Controlling Alien Species: Ecological and Management Principles | 控制外来物种：生态与管理原理

📚 Controlling Alien Species: Ecological and Management Principles | 控制外来物种：生态与管理原理

Human movement of organisms beyond their natural ranges is one of the greatest threats to biodiversity. When an introduced species becomes invasive, it can outcompete native species, alter food webs and transform entire ecosystems.

人类将生物带出其自然分布范围，已成为对生物多样性最大的威胁之一。当引入物种成为入侵物种时，它会竞争排斥本地物种、改变食物网并彻底改变整个生态系统。

---

1. What Is an Alien Species? | 什么是外来物种？

In ecology, an alien species, also called a non-native, exotic or introduced species, is a species living outside its natural geographical range because of human transport or introduction. This distinguishes it from a species that expands its range naturally, for example through climate-driven dispersal.

在生态学中，外来物种又称非本地物种、外来引入物种，是指因人类运输或引入而生活在其自然地理分布范围之外的物种。这将其与通过气候驱动的扩散等方式自然扩大分布范围的物种区分开来。

An alien species only becomes invasive when it establishes a self-sustaining population and spreads rapidly, causing measurable harm to native biodiversity, ecosystem services or human activities. Many alien species remain local and harmless; only a minority become invasive.

外来物种只有在建立了能够自我维持的种群并迅速扩散，对本地生物多样性、生态系统服务或人类活动造成明显危害时，才被称为入侵物种。许多外来物种仍局限于局部并且无害，只有少数会成为入侵物种。

---

2. Why Are Alien Species a Problem? | 为什么外来物种会成为问题？

In their native range, populations are usually regulated by co-evolved predators, parasites, pathogens and competitors. When an alien species arrives in a new region, these natural control agents are often absent, allowing rapid population growth and spread.

在原产地，种群通常受到共同进化的捕食者、寄生虫、病原体和竞争者的调节。当外来物种到达新地区时，这些自然控制因素往往不存在，从而使种群迅速增长和扩散。

Alien species can harm native communities through competition for resources, predation, herbivory, hybridisation, disease transmission and ecosystem engineering. For example, an invasive predator can reduce endemic prey that have no evolved defences, while an invasive plant can alter soil chemistry and fire regimes.

外来物种可通过竞争资源、捕食、取食植物、杂交、传播疾病以及生态系统工程等方式危害本地群落。例如，入侵捕食者可以减少没有演化出防御能力的特有猎物，而入侵植物则可能改变土壤化学性质和火灾规律。

---

3. Aims of Control Programmes | 控制计划的目标

Management of alien species follows a hierarchy: prevention, early detection and rapid response, eradication, containment, and ongoing control. Prevention is usually the most cost-effective stage, before a species becomes widely established.

外来物种管理遵循一个层级：预防、早期发现和快速反应、根除、遏制以及持续控制。预防通常是最具成本效益的阶段，因为此时物种尚未广泛建立。

Eradication aims to remove every individual from a defined area, which is usually feasible only for small, isolated populations. Containment limits spread to a geographical zone, while control reduces population density to acceptable levels where eradication is impossible.

根除旨在将一个限定区域内的每一个个体都清除，这通常只对小型、孤立的种群可行。遏制是将扩散限制在一定地理区域内，而控制则是在无法根除时，将种群密度降低到可接受的水平。

---

4. Physical and Mechanical Control | 物理与机械控制

Physical control involves directly removing or excluding individuals using traps, hunting, netting, fencing, barriers, manual pulling, cutting, or dredging. These methods are often selective if targeted carefully, and they avoid introducing toxic chemicals.

物理控制是指利用诱捕、猎杀、网捕、围栏、屏障、人工拔除、砍伐或疏浚等方式直接清除或隔离个体。如果目标明确，这些方法通常具有选择性，并且不会引入有毒化学物质。

However, physical methods can be labour-intensive, expensive, and may only provide temporary suppression. For mobile or cryptic species, achieving complete removal is extremely difficult. Trapping may also cause animal welfare concerns or accidentally capture native species.

然而，物理方法可能耗费大量人力、费用高昂，并且可能只能提供暂时的抑制效果。对于活动性强或隐蔽性高的物种，要实现彻底清除极其困难。诱捕还可能引起动物福利问题，或误捕本地物种。

---

5. Chemical Control | 化学控制

Chemical control uses pesticides, herbicides or rodenticides to kill invasive species. It can be rapid, highly effective over large areas, and relatively cheap in the short term, which makes it attractive for severe infestations.

化学控制利用杀虫剂、除草剂或灭鼠剂来杀灭入侵物种。它可以迅速起效，在大范围内非常有效，并且短期内相对便宜，因此在严重入侵情况下具有吸引力。

The main disadvantages include non-target toxicity, pollution, bioaccumulation through food chains, and the evolution of resistance. Repeated application is often needed, and public concerns about chemical residues can limit its use in sensitive habitats such as wetlands.

其主要缺点包括对非目标生物的毒性、污染、通过食物链的生物累积以及抗药性的产生。通常需要反复施药，而公众对化学残留的担忧也会限制其在湿地等敏感栖息地的使用。

---

6. Biological Control | 生物控制

Biological control introduces or enhances natural enemies, such as predators, parasitoids, herbivores or pathogens, to reduce an invasive population. Classical biological control imports a co-evolved enemy from the pest’s native range and releases it into the new environment.

