Forest Service Moving Trees to Save Them

Forest Service Moving Trees to Save Them

森林服务部门移栽树木以保护它们

【听力音频】

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　　By Dan Friedell

　　04 January 2024

　　Some important tree species native to the northwestern states in the U.S. are no longer growing well because of climate change.

　　As conditions change in states such as Washington, Oregon and California, trees such as the Douglas fir, Western red cedar, giant sequoia and redwood may need to move -- with the help of humans.

　　Some of the trees do not do well when temperatures rise. Others suffer during times of drought. The goal is to move the trees to areas where the climate might more suitable.

　　Forest scientists are generally in favor of moving the trees so they do not die out. However, not all of the scientists agree on the best way to do it.

　　There are three ways to move trees: assisted population migration, assisted species migration and range expansion.

　　Assisted population migration involves scientists moving a tree's seeds within its current growing range. Assisted species migration involves scientists moving a species far from its existing area. In this case, that would include moving redwoods and sequoias from California to Washington.

　　The third way, range expansion, moves trees just outside their current growing range. Each way has different results for the trees and other animals and insects that depend on the trees.

　　Michael Case is a forest ecologist at the Nature Conservancy in Virginia. He said "there is a huge difference" among the different migration methods.

　　He said the risk of failure increases "whenever you plant something in an area where it is not locally found." He said the risk is not only to the trees. There is also the risk of causing problems in the ecosystem.

　　Case is working on an assisted population migration program with Douglas fir and Western hemlock trees. He is testing whether the trees, originally from drier parts of the northwest, can do well in western Washington where there is a drought. His organization believes that assisted population migration has fewer risks.

　　The U.S. Forest Service also takes part in assisted population migration programs. Dr. David Lytle is the agency's deputy chief for research and development. He said the agency is "very very cautious" about moving plants outside of their "historic range."

　　Douglas Tallamy is a professor of entomology and wildlife ecology at the University of Delaware. He said one worry about species migration is that local caterpillars might not eat the leaves of trees that are new to the area. The caterpillars serve as food for birds and other animals, so they must have a good food source.

　　Although the concerns are documented, the city of Portland, Oregon, is working on a species migration project for 11 tree species. The project includes three oak trees: California black oak, canyon live oak and interior live oak. Tallamy said oak trees are among the most important in North America. "When you move them out of range," he said, "the things that are adapted to eating them no longer have access to them."

　　The city responded to questions from the Associated Press, and said it is using guidelines "from universities, state and federal sources" and more, in its project.

　　Another group working on species migration projects in the northwest is called PropagationNation. To propagate means to produce a new plant through the use of seeds or parts of another plant.

　　That organization is planting non-local trees around the Seattle, Washington area in hopes that they will start growing in places where Western red cedar, Western hemlock and big leaf maple are having trouble.

　　David Milarch is the leader of a group in Michigan that supports keeping old trees alive. It is called Archangel Ancient Tree Archive. Milarch said the hope is to permit redwoods and sequoias to grow in areas to the north. The hope is not to replace native trees.

　　He said his group hopes the trees "will still be here in 100 to 200 years and not join the list of trees that are going extinct."

　　The organizations that are not practicing widely accepted methods for moving species feel like the risks are worth it.

　　But Robert Slesak is not sure about either practice. He oversees population migration sites run by the U.S. Forest Service in California, Oregon and Washington.

　　He said he has concerns about assisted species migrations and assisted population migrations that lack experimental rigor. Rigor describes an activity that has been tested with high standards.

　　He said all of the ideas about how to move trees should follow experiments that have already produced strong results.

　　"Everyone knows we need to do some kind of action related to climate, but there's a real risk of making it worse."

　　I'm Dan Friedell.

　　Dan Friedell adapted this story for Learning English based on a report by the Associated Press.

