Rubber tree plantations (Hevea brasiliensis) cover large areas in the tropics. In historical producing regions like South Thailand, rubber has been planted by smallholders for three successive rotations lasting a total of 75 years. Despite possible consequences on topsoil, the long-term impacts of repeated rubber plantations on soil quality remain unknown. This study aims to better understand how various factors linked to long-term rubber land use and land use change affect topsoil physico-chemical properties and soil organic carbon (SOC) thermal stability. We focus on the effects of three factors: i. deforestation (change from forest to first rubber plantation); ii. the age of the rubber stand (immature vs. mature); and iii. long-term rubber cultivation (first, second or third successive rotation) over a chronosequence in farmers plots. Our results show that soil was deeply degraded after deforestation to a rubber plantation. Long-term rubber cultivation is also detrimental for the soil and has a more negative impact on soil physico-chemical properties and carbon dynamics, than the age of the rubber stand (e.g., on average, decrease of 50% of SOC content between forest and third rotation). At the third rotation, after 50 years of rubber cultivation, the quality of the 0–10 cm soil layer was very low, with an increase in SOC thermal stability. At this stage, logging practices upset the sustainability of the system. These impacts could be limited by less destructive practices during planting.

中文翻译：

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橡胶、橡胶和橡胶：连续 75 年的橡胶种植园轮作如何影响表土质量？

橡胶树种植园 ( Hevea brasiliensis )) 覆盖热带地区的大片区域。在泰国南部等历史悠久的产区，小农已经连续三轮种植橡胶，总共持续了 75 年。尽管可能对表土产生影响，但重复种植橡胶园对土壤质量的长期影响仍然未知。本研究旨在更好地了解与长期橡胶土地利用和土地利用变化相关的各种因素如何影响表土理化性质和土壤有机碳 (SOC) 热稳定性。我们关注三个因素的影响：i。砍伐森林（从森林变为第一个橡胶种植园）；ii. 橡皮架的年龄（未成熟与成熟）；iii. 在农民地块上按时间顺序进行长期橡胶种植（第一、第二或第三轮连续轮作）。我们的研究结果表明，在将森林砍伐为橡胶种植园后，土壤严重退化。与橡胶林的年龄相比，长期种植橡胶对土壤也是有害的，对土壤理化性质和碳动态的负面影响更大（例如，森林与橡胶之间的 SOC 含量平均减少 50%）第三轮转）。在第三轮，经过 50 年的橡胶种植，0-10 cm 土层质量非常低，SOC 热稳定性增加。在这个阶段，伐木实践破坏了系统的可持续性。这些影响可能会受到种植期间破坏性较小的做法的限制。比橡胶林的年龄（例如，在森林和第三轮之间平均减少 50% 的 SOC 含量）。在第三轮，经过 50 年的橡胶种植，0-10 cm 土层质量非常低，SOC 热稳定性增加。在这个阶段，伐木实践破坏了系统的可持续性。这些影响可能会受到种植期间破坏性较小的做法的限制。比橡胶林的年龄（例如，在森林和第三轮之间平均减少 50% 的 SOC 含量）。在第三轮，经过 50 年的橡胶种植，0-10 cm 土层质量非常低，SOC 热稳定性增加。在这个阶段，伐木实践破坏了系统的可持续性。这些影响可能会受到种植期间破坏性较小的做法的限制。