植物絕種將造成人類利益損失 - 生態環境討論

來源: http://e-info.org.tw/node/28037

摘譯自2007年11月5日ENS美國加州，聖塔芭芭拉報導；朱以方編譯；蔡麗伶審校

Del Mar manzanita，一種加州濱臨絕種的灌木。圖片來源﹕USDA根據一份最新科學報告
指出，物種滅絕將可能造成地球上植物的生產力大幅降低50%，而人類將因此喪失植物所
能提供的一些非常重要的利益，包括吸收溫室氣體，以及植物棲息地所製造的氧氣、食物
、纖維和生質燃料。此外，不論是生物個體大量消失，或是物種滅絕的種類多寡，都會改
變生態系統所能提供給人類的各項服務，而且這項改變正在發生。

卡丁奈爾（Bradley Cardinale）是本項研究的主筆者，同時也是加州大學聖塔芭芭拉校
區的副教授，他表示：「植物生長與製造「生質物」（biomass）的過程，是地球上最基
本的生物歷程之一。」

他還指出：「實驗時間越長的研究，會發現物種多樣性對植物生產力的衝擊越強。但很不
幸的，大部份研究都因為經費的關係，一次只能做短短幾年的實驗。因此，我們很可能低
估了物種滅絕對天然棲地的影響。」

這篇報告本週將刊登在《美國國家科學院學報》線上版，報告中共彙整了來自全球44篇模
擬植物滅絕的實驗研究。該報告顯示，相較於具有較原始天然狀態的生物多樣性環境，擁
有較少物種數量的生態系，將製造較少的植物「生質物」，低至50%。

卡丁奈爾博士表示：「因此，物種滅絕將抵消大自然帶給人類社會的好處。」實務上來說
，這表示多樣性高的生態系應更能控制蟲害、分解有機物質，並且吸收二氧化碳。

來自蒙特羅梅基大學的羅洛（Michel Loreau）教授，同時也是本研究的共同作者，他表
示：「我們的分析提供了最充份的證據證明，植物多樣性高的天然棲息地更具生產力。但
更重要的是，生物群落越多樣，其生產力就越高，因為植物在利用生物資源時具有互補性
。換句話說，不同的植物品種在環境中都扮演了非常獨特的角色。」

Plant Extinctions Erode Benefits to Humanity
Authorship: SANTA BARBARA, California, November 5, 2007 (ENS)

Scientists are warning that species extinctions could reduce the productivity
of plants on Earth by half. A new analysis shows that humans could lose some
of the most important benefits that plants provide - the absorption of
greenhouse gases, as well as the ability of habitats to produce oxygen, food,
fiber, and biofuels.

Both the number and types of species going extinct are changing the
"services" that ecosystems provide to humanity, the authors conclude.

"The process by which plants grow and produce more plant biomass is one of
the most fundamental biological processes on the planet," said Bradley
Cardinale, lead author of the paper and assistant professor of biology at UC
Santa Barbara.

"We found that as experiments were run longer, they detected increasingly
strong impacts of species diversity on plant productivity," Dr. Cardinale
said. "Unfortunately, because most experiments have only been funded to run
for a few years at a time, they have probably underestimated the impacts of
extinction on natural habitats."

The article will appear this week in the online issue of the "Proceedings of
the National Academy of Sciences."

The study summarized the results of 44 experiments from around the world that
simulated plant species extinction. It shows that ecosystems with fewer
species produce up to 50 percent less plant biomass than those with more
"natural" levels of diversity.

"Therefore, species extinctions could compromise the benefits that nature
provides to society," said Cardinale. In practical terms, this means that
diverse ecosystems are likely to be better at controlling pests, breaking
down organic matter, and absorbing carbon dioxide.

"Our analyses provide the most comprehensive evidence yet that natural
habitats with a greater variety of plant species are more productive," said
co-author Michel Loreau of McGill University in Montreal.

"But even more important, our analyses show that diverse communities are more
productive because plants are complementary in how they use biological
resources. In other words, different plant species play unique roles in the
environment." said Loreau.

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