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　　作者：Dan Friedell

　　2024年1月4日

　　由于气候变化，美国西北部的一些重要本土树种不再生长良好。

　　随着华盛顿、俄勒冈和加利福尼亚等州的环境条件发生变化，道格拉斯冷杉、西部红雪松、巨型红杉和红木等树种可能需要移栽 -- 这需要人类的帮助。

　　一些树种在温度升高时生长不良。其他一些在干旱时期受苦。目标是将这些树木移栽到气候可能更适宜的地方。

　　森林科学家们普遍支持移栽树木，以防止它们灭绝。然而，并非所有的科学家都同意最佳的移栽方式。

　　移栽树木有三种方式：辅助种群迁移、辅助物种迁移和范围扩展。

　　辅助种群迁移涉及到科学家在树木当前生长范围内移动其种子。辅助物种迁移涉及到科学家将一个物种迁移到远离其现有区域的地方。在这种情况下，这将包括将红木和红杉从加利福尼亚移栽到华盛顿。

　　第三种方式，范围扩展，是将树木移栽到其当前生长范围的外围。每种方式对树木以及依赖这些树木的其他动物和昆虫都有不同的影响。

　　Michael Case是弗吁尼亚州自然保护协会的森林生态学家。他表示，不同的迁移方法之间存在“巨大的差异”。

　　他说，“每当你在一个本地没有发现的区域种植东西时，失败的风险就会增加。”他说，风险不仅仅是对树木的。还有可能在生态系统中引发问题的风险。

　　Case正在进行一项与道格拉斯冷杉和西部铁杉树有关的辅助种群迁移项目。他正在测试这些原产于西北部较干燥地区的树木是否能在华盛顿西部的干旱地区生长良好。他的组织认为，辅助种群迁移的风险较小。

　　美国森林服务局也参与辅助种群迁移项目。David Lytle博士是该机构的研究和开发副主任。他说，该机构对于将植物移出其“历史范围”是“非常非常谨慎”的。

　　Douglas Tallamy是特拉华大学昆虫学和野生生态学教授。他说，关于物种迁移的一个担忧是，当地的毛虫可能不会吃新来的树木的叶子。毛虫为鸟类和其他动物提供食物，因此它们必须有良好的食物来源。

　　尽管这些担忧已经被记录下来，但俄勒冈州波特兰市正在进行一个针对11种树木的物种迁移项目。该项目包括三种橡树：加利福尼亚黑橡、峡谷活橡和内陆活橡。Tallamy说，橡树是北美最重要的树木之一。他说，“当你把它们移出范围时，适应吃它们的东西就无法再接触到它们了。”

　　该市回应了来自美联社的问题，并表示在其项目中，它正在使用“来自大学、州和联邦来源”的指导方针，以及更多的指导方针。

　　另一个在西北部进行物种迁移项目的团体叫PropagationNation。繁殖意味着通过使用种子或另一棵植物的部分来产生新的植物。

　　该组织正在华盛顿州西雅图地区种植非本地树木，希望它们能开始在西部红雪松、西部铁杉和大叶枫树困难的地方生长。

　　David Milarch是密歇根州一个支持保护老树的团体的领导者，该团体名为Archangel Ancient Tree Archive。Milarch说，他们希望让红杉和巨杉能在北部地区生长，但并不是要取代本地树木。

　　他说，他的团体希望这些树“在100到200年后仍然存在，而不是加入濒临灭绝的树木名单”。

　　那些没有采用广泛接受的物种迁移方法的组织认为，这些风险是值得的。

　　但是，Robert Slesak对这两种做法都不确定。他负责监督由美国森林服务局在加利福尼亚、俄勒冈和华盛顿运营的种群迁移站点。

　　他表示，他对缺乏实验严谨性的辅助物种迁移和辅助种群迁移感到担忧。严谨性描述的是已经通过高标准测试的活动。

　　他说，所有关于如何移动树木的想法都应该遵循已经产生强大结果的实验。

　　他说：“每个人都知道我们需要做一些与气候相关的行动，但是有真正的风险会使情况变得更糟。”

　　我是Dan Friedell。

　　Dan Friedell根据美联社的报道为英语学习改编了这个故事。

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　　这个故事中的词汇

　　drought –n. 一段干燥的天气期

　　suitable –adj. 舒适或正确

　　migration –n. 某物到新地方的移动

　　range –n. 植物或树木（在这种情况下）通常覆盖的土地面积

　　ecologist –n.研究生物和其环境的人

　　locally –adj. 某物最初发现的小区域

　　cautious –adj. 小心或关心

　　adapted –adj. 已经改变并在新地方运作的东西

　　respond –v.回答

　　replace –v.将新的东西放在某物的位置

　　to go extinct –v. 消亡

　　rigor –n. 精确、小心或严格的品质