• 2005-06-22

    交作业了:Cheat Grass Vs. Sagebrush

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    http://www.blogbus.com/newswolf-logs/1280592.html

    这丑巴巴的灌木丛居然就是内华达的州花sagebrush,不信吧?本校学生办的校报就用它命名。


    在学校农学院打工,老板一口气给开出十篇文章的单子,可以够我忙一阵了。磨蹭了半天,周一终于交了两篇。都是小稿,一篇500字,一篇200字。别看小,工作可不少。分别采访有关教授和学生,再阅读有关资料,第一篇文章的资料就是一个150多页的研究规划报告,啃去吧。

    这篇报道是关于一个资源经济学教授得到政府一百万美元资金拨款用于研究西部地区一种叫sagebrush的沙漠植物的项目。事实上此项研究规模庞大,总共需要五年时间,涉及上千万美元的资金投入和在西部包括几个州的Great Basin地区若干大学和研究机构,而且研究人员不但有生物学家,也有土壤专家、社会学家、经济学家等多学科的研究人员。本校教授得到的百万美元拨款只是经济学研究的部分。

    Sagebrush是覆盖西部地区上亿公顷的Sagebrush植物群落一直在水土保持、提供野生动物栖息地、畜牧业养殖和生态平衡方面起着重要作用。但近年来由于草本植物如cheatgrass以及小型松树类植物pinyon pine和juniper等的入侵,造成山火频率和/或强度的增加。这不但“给人民生命财产造成损失”(不知为何,顺口引用起中国官方发言的腔调),还破坏了生态平衡,尤其sagebrush在强度太大的山火之后很可能因为树根和种子也被烤死,逐渐失去了在生的可能,因而其生态群落逐渐被生命力强大的cheatgrass取代,生态失去平衡。

    科学家们要研究的是,为了控制外来种群的入侵,目前可能采取的几种办法哪一种最适合特定的地区。目前可选的办法大致有三种。一是机械方法,就是动用机械,把外来的杂草给拔掉。其二是用化学方法,喷洒除草剂定向消灭外来物种。第三种办法是人工制造山火,在外来物种引起可燃物质过渡堆积之前,一把火烧掉表面的枯草,让植被得以健康循环。

    头两种办法都比较笨,这么大面积的植被,一点点的去拔或者洒药,成本实在太高。第三种办法最为有趣,很有以毒攻毒的味道。其实自然界因为闪电造成山火爆发,野火燎原,第二年“春风吹又生”是很正常的事情,是大自然新陈代谢的过程。在内华达州这个干旱的沙漠地区,几乎年年有山火。曾经听教新闻的教授说,这里要是哪年没有山火,那才叫奇怪了呢。

    问题在于,由于人的到来,每有山火便迅速扑灭,结果是枯枝败叶越积越多,按照科学家们的说法,是fuel load越来越大。到有一天发生一次剧烈的山火时,因为易燃物质太多导致火势太强,人不一定能扑灭这样的山火。这种catastrophobic fire(灾难性或毁灭性大火)的最大的弊端就是将把sagebrush的根和种子等全部烤死,结果来年它们将失去再生的能力,其种群将逐渐萎缩。

    这就是为什么科学家要提议人工引火。而人工引火的关键在于,什么时候才是最恰当的引火时间?如果cheatgrass还不多,就没有必要引火;如果cheatgrass已经过量生长,fuel load已经过了量,引火又可能造成毁灭性的大火。科学家在今后的五年中要做的就是实验在不同地区、不同的土壤和气候条件、不同的cheatgrass比例等情况下,采取上面三种措施哪种最合适,最有效。

    我的文章因为是用于UNR农学院的内部刊物,所以主要是写本院的经济学家涉及的研究内容。因为字数限制在500字,所以整个也就浮光掠影的谈了一下,且多有吹嘘其成就之意。老板说了,对他们的报道多边是因为要让他们在学术等方面的成果得到肯定(recognition)。看来公关稿就是公关稿,显然跟新闻稿的critical角度不一样。

    下面是我的初稿,写得不好,也算给大家个交待把。欢迎砖头。下回再跟大家汇报老板改稿的结果,作好挨批的准备了。


    Kim Rollins got $1 million for sagebrush project

    In her working life as a resource economist, Dr. Kim Rollins seldom saw a project as innovative as this multi-disciplinary experiment to evaluate fire and fire surrogate treatments in the sagebrush biomes of the Great Basin.
    The usual practice of such kind of research is that biologists do the research first. Economists are added in at the end as an afterthought.
    “They would say, ‘oh, here’s all the result, now find the cheapest way to do it,’” Rollins said.
    In this five-year project that has recently been approved by the Joint Fire Science Program, the economists were incorporated right at the beginning as an integral part of the research design, she said.
    She will get $1 million of funding for her part of research as well as that of soil scientist Dr. Dale Johnson, who is also in the College of Agriculture, Biotechnology and Natural Resources in UNR.
    Involving about $13 million of funding as a whole, this project will be closely collaborated among ecologists, wildlife biologists, soil scientists, hydrologists, sociologists as well as economists.
    The researchers come from various institutions around the Great Basin, including University of Nevada-Reno, Oregon State University, Utah State University, Brigham Young University, University of Idaho, and a number of branches under the US Geological Survey (USGS) or US Department of Agriculture’s Forest Service (USFS).
    The goal is to provide federal land managers with the most effective treatments to save the endangered sagebrush communities from the invasion of exotic plants and catastrophic fires the plants may cause, according to the project proposal.
    Leading the economist team consisting of researchers from University of Utah and Oregon State University, and collaborators including her colleagues in UNR, Rollins said the economists’ role is to prioritize the options as for what treatments to apply, where to apply, and when.
    “Of course we would like to protect everything,” said Rollins. “But the reality is we have only so many resources, so many land managers, and only annual budget of certain sizes.”
    Given these constraints, the economists have to consider the values of different lands. Some of them have areas that are closed to human population, some are more valuable for forage of live stock, some are extremely valuable for protection of endangered spices and habitats, other ones may be not as important.
    They will build economic models based on information provided by the biologists and other scientists, Rollins said.
    The sagebrush biome occupies 100 million acres in the West and is the largest biome in North America. Home to more than 300 wildlife species, the biome is the primary forage base for the western livestock industry. While serving as an important recreation area, the biome also provides precious water in a semi-arid region that has one of the fastest growing human populations in North America.
    Unfortunately, the sagebrush biome is considered to be one of the most endangered in the United States as a result of the invasion of exotic weeds such as cheatgrass (Bromus tectorum) and native pine trees like pinyon pine and juniper (Juniperus sp.). Scientists estimate that perhaps a third of the biome has been lost, and as much as half in the Great Basin region.
    The invaders builds up highly flammable fuel amid the native sagebrush, resulting in increased frequency and intensity of wildfires that threatens not only the sagebrush communities, but also properties and perhaps human lives, the proposal reported.
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