新托福TPO 18综合写作训练详细解析：怎样防止香榧数量下降

　　阅读材料：

　　In the 1950s Torreya Taxifolia, a type of evergreen tree once very common in the state of Florida started to die out. No one is sure exactly what caused the decline, but chances are good that if nothing is done, Torreya will soon become extinct. Experts are considering three ways to address the decline of Torreya.

　　在佛罗里达州，佛罗里达香榧是一种非常常见的常绿乔木。从1950年代开始，佛罗里达香榧数量开始减少，并濒于灭绝。目前尚不清楚导致其濒危的确切原因，但是如果不采取任何行动的话，香榧很可能会灭绝。目前，专家们提出了三个方式去解决香榧数量下降。

　　The first option is to reestablish Torreya in the same location in which it thrived for thousands of years. Torreya used to be found in abundance in the northern part of Florida, which has a specific microclimate. A microclimate exists when weather conditions inside a relatively small area differs from the region of which that area is a part. Northern Floridas microclimate is very favorable to Torreyas growth. This microclimate is wetter and cooler than the surrounding regions relatively dry, warm climate. Scientists have been working to plant Torreya seeds in the coolest, dampest areas of the microclimate.

　　第一个选择是把香榧重新种植在它们已经茂盛生长数千年的原生长地。在拥有特殊微气候的北佛罗里达，香榧树曾经数量众多。所谓微气候是指在一片独立区域内，内部一小部分地区的气候状况同该区域有区别。而被佛罗里达的微气候非常时候香榧的生长。该地区同周围干热的气候不同，是非常潮湿和凉爽的。科学家计划在拥有最冷和最潮湿微气候的地区种植香榧。

　　The second option is to move Torreya to an entirely different location, far from its Florida microclimate. Torrey seeds and saplings have been successfully plated and growth in forests further north, where the temperature is significantly cooler. Some scientists believe that Torreya probably thrived in areas much further north in the distant past, so by relocating it now, in a process known as assisted migration, humans would simply be helping Torreya return to an environment that is more suited to its survival.

　　第二个选择是把香榧移植到完全不同的地区，该地区远离其原生的微气候。目前，香榧的种子和幼苗在佛罗里达州北部很远的地方可以生长，那里相对来说冷很多。有些科学家相信在离原生地很远的北方，香榧或许可以茂盛生长。所以，如果现在进行辅助迁移，也就是说把香榧移到北方，那么人们可能就这么简单地帮助香榧重新找到适合它们生存的环境。

　　The third option is to preserve Torreya in research centers. Seeds and saplings can be moved from the wild and preserved in a closely monitored environment where it will be easier for scientists both to protect the species and conduct research on Torreya. This research can then be used to ensure the continued survival of the species.

　　第三个选择是把香榧保存在研究中心。把种子和幼苗从野外移植并保护在研究中心这样一个严格人工监视的环境里。这样，既方便科学家的保护该物种，同时也方便研究香榧。而所进行的研究可以有助于该物种持续的存活发展。

　　阅读部分需要提取的观点是：

　　- Main point: 专家提出三种方法来解决香榧树数量减少、濒于灭绝的问题

　　- Sub point 1: 在原地种植香榧树

　　- Sub point 2: 把香榧移到比原生地往北的地方

　　- Sub point 3: 把香榧移到研究中心

　　听力材料：

　　Youve just read about three ways to save Torreya Taxifolia. Unfortunately, none of these three options provides a satisfactory solution.

　　你梦刚刚听到了三种保护佛罗里达香榧树的方法。很遗憾，这三个方法都不能解决这个问题。

　　About the first solution reestablishing Torreya in the same location thats unlikely to be successful, because of whats happening to the coolest dampest areas within Torreyas micro-climate. These areas are being strongly affected by changes in the climate of the larger region. This could be because global warming has contributed to an increase in overall temperatures in the region or because wetlands throughout Florida have been drained. Either way, many areas across the region are becoming dries, so its unlikely that Torrey would have the conditions it needs to survive anywhere within its original Florida micro-climate.

　　先说第一个方法。在原地种植香榧树是不可行的。这是因为原来适合香榧生长的湿冷微气候已经发生了变化。这些地方的微气候受到了整个大区域气候变化的严重影响。这可能是因为全球变暖导致了该地区整体温度的上升，也可能是因为整个佛罗里达地区的湿地变干。无论是那种原因，该区域的很多地方都变得很干旱，同原来香榧树生长的佛罗里达微气候已经不同。

　　Now about the second solution, relocating Torreya far from where it currently grows. Well, lets look at what happened when humans helped another tree, the black locust tree, move north to a new environment. When they did this, some of these plants and trees were themselves already in danger of becoming extinct.

　　现在说一下第二个方法，就是把香榧种在远离它们原来生长地的区域。恩，让我们看看人类帮助另一种树的。人们把洋槐树向北移，移到了一个全新的环境。这么做了之后，当地一些本来已经濒危的植物或者树木因而灭绝了。

　　Third, research centers are probably not a solution either. Thats because the population of Torreya trees that can be kept in the centers will probably not be able to resist diseases. For a population of trees to survive a disease, it needs to be relatively large and it needs to be genetically diverse. Tree populations in the wild usually satisfy those criteria, but research centers would simply not have enough capacity to keep a large and diverse population of Torreya trees. So, trees in such centers will not be capable of surviving diseases in the long term.

　　第三，移到研究中心也不是一个有效的方法。这是因为研究中心能够保护的香榧的数量不足以帮助香榧抵御病虫害。如果一种树木想要抵御病虫害，就需要它的数量达到一定规模，并且具有基因多样性。在野外生长的树木一般可以满足这些要求，但是研究中心没有能力保护数量足够多，基因足够多样化的香榧树。所以，长期看来，这样的研究中心是不能保证香榧树抵抗病虫害的。

　　听力部分需要提取的观点是：

　　- Main point: 三种方法都不能解决问题

　　- Sub point 1: 原有气候已经不适合香榧生长

　　- Sub point 2: 往北迁移可能会因生态入侵造成其他物种灭绝

　　- Sub point 3: 研究中心承载能力有限，不能确保香榧能抵抗病虫害。