植物入侵的影响会随时间减弱
文章来源:未知 文章作者:enread 发布时间:2013-11-21 08:46 字体: [ ]  进入论坛
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Among the most impressive ecological1 findings of the past 25 years is the ability of invasive plants to radically2 change ecosystem3 function. Yet few if any studies have examined whether ecosystem impacts of invasions persist over time, and what that means for plant communities and ecosystem restoration. UC Santa Barbara's Carla D'Antonio, Schuyler Professor of Environmental Studies, has conducted one of the only long-term studies of plant invader4 impacts that spans two decades. Returning to the same grass-invaded field sites in Hawaii Volcanoes National Park that she used in her 1990-1995 studies, D'Antonio, along with postdoctoral scholar Stephanie Yelenik, gathered new data that shed light on mechanisms5 regulating exotic plant dominance and community change through invasion. The findings are published online today in Nature.
 
"We were able to take advantage of detailed6 studies I and others had conducted in the 1990s. We permanently7 marked sites we had set up and were able to go back and gain insight into how plant invasions changed over time without management," said D'Antonio, who also is a professor in the Department of Ecology, Evolution and Marine8 Biology. "Such studies are important because managers have little money to control invasive species or to study how impacts might change without management."
 
"Non-native plants can have very large impacts on ecosystem functioning -- including altering groundwater, soil salinity9(土壤盐渍度) or pH and pollination10(授粉) syndromes," said lead author Yelenik, who earned her doctorate11 from UCSB's Department of Ecology, Evolution and Marine Biology and now works for the U.S. Geological Survey's Pacific Island Ecosystems12 Research Center on the island of Hawaii.
 
When D'Antonio and Yelenik revisited the study sites, they noticed that the invasive exotic perennial13(多年生的) grasses (primarily an African invader called Melinis minutiflora) were dying, so they decided14 to repeat measures of nutrient15 cycling and plant community change. They found that the grasses' self-reinforcing effects on soil nutrients16 had disappeared and the percentage of invader coverage17 had declined.
 
Data showed that in the past 17 years, nitrogen mineralization rates at the sites dominated by the exotic grasses declined by half, returning them to pre-invasion levels. Nitrogen mineralization is the process by which organic nitrogen is converted to plant-available inorganic18 forms.
 
"Measuring mineralization the way we do is extremely time-consuming and expensive, so we did it in snapshots of time (mid-1990s versus19 2010-2012)," Yelenik explained. "This is less than ideal because differences between the two study periods could be due to differences in rainfall."


