Erect shrub encroachment in the High Arctic: evidence and consequences

高北极地区的直立灌木侵占：证据和后果

• 批准号: RGPIN-2015-05319
• 负责人: Lévesque, Esther
• 金额: $ 2.33万
• 依托单位: Université du Québec à Trois-Rivières
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=632013
• 关键词: Erect; shrub; encroachment; Arctic; evidence

Reports of increasing shrub cover in the Low Arctic are mounting whereas the situation at the transition between Low and High Arctic, remains understudied. Yet we recently highlighted the sensitivity of shrubs to climate variability near their longitudinal limit. An increase in erect shrub cover (20 to 70cm high or more) where only prostrate vegetation grows would drastically transform the High Arctic. Similarly to the treeline, I refer to this transition as the erect shrubline. Isolated populations of these shrubs have maintained themselves for years at these latitudes but the recent warming may have promoted better growth and/or production of more viable seeds. If this is the case, erect shrubs may invade adjacent prostrate communities.

关于低北极地区灌木覆盖增加的报告越来越多，而低北极和高北极之间过渡的情况仍未得到充分研究。然而，我们最近强调了灌木在其纵向极限附近对气候变率的敏感性。在只有匍匐植被生长的地方，增加直立灌木覆盖（20至70厘米高或更高）将彻底改变北极高地。与树线相似，我把这种转变称为直立灌木线。这些灌木的孤立种群在这些纬度维持了多年，但最近的变暖可能促进了更好的生长和/或产生更多的可存活种子。如果是这种情况，直立灌木可能会入侵邻近的匍匐群落。