Contribute substantially to canopy dynamics by stabilizing canopy organic soils (i.e., humus) that impact the interception of atmospheric moisture (e.g., fog and rainfall). In the subtropical MCF of Southwest China, also called the montane moist evergreen broadleaved forest, the diversity of epiphytes is really high (600 species, like epiphytic lichens, epiphytic bryophytes, epiphytic ferns, and epiphytic seed plants) [15,16]. Even so, a six-month-long dry season lasts from November towards the subsequent April, implying that the epiphytes will need to overcome seasonal drought strain [7,17]. In addition, the epiphytic habitats are often harsh and heterogeneous with substantial variations in water availability at small spatiotemporal scales, and short-term drought happens even in rainy seasons [17,18]. Mechanisms on adaptation strategies of epiphytes to forest canopies with limited and unstable water availability stay among the most captivating queries in plant ecology [19,20]. Numerous morphological and structural traits permit epiphytes to cope together with the water deficits, for example early dormant, water storage stems and leaves, rhizomes, and air moisture absorption [213]. Current studies confirm that epiphytes could take up atmospheric water (e.g., water vapor, rainwater, and fog water) straight all through their surface structures, especially for epiphytic lichens that lack roots and an outer waxy cuticle [24,25]. Atmospheric water enhances the development of epiphytes by alleviating the desiccation degrees and lengthening their photosynthetic activities [26]. Among them, Liu et al. [13] indicated that the Ficus tinctoria in the epiphytic stage would utilize a combination of fog water and rainwater present in canopy humus. Similarly, Wu et al. [27] discovered that fog water is often a crucial supplemental source (contributing ratio 87 ) to preserve the water budgets of epiphytes throughout the dry season. To adapt towards the water deficits, epiphytes was recommended to exhibit higher intrinsic water use efficiency (WUEi ) than the ground-rooted SC-19220 supplier plants [28]. Even so, far too small interest has been paid to the quantitative connection involving the prospective water sources plus the water WUEi amongst diverse groups of epiphytes. Epiphytes are often Alvelestat custom synthesis divided into diverse groups (namely epiphytic lichens, epiphytic bryophytes, epiphytic ferns, and epiphytic seed plants) based on their systematic positions, life cycles, and biological traits. Epiphytic lichens are complex life types that reside within a symbiotic connection with algae and fungi, which can attach to tree trunks only with the support of thalli base plates [29,30]. Epiphytic bryophytes, with no accurate roots (only rhizoid) and vascular systems (only rib), usually develop on barks or thick mats of humus [313]. As vascular plants, on the other hand, both epiphytic ferns and epiphytic seed plants have created correct roots and networks of the vascular method, permitting effective water uptake, water and nutrient transport, and photosynthates [34,35], despite the fact that roots and vascular systems within the former are a great deal simpler than the latter. As a result of these variations in structure, water uptake and transport, diverse epiphytic groups are anticipated to show variations in their water sources and water use efficiencies, which has not been well-quantified. Early findings recommended that the WUEi of epiphytic bryophytes were reduced than the vascular plants [36]. While the water use of various epiphyte species has been studied, invest.