Abstract Vascular epiphytes are mainly associated with tropical and subtropical forest ecosystems. However, the frequent occurrence of accidental epiphytes in temperate forests proves that epiphytic growth of vascular plants is possible in tree crowns at these latitudes. Comparing the abiotic conditions of epiphytic and terrestrial microhabitats in conjunction with intraspecific differences in functional traits of the inhabiting plants, we identified limitations to vascular epiphytism in the study area in a Central European low mountain range. We determined light availability, winter temperatures, soil moisture, nutrient concentrations, and pH of arboreal soil in crotches of broad-leaved trees and in the immediate vicinity of each tree on the ground. Similarly, we quantified total plant water content, relative foliar chlorophyll content, specific leaf area (SLA), leaf dry matter content (LDMC), root-mass fraction, and aboveground nutrient concentrations of 110 pairs of epiphytic and terrestrial conspecifics. Water and nutrient availability were generally high in crotches filled with arboreal soil, suggesting better growth conditions than on the ground. A trophic advantage of epiphytic individuals over terrestrial conspecifics can be deduced from higher plant nutrient concentrations, higher SLA, and lower LDMC. Advantageous growth conditions might even result in higher growth rates and higher fitness of epiphytic individuals. Our findings highlight that vascular epiphytism in the study area is not necessarily limited by abiotic conditions but at least partly by the availability of old and structurally diverse trees providing suitable microhabitats. Accordingly, management actions in these secondary forest ecosystems should incorporate the preservation of old and large deciduous trees in order to sustain arboreal microhabitats and the associated biota.

中文翻译：

---

毕竟压力不大：偶然附生植物的附生个体比陆地同种植物经历更有利的非生物条件

摘要 维管附生植物主要与热带和亚热带森林生态系统有关。然而，温带森林中偶然附生植物的频繁发生证明，这些纬度的树冠中可能有维管植物的附生生长。比较附生和陆生微生境的非生物条件以及栖息植物功能性状的种内差异，我们确定了中欧低山脉研究区域中血管附生的局限性。我们确定了阔叶树的胯部和地面上每棵树附近的树栖土壤的光照可用性、冬季温度、土壤湿度、养分浓度和 pH 值。同样，我们量化了植物总含水量、相对叶绿素含量、110 对附生和陆生同种植物的比叶面积 (SLA)、叶干物质含量 (LDMC)、根质量分数和地上养分浓度。在充满树栖土壤的胯部中，水和养分的可用性通常很高，这表明生长条件比在地面上更好。附生个体相对于陆地同种个体的营养优势可以从更高的植物营养浓度、更高的 SLA 和更低的 LDMC 中推断出来。有利的生长条件甚至可能导致附生个体更高的生长速率和更高的适应性。我们的研究结果强调，研究区域的维管附生并不一定受到非生物条件的限制，但至少部分受到提供合适微生境的老树和结构多样的树木的可用性的限制。因此，