Damage to the remaining stand on steep terrain can be quite severe and is usually difficult to control during winching. Timber skidding, especially by agricultural tractor, is a common solution in small-scale forestry. One of the factors influencing remaining stand damage is winching on steep terrain, although, to date, this has only been studied in general. Limiting stand damage is possible when the factors causing the damage are well-known. Therefore, the aim of this paper was to study in detail the impact of slope steepness on different types of damage in the stand after winching, focusing in particular on: (1) the share of trees with damage (including natural regeneration), (2) the size of the wound, (3) the number of wounds per tree, (4) wound intensity, and (5) the position of the wound on a tree. Field observations were carried out in three beech (two in Italy and one in Iran) and two pine stands (in Italy), in which four classes of slope steepness were selected for each stand. After timber harvesting, damage to the remaining stand as well as to any natural regeneration was recorded. It was found that the share of wounded trees was directly related to slope steepness, although this was less obvious in the natural regeneration. On steeper slopes, there were larger wounds and, on average, there were more wounds per tree. Wound intensity also depended on the gradient of the slope. The size, understood as diameter at breast height, of the remaining trees on the slopes also had an impact on the wound characteristics: on thicker trees, bigger wounds were detected and a higher number of them. However, thicker trees were less often wounded. Wound position on a tree did not depend on slope steepness but it may have been related to stand density and size of winched timber.

中文翻译：

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陡峭地形上绞车造成的剩余林分破坏的详细分析

在陡峭的地形上对剩余林分的破坏可能非常严重，通常在绞车过程中很难控制。木材打滑，特别是用农用拖拉机打滑，是小型林业的一种常见解决方案。影响剩余林分损害的因素之一是在陡峭的地形上绞车，尽管迄今为止，仅在总体上对此进行了研究。当引起损坏的因素众所周知时，可能会造成极限机架损坏。因此，本文的目的是详细研究斜坡陡度对绞车后林分中不同类型损害的影响，特别着重于：（1）受损害树木（包括自然更新）的比例，（2 ）伤口的大小，（3）每棵树的伤口数，（4）伤口的强度，以及（5）伤口在树上的位置。在三个山毛榉（意大利两个，意大利一个）和两个松林（意大利）中进行了实地观察，其中每个林分选择了四类坡度。砍伐木材后，记录了对剩余林分以及任何自然更新的损害。发现受伤树木的份额与坡度直接相关，尽管在自然更新中不太明显。在陡峭的斜坡上，伤口更大，平均而言，每棵树上的伤口更多。伤口强度还取决于斜率的梯度。斜坡上其余树木的大小（被理解为胸高处的直径）也影响了伤口的特性：在较厚的树木上，发现的伤口更大，并且伤口数量更多。但是，较厚的树木很少受伤。