As one of the main components of land-use change, deforestation is considered the greatest threat to global environmental diversity with possible irreversible environmental consequences. Specifically, one example could be the impacts of land-use changes from oak forests into agricultural ecosystems, which may have detrimental impacts on soil mobilization across hillslopes. However, to date, scarce studies are assessing these impacts at different slope positions and soil depths, shedding light on key geomorphological processes. In this research, the Caesium-137 (137Cs) technique was applied to evaluate soil redistribution and soil erosion rates due to the effects of these above-mentioned land-use changes. To achieve this goal, we select a representative area in the Lordegan district, central Iran. 137Cs depth distribution profiles were established in four different hillslope positions after converting natural oak forests to rainfed farming. In each hillslope, soil samples from three depths (0–10, 10–20, and 20–50 cm) and in four different slope positions (summit, shoulder, backslope, and footslope) were taken in three transects of about 20 m away from each other. The activity of 137Cs was determined in all the soil samples (72 soil samples) by a gamma spectrometer. In addition, some physicochemical properties and the magnetic susceptibility (MS) of soil samples were measured. Erosion rates reached 51.1 t·ha− 1·yr− 1 in rainfed farming, whereas in the natural forest, the erosion rate was 9.3 t·ha− 1·yr− 1. Magnetic susceptibility was considerably lower in the cultivated land (χhf = 43.5 × 10− 8 m3·kg− 1) than in the natural forest (χhf = 55.1 × 10− 8 m3·kg− 1). The lower soil erosion rate in the natural forest land indicated significantly higher MS in all landform positions except at the summit one, compared to that in the rainfed farming land. The shoulder and summit positions were the most erodible hillslope positions in the natural forest and rainfed farming, respectively. We concluded that land-use change and hillslope positions played a key role in eroding the surface soils in this area. Moreover, land management can influence soil erosion intensity and may both mitigate and amplify soil loss.

中文翻译：

---

利用¹³⁷ Cs技术对橡树砍伐和雨养对山坡土壤再分配过程的影响

作为土地利用变化的主要组成部分之一，森林砍伐被认为是对全球环境多样性的最大威胁，可能带来不可逆转的环境后果。具体而言，一个例子可能是土地利用变化（从橡树林变成农业生态系统的影响），这可能对跨山坡的土壤动员产生不利影响。然而，迄今为止，稀少的研究正在评估在不同的坡度位置和土壤深度下的这些影响，从而揭示了关键的地貌过程。在这项研究中，由于上述土地利用变化的影响，采用了Caesium-137（137Cs）技术来评估土壤再分配和土壤侵蚀速率。为了实现这一目标，我们在伊朗中部的洛迪甘区选择一个代表性地区。在将天然橡树林转换为雨养后，在四个不同的山坡位置建立了137Cs深度分布图。在每个山坡上，在大约20 m远的三个样带中，从三个深度（0-10、10-20和20-50厘米）和四个不同的坡度位置（坡，肩，后坡和山坡）采集土壤样品。彼此。用伽马能谱仪测定了所有土壤样品（72个土壤样品）中137Cs的活性。另外，还测量了土壤样品的一些理化性质和磁化率（MS）。雨养农业的侵蚀率达到51.1 t·ha-1·yr-1，而天然林的侵蚀率是9.3 t·ha-1·yr-1。耕地的磁化率明显较低（χhf=比天然林（χhf= 55）高43.5×10−8 m3·kg−1）。1×10−8 m3·kg−1）。与雨养耕地相比，天然林地的土壤侵蚀率较低，表明除山顶一处以外，所有地貌位置的MS均显着较高。肩部和山顶位置分别是天然林和雨养农业中最易侵蚀的山坡位置。我们得出的结论是，土地利用变化和山坡位置在侵蚀该地区的表层土壤中起着关键作用。此外，土地管理会影响土壤侵蚀强度，并可能减轻和加剧土壤流失。肩部和山顶位置分别是天然林和雨养农业中最易侵蚀的山坡位置。我们得出的结论是，土地利用变化和山坡位置在侵蚀该地区的表层土壤中起着关键作用。此外，土地管理会影响土壤侵蚀强度，并可能减轻和加剧土壤流失。肩部和山顶位置分别是天然林和雨养农业中最易侵蚀的山坡位置。我们得出的结论是，土地利用变化和山坡位置在侵蚀该地区的表层土壤中起着关键作用。此外，土地管理会影响土壤侵蚀强度，并可能减轻和加剧土壤流失。