Science: Can the pine tree species Pinus hartwegii help terraform Mars?

PlanetEarth Online, a website maintained by the UK's Natural Environment Research Council, has an interesting article about the pine tree species Pinus hartwegii, which grows in the high mountains of Mexico, and whether it has the potential for introducing terrestrial ecosystems to Mars. This seems to be the key paragraph:

“However, in line with recent ideas about geo-engineering our climate on planet Earth, we might be able to heat up Mars and increase its atmospheric density by introducing greenhouse gases. Once there is liquid water on Mars, the planet should be ready to support living plants, and the Martian soil has been shown to contain all the nutrients they need. Pinus hartwegii, and other plants that are well adapted to frost, drought, high solar radiation and low oxygen levels, could play a crucial role in the terraforming of Mars, because plants will produce oxygen and accelerate the warming of the planet.”

Pictured: Pinus hartwegii. Image by Chris Earle.