Dickinson Christopher C, Jelesko John G, Barney Jacob N
School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA 24061, USA.
Plants (Basel). 2021 Jan 29;10(2):263. doi: 10.3390/plants10020263.
The US native liana, poison ivy ), responsible for contact dermatitis in humans, is a competitive weed with great potential for expansion in disturbed habitats. To facilitate a better understanding of this threat, we sought to evaluate habitat suitability, population demography, and biotic interactions of poison ivy, using a series of complementary field studies in the two habitats where it most commonly occurs-forest interiors and edges. Of the 2500 seeds planted across both habitats, poison ivy initially colonized forest interiors (32% emergence) at a higher rate than edge habitats (16.5% emergence). However, forest interior seedlings were less likely to survive (interior = 3; edge = 15), which might be attributed to herbivore pressure when the seedlings were smaller in the less competitive forest interior. Once established, the poison ivy seedlings appeared to be more tolerant of herbivory, except that of large grazers such as deer. The early life stage of seedling emergence, survival, and establishment are critical in poison ivy success, with biotic pressure, especially from plant competition and deer, limiting recruitment. A suitable habitat of this expanding native liana would increase with increasing forest fragmentation, but might be buffered by the expanding deer population.
美国本土藤本植物毒葛会引发人类接触性皮炎，是一种具有很强扩张潜力的竞争性杂草，在受干扰的栖息地中蔓延趋势明显。为了更好地了解这种威胁，我们通过在毒葛最常见的两种栖息地——森林内部和边缘开展一系列补充性实地研究，来评估毒葛的栖息地适宜性、种群动态及生物相互作用。在两个栖息地共种植了2500颗种子，毒葛最初在森林内部的定植率（32%出苗率）高于边缘栖息地（16.5%出苗率）。然而，森林内部的幼苗存活率较低（森林内部=3%；边缘=15%），这可能是由于在竞争较弱的森林内部，幼苗较小时受到了食草动物的压力。一旦定植，毒葛幼苗似乎对食草动物的啃食更具耐受性，但大型食草动物如鹿除外。幼苗出苗、存活和定植的早期阶段对毒葛的成功繁衍至关重要，生物压力，尤其是来自植物竞争和鹿的压力，限制了其补充更新。随着森林破碎化加剧，这种不断扩张的本土藤本植物的适宜栖息地可能会增加，但鹿种群数量的增加可能会起到缓冲作用。
