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科学の世界では、各人の研究報告はjournal（ジャーナル／雑誌）への投稿によって広く世間に公開されます。
雑誌にはscienceやnatureのような広い分野にまたがるものもありますが、ほとんどの雑誌は各々の分野に特化しており、同じ専門を持つ多くの科学者の目にふれることにより、その内容が検証されるのです。
こういった雑誌はその分野に専門でないと入手できないわけではなく、一般の人でも大きな書店あたりに行けば簡単に入手できます。ただ、科学の世界での公用語は英語ですし内容も専門的ですのでよほどのことがないと見る機会もないでしょう。
そんなわけでここでは、移入種問題がどのように取り扱われているのかを紹介したいと思います。（なお、最近は雑誌の電子化が進みウェブ上でほとんどの雑誌が検索できる（web of scienceなど）ようになっていますが、有料なので大学や企業の研究職といった分野の人でないと利用は難しいかもしれません。大学には雑誌そのものが置いてあるので、利用申し込みをすれば閲覧できると思います。）
紹介する雑誌と内容について
ブラックバスとアメリカザリガニと水草の３者がそろったため池数か所でバスを駆除したら、ザリガニが増えて水草が減ったという研究結果を発表していた人。その論文は未発表のようであるが、別の論文がBiological Conservationに投稿されている。
Biological Conservation 109(2003) 111-121
Community-level
impacts induced by introduced largemouth bass and bluegill in farm ponds in
Japan（ブラックバスとブルーギルがため池の生物群集に及ぼす影響）
ゼミでの発表
ブラックバスとブルーギルがため池の生物群集に及ぼす影響
外来魚が日本の代表的な止水域であるため池の生物群集に直接的，間接的に影響を及ぼすメカニズムを明らかにすることを目的としてきた．本研究は，小水域における在来生物の早急な保全や，今後のより詳細な考察のための基礎データを提示するものとして十分な意義があると思われる．
現在は、九州大学の矢原徹一研究室にいらっしゃるようです。
Direct and
indirect effects of introduced largemouth bass and bluegill on native
communities in farm
ponds
（外来のオオクチバスとブルーギルがため池の在来生物群集に及ぼす直接的，間接的影響）
2003年2月号（通し番号17-1）の特集として、“Population Biology of Invasive Species”（侵略種の個体数の生態学）というのが組まれています。そのテーマにそって7つのレポートが掲載されていますが、ここでは83ページからの“How Much 〜”というレポートの一部を紹介しようと思います。ちなみにConservation Biologyとは保全生態学のことです。この雑誌の発行が1987年からなので若い学問であるということがわかるでしょう。なお、紹介と言っておきながら今のところ不親切にも日本語訳しておりません。ごめんなさい。
Conservation
Biology（雑誌名）
February 2003 - Volume 17 Issue
1（巻数）
Special Section: Population Biology of Invasive Species
24 Introduction: Population Biology, Evolution, and Control of
Invasive Species
Fred W. Allendorf, Laura
L. Lundquist
31 Nonindigenous Species: Ecological Explanation,
Environmental Ethics, and Public Policy
David M. Lodge,
Kristin Shrader-Frechette
38 Individual, Population, Community,
and Ecosystem Consequences of a Fish Invader in New Zealand
Streams
Colin R. Townsend
48 The Colony Structure
and Population Biology of Invasive Ants
Neil D. Tsutsui,
Andrew V. Suarez
59 An Evolutionary Approach to Understanding
the Biology of Invasions:
Local Adaptation and General-Purpose Genotypes in
the Weed Verbascum thapsus
Ingrid
M. Parker, Joseph Rodriguez, Michael E. Loik
73
Invasiveness of Some Biological Control Insects and Adequacy of Their
Ecological Risk Assessment and Regulation
S. M. Louda, A.
E. Arnett, T. A. Rand, F. L. Russell
83 How Much
Information on Population Biology Is Needed to Manage Introduced
Species?
Daniel Simberloff
How Much Information on Population Biology Is Needed to Manage Introduced Species?
