【地球日】蜂類的十個真相 | 台灣環境資訊協會-環境資訊中心

【地球日】蜂類的十個真相

2019年04月19日
環境資訊中心外電;吳宜靜、許瀞文 編譯;林大利 審校;稿源:EARTH DAY NETWORK

過去幾十年間,各物種的數量都有減少的趨勢。然而,重要的授粉者——蜂類的銳減,已逐漸成為大眾關心的議題。如果沒有蜂,世界上最重要的穀物將無法存活,進而將直接影響人類及無數物種的食物供給。

熊蜂。圖片來源:Smudge 9000(CC BY-NC-ND 2.0)
熊蜂。圖片來源:Smudge 9000(CC BY-NC-ND 2.0)

真相一

全世界有超過2萬種的蜂,其中超過4000種是美國的特有種。過去十年間,美國及歐洲的養蜂者紛紛表示,每年蜂巢的數量已減少30%,甚至更高。這個比例已超出蜂類長期持續生存的正常數值。除此之外,美國四分之一的野生蜂種亦面臨絕種的危機。

真相二

有許多因素會使蜂類的數量減少:支離破碎的棲息地、使用愈趨頻繁的新菸鹼類殺蟲劑(Neonicotinoid Pesticide)、蜂群崩壞症候群(Colony Collapse Disorder)以及氣候變遷。

真相三

蜂類生活在世界上各種氣候帶中:從歐洲的森林到非洲的沙漠,甚至是在北極圈內,都能看到蜂的蹤影。有別於蜜蜂住在蜂巢,美國野生蜂居住在許多不同的環境裡,例如地底下、樹間、坑洞裡面。

真相四

世界上常見的蜂類包括:美國的木蜂(Carpenter Bee)及熊蜂(Bumble Bee)、英國的地花蜂(Mining Bee)及壁蜂(Mason Bee)、非洲的海角蜜蜂(Cape Bee)、亞洲及澳洲的東方蜜蜂(Asian Honey Bee)。


亞洲東方蜜蜂。圖片來源:57Andrew via flickr (CC BY-NC-ND 2.0)

真相五

在大多數的生態系裡面,蜂類是不可缺的授粉者。全世界有36萬9000種的開花植物,而其中有90%需要倚靠昆蟲授粉。

在一般的情況下,一隻蜜蜂飛行一趟,會經過50至1000朵花。因此,以一個2萬5000隻工蜂的蜂群、每隻蜜蜂每天飛行十趟來計算 ,每天將能夠幫助2億5000萬朵花授粉。

真相六

很多動物必須要依靠蜂類才能生存,因為牠們的食物須仰賴昆蟲授粉──包括堅果、莓果、種子、和水果等等。而授粉帶來的效益,不僅僅在於提供其他生物食物的來源,同時更促使花朵生長,使其成為鳥類和其他昆蟲的棲息地。


蜂類授粉不僅提供生物的食物來源,花朵也是鳥和昆蟲的棲息所在。(Martin Nikolaj Christensen via flickr CC BY-NC-ND 2.0 )

真相七

北美熊蜂(Rusty-patched Bumble Bee)的數量在近幾年中已銳減87%,因此於2017年被列入美國魚類及野生動物管理局(U.S. Fish and Wildlife Service)的瀕危物種名錄。

在此之前,聯邦政府已將七種面花蜂屬(Yellow-faced Bee)的分支列入該清單,並依照《瀕臨滅絕物種法》(Endangered Species Act)將之納入保護範圍。面花蜂屬是夏威夷唯一的原生蜂類,亦是首個被美國列為瀕臨絕種的蜂類。


熊蜂。圖片來源:Laura Pontiggia via flickr CC BY-NC-ND 2.0

真相八

藉由蜂類授粉的穀物占全球食物產量的35%。


蜂類授粉的穀物占全球食物產量的35%。圖片來源:verchmarco(CC BY-NC-ND 2.0) 

真相九

全世界由蜂類授粉的糧食作物總產值高達5770億美元,對美國農業有240億美元的貢獻,也提供整個美國1/3的食物來源。

真相十

加州杏仁的產量占世界總產量的50%至80%,當地的杏仁果園通常需要160萬批家養蜂群。這些蜂群在相當119個台北市面積(80萬英畝)的果園裡頭幫忙樹木授粉,製造加州最大宗的外銷農產品。


加州杏仁需家養蜂群授粉。圖片來源:Rachel(CC BY-NC-ND 2.0)

Fact Sheet: Bees

While the population of all species has declined over the last few decades, the dramatic drop in the population of bees has increasingly been of concern because of the important role they play as pollinators. Without bees, many of the world’s most important crops would fail and directly affect the food supply of humans and countless other species.

FACT #1

There are more than 20,000 distinct bee species around the world, and more than 4,000 in the U.S. alone. For much of the past ten years, beekeepers, primarily in the United States and Europe, have been reporting annual hive losses of 30 percent or higher, substantially more than is considered normal or sustainable. Also, 1 in 4 wild bee species in the U.S. is at risk of extinction.

FACT #2

Many factors are influencing the decline of bees, including habitat fragmentation, increased use of neonicotinoid pesticides, colony collapse disorder, and climate change.

FACT #3

Bees exist in all types of climates around the world, from forests in Europe to deserts in Africa–even in the Arctic Circle. Unlike honeybees and their hives, wild bees in the U.S. live in many different places: under the ground, in holes, and in trees.

FACT #4

Some of the world’s bee species include carpenter bees and bumble bees in the U.S., the mining bee and the mason bee in the U.K., the Cape bee in Africa, and the Asian honeybee in Asia and Australia.

FACT #5

Bees are indispensable pollinators of most ecosystems. There are 369,000 flowering plant species, and 90% of them are dependent on insect pollination. Usually, a honeybee can visit 50-1000 flowers in one trip. Therefore, if each bee takes ten trips a day, a colony with 25,000 forager bees can pollinate 250 million flowers in a day.

FACT #6

Many species of animal dependent on bees for their survival because their food source, including nuts, berries, seeds, and fruits, relies on insect pollination. Pollination not only makes food available for other organisms but also allows floral growth, which provides habitats for animals, including other insects and birds.

FACT #7

In 2017, the rusty-patched bumble bee was added to the U.S. Fish and Wildlife Service endangered species list, after a population decline of 87% in recent years. Previously, Federal authorities added to the list seven yellow-faced bee species, Hawaii’s only native bees, for protection under the Endangered Species Act, a first for any bees in the United States.

FACT #8

Crops pollinated by bees make up 35% of global food production.

FACT #9

The global crop production pollinated by bees is valued at $577 billion. Pollinators contribute $24 billion to the U.S. agriculture industry, making up a third of the food consumed by Americans.

FACT #10

California produces 50-80% of the world’s almond harvest. Spread across 800,000 acres, California’s almond orchards typically require 1.6 million domesticated bee colonies to pollinate the flowering trees and produce what has become the state’s largest overseas agricultural export.

※ 全文及圖片詳見:EARTH DAY NETWORK

作者

林大利

於特有生物研究保育中心服務,小鳥和棲地是主要的研究對象。是龜毛的讀者,認為龜毛是探索世界的美德。

吳宜靜

右手按快門,也寫字。念過歷史、勞工關係和攝影。企圖用說得動自己的方式傳達環境訊息。