Climate change portends serious implications for Arctic vegetation. Understanding these effects is likely to be enhanced with long-term observations from permanent plots. I evaluated three decades of change in tundra vegetation from 80 permanent plots on south-eastern Victoria Island, Nunavut, Canada. I compared baseline (1991 and 1992) and contemporary (2019 and 2022) periods in the cover and frequency of graminoids, mosses and common species of forbs, shrubs and lichens. I found substantial shifts in cover of several species and growth forms—an increase in graminoids, decreases in Dryas integrifolia, Polygonum viviparum and Saxifraga oppositifolia, and marginally significant declines in mosses and Cassiope tetragona, but no detectable changes in other groups. The decline in Dryas integrifolia was more pronounced at lower elevations and was noticeable as patches of apparent mortality, inside the plots and elsewhere. The shifts in species abundance were not significantly correlated with each other, nor with changes in soil depth. These changes, manifest as communities with more abundant graminoids, are consistent with expected climate change effects in colder regions of the Arctic. Repeated observations of permanent plots can aid in detecting and understanding long-term ecological change.

气候变化预示着对北极植被的严重影响。通过对永久地块的长期观察，可能会加深对这些影响的理解。我评估了加拿大努勒维特维多利亚岛东南部 80 个永久地块的苔原植被三十年来的变化。我比较了基线（1991 年和 1992 年）和当代（2019 年和 2022 年）时期禾本科植物、苔藓和常见杂草、灌木和地衣物种的覆盖范围和频率。我发现几个物种和生长形式的覆盖范围发生了重大变化——禾本科植物增加，仙女木、 胎生蓼 和 虎耳草减少，苔藓和仙草略有显着减少 ，但其他类群没有明显变化。仙女木的下降  在较低海拔地区更为明显，并且在地块内和其他地方表现为明显死亡的斑块。物种丰度的变化彼此之间不显着相关，也与土壤深度的变化不显着相关。这些变化表现为具有更丰富的禾本科植物的群落，与北极寒冷地区预期的气候变化影响一致。对永久性地块的重复观察有助于发现和了解长期的生态变化。