隨著氣候暖化逐漸明顯，部分授粉昆蟲開始北移求生存，但是科學家發現，熊蜂卻沒有北移的趨勢；相反地，牠們的活動範圍縮水了。近期《科學》期刊上一份研究指出，北美和歐洲南部的熊蜂已大量減少，更因氣候變遷而快速消失。
 |
| 熊蜂。圖片來源：William Warby。（CC BY 2.0） |
鏽補丁熊蜂 10年只見過2隻
歷史上，許多熊蜂物種都曾是常見物種，例如鏽補丁熊蜂（the rusty-patched bumblebee），是70年代至80年代初期南安大略第四常見的熊蜂。
在加拿大和美國鏽補丁熊蜂出沒的範圍大規模搜尋，紐約大學環境學教授Sheila Colla努力尋找的結果卻令人驚訝──10年間只見過2隻。
「約1/3的北美熊蜂物種正在減少，有些物種個體數量甚至減少超過90%。」Colla說。
「這顯示部分熊蜂族群的活動範圍內的確出現變化，連歷史上曾經相當常見的熊蜂物種也大受影響。」Colla說，「更可怕的是，研究顯示這樣的變化非常快速。大量減少的熊蜂50年前都還活得很好。數十年間，重要授粉昆蟲的社群組成就出現劇變。」
學者：減緩氣候變遷是第一要務
為了這份研究，科學家檢視北美和歐洲67種熊蜂過去110年的博物館記錄。研究共同作者、紐約大學的蜜蜂專家Laurence Packer教授認為，這樣的研究必須從博物館的大量展示品，以及他蒐集數十萬蜜蜂樣本的實驗室開始。「博物館提供基本的生物學資訊，告訴我們人類影響世界的歷史。博物館的標本可作為各種比較的基礎，以確保鑑定結果可靠。」他說。
「熊蜂活動範圍沒有因為氣候變遷北移，這樣的現象相當令人憂心。」Packer說。
「授粉昆蟲對糧食安全和經濟至關重要。氣候變遷造成授粉昆蟲大量減少，則糧食安全和經濟都會受威脅。我們必須想辦法改善授粉昆蟲在整個大陸的數量趨勢。」
「首先最重要的是減緩氣候變遷。」研究主要作者、渥太華大學生物學教授Jeremy Kerr表示。
Bumblebees are disappearing from North America and Europe due to climate change, according to a study by Canadian scientists published in the current issue of the journal “Science.”
“Pollinators are vital for food security and our economy, and widespread losses due to climate change will diminish both,” said Jeremy Kerr, lead researcher and professor at the University of Ottawa’s Department of Biology. “We need to figure out how we can improve the outlook for pollinators on continental scales. But the most important thing we can do is begin to take serious action to reduce the rate of climate change.”
Bumblebees are losing large sections of the southern portion of their ranges, but unlike other species, which are compensating by moving further north as the climate warms, bumblebees are not heading north. Instead, their range areas are shrinking, causing their populations to decline.
“The fact that at the northern edges of their ranges they are not moving north as the climate changes is actually really quite worrying.” says York University Professor Laurence Packer, an expert on bees and a co-author on the study.
For this study, researchers looked at museum records of 67 species of bumblebees in North America and Europe over the past 110 years.
Packer insists this kind of research would be impossible without access to vast collections of curated specimens in museums, as well as in labs such as his, the Packer Lab at York University, which holds hundreds of thousands of bees.
“Museums hold the basic biological information that tells us about the history of our impact on the world. They also contain the specimens that everything ultimately has to be compared to in order for identifications to be reliable,” he said.
“For the North American species that I work on, we know that about a third of them are in decline and in some cases this has been quite dramatically, more than 90 per cent,” said co-author York University environmental studies Professor Sheila Colla.
Historically, many species of bumblebees were quite common, including the Rusty-patched Bumblebee, which was the fourth most common species in southern Ontario in the ’70s and early ’80s, says Colla.
She has only seen two in 10 years despite extensive searching throughout the range of the Rusty-patched Bumblebee in Canada and the United States.
“That’s an indication that there’s something going on with some species of bumblebees throughout their large ranges even for species which historically had been doing quite well,” she said.
“One of the scariest parts of the work that I’ve done is just realizing how quickly the situation is changing,” said Colla. “The bumblebees that are in decline were doing fine 50 years ago. We’re talking about large changes in community composition of essential pollinators over just a few decades.”
作者
In my healing journey and learning to attain the breath awareness, I become aware of the reality that all the creatures of the world are breathing the same breath. Take action, here and now. From my physical being to the every corner of this out of balance's planet.
