INcas and alders
Article Abstract:
Pollen and stratigraphical record of a small lake in the Peruvian Andes, investigated by Chepstow-Lusty and colleagues, shows that charcoal was abundant about 4,000 years ago, suggesting vegetation management by burning. Grasslands may have been grazed by herds of camelids, encouraging the abundance of weeds such as Ambrosia. The decline in the abundance of pollen of Chenopodiaceae and Ambrosia is explained by the general fall in temperature. A sudden expansion of alder trees took place around AD 1050 and this may be explained by the reduction of human activity in the area, leading to natural vegetative recovery.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1998
User Contributions:
Comment about this article or add new information about this topic:
Back to the little ice age
Article Abstract:
A study of twelve well preserved shoots of Cassiope tetragona, an arctic dwarf-shrub, found in Ellesmere island in Canada provides important clues about the ecological conditions prevailing between AD 1425 and 1665, known as the Little Ice Age. Results reveal that the July temperature of the region was about 0.7 degrees lower at the time when the shrubs became fossilized under the snow than the present temperature. Growth rings of the shrubs yield an estimation of the climate.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1995
User Contributions:
Comment about this article or add new information about this topic:
Seeds of doubt
Article Abstract:
Researchers have studied three weed species to measure features such as biomass yield, survivorship and seed mass.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2000
User Contributions:
Comment about this article or add new information about this topic:
- Abstracts: Alarm calls and chick reactions in the moustached warbler, Acrocephalus melanopogon. Clarification of the chick reaction hypothesis
- Abstracts: Home on the range. Back to basics. A time for discovery
- Abstracts: Agony and ecstasy. No Justification. On zoophilia
- Abstracts: A powerful bursting radio source towards the Galactic Centre. Deuterium in the Galactic Centre as a result of recent infall of law-metallicity gas
- Abstracts: The trailer park tom. A lesson in life. Ruff love