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1 ecological IrRxX     
adj.生态的,生态学的
参考例句:
  • The region has been declared an ecological disaster zone.这个地区已经宣布为生态灾难区。
  • Each animal has its ecological niche.每种动物都有自己的生态位.
2 radically ITQxu     
ad.根本地,本质地
参考例句:
  • I think we may have to rethink our policies fairly radically. 我认为我们可能要对我们的政策进行根本的反思。
  • The health service must be radically reformed. 公共医疗卫生服务必须进行彻底改革。
3 ecosystem Wq4xz     
n.生态系统
参考例句:
  • This destroyed the ecosystem of the island.这样破坏了岛上的生态系统。
  • We all have an interest in maintaining the integrity of the ecosystem.维持生态系统的完整是我们共同的利益。
4 invader RqzzMm     
n.侵略者,侵犯者,入侵者
参考例句:
  • They suffered a lot under the invader's heel.在侵略者的铁蹄下,他们受尽了奴役。
  • A country must have the will to repel any invader.一个国家得有决心击退任何入侵者。
5 mechanisms d0db71d70348ef1c49f05f59097917b8     
n.机械( mechanism的名词复数 );机械装置;[生物学] 机制;机械作用
参考例句:
  • The research will provide direct insight into molecular mechanisms. 这项研究将使人能够直接地了解分子的机理。 来自《简明英汉词典》
  • He explained how the two mechanisms worked. 他解释这两台机械装置是如何工作的。 来自《简明英汉词典》
6 detailed xuNzms     
adj.详细的,详尽的,极注意细节的,完全的
参考例句:
  • He had made a detailed study of the terrain.他对地形作了缜密的研究。
  • A detailed list of our publications is available on request.我们的出版物有一份详细的目录备索。
7 permanently KluzuU     
adv.永恒地,永久地,固定不变地
参考例句:
  • The accident left him permanently scarred.那次事故给他留下了永久的伤疤。
  • The ship is now permanently moored on the Thames in London.该船现在永久地停泊在伦敦泰晤士河边。
8 marine 77Izo     
adj.海的;海生的;航海的;海事的;n.水兵
参考例句:
  • Marine creatures are those which live in the sea. 海洋生物是生存在海里的生物。
  • When the war broke out,he volunteered for the Marine Corps.战争爆发时,他自愿参加了海军陆战队。
9 salinity uYvx9     
n.盐分;咸度;盐浓度;咸性
参考例句:
  • In the sea water sampled the salinity is two parts per thousand.在取样的海水中,盐度为千分之二。
  • In many sedimentary basins the salinity of the formation water increases with depth or compaction.在许多沉积盆地中,地层水的含盐量随深度或压实作用而增高。
10 pollination FOGxH     
n.授粉
参考例句:
  • The flowers get pollination by insects.这些花通过昆虫授粉。
  • Without sufficient pollination,the growth of the corn is stunted.没有得到充足的授粉,谷物的长势就会受阻。
11 doctorate fkEzt     
n.(大学授予的)博士学位
参考例句:
  • He hasn't enough credits to get his doctorate.他的学分不够取得博士学位。
  • Where did she do her doctorate?她在哪里攻读博士?
12 ecosystems 94cb0e40a815bea1157ac8aab9a5380d     
n.生态系统( ecosystem的名词复数 )
参考例句:
  • There are highly sensitive and delicately balanced ecosystems in the forest. 森林里有高度敏感、灵敏平衡的各种生态系统。 来自《简明英汉词典》
  • Madagascar's ecosystems range from rainforest to semi-desert. 马达加斯加生态系统类型多样,从雨林到半荒漠等不一而足。 来自辞典例句
13 perennial i3bz7     
adj.终年的;长久的
参考例句:
  • I wonder at her perennial youthfulness.我对她青春常驻感到惊讶。
  • There's a perennial shortage of teachers with science qualifications.有理科教学资格的老师一直都很短缺。
14 decided lvqzZd     
adj.决定了的,坚决的;明显的,明确的
参考例句:
  • This gave them a decided advantage over their opponents.这使他们比对手具有明显的优势。
  • There is a decided difference between British and Chinese way of greeting.英国人和中国人打招呼的方式有很明显的区别。
15 nutrient 3vpye     
adj.营养的,滋养的;n.营养物,营养品
参考例句:
  • Magnesium is the nutrient element in plant growth.镁是植物生长的营养要素。
  • The roots transmit moisture and nutrient to the trunk and branches.根将水分和养料输送到干和枝。
16 nutrients 6a1e1ed248a3ac49744c39cc962fb607     
n.(食品或化学品)营养物,营养品( nutrient的名词复数 )
参考例句:
  • a lack of essential nutrients 基本营养的缺乏
  • Nutrients are absorbed into the bloodstream. 营养素被吸收进血液。 来自《简明英汉词典》
17 coverage nvwz7v     
n.报导,保险范围,保险额,范围,覆盖
参考例句:
  • There's little coverage of foreign news in the newspaper.报纸上几乎没有国外新闻报道。
  • This is an insurance policy with extensive coverage.这是一项承保范围广泛的保险。
18 inorganic P6Sxn     
adj.无生物的;无机的
参考例句:
  • The fundamentals of inorganic chemistry are very important.无机化学的基础很重要。
  • This chemical plant recently bought a large quantity of inorganic salt.这家化工厂又买进了大量的无机盐。
19 versus wi7wU     
prep.以…为对手,对;与…相比之下
参考例句:
  • The big match tonight is England versus Spain.今晚的大赛是英格兰对西班牙。
  • The most exciting game was Harvard versus Yale.最富紧张刺激的球赛是哈佛队对耶鲁队。
TAG标签: plants ecosystem function
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