Abstract:（要約）
Study of the
population biology of introduced species has elucidated many fundamental
questions in ecology and evolution. Detailed population biological research is
likely to aid in fine-tuning control of widespread and/or long-established
invasions, and it may lead to novel control methods. It will also contribute to
an overall understanding of the invasion process that may aid in the formulation
of policy and help to
focus attention on invasions that are especially prone
to becoming problematic. But the importance of intensive population biological
research in dealing with introduced species, especially those recently
introduced, is often limited. In the worst instances, the absence of population
biological data can be an excuse for inaction, when a prudent decision or quick
and dirty operation might have excluded or eliminated an invader. The
most
effective way to deal with invasive introduced species, short of keeping them
out, is to discover them early and attempt to eradicate or at least contain them
before they spread. This approach has often been successful, but its success has
usually relied on brute-force chemical and mechanical techniques, not on
population biological research.
Introduction（序論）
That
invasive introduced species are a global scourge is well-publicized in both the
scientific and the popular literatures(e.g., Williamson 1996; Bright 1998; Cox
1999;Devine 1999; Low 1999; Mooney & Hobbs 2000). Less understood are the
various approaches used to deal with such invaders and particularly the degree
of success achieved. In fact, some authors see global homogenization as
inevitable because of rapidly increasing travel and trade (e.g., Quammen 1998).
However, there have been many successes in keeping out introduced species(e.g.,
arliamentary Commissioner for the Environment 2001), in eradicating them
completely ( Myers et al. 2000; Forsyth et al. 2001; Simberloff 2002a ; Veitch
&
Clout 2002), and in controlling them at acceptably low levels
(Simberloff 2002b). Species can often be eradicated early with little or, at
most, superficial knowledge of their population biology, and failure to do so is
rarely a consequence of inadequate knowledge in this realm. Once the opportunity
for rapid eradication has been lost, it is more likely that population
biological details will be important in creating procedures for effective
maintenance management (or even eradication). Even then, the important
population biology may sometimes be of the most basic kind, and sometimes
population biological information is unnecessary. I examined some successes and
failures in introduced species policy and management, beginning with exclusion
and continuing through maintenance management, in an attempt to clarify and
project the role of population biological research.
Failure to Exclude（略）
Failure to Eradicate Early（略）
Some Successful Early Interventions（略）
Eradicating Longstanding Invasions（定着した侵入種の駆除）
Further, there are success stories in which an invasion was not caught
early but was nevertheless eradicated and success stories in which effective
management was achieved without eradication. At least some examples in both
categories seem to have relied on superficial population biological
understanding.
A dedicated group of scientists, the Island Conservation
and Ecology Group, has succeeded in removing longestablished populations of
various combinations of feral cats (Felis catus), Norway and black rats (Rattus
norvegicus and R. rattus respectively), house mice (Mus musculus), rabbits
(Oryctolagus cuniculus), goats (Capra hircus), sheep (Ovis aries), and burros
(Equus asinus) from several islands in northwestern Mexico by using traps,
hunting dogs, and rifles (Donlan et al. 2000; Wood et al. 2001). They have not
engaged in detailed population biological studies but in what might be called
applied ethology, such as determining where to place traps. The entire project
has cost about $700,000 so far.
There have been successful eradication
campaigns against invaders established over much larger areas. An African
malaria vector, the mosquito
Anopheles gambiae, was eradicated from
northeastern Brazil (Soper & Wilson 1943; Davis & Garcia 1989). The
mosquito was recorded in 1930, but the eradication campaign did not begin until
after major malaria outbreaks in 1938. By then, A. gambiae had spread over
31,000 km2. The
project featured chemical treatments for adults and larvae
and achieved the complete eradication of A. gambiae by late 1940. Several
aspects of the mosquito’s natural history, including the facts that in Brazil it
dispersed poorly and its microhabitat requirements were satisfied almost
exclusively in human habitations, contributed to the success of the campaign.
However, detailed population biological study was not necessary.
The African
root parasite witchweed (Striga asiatica) reached the Carolinas in the 1950s. It
has been reduced from 162,000 ha in the 1950s to approximately 2800 haand will
almost certainly be eliminated ( Westbrooks 1993; Eplee 2001). This project
entailed the massive support and cooperation of the U.S. government and the
state governments of North and South Carolina, and it cost about $250 million.
