Forest operations have become increasingly reliant on mechanized harvesting equipment due to their increased production capacities in competitive markets. However, operating heavy machinery in mountainous terrain poses numerous operational and accessibility challenges from steep slopes, erosion risk, and poor road access. Geographic Information Systems (GIS) have effectively been used in various studies to identify areas in mountainous landscapes that pose no or reduced constraints for harvesting equipment operation. This study introduces the Harvest Operability Index (HOI), which rates a landscape for wheel-based equipment suitability (i.e., operability) and assesses its application in 13,118 ha of the Jocassee Gorges Natural Resource Area, situated on the Southern Blue Ridge Escarpment in Northwestern South Carolina, USA. The HOI incorporated slope, distance from roads, cost distance from major highways, primary Streamside Management Zones (SMZ), stand age, and soil suitability ratings for harvesting equipment operation. Upon reclassification to a 5-tier suitability scale, the HOI revealed 60% (7824 ha) of the case study area was in a Slope Exclusion Zone, or land area inoperable for wheel-based equipment due to steep slopes. Values of Very Poor and Poor Operability occupied less than 1% (213 ha) of land area whereas Moderate Operability values were 9% of the land area (1257 ha). Values of Good Operability occupied 18% (2442 ha) of the study area and values of Very Good Operability occupied 10% (1381 ha). These results reflected the challenges of mechanized harvesting in the study area due to a preponderance of steep slopes and poorly suited soil. Our model delineated areas of high equipment operability in two locations in the study area, despite a lack of recent logging activity around them. Results of the HOI analysis offer an accessible way for forest managers to better prioritize logging operations in areas that are highly operable and therefore more likely to possess lower overall harvesting costs, for wheel-based harvesting systems. The HOI can also be used as an asset for other forest management priorities, such as identifying highly operable areas that can use timber harvesting for fuel reduction and ecological restoration in fire-dependent forests. This model can be applied to various other regions where mountainous terrain poses a limitation to wheel-based harvesting equipment operation- and where wheel-based equipment is essential to advance the pace and scale of harvesting for ecological restoration.

中文翻译：

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收获可操作性指数 (HOI)：山区机械化木材采伐的决策支持工具

由于机械化采伐设备在竞争激烈的市场中生产能力的提高，森林经营越来越依赖机械化采伐设备。然而，在山区操作重型机械会带来许多操作和可达性挑战，包括陡峭的斜坡、侵蚀风险和道路不畅通。地理信息系统 (GIS) 已有效地用于各种研究，以识别山区景观中对收割设备操作没有限制或限制较少的区域。本研究介绍了收获可操作性指数 (HOI)，该指数对轮式设备适用性（即可操作性）的景观进行评级，并评估其在位于西北部南部蓝岭悬崖的 Jocassee Gorges 自然资源区的 13,118 公顷中的应用。美国南卡罗来纳州。HOI 包括坡度、与道路的距离、与主要高速公路的成本距离、主要的河边管理区 (SMZ)、林龄和土壤适宜性评级以用于收割设备操作。重新分类为 5 级适宜性等级后，HOI 显示案例研究区域的 60%（7824 公顷）位于斜坡禁区，或由于陡坡而无法用于轮式设备的土地区域。非常差和可操作性差的值占土地面积的不到 1%（213 公顷），而中等可操作性值占土地面积（1257 公顷）的 9%。可操作性良好的值占研究区域的 18%（2442 公顷），可操作性非常好的值占研究区域的 10%（1381 公顷）。这些结果反映了由于陡坡和不适合土壤的优势，研究区域机械化收获面临的挑战。我们的模型在研究区域的两个位置描绘了设备可操作性高的区域，尽管它们周围缺乏近期的伐木活动。对于轮式采伐系统，HOI 分析的结果为森林管理者提供了一种可行的方法，可以在高度可操作的地区更好地优先考虑伐木作业，因此更有可能拥有较低的总体采伐成本。HOI 还可用作其他森林管理优先事项的资产，例如确定可使用木材采伐以减少依赖火的森林中的燃料和生态恢复的高度可操作区域。