文獻來源：I-C Chen, JK Hill, H-J Shiu, JD Holloway, S Benedick, VK Chey, HS Barlow and CD Thomas. 2010. Asymmetric boundary shifts of tropical montane Lepidoptera over four decades of climate warming. Global Ecology and Biogeography. DOI: 10.1111/j.1466-8238.2010.00594.x
www.blackwellpublishing.com/geb
本文之研究群曾於PNAS (2009) 發表過本研究的初步探討分析，詳見這篇部落格介紹文章：氣候暖化造成熱帶型高山的蛾類群落往較高海拔移動 ，本文為對其資料進行較深入的比較與分析。
摘要：
目標 評估物種因應氣候變遷而移動其分布界限移動（寒冷的海拔上限與溫暖的分布下限）之現象，是否是以相等的速度發生。作者首先針對熱帶昆蟲提出證據，測試山區蛾類海拔分布上限與下界之移動，同時也考慮到熱帶山地物種之威脅。
地點 馬來西亞沙巴州 京那巴魯山
方法 作者於2007年調查京那巴魯山的尺蛾，與1965年所作的調查資料進行比較。物種的海拔分布上限和下界均有改變，海拔廣度和範圍地區均有評估。作者隨 機在幾年間進行亞取樣以確保有可進行比較之資料。資料分析的評估針對特有種和廣布種進行比較，以及在不同海拔高度達到其分布界限之物種。
結果 分布上限在2500–2700 m的物種（n = 28）皆撤退其上限與下界，且平均分布有收縮的趨勢(垂直分布約減少300 m, 分布範圍之面積約減少45 km2)。這些消退可能與雲量的變化有關，以及其他地理障蔽的影響(如地質與植被的轉變)可能阻擋其往山頂移動。除了這組物種外，大部份的物種（n = 109, 占本調查約80%）拓展了其分布的上限(平均約152 m)，且較其撤退的下界(77m)更多。
主要結論 在沒有阻礙的情形下，往山頂遷移的前進邊緣挪動較下限的退縮快速，因此許多物種因而擴增了其海拔分布之廣度。然而此結果並不表示分布範圍區域有所增加， 原因是可使用的的陸地面積會隨著海拔的上升縮減。接近山區主要生態上/地質上交會帶之物種受到兩面包抄而縮減其分布範圍區域。儘管目前尚未分布未及的棲地 是可以獲得的，這些物種可能早在將分布提升到山頂之前、就已面臨了物種滅絕的危機。
ABSTRACT
Aim To estimate whether species have shifted at equal rates at their leading edges (cool boundaries) and trailing edges (warm boundaries) in response to climate change. We provide the first such evidence for tropical insects, here examining elevation shifts for the upper and lower boundaries shifts of montane moths. Threats to species on tropical mountains are considered.
Location Mount Kinabalu, Sabah, Malaysia.
Methods We surveyed Lepidoptera (Geometridae) on Mount Kinabalu in 2007, 42 years after the previous surveys in 1965. Changes in species upper and lower boundaries, elevational extents and range areas were assessed. We randomly subsampled the data to ensure comparable datasets between years. Estimated shifts were compared for endemic versus more widespread species, and for species that reached their range limits at different elevations.
Results Species that reached their upper limits at 2500–2700 m (n = 28 species, 20% of those considered) retreated at both their lower and upper boundaries, and hence showed substantial average range contractions (-300 m in elevational extent and -45 km2 in estimated range area). These declines may be associated with changes in cloud cover and the presence of ecological barriers (geological and vegetation transitions) which impede uphill movement. Other than this group, most species (n = 109, 80% of the species considered) expanded their upper boundaries
upwards (by an average of 152 m) more than they retreated at their lower boundaries (77 m).
Main conclusions Without constraints, leading margins shifted uphill faster than trailing margins retreated, such that many species increased their elevational extents. However, this did not result in increases in range area because the area of land available declines with increasing elevation. Species close to a major ecological/geological transition zone on the mountain flank declined in their range areas. Extinction risk may increase long before species reach the summit, even when undisturbed habitats are available.
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