BirdLife International - Lipu (Lega Italiana Protezione Uccelli), Conservation Department, Via Udine 3/a, I-43122 Parma, Italy.
Department of Biological and Environmental Sciences, College of Arts and Sciences, Qatar University, P.O. Box 2713, Doha, Qatar.
Sci Total Environ. 2017 Jul 15;590-591:686-694. doi: 10.1016/j.scitotenv.2017.03.027. Epub 2017 Mar 9.
High mountain systems are predicted to be especially vulnerable to the impact of climate change, with the climatically-constrained tree limit rapidly shifted upslope. In turn, the impact of upward treeline migration on mountain-dwelling bird species is expected to significantly reduce habitat suitability. We developed the first projection of the expected climate-driven rise of the whole treeline (19,256km) of the Italian Alps. The study area extends over 20,700km, ranging over 550km in longitude and 320km in latitude. We then investigated how much the expected treeline rise will induce a) shrinking and shifting of the elevation range and b) loss in suitable habitat for the flagship species rock ptarmigan, an alpine bird species dwelling above the treeline and, similarly to many other alpine species, highly vulnerable to treeline rise. We also investigated the potential gain in suitable habitat for rock ptarmigan due to the climate-driven upshift in the uppermost thermal limit. At lower altitudes (1500-1600m a.s.l.), the average expected upshift in the current treeline resulted in 195, 274 and 354m over the short (2010-2039), medium (2040-2069) and long term (2070-2099) respectively. Above 2400m a.s.l., it was less than 30m even in the long term. Overall, during the three climate periods the extent of suitable habitat for rock ptarmigan above the current treeline is projected to decrease by 28.12%, 38.43% and 49.11% respectively. In contrast, the expected gain in suitable habitat due to the shift in the uppermost thermal limit will be severely restrained by the limited surface extension in the top portion of the Italian Alps. The presented approach can promote similar studies elsewhere in the globe, providing a regional perspective to the projection of climate change impact on bird species dwelling above the treeline.
高山系统预计特别容易受到气候变化的影响，气候限制的树木上限迅速向上移动。反过来，林线向上迁移对山区鸟类的影响预计将大大降低栖息地的适宜性。我们首次预测了意大利阿尔卑斯山整个林线（19256 公里）预计的气候驱动上升。研究区域覆盖 20700 公里，跨越 550 公里的经度和 320 公里的纬度。然后，我们研究了预期的林线上升将导致以下情况的程度：a）海拔范围的缩小和移动，b）标志性物种岩雷鸟的栖息地丧失，岩雷鸟是一种栖息在林线以上的高山鸟类，与许多其他高山物种一样，对林线上升高度敏感。我们还研究了由于气候驱动的最上限热极限上移而导致岩雷鸟栖息地适宜性的潜在增加。在较低海拔（1500-1600 米），当前林线的预期平均上升幅度在短期（2010-2039 年）、中期（2040-2069 年）和长期（2070-2099 年）分别为 195、274 和 354 米。在 2400 米以上，即使在长期内，也不到 30 米。总体而言，在三个气候时期内，当前林线以上岩雷鸟的适宜栖息地范围预计将分别减少 28.12%、38.43%和 49.11%。相比之下，由于最上限热极限的变化而导致的适宜栖息地的预期增加将受到意大利阿尔卑斯山顶部有限的表面积限制。所提出的方法可以在全球其他地方促进类似的研究，为气候变化对林线以上栖息的鸟类的影响的预测提供区域视角。
