Bush M B, Rozas-Davila A, Raczka M, Nascimento M, Valencia B, Sales R K, McMichael C N H, Gosling W D
Institute for Global Ecology, Florida Institute of Technology, Melbourne, FL 32901, USA.
Department of Geography and Environmental Science, University of Reading, Whiteknights, Reading, Berkshire RG6 6AH, UK.
Philos Trans R Soc Lond B Biol Sci. 2022 Apr 25;377(1849):20200497. doi: 10.1098/rstb.2020.0497. Epub 2022 Mar 7.
Palaeoecological records suggest that humans have been in the Andes since at least 14 000 years ago. Early human impacts on Andean ecosystems included an increase in fire activity and the extinction of the Pleistocene megafauna. These changes in Andean ecosystems coincided with rapid climate change as species were migrating upslope in response to deglacial warming. Microrefugia probably played a vital role in the speed and genetic composition of that migration. The period from 14 500 to 12 500 years ago was when novel combinations of plant species appeared to form no-analogue assemblages in the Andes. By 12 000 years ago most areas in what are today the Andean grasslands were being burned and modified by human activity. As the vegetation of these highland settings has been modified by human activity for the entirety of the Holocene, they should be regarded as long-term manufactutred landscapes. The sharp tree lines separating Andean forests from grasslands that we see today were probably also created by repeated burning and owe their position more to human-induced fire than climatic constraints. In areas that were readly penetrated by humans on the forested slopes of the Andes, substantial modification and settlement had occurred by the mid-Holocene. In hard-to-reach areas, however, the amount of human modification may always have been minimal, and these slopes can be considered as being close to natural in their vegetation. This article is part of the theme issue 'Tropical forests in the deep human past'.
古生态记录表明，人类至少从14000年前就已出现在安第斯山脉。早期人类对安第斯生态系统的影响包括火灾活动增加以及更新世巨型动物的灭绝。随着物种因冰消期变暖而向山坡上迁移，安第斯生态系统的这些变化与快速的气候变化同时发生。微避难所可能在那次迁移的速度和遗传组成方面发挥了至关重要的作用。在距今14500年至12500年期间，安第斯山脉出现了新的植物物种组合，似乎形成了非类似组合。到12000年前，如今安第斯草原的大部分地区都因人类活动而被焚烧和改造。由于这些高地环境的植被在全新世整个时期都受到人类活动的改造，它们应被视为长期的人工景观。我们今天看到的将安第斯森林与草原分隔开来的明显树线，可能也是由反复焚烧造成的，其位置更多地归因于人为引发的火灾而非气候限制。在安第斯山脉森林山坡上人类容易进入的地区，到全新世中期已经发生了大量的改造和定居。然而，在难以到达的地区，人类改造的程度可能一直很小，这些山坡的植被可以被认为接近自然状态。本文是主题为“人类深层历史中的热带森林”的一部分。