生物控制通过引入或增加天敌，如捕食者、拟寄生物、植食性动物或病原体，来降低入侵种群数量。经典生物控制是从有害生物的原产地引进共同进化的天敌，并将其释放到新环境中。

Successful biological control can become self-sustaining and reduce the need for chemicals, but it carries serious risks. The control agent may attack non-target native species or become invasive itself. A famous failure is the cane toad in Australia, introduced to control sugar cane beetles; it spread rapidly, poisoned native predators and became a major pest.

成功的生物控制可以自我维持，并减少对化学药剂的依赖，但它也有严重风险。控制生物可能攻击非目标本地物种，或自身成为入侵物种。一个著名的失败案例是澳大利亚的蔗蟾蜍，它被引入以控制甘蔗甲虫，却迅速扩散、毒害本地捕食者并成为主要有害生物。

Host-specificity testing is therefore essential before any release. An example of success is the use of the moth Cactoblastis cactorum against invasive prickly pear cactus in Australia, where the larvae selectively destroyed the cactus and brought it under control.

因此，在任何释放之前，宿主专一性测试至关重要。一个成功案例是利用蛾类 Cactoblastis cactorum 防治澳大利亚入侵的仙人掌，其幼虫选择性地摧毁仙人掌，使其得到控制。

---

7. Habitat and Ecosystem Management | 栖息地与生态系统管理

Alien species often invade disturbed or degraded habitats. Restoring native vegetation, reducing soil disturbance, managing nutrient inputs and reinstating natural fire or hydrological regimes can make conditions less suitable for invaders and more favourable for native species.

外来物种常常入侵受干扰或退化的栖息地。恢复本地植被、减少土壤扰动、管理养分输入以及恢复自然的火灾或水文状况，可以降低环境对外来入侵者的适合度，同时更有利于本地物种。

Habitat management is often used alongside direct removal; removing an invader without restoring the ecosystem may simply allow the same or another alien species to recolonise. For example, re-establishing native riparian plants can shade out invasive aquatic weeds after physical clearance.

栖息地管理通常与直接清除结合使用；如果只清除入侵者而不恢复生态系统，同一外来物种或其他外来物种可能简单地重新定殖。例如，在物理清理后，重新种植本地河岸植物可以遮蔽并抑制入侵水生杂草。

---

8. Legislation, Quarantine and Risk Assessment | 立法、检疫与风险评估

Governments reduce introductions through biosecurity measures: pre-border risk assessment, import bans, quarantine inspection at borders, and post-border surveillance. International agreements and national laws list prohibited species and require permits for high-risk organisms.

政府通过生物安全措施减少外来物种的引入：边界前的风险评估、进口禁令、边境检疫检查以及入境后监测。国际协定和国家法律列出禁止物种，并要求高风险生物必须获得许可。

Risk assessment evaluates the likelihood that a species will establish, spread and cause harm. Factors include its invasion history elsewhere, reproductive rate, dispersal ability, climatic match and potential non-target ecological effects. The precautionary principle favours preventing introduction when scientific uncertainty is high.

风险评估用于评价一个物种建立种群、扩散并造成危害的可能性。考虑因素包括其在其他地区的入侵历史、繁殖率、扩散能力、气候匹配度以及对非目标生物的潜在生态影响。当科学不确定性较高时，预防原则倾向于阻止引入。

---

9. Monitoring and Evaluating Control | 监测与评估控制效果

Effective control requires monitoring population size, distribution and ecosystem response before, during and after management. Methods include transect surveys, camera traps, remote sensing and environmental DNA (eDNA) sampling.

有效的控制需要在管理前、管理期间和管理后监测种群大小、分布以及生态系统的响应。方法包括样线调查、相机陷阱、遥感和环境 DNA（eDNA）采样。

Success criteria should be defined in advance, such as a percentage reduction in invasive cover, increased native species richness, or the absence of new recruits. Evaluation allows managers to adapt methods, stop ineffective actions and demonstrate whether biodiversity objectives have been met.

应事先确定成功标准，例如入侵物种覆盖度下降的百分比、本地物种丰富度增加，或没有新个体补充。评估使管理者能够调整方法、停止无效行动，并证明生物多样性目标是否已经实现。

---

10. Integrated Management and Case Studies | 综合管理与案例研究

Integrated pest management (IPM) combines physical, chemical, biological, cultural and habitat-based methods to achieve sustainable control with minimal environmental harm. It selects methods according to the invasion stage, target species biology and local ecosystem sensitivity.

综合有害生物管理（IPM）将物理、化学、生物、栽培和基于栖息地的方法结合起来，以最小的环境危害实现可持续控制。它根据入侵阶段、目标物种生物学和当地生态系统敏感性选择方法。

A comparison of the main control approaches is shown below. Successful programmes usually integrate several approaches rather than relying on one method.

下表比较了几种主要控制方法。成功的计划通常综合运用多种方法，而不是依赖单一方法。

Method 方法	Advantages 优点	Disadvantages 缺点
Physical 物理	Selective, no toxins 选择性强，无毒素	Labour-intensive, temporary 费时费力，效果短暂
Chemical 化学	Rapid, large-scale 迅速，可大规模使用	Non-target effects, resistance 对非目标生物有影响，易产生抗性
Biological 生物	Self-sustaining, no residues 自我维持，无残留	Unpredictable, non-target risk 不可预测，对非目标生物有风险

Published by TutorHao | Biology Revision Series | aleveler.com

更多咨询请联系16621398022（同微信）