The arctic tree invasion – Spruce trees are popping up in the tundra, a region that by definition is too cold to support trees. Global warming is the likely culprit, extending the tree line to the north. While the appearance of trees is normally beneficial, in this case the tree invasion is putting ecological pressure on native plant species and large animals such as caribou. Work published in the Journal of Ecology.

Poisonous beauties – For unknown reasons, some flowers pollinated by bees contain toxins in their nectar. A new study finds that honeybees may be able to detect the toxins and avoid toxin-producing flowers.

Communication between chloroplast and nucleus decoded – Researchers from the Salk Institute have discovered how the green-pigmented chloroplast sends distress signals to the cell’s nucleus when something goes wrong. The signal, which is mediated by the protein GUN1, shuts down protein synthesis and relieves the strain on the chloroplast’s photosynthetic machinery in times of stress. Appearing in the March 29 issue of Science Express.

News Briefs:

Climate change: U.S. Churches Go ‘Green’ for Palm Sunday; Scientists weigh downside of palm oil

Trees: Tree planting campaign: United Nations campaign to plant one billion trees worldwide during 2007.