Abstract Overexploitation is a main driver of biodiversity loss globally. Protected areas may have a key role in reducing overexploitation, yet their actual effectiveness in maintaining high-density and viable populations of overexploited species has rarely been evaluated. For overharvested plants, in particular, available information is extremely limited, making it unclear whether protected areas are indeed effective at protecting species. Here, we provide the first biome-wide assessment of the effectiveness of protected areas in maintaining populations of overexploited plants. We analyzed data from 50 populations of the overexploited and threatened palm Euterpe edulis, an ecologically and economically important species of the Atlantic Forest biodiversity hotspot. By integrating these data with species distribution modelling and matrix population modelling, we were able to evaluate the most likely causes and possible consequences of differences in population density inside and outside protected areas. Forest sites located inside protected areas had, on average, almost three times higher adult density of E. edulis than sites located outside protected areas, and a corresponding higher frequency of viable populations (≥60 adults/ha). Our analyses indicate that these differences are a direct consequence of the lower frequency of palm heart harvest inside protected areas, rather than differences in climatic suitability or forest cover. The matrix model showed that the higher density and lower harvest frequency inside protected areas may significantly increase long-term persistence of E. edulis populations, reducing their extinction risk. Our findings provide new and compelling evidence that terrestrial protected areas may be crucial for long-term conservation of overexploited plants.

中文翻译：

---

保护区对过度开发植物的重要性：来自生物多样性热点的证据

摘要 过度开发是全球生物多样性丧失的主要驱动因素。保护区可能在减少过度开发方面发挥关键作用，但很少评估它们在维持高密度和可生存的过度开发物种种群方面的实际效果。特别是对于过度采伐的植物，可用信息极其有限，因此不清楚保护区是否确实有效地保护了物种。在这里，我们首次对保护区在维持过度开发植物种群方面的有效性进行了全生物群落评估。我们分析了来自 50 个过度开发和受到威胁的棕榈 Euterpe edulis 种群的数据，Euterpe edulis 是大西洋森林生物多样性热点的生态和经济重要物种。通过将这些数据与物种分布建模和矩阵种群建模相结合，我们能够评估保护区内外人口密度差异的最可能原因和可能后果。平均而言，位于保护区内的森林站点的 E. edulis 成虫密度几乎是位于保护区外的站点的三倍，并且相应的存活种群频率更高（≥60 成虫/公顷）。我们的分析表明，这些差异是保护区内棕榈心收获频率较低的直接结果，而不是气候适宜性或森林覆盖率的差异。矩阵模型表明，保护区内较高的密度和较低的收获频率可能会显着增加 E. edulis 种群的长期持久性，减少它们的灭绝风险。我们的研究结果提供了新的令人信服的证据，表明陆地保护区可能对过度开发植物的长期保护至关重要。