澳大利亚纪的生态系统崩以及人类在巨型动物灭绝中的作用
Gifford H Miller1, Marilyn L Fogel, John W Magee
1INSTAAR and Geological Sciences, University of Colorado, Boulder, CO 80309-0450 USA.
概括
澳大利亚大型动物大灭绝5万45000年前与人类殖民有关. 新的饮食证据表明,人类对景观的燃烧减少了食物来源,导致了灭绝.
科学领域:
- 古生物学的古生物学
- 考古学的考古学
- 环境科学 环境科学
背景情况:
- 澳大利亚大约在5万至4万5千年前经历了重大的巨型动物灭绝,这与人类的到来相吻合.
- 这些灭绝的确切原因和机制,特别是人类的作用,仍在争论中.
- 气候变化在很大程度上被排除在此期间作为主要驱动因素之外.
研究的目的:
- 调查人类殖民对澳大利亚巨型动物的饮食影响.
- 确定将人类活动与观察到的灭绝联系起来的潜在机制.
- 重建人类到来之前和之后的长期环境和饮食变化.
主要方法:
- 从化石遗骸中分析了14万年来的饮食碳同位素 (delta) 记录.
- 在三个地理上不同的澳大利亚地点检查和巴的饮食变化.
- 饮食变化的关系与人类殖民的时间和推断的景观修改.
主要成果:
- 记录了澳大利亚猫头可用的食物来源的永久减少,从人类殖民时期开始.
- 这种饮食转变在多个地点一致观察到,表明整个大陆的影响.
- 类似的饮食变化在有袋动物巴身上也被发现,这表明了更广泛的生态效应.
结论:
- 人类诱导的景观焚烧被认为是驱动大野生动物灭绝的机制.
- 多样化的植被迅速转化为适应火灾的灌木,大大减少了专门的食草动物的食物供应.
- 无法适应环境变化的物种,如大型哺乳动物,面临灭绝.
相关概念视频
Threats to Biodiversity
There have been five major extinction events throughout geological history, resulting in the elimination of biodiversity, followed by a rebound of species that adapted to the new conditions. In the current geological epoch, the Holocene, there is a sixth extinction event in progress. This mass extinction has been attributed to human activities and is thus provisionally called the Anthropocene. In 2019 the human population reached 7.7 billion people and is projected to comprise 10 billion by...
Keystone Species
Measures of species biodiversity, such as richness (i.e., the number of species present) and evenness (i.e., their relative abundance), describe an ecological community’s structure. Many factors affect community structure, including abiotic factors (e.g., sunlight and nutrients), disturbances (e.g., fire or flood), species interactions (e.g., predation or competition), and chance events (e.g., foreign species invasion). Certain species—such as keystone species—also play a pivotal role in the...
What is Conservation Biology?
Conservation biology is a scientific field that focuses on the preservation of biodiversity in order to protect ecosystems while meeting the needs of the human population. Humans require properly functioning ecosystems to maintain our supply of natural resources, including food, medicines, and building materials.
Ecological Disturbance
An ecological disturbance is a temporary disruption in the environment resulting from abiotic, biotic, or anthropogenic factors, causing a pronounced change in an ecosystem. The impact of an ecological disturbance, which can depend on its intensity, frequency, and spatial distribution, plays a significant role in shaping the species diversity within the ecosystem.Ecological disturbances can be caused by an event as small as the trampling of underbrush to an incident as wide-ranging as a forest...
Conservation of Declining Populations
Conservation of declining population focuses on ways of detecting, diagnosing, and halting a population decline. The approach uses methods to prevent populations from going extinct.
Habitat Fragmentation
Habitat fragmentation describes the division of a more extensive, continuous habitat into smaller, discontinuous areas. Human activities such as land conversion, as well as slower geological processes leading to changes in the physical environment, are the two leading causes of habitat fragmentation. The fragmentation process typically follows the same steps: perforation, dissection, fragmentation, shrinkage, and attrition.


