The potential levels of foregone income and business activity found in this study reaffirm the need to devote resources to develop a viable, economical and effective control.

中文翻译：

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刺槐对南非农业生产的经济影响

摘要刺槐（Robinia pseudoacacia L.）（黑刺槐）是一种侵入性的落叶阔叶树，有可能在南非广泛分布。它已经入侵了南非的所有九个省。刺槐对农业生产的潜在经济影响源于该树降低牲畜承载​​能力的能力。本研究估计了刺槐对南非农业生产，特别是畜牧业的潜在经济影响。R. pseudoacacia 的潜在分布是通过使用最大熵预测栖息地模型 MaxEnt 计算的。然后根据南非的放牧能力（公顷/大牲畜单​​位）确定牲畜的分布。通过评估刺槐的潜在分布对牲畜承载能力的影响来估计潜在的直接经济影响。结果表明，刺槐的侵染有可能使畜牧业的总毛利率降低约 1.35 亿兰特至 6.74 亿兰特，具体取决于入侵水平。本研究中发现的潜在收入损失和商业活动水平重申了投入资源开发可行、经济和有效的控制措施的必要性。