Christmas trees are increasingly being cultivated throughout Europe. Christmas-tree plantations (CTP) are characterised by intensive vegetation management, which is essential for ensuring tree quality. Within conventional CTP, herbicides are applied extensively, whereas in organic plantations, alternative methods for vegetation management, such as grazing, are implemented. A further characteristic of organic CTP is the application of organic fertiliser. We compared soil conditions, habitat structure and phytodiversity of differently managed CTP for deriving management recommendations for promoting plant species diversity in CTP. We focused on four different plantation types, representing a gradient of land-use intensity: conventional CTP in open landscapes (CTP-OPEN) and on former windthrows (CTP-WIND), organic CTP (CTP-ORG) and fir-greenery plantations (FIR) as a baseline for lowest land-use intensity. Our study discovered clear differences in soil characteristics, habitat structure and phytodiversity among the different plantation types. However, former land use had only little impact, as the differences between the two conventional CTP (CTP-OPEN/-WIND) were small. Soil conditions were similar among the three types of CTP compared to FIR. In contrast, habitat structure and phytodiversity differed between the two conventional CTP and the less intensively managed CTP-ORG and FIR. Conventional CTP were characterised by open vegetation with relatively low plant species richness and a low number of stress-tolerant species, but some neophytes. In contrast, CTP-ORG and FIR had a high cover of grasses, the highest overall species richness and the highest number of stress-tolerant species. For promoting plant species diversity in CTP, we recommend a reduction in management intensity, especially herbicide application.

中文翻译：

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不同管理体制下圣诞树人工林的植物多样性

整个欧洲越来越多地种植圣诞树。圣诞树种植园（CTP）的特点是密集的植被管理，这对于确保树木的质量至关重要。在常规的CTP中，除草剂得到了广泛的应用，而在有机人工林中，则采用了替代性的植被管理方法，例如放牧。有机CTP的另一个特征是有机肥料的应用。我们比较了不同管理的CTP的土壤条件，生境结构和植物多样性，以得出促进CTP中植物物种多样性的管理建议。我们着眼于四种不同的人工林类型，它们代表了土地利用强度的梯度：开放式景观中的常规CTP（CTP-OPEN）和前风积（CTP-WIND），有机CTP（CTP-ORG）和冷杉绿化人工林（FIR）作为最低土地利用强度的基准。我们的研究发现不同类型人工林在土壤特征，生境结构和植物多样性方面存在明显差异。但是，以前的土地使用影响很小，因为两个常规CTP（CTP-OPEN / -WIND）之间的差异很小。与FIR相比，三种CTP类型的土壤条件相似。相比之下，两种常规CTP与管理不那么集中的CTP-ORG和FIR之间的栖息地结构和植物多样性是不同的。常规的CTP的特征是开放的植被，植物物种丰富度相对较低，耐逆性物种的数量较少，但有一些新生植物。相比之下，CTP-ORG和FIR的草覆盖率很高，总体物种丰富度最高，并且耐胁迫物种的数量最高。为了促进CTP中植物物种的多样性，我们建议降低管理强度，尤其是使用除草剂。