The basic biology of the plant was known, but the control strategy did not rely
on much of it. The program entailed a rigorous quarantine on the movement of
anything that could carry soil outside the infested area, various herbicides to
kill the plants, and soil fumigation with ethylene gas to kill the
seeds.
However, there have been eradications of invasive introduced plants
established over large areas that cost nowhere near $250 million. A recent
example is the eradication from Western Australia of Kochia scoparia, described
by Randall (2001; R. Randall, personal communication). It was introduced in 1990
and promoted as a living haystack, in spite of its well-known status as a major
weed elsewhere. It was widely planted on 52
properties, and by 1992 it was
recognized as a pest and an eradication campaign was started. By 1993 it had
reached 270 properties spread out over a linear distance of over 900 km. The
eradication team searched over 20,000 ha, finding more than 3200 ha to be
infested. By 1995 that area was reduced to 139 ha and by 2000 to 5 ha, at a
total cost of $250,000. A variety of herbicides was used, and the project did
not entail population biological studies.
In each of these
eradications, it was important to know something about the biology of the target
to avoid wasting a lot of time and money, but it was unnecessary to know very
much. For Anopheles gambiae, it was important to know that it disperses poorly
and that in Brazil it was found exclusively around homes. For the various
plants, it was important to know whether they had soil seed banks and which
herbicides worked. For the giant African snail, it was important to know that it
does not self-fertilize. For many mammals, it was important to know how to trap
them. These and other eradication campaigns suggest the conditions that must be
met for such a campaign to be successful (Myers et al. 2000; Forsyth et al.
2001; Simberloff 2002a), which is not the same question as whether a campaign is
worth undertaking (Simberloff 2002a).
Often, substantial population
biological knowledge at the outset would have allowed a better estimate of the
probability of success of an eradication campaign or even improved the
likelihood of success. For example, release of massive numbers of sterile males
has frequently been used successfully to eradicate insect populations. Some
failures and temporary setbacks have arisen, however, because males have evolved
in domestication to be less competitive than wild males in mating(e.g., in the
campaign against the apple codling moth [Cydia pomenella] in British Columbia
[Myers et al.2000]) and wild females have evolved to discriminate against
sterile males (e.g., in the eradication of the melon fly [Bactrocera cucurbitae]
from the Ryukyu Archipelago [Iwahashi 1996]). Detailed population study and
modeling in several instances has led to improved success through the use of
initial procedures to reduce the number of wild males and better estimates of
just how many sterile males must be released (e.g., Iwahashi 1996). Gleaning
such knowledge will frequently necessitate a long research effort, however, and
the ability of some invasions to spread quickly suggests that we should often
proceed with an eradication attempt even with very uncertain prospects for
success.
Of course, the methods deployed in such a rapid response are
likely to resemble a blunderbuss attack rather than a surgical strike. But
because of their population growth and dispersal abilities, introduced species
are one target of resource management at which it is often better to shoot first
and ask questions later. The methods I have described were generally preemptive
strikes by brute force. I am not arguing that more elegant methods were not
possible in some instances but that we do not know what would have worked. Many
supposedly theoretically surefire methods turn out not to work when tried. But
by acting quickly, without much biological knowledge, these projects saved a
huge amount of trouble and expense and avoided uncertain prospects for
successful subsequent management. Because many invaders have a distinct lag time
before they start to spread (Kowarik 1995; Crooks & Soulé 1996), this entire
litany of successes constitutes a strong argument for an effective early warning
and rapid-response mechanism (cf. Braithwaite 2000; Westbrooks et al. 2000;
Timmins & Braithwaite 2002). They also argue for applying the precautionary
principle when a relatively recent invasion is found.
Absence of
knowledge should rarely be used to justify an attempt at quick action.
Successful Maintenance Management（略）
Effectiveness of Population Biological Research（略）
Conclusion（略）
がんばって英語を読んでくださった方、どうもありがとうございました。このような研究、考え方があるということを知っていただければ幸いです。
参考としてこれ以外の生態学関連リンク集（生態学関連のjournalへのリンクがピックアップしてあります）を集めたサイトを示しておきます。他にもあるかもしれませんが・・・。
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