美國林火不斷，氣候變遷讓森林生態系面臨新挑戰！

美國林火不斷，氣候變遷讓森林生態系面臨新挑戰！

文 / 美國林務署 http://www.fs.fed.us/news/2013/releases/01/climatechange.shtml
譯 / 人禾環境倫理發展基金會

美國農業部(USDA)綜合文獻，探討農業與森林的氣候變遷影響與調適策略
USDA Reports Synthesize Literature on Climate Change Effects and Adaptation Strategies for U.S. Agriculture and Forests

摘要
　　美國農業部綜合兩份文獻報告，提出農業與森林面對氣候變遷所造成的挑戰，包含糧食及能源等資源的需求、病蟲害的發生、經濟損失、森林火災、水質的惡化等。面對挑戰，需找出合適的調適方法、增加生態系的韌性…等。相關的研究成果，以及森林與固碳、氣候變遷的關係，可閱讀報告書「氣候變遷與農業：影響及調適」和「氣候變化率及改變對森林生態系的影響」。

華盛頓，2013年2月5日

        美國農業部(USDA)公佈的兩個綜合報告，內容有關美國農業與森林因氣候變遷造成的影響及調適策略。報告名為：「氣候變遷與農業：影響及調適」和「氣候變化率及改變對森林生態系的影響」，提供了國家氣候評估的資料。聯邦、大學、非政府組織、工業、部落土地和私有部門都在這篇評論報告中有所貢獻。

WASHINGTON, Feb. 5, 2013

       The U.S. Department of Agriculture (USDA) released two comprehensive reports today that synthesize the scientific literature on climate change effects and adaptation strategies for U.S. agriculture and forests. The reports, entitled Climate Change and Agriculture: Effects and Adaptation and the Effects of Climate Variability and Change on Forest Ecosystems: A Comprehensive Science Synthesis for the U.S. Forest Sector, were created as inputs to the National Climate Assessment.  Scientists from the federal service, universities, non-governmental organizations, industry, tribal lands and the private sector contributed to the peer-reviewed studies.

       美國農業部首席經濟學家辦公室的氣候變遷計畫辦公室主任William Hohenstein說：「這些報告呈現了美國農業與森林，本世紀將面臨因全球氣候變遷而產生的挑戰」；「報告讓我們能瞭解氣候變遷的影響，以便滿足未來我們對食物、飼料、纖維及燃料的需求」。

      “These reports present the challenges that U.S. agriculture and forests will face in this century from global climate change,” said William Hohenstein, Director of the Climate Change Program Office in USDA’s Office of the Chief Economist.  “They give us a framework for understanding the implications of climate change, in order to meet our future demands for food, feed, fiber, and fuel.”

       報告指出氣候變遷是如何影響美國的農牧場、森林、草原及鄉村社區。雖然美國在農業和資源管理方面，過去成功的適應了氣候的變化，但氣候變遷的加速與強度造成了新的挑戰有待解決。

The reports indicate how climate change is affecting U.S. farms, forests, grasslands, and rural communities. While U.S. agriculture and resource management have long histories of successful adaptation to climate variability, the accelerating pace and intensity of climate change presents new challenges to be addressed, as highlighted in the reports.

       例如農業報告中指出，大氣中的二氧化碳含量增加，氣溫上升，降水模式改變將影響農業的生產力。氣候變遷將加劇因野草、昆蟲和疾病所造成的壓力。極端氣候事件的發生率增加，將對農業生產力造成更多影響。未來25年，氣候變遷對美國的農業生產與經濟成果（包含生產者端與消費者端），將視區域的狀況產生綜合的影響。2050年後，預期農作物生產地區的蟲害防制的費用將會增加，病害也會加劇。

       For example, the agricultural report indicates increases in atmospheric carbon dioxide, rising temperatures, and altered precipitation patterns will affect agricultural productivity. Climate change will exacerbate the stresses already occurring from weeds, insects, and disease.  Increases in the incidence of extreme weather events will have an increasing influence on agricultural productivity.  Over the next 25 years, the effects of climate change on agricultural production and economic outcomes for both producers and consumers in the United States are expected to be mixed, depending on regional conditions.  Beyond 2050, changes are expected to include shifts in crop production areas, increases in pest control expenses, and greater disease prevalence.

        林業部門的報告指出，對森林生態系統最迅速可見的短期影響包含火災、蟲害、外來入侵種，以及多重壓力的結合。野火在美國各地將增加，焚燒的區域至少為21世紀中葉的一倍。

        The forest sector report indicates that the most rapidly visible and significant short-term effects on forest ecosystems will be caused by fire, insects, invasive species, and combinations of multiple stressors. Wildfire is expected to increase throughout the United States, causing at least a doubling of area burned by the mid-21st century.

        美國林務署署長Tom Tidwell說：「這份報告增強了我們的決心，將積極的持續處理與恢復國家的森林，來減少未來林火的影響。」；「最近在科羅拉多洲和全國各地區的火災可作為一個嚴峻的預兆，未來我們預期將會看到更多這種案例。我相信我們的計畫能跟上氣候變遷對森林和草原的衝擊。」

        “This report strengthens our resolve to aggressively continue treating and restoring our nation's forests to reduce future fire impacts," said U.S. Forest Service Chief Tom Tidwell.  "Recent fires in Colorado and other areas throughout the country serve as a grim portent for what we expect to see more of in the future.  I'm confident that we have a strong plan in place to keep pace with the impacts a changing climate will have on our forests and grasslands.”

        雖然某些地區將較其他地區更受影響，這些干擾可能會改變生態系統的結構和功能，在很短的時間內對橫跨數百萬英畝的森林造成影響。預期的影響包含樹木的死亡率增加、物種組成的改變，以及水質的惡化。

       Although some regions will be affected more than others, these disturbances are likely to change the structure and function of ecosystems across millions of acres over a short period of time with detrimental effects on forest resources.  Anticipated effects include increased tree mortality, changes in species assemblages, and reduced water quality.

       報告也探索了調適對減少氣候變遷造成的負面影響的潛力，以及林業和農業部門對此可能產生的利用機會。成功的調適需要研究來找出管理方法，增加整體系統對氣候變遷影響的韌性，發展抗逆境植物和動物的品種，並建立新的方法來保護土壤及水資源。

       The reports also explore the potential for adaptive practices to reduce the negative effects of climate change and to potentially take advantage of new opportunities in the forestry and agriculture sectors. Successful adaptation will require research to identify management practices that enhance the resilience of these systems to climate change effects, develops stress-tolerant plant and animal varieties, and establishes new approaches to conserve soil and water resources.