Miller Norton G, McDaniel Stuart F
Biological Survey, New York State Museum, Albany, New York 12230 USA.
Am J Bot. 2004 Aug;91(8):1173-82. doi: 10.3732/ajb.91.8.1173.
A long-standing debate in bryophyte biogeography concerns the frequency of long-distance spore dispersal. The diversity of bryophytes on mortared rock walls along the Veterans Memorial Highway on Whiteface Mountain, New York, USA, was studied to document the recruitment of species over the 65 years since the highway was constructed. The highway is situated in the Adirondack Mountains, a relatively unpopulated region with a largely acidic flora. The introduction of mortar has increased the bryophyte diversity by 50% above that of native lithic substrata on the mountain. The composition of the native and mortar floras differed greatly, suggesting that the walls were not colonized by locally abundant ruderal species. Many of the species sampled on the walls are typically found only in lower elevation forested sites, distant (∼5 km or more) from the highway, and not on anthropogenic calcium carbonate. These results suggest that a bryophyte community consisting of common and uncommon species assembled from distant sites at the rate of at least one species per year in the last 65 years. These data provide the ecological context for experimental and phylogeographic studies and suggest that some bryophytes may be capable of routine dispersal over distances of at least 5 km.
苔藓植物生物地理学中一个长期存在的争论涉及远距离孢子传播的频率。对美国纽约州白脸山退伍军人纪念公路沿线灰浆石壁上的苔藓植物多样性进行了研究，以记录自公路建成65年来物种的迁入情况。这条公路位于阿迪朗达克山脉，该地区人口相对稀少，植物区系主要呈酸性。灰浆的引入使苔藓植物的多样性比山上原生岩石基质上的多样性增加了50%。原生植物区系和灰浆植物区系的组成差异很大，这表明这些石壁并非由当地常见的杂草物种定殖而来。在石壁上采样的许多物种通常只在距离公路较远（约5公里或更远）的低海拔森林地区发现，而不在人为形成的碳酸钙上生长。这些结果表明，在过去65年里，一个由常见和不常见物种组成的苔藓植物群落以每年至少一个物种的速度从遥远的地点聚集而来。这些数据为实验和系统地理学研究提供了生态背景，并表明一些苔藓植物可能能够常规性地传播至少5公里的